Merge tag 'OTP-19.0' into sverker/19/binary_to_atom-utf8-crash/ERL-474/OTP-14590

55 files changed, 8205 insertions, 4649 deletions

diff --git a/lib/compiler/src/Makefile b/lib/compiler/src/Makefile
index c6d09d85eb..518c89d044 100644
--- a/lib/compiler/src/Makefile
+++ b/lib/compiler/src/Makefile
@@ -1,18 +1,19 @@
 #
 # %CopyrightBegin%
 #
-# Copyright Ericsson AB 1996-2013. All Rights Reserved.
+# Copyright Ericsson AB 1996-2016. All Rights Reserved.
 #
-# The contents of this file are subject to the Erlang Public License,
-# Version 1.1, (the "License"); you may not use this file except in
-# compliance with the License. You should have received a copy of the
-# Erlang Public License along with this software. If not, it can be
-# retrieved online at http://www.erlang.org/.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# Software distributed under the License is distributed on an "AS IS"
-# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-# the License for the specific language governing rights and limitations
-# under the License.
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 #
 # %CopyrightEnd%
 #
@@ -49,6 +50,7 @@ MODULES =  \
 	beam_asm \
 	beam_block \
 	beam_bool \
+	beam_bs \
 	beam_bsm \
 	beam_clean \
 	beam_dead \
@@ -61,6 +63,7 @@ MODULES =  \
 	beam_opcodes \
 	beam_peep \
 	beam_receive \
+	beam_reorder \
 	beam_split \
 	beam_trim \
 	beam_type \
@@ -70,6 +73,7 @@ MODULES =  \
 	cerl \
 	cerl_clauses \
 	cerl_inline \
+	cerl_sets \
 	cerl_trees \
 	compile \
 	core_lib \
@@ -81,6 +85,7 @@ MODULES =  \
 	rec_env \
 	sys_core_dsetel \
 	sys_core_fold \
+	sys_core_fold_lists \
 	sys_core_inline \
 	sys_pre_attributes \
 	sys_pre_expand \
@@ -158,6 +163,10 @@ $(EBIN)/beam_asm.beam: $(ESRC)/beam_asm.erl $(EGEN)/beam_opcodes.hrl
 $(EBIN)/cerl_inline.beam: $(ESRC)/cerl_inline.erl
 	$(V_ERLC) $(ERL_COMPILE_FLAGS) +nowarn_shadow_vars -o$(EBIN) $<
 
+# Inlining core_parse is slow and has no benefit.
+$(EBIN)/core_parse.beam: $(EGEN)/core_parse.erl
+	$(V_ERLC) $(subst +inline,,$(ERL_COMPILE_FLAGS)) -o$(EBIN) $<
+
 # ----------------------------------------------------
 # Release Target
 # ---------------------------------------------------- 
@@ -187,6 +196,7 @@ $(EBIN)/core_parse.beam: core_parse.hrl $(EGEN)/core_parse.erl
 $(EBIN)/core_pp.beam: core_parse.hrl
 $(EBIN)/sys_core_dsetel.beam: core_parse.hrl
 $(EBIN)/sys_core_fold.beam: core_parse.hrl
+$(EBIN)/sys_core_fold_lists.beam: core_parse.hrl
 $(EBIN)/sys_core_inline.beam: core_parse.hrl
 $(EBIN)/sys_pre_expand.beam: ../../stdlib/include/erl_bits.hrl
 $(EBIN)/v3_codegen.beam: v3_life.hrl
diff --git a/lib/compiler/src/beam_a.erl b/lib/compiler/src/beam_a.erl
index c590c5e35b..91e6d80da3 100644
--- a/lib/compiler/src/beam_a.erl
+++ b/lib/compiler/src/beam_a.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2012-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2012-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -54,6 +55,9 @@ rename_instrs([{call_only,A,F}|Is]) ->
     [{call,A,F},return|rename_instrs(Is)];
 rename_instrs([{call_ext_only,A,F}|Is]) ->
     [{call_ext,A,F},return|rename_instrs(Is)];
+rename_instrs([{'%live',_}|Is]) ->
+    %% When compiling from old .S files.
+    rename_instrs(Is);
 rename_instrs([I|Is]) ->
     [rename_instr(I)|rename_instrs(Is)];
 rename_instrs([]) -> [].
@@ -88,6 +92,16 @@ rename_instr({bs_private_append=I,F,Sz,U,Src,Flags,Dst}) ->
     {bs_init,F,{I,U,Flags},none,[Sz,Src],Dst};
 rename_instr(bs_init_writable=I) ->
     {bs_init,{f,0},I,1,[{x,0}],{x,0}};
+rename_instr({test,Op,F,[Ctx,Bits,{string,Str}]}) ->
+    %% When compiling from a .S file.
+    <<Bs:Bits/bits,_/bits>> = list_to_binary(Str),
+    {test,Op,F,[Ctx,Bs]};
+rename_instr({put_map_assoc,Fail,S,D,R,L}) ->
+    {put_map,Fail,assoc,S,D,R,L};
+rename_instr({put_map_exact,Fail,S,D,R,L}) ->
+    {put_map,Fail,exact,S,D,R,L};
+rename_instr({test,has_map_fields,Fail,Src,{list,List}}) ->
+    {test,has_map_fields,Fail,[Src|List]};
 rename_instr({select_val=I,Reg,Fail,{list,List}}) ->
     {select,I,Reg,Fail,List};
 rename_instr({select_tuple_arity=I,Reg,Fail,{list,List}}) ->
diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index 112b087f3c..f6ca7a0afb 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -29,11 +30,12 @@
 module(Code, Abst, SourceFile, Opts) ->
     {ok,assemble(Code, Abst, SourceFile, Opts)}.
 
-assemble({Mod,Exp,Attr0,Asm0,NumLabels}, Abst, SourceFile, Opts) ->
+assemble({Mod,Exp0,Attr0,Asm0,NumLabels}, Abst, SourceFile, Opts) ->
     {1,Dict0} = beam_dict:atom(Mod, beam_dict:new()),
     {0,Dict1} = beam_dict:fname(atom_to_list(Mod) ++ ".erl", Dict0),
     NumFuncs = length(Asm0),
     {Asm,Attr} = on_load(Asm0, Attr0),
+    Exp = cerl_sets:from_list(Exp0),
     {Code,Dict2} = assemble_1(Asm, Exp, Dict1, []),
     build_file(Code, Attr, Dict2, NumLabels, NumFuncs, Abst, SourceFile, Opts).
 
@@ -60,7 +62,7 @@ insert_on_load_instruction(Is0, Entry) ->
     Bef ++ [El,on_load|Is].
 
 assemble_1([{function,Name,Arity,Entry,Asm}|T], Exp, Dict0, Acc) ->
-    Dict1 = case member({Name,Arity}, Exp) of
+    Dict1 = case cerl_sets:is_element({Name,Arity}, Exp) of
 		true ->
 		    beam_dict:export(Name, Arity, Entry, Dict0);
 		false ->
@@ -132,10 +134,10 @@ build_file(Code, Attr, Dict, NumLabels, NumFuncs, Abst, SourceFile, Opts) ->
     LiteralChunk = case beam_dict:literal_table(Dict) of
 		       {0,[]} -> [];
 		       {NumLiterals,LitTab0} ->
-			   LitTab1 = iolist_to_binary(LitTab0),
-			   LitTab2 = <<NumLiterals:32,LitTab1/binary>>,
-			   LitTab = iolist_to_binary(zlib:compress(LitTab2)),
-			   chunk(<<"LitT">>, <<(byte_size(LitTab2)):32>>, LitTab)
+			   LitTab1 = [<<NumLiterals:32>>,LitTab0],
+			   LitTab = zlib:compress(LitTab1),
+			   chunk(<<"LitT">>, <<(iolist_size(LitTab1)):32>>,
+				 LitTab)
 		   end,
 
     %% Create the line chunk.
@@ -223,10 +225,12 @@ flatten_imports(Imps) ->
     list_to_binary(map(fun({M,F,A}) -> <<M:32,F:32,A:32>> end, Imps)).
 
 build_attributes(Opts, SourceFile, Attr, MD5) ->
+    Misc0 = case SourceFile of
+		[] -> [];
+		[_|_] -> [{source,SourceFile}]
+	    end,
     Misc = case member(slim, Opts) of
-	       false ->
-		   {{Y,Mo,D},{H,Mi,S}} = erlang:universaltime(),
-		   [{time,{Y,Mo,D,H,Mi,S}},{source,SourceFile}];
+	       false -> Misc0;
 	       true -> []
 	   end,
     Compile = [{options,Opts},{version,?COMPILER_VSN}|Misc],
@@ -324,6 +328,8 @@ make_op({gc_bif,Bif,Fail,Live,Args,Dest}, Dict) ->
     encode_op(BifOp, [Fail,Live,{extfunc,erlang,Bif,Arity}|Args++[Dest]],Dict);
 make_op({bs_add=Op,Fail,[Src1,Src2,Unit],Dest}, Dict) ->
     encode_op(Op, [Fail,Src1,Src2,Unit,Dest], Dict);
+make_op({test,Cond,Fail,Src,{list,_}=Ops}, Dict) ->
+    encode_op(Cond, [Fail,Src,Ops], Dict);
 make_op({test,Cond,Fail,Ops}, Dict) when is_list(Ops) ->
     encode_op(Cond, [Fail|Ops], Dict);
 make_op({test,Cond,Fail,Live,[Op|Ops],Dst}, Dict) when is_list(Ops) ->
@@ -429,45 +435,35 @@ encode_alloc_list_1([], Dict, Acc) ->
     {iolist_to_binary(Acc),Dict}.
 
 encode(Tag, N) when N < 0 ->
-    encode1(Tag, negative_to_bytes(N, []));
+    encode1(Tag, negative_to_bytes(N));
 encode(Tag, N) when N < 16 ->
     (N bsl 4) bor Tag;
 encode(Tag, N) when N < 16#800  ->
     [((N bsr 3) band 2#11100000) bor Tag bor 2#00001000, N band 16#ff];
 encode(Tag, N) ->
-    encode1(Tag, to_bytes(N, [])).
+    encode1(Tag, to_bytes(N)).
 
 encode1(Tag, Bytes) ->
-    case length(Bytes) of
+    case iolist_size(Bytes) of
 	Num when 2 =< Num, Num =< 8 ->
 	    [((Num-2) bsl 5) bor 2#00011000 bor Tag| Bytes];
 	Num when 8 < Num ->
 	    [2#11111000 bor Tag, encode(?tag_u, Num-9)| Bytes]
     end.
 
-
-to_bytes(N0, Acc) ->
-    Bits = 3*128,
-    case N0 bsr Bits of
-	0 ->
-	    to_bytes_1(N0, Acc);
-	N ->
-	    to_bytes(N, binary_to_list(<<N0:Bits>>) ++ Acc)
-    end.
-    
-to_bytes_1(0, [B|_]=Done) when B < 128 -> Done;
-to_bytes_1(N, Acc) -> to_bytes(N bsr 8, [N band 16#ff|Acc]).
-
-negative_to_bytes(N0, Acc) ->
-    Bits = 3*128,
-    case N0 bsr Bits of
-	-1 ->
-	    negative_to_bytes_1(N0, Acc);
-	N ->
-	    negative_to_bytes_1(N, binary_to_list(<<N0:Bits>>) ++ Acc)
+to_bytes(N) ->
+    Bin = binary:encode_unsigned(N),
+    case Bin of
+	<<0:1,_/bits>> -> Bin;
+	<<1:1,_/bits>> -> [0,Bin]
     end.
 
-negative_to_bytes_1(-1, [B1,_B2|_]=Done) when B1 > 127 ->
-    Done;
-negative_to_bytes_1(N, Acc) ->
-    negative_to_bytes_1(N bsr 8, [N band 16#ff|Acc]).
+negative_to_bytes(N) when N >= -16#8000 ->
+    <<N:16>>;
+negative_to_bytes(N) ->
+    Bytes = byte_size(binary:encode_unsigned(-N)),
+    Bin = <<N:Bytes/unit:8>>,
+    case Bin of
+	<<0:1,_/bits>> -> [16#ff,Bin];
+	<<1:1,_/bits>> -> Bin
+    end.
diff --git a/lib/compiler/src/beam_block.erl b/lib/compiler/src/beam_block.erl
index cf5244e1ce..85d332c56e 100644
--- a/lib/compiler/src/beam_block.erl
+++ b/lib/compiler/src/beam_block.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -22,14 +23,13 @@
 -module(beam_block).
 
 -export([module/2]).
--import(lists, [mapfoldl/3,reverse/1,reverse/2,foldl/3,member/2]).
--define(MAXREG, 1024).
+-import(lists, [reverse/1,reverse/2,foldl/3,member/2]).
 
-module({Mod,Exp,Attr,Fs0,Lc0}, _Opt) ->
-    {Fs,Lc} = mapfoldl(fun function/2, Lc0, Fs0),
+module({Mod,Exp,Attr,Fs0,Lc}, _Opt) ->
+    Fs = [function(F) || F <- Fs0],
     {ok,{Mod,Exp,Attr,Fs,Lc}}.
 
-function({function,Name,Arity,CLabel,Is0}, Lc0) ->
+function({function,Name,Arity,CLabel,Is0}) ->
     try
 	%% Collect basic blocks and optimize them.
 	Is1 = blockify(Is0),
@@ -39,11 +39,8 @@ function({function,Name,Arity,CLabel,Is0}, Lc0) ->
 	Is5 = opt_blocks(Is4),
 	Is6 = beam_utils:delete_live_annos(Is5),
 
-	%% Optimize bit syntax.
-	{Is,Lc} = bsm_opt(Is6, Lc0),
-
 	%% Done.
-	{{function,Name,Arity,CLabel,Is},Lc}
+	{function,Name,Arity,CLabel,Is6}
     catch
 	Class:Error ->
 	    Stack = erlang:get_stacktrace(),
@@ -61,77 +58,45 @@ blockify(Is) ->
 blockify([{loop_rec,{f,Fail},{x,0}},{loop_rec_end,_Lbl},{label,Fail}|Is], Acc) ->
     %% Useless instruction sequence.
     blockify(Is, Acc);
-
-%% New bit syntax matching.
-blockify([{bs_save2,R,Point}=I,{bs_restore2,R,Point}|Is], Acc) ->
-    blockify([I|Is], Acc);
-blockify([{bs_save2,R,Point}=I,{test,is_eq_exact,_,_}=Test,
-	  {bs_restore2,R,Point}|Is], Acc) ->
-    blockify([I,Test|Is], Acc);
-
-%% Do other peep-hole optimizations.
-blockify([{test,is_atom,{f,Fail},[Reg]}=I|
-	  [{select,select_val,Reg,{f,Fail},
-	    [{atom,false},{f,_}=BrFalse,
-	     {atom,true}=AtomTrue,{f,_}=BrTrue]}|Is]=Is0],
-	 [{block,Bl}|_]=Acc) ->
-    case is_last_bool(Bl, Reg) of
-	false ->
-	    blockify(Is0, [I|Acc]);
-	true ->
-	    %% The last instruction is a boolean operator/guard BIF that can't fail.
-	    %% We can convert the three-way branch to a two-way branch (eliminating
-	    %% the reference to the failure label).
-	    blockify(Is, [{jump,BrTrue},
-			  {test,is_eq_exact,BrFalse,[Reg,AtomTrue]}|Acc])
-    end;
-blockify([{test,is_atom,{f,Fail},[Reg]}=I|
-	  [{select,select_val,Reg,{f,Fail},
-	    [{atom,true}=AtomTrue,{f,_}=BrTrue,
-	     {atom,false},{f,_}=BrFalse]}|Is]=Is0],
-	 [{block,Bl}|_]=Acc) ->
-    case is_last_bool(Bl, Reg) of
-	false ->
-	    blockify(Is0, [I|Acc]);
-	true ->
-	    blockify(Is, [{jump,BrTrue},
-			  {test,is_eq_exact,BrFalse,[Reg,AtomTrue]}|Acc])
-    end;
+blockify([{get_map_elements,F,S,{list,Gets}}|Is0], Acc) ->
+    %% A get_map_elements instruction is only safe at the beginning of
+    %% a block because of the failure label.
+    {Ss,Ds} = beam_utils:split_even(Gets),
+    I = {set,Ds,[S|Ss],{get_map_elements,F}},
+    {Block,Is} = collect_block(Is0, [I]),
+    blockify(Is, [{block,Block}|Acc]);
 blockify([I|Is0]=IsAll, Acc) ->
-    case is_bs_put(I) of
-	true ->
-	    {BsPuts0,Is} = collect_bs_puts(IsAll),
-	    BsPuts = opt_bs_puts(BsPuts0),
-	    blockify(Is, reverse(BsPuts, Acc));
-	false ->
-	    case collect(I) of
-		error -> blockify(Is0, [I|Acc]);
-		Instr when is_tuple(Instr) ->
-		    {Block,Is} = collect_block(IsAll),
-		    blockify(Is, [{block,Block}|Acc])
-	    end
+    case collect(I) of
+	error -> blockify(Is0, [I|Acc]);
+	Instr when is_tuple(Instr) ->
+	    {Block,Is} = collect_block(IsAll),
+	    blockify(Is, [{block,Block}|Acc])
     end;
 blockify([], Acc) -> reverse(Acc).
 
-is_last_bool([{set,[Reg],As,{bif,N,_}}], Reg) ->
-    Ar = length(As),
-    erl_internal:new_type_test(N, Ar) orelse erl_internal:comp_op(N, Ar)
-	orelse erl_internal:bool_op(N, Ar);
-is_last_bool([_|Is], Reg) -> is_last_bool(Is, Reg);
-is_last_bool([], _) -> false.
-
 collect_block(Is) ->
     collect_block(Is, []).
 
+collect_block([{allocate,N,R}|Is0], Acc) ->
+    {Inits,Is} = lists:splitwith(fun ({init,{y,_}}) -> true;
+                                     (_) -> false
+                                 end, Is0),
+    collect_block(Is, [{set,[],[],{alloc,R,{nozero,N,0,Inits}}}|Acc]);
 collect_block([{allocate_zero,Ns,R},{test_heap,Nh,R}|Is], Acc) ->
-    collect_block(Is, [{set,[],[],{alloc,R,{no_opt,Ns,Nh,[]}}}|Acc]);
+    collect_block(Is, [{set,[],[],{alloc,R,{zero,Ns,Nh,[]}}}|Acc]);
 collect_block([I|Is]=Is0, Acc) ->
     case collect(I) of
 	error -> {reverse(Acc),Is0};
 	Instr -> collect_block(Is, [Instr|Acc])
-    end.
+    end;
+collect_block([], Acc) ->
+    {reverse(Acc),[]}.
 
+collect({allocate,N,R})      -> {set,[],[],{alloc,R,{nozero,N,0,[]}}};
 collect({allocate_zero,N,R}) -> {set,[],[],{alloc,R,{zero,N,0,[]}}};
+collect({allocate_heap,Ns,Nh,R}) -> {set,[],[],{alloc,R,{nozero,Ns,Nh,[]}}};
+collect({allocate_heap_zero,Ns,Nh,R}) -> {set,[],[],{alloc,R,{zero,Ns,Nh,[]}}};
+collect({init,D})            -> {set,[D],[],init};
 collect({test_heap,N,R})     -> {set,[],[],{alloc,R,{nozero,nostack,N,[]}}};
 collect({bif,N,F,As,D})      -> {set,[D],As,{bif,N,F}};
 collect({gc_bif,N,F,R,As,D}) -> {set,[D],As,{alloc,R,{gc_bif,N,F}}};
@@ -143,7 +108,16 @@ collect({get_tuple_element,S,I,D}) -> {set,[D],[S],{get_tuple_element,I}};
 collect({set_tuple_element,S,D,I}) -> {set,[],[S,D],{set_tuple_element,I}};
 collect({get_list,S,D1,D2})  -> {set,[D1,D2],[S],get_list};
 collect(remove_message)      -> {set,[],[],remove_message};
-collect({'catch',R,L})       -> {set,[R],[],{'catch',L}};
+collect({put_map,F,Op,S,D,R,{list,Puts}}) ->
+    {set,[D],[S|Puts],{alloc,R,{put_map,Op,F}}};
+collect({'catch'=Op,R,L}) ->
+    {set,[R],[],{try_catch,Op,L}};
+collect({'try'=Op,R,L}) ->
+    {set,[R],[],{try_catch,Op,L}};
+collect(fclearerror)         -> {set,[],[],fclearerror};
+collect({fcheckerror,{f,0}}) -> {set,[],[],fcheckerror};
+collect({fmove,S,D})         -> {set,[D],[S],fmove};
+collect({fconv,S,D})         -> {set,[D],[S],fconv};
 collect(_)                   -> error.
 
 %% embed_lines([Instruction]) -> [Instruction]
@@ -166,14 +140,16 @@ embed_lines([], Acc) -> Acc.
 
 opt_blocks([{block,Bl0}|Is]) ->
     %% The live annotation at the beginning is not useful.
-    [{'%live',_}|Bl] = Bl0,
+    [{'%live',_,_}|Bl] = Bl0,
     [{block,opt_block(Bl)}|opt_blocks(Is)];
 opt_blocks([I|Is]) ->
     [I|opt_blocks(Is)];
 opt_blocks([]) -> [].
 
 opt_block(Is0) ->
-    Is = find_fixpoint(fun opt/1, Is0),
+    Is = find_fixpoint(fun(Is) ->
+			       opt_tuple_element(opt(Is))
+		       end, Is0),
     opt_alloc(Is).
 
 find_fixpoint(OptFun, Is0) ->
@@ -223,6 +199,7 @@ move_allocates_2(Alloc, [], Acc) ->
 
 alloc_may_pass({set,_,_,{alloc,_,_}}) -> false;
 alloc_may_pass({set,_,_,{set_tuple_element,_}}) -> false;
+alloc_may_pass({set,_,_,{get_map_elements,_}}) -> false;
 alloc_may_pass({set,_,_,put_list}) -> false;
 alloc_may_pass({set,_,_,put}) -> false;
 alloc_may_pass({set,_,_,_}) -> true.
@@ -233,13 +210,6 @@ combine_alloc({_,Ns,Nh1,Init}, {_,nostack,Nh2,[]})  ->
 %% opt([Instruction]) -> [Instruction]
 %%  Optimize the instruction stream inside a basic block.
 
-opt([{set,[Dst],As,{bif,Bif,Fail}}=I1,
-     {set,[Dst],[Dst],{bif,'not',Fail}}=I2|Is]) ->
-    %% Get rid of the 'not' if the operation can be inverted.
-    case inverse_comp_op(Bif) of
- 	none -> [I1,I2|opt(Is)];
- 	RevBif -> [{set,[Dst],As,{bif,RevBif,Fail}}|opt(Is)]
-    end;
 opt([{set,[X],[X],move}|Is]) -> opt(Is);
 opt([{set,_,_,{line,_}}=Line1,
      {set,[D1],[{integer,Idx1},Reg],{bif,element,{f,0}}}=I1,
@@ -247,10 +217,12 @@ opt([{set,_,_,{line,_}}=Line1,
      {set,[D2],[{integer,Idx2},Reg],{bif,element,{f,0}}}=I2|Is])
   when Idx1 < Idx2, D1 =/= D2, D1 =/= Reg, D2 =/= Reg ->
     opt([Line2,I2,Line1,I1|Is]);
-opt([{set,Ds0,Ss,Op}|Is0]) ->	
+opt([{set,[_|_],_Ss,{get_map_elements,_F}}=I|Is]) ->
+    [I|opt(Is)];
+opt([{set,Ds0,Ss,Op}|Is0]) ->
     {Ds,Is} = opt_moves(Ds0, Is0),
     [{set,Ds,Ss,Op}|opt(Is)];
-opt([{'%live',_}=I|Is]) ->
+opt([{'%live',_,_}=I|Is]) ->
     [I|opt(Is)];
 opt([]) -> [].
 
@@ -279,66 +251,150 @@ opt_moves([X0,Y0], Is0) ->
 %%  If there is a {move,Dest,FinalDest} instruction
 %%  in the instruction stream, remove the move instruction
 %%  and let FinalDest be the destination.
-%%
-%%  For this optimization to be safe, we must be sure that
-%%  Dest will not be referenced in any other by other instructions
-%%  in the rest of the instruction stream. Not even the indirect
-%%  reference by an instruction that may allocate (such as
-%%  test_heap/2 or a GC Bif) is allowed.
 
 opt_move(Dest, Is) ->
-    opt_move_1(Dest, Is, ?MAXREG, []).
-
-opt_move_1(R, [{set,_,_,{alloc,Live,_}}|_]=Is, SafeRegs, Acc) when Live < SafeRegs ->
-    %% Downgrade number of safe regs and rescan the instruction, as it most probably
-    %% is a gc_bif instruction.
-    opt_move_1(R, Is, Live, Acc);
-opt_move_1(R, [{set,[{x,X}=D],[R],move}|Is], SafeRegs, Acc) ->
-    case X < SafeRegs andalso beam_utils:is_killed_block(R, Is) of
-	true -> opt_move_2(D, Acc, Is);
-	false -> not_possible
+    opt_move_1(Dest, Is, []).
+
+opt_move_1(R, [{set,[D],[R],move}|Is0], Acc) ->
+    %% Provided that the source register is killed by instructions
+    %% that follow, the optimization is safe.
+    case eliminate_use_of_from_reg(Is0, R, D, []) of
+	{yes,Is} -> opt_move_rev(D, Acc, Is);
+	no -> not_possible
     end;
-opt_move_1(R, [{set,[D],[R],move}|Is], _SafeRegs, Acc) ->
-    case beam_utils:is_killed_block(R, Is) of
-	true -> opt_move_2(D, Acc, Is);
-	false -> not_possible
+opt_move_1(_R, [{set,_,_,{alloc,_,_}}|_], _) ->
+    %% The optimization is either not possible or not safe.
+    %%
+    %% If R is an X register killed by allocation, the optimization is
+    %% not safe. On the other hand, if the X register is killed, there
+    %% will not follow a 'move' instruction with this X register as
+    %% the source.
+    %%
+    %% If R is a Y register, the optimization is still not safe
+    %% because the new target register is an X register that cannot
+    %% safely pass the alloc instruction.
+    not_possible;
+opt_move_1(R, [{set,_,_,_}=I|Is], Acc) ->
+    %% If the source register is either killed or used by this
+    %% instruction, the optimimization is not possible.
+    case is_killed_or_used(R, I) of
+	true -> not_possible;
+	false -> opt_move_1(R, Is, [I|Acc])
     end;
-opt_move_1(R, [I|Is], SafeRegs, Acc) ->
-    case is_transparent(R, I) of
-	false -> not_possible;
-	true -> opt_move_1(R, Is, SafeRegs, [I|Acc])
-    end.
+opt_move_1(_, _, _) ->
+    not_possible.
 
-%% Reverse the instructions, while checking that there are no instructions that
-%% would interfere with using the new destination register chosen.
+%% opt_tuple_element([Instruction]) -> [Instruction]
+%%  If possible, move get_tuple_element instructions forward
+%%  in the instruction stream to a move instruction, eliminating
+%%  the move instruction. Example:
+%%
+%%    get_tuple_element Tuple Pos Dst1
+%%    ...
+%%    move Dst1 Dst2
+%%
+%%  This code may be possible to rewrite to:
+%%
+%%    %%(Moved get_tuple_element instruction)
+%%    ...
+%%    get_tuple_element Tuple Pos Dst2
+%%
 
-opt_move_2(D, [I|Is], Acc) ->
-    case is_transparent(D, I) of
-	false -> not_possible;
-	true -> opt_move_2(D, Is, [I|Acc])
+opt_tuple_element([{set,[D],[S],{get_tuple_element,_}}=I|Is0]) ->
+    case opt_tuple_element_1(Is0, I, {S,D}, []) of
+	no ->
+	    [I|opt_tuple_element(Is0)];
+	{yes,Is} ->
+	    opt_tuple_element(Is)
     end;
-opt_move_2(D, [], Acc) -> {D,Acc}.
-
-%% is_transparent(Register, Instruction) -> true | false
-%%  Returns true if Instruction does not in any way references Register
-%%  (even indirectly by an allocation instruction).
-%%  Returns false if Instruction does reference Register, or we are
-%%  not sure.
-
-is_transparent({x,X}, {set,_,_,{alloc,Live,_}}) when X < Live ->
-    false;
-is_transparent(R, {set,Ds,Ss,_Op}) ->
-    case member(R, Ds) of
-	true -> false;
-	false -> not member(R, Ss)
+opt_tuple_element([I|Is]) ->
+    [I|opt_tuple_element(Is)];
+opt_tuple_element([]) -> [].
+
+opt_tuple_element_1([{set,_,_,{alloc,_,_}}|_], _, _, _) ->
+    no;
+opt_tuple_element_1([{set,_,_,{try_catch,_,_}}|_], _, _, _) ->
+    no;
+opt_tuple_element_1([{set,[D],[S],move}|Is0], I0, {_,S}, Acc) ->
+    case eliminate_use_of_from_reg(Is0, S, D, []) of
+	no ->
+	    no;
+	{yes,Is} ->
+	    {set,[S],Ss,Op} = I0,
+	    I = {set,[D],Ss,Op},
+	    {yes,reverse(Acc, [I|Is])}
     end;
-is_transparent(_, _) -> false.
+opt_tuple_element_1([{set,Ds,Ss,_}=I|Is], MovedI, {S,D}=Regs, Acc) ->
+    case member(S, Ds) orelse member(D, Ss) of
+	true ->
+	    no;
+	false ->
+	    opt_tuple_element_1(Is, MovedI, Regs, [I|Acc])
+    end;
+opt_tuple_element_1(_, _, _, _) -> no.
+
+%% Reverse the instructions, while checking that there are no
+%% instructions that would interfere with using the new destination
+%% register (D).
+
+opt_move_rev(D, [I|Is], Acc) ->
+    case is_killed_or_used(D, I) of
+	true -> not_possible;
+	false -> opt_move_rev(D, Is, [I|Acc])
+    end;
+opt_move_rev(D, [], Acc) -> {D,Acc}.
+
+%% is_killed_or_used(Register, {set,_,_,_}) -> bool()
+%%  Test whether the register is used by the instruction.
+
+is_killed_or_used(R, {set,Ss,Ds,_}) ->
+    member(R, Ds) orelse member(R, Ss).
+
+%% eliminate_use_of_from_reg([Instruction], FromRegister, ToRegister, Acc) ->
+%%       {yes,Is} | no
+%%  Eliminate any use of FromRegister in the instruction sequence
+%%  by replacing uses of FromRegister with ToRegister. If FromRegister
+%%  is referenced by an allocation instruction, return 'no' to indicate
+%%  that FromRegister is still used and that the optimization is not
+%%  possible.
+
+eliminate_use_of_from_reg([{set,_,_,{alloc,Live,_}}|_]=Is0, {x,X}, _, Acc) ->
+    if
+	X < Live ->
+	    no;
+	true ->
+	    {yes,reverse(Acc, Is0)}
+    end;
+eliminate_use_of_from_reg([{set,Ds,Ss0,Op}=I0|Is], From, To, Acc) ->
+    I = case member(From, Ss0) of
+	    true ->
+		Ss = [case S of
+			  From -> To;
+			  _ -> S
+		      end || S <- Ss0],
+		{set,Ds,Ss,Op};
+	    false ->
+		I0
+	end,
+    case member(From, Ds) of
+	true ->
+	    {yes,reverse(Acc, [I|Is])};
+	false ->
+	    eliminate_use_of_from_reg(Is, From, To, [I|Acc])
+    end;
+eliminate_use_of_from_reg([I]=Is, From, _To, Acc) ->
+    case beam_utils:is_killed_block(From, [I]) of
+	true ->
+	    {yes,reverse(Acc, Is)};
+	false ->
+	    no
+    end.
 
 %% opt_alloc(Instructions) -> Instructions'
 %%  Optimises all allocate instructions.
 
 opt_alloc([{set,[],[],{alloc,R,{_,Ns,Nh,[]}}}|Is]) ->
-    [{set,[],[],opt_alloc(Is, Ns, Nh, R)}|opt(Is)];
+    [{set,[],[],opt_alloc(Is, Ns, Nh, R)}|Is];
 opt_alloc([I|Is]) -> [I|opt_alloc(Is)];
 opt_alloc([]) -> [].
 	
@@ -370,6 +426,7 @@ gen_init(Fs, Regs, Y, Acc) ->
 
 init_yreg([{set,_,_,{bif,_,_}}|_], Reg) -> Reg;
 init_yreg([{set,_,_,{alloc,_,{gc_bif,_,_}}}|_], Reg) -> Reg;
+init_yreg([{set,_,_,{alloc,_,{put_map,_,_}}}|_], Reg) -> Reg;
 init_yreg([{set,Ds,_,_}|Is], Reg) -> init_yreg(Is, add_yregs(Ds, Reg));
 init_yreg(_Is, Reg) -> Reg.
 
@@ -403,246 +460,3 @@ x_dead([], Regs) -> Regs.
 x_live([{x,N}|Rs], Regs) -> x_live(Rs, Regs bor (1 bsl N));
 x_live([_|Rs], Regs) -> x_live(Rs, Regs);
 x_live([], Regs) -> Regs.
-
-%% inverse_comp_op(Op) -> none|RevOp
-
-inverse_comp_op('=:=') -> '=/=';
-inverse_comp_op('=/=') -> '=:=';
-inverse_comp_op('==') -> '/=';
-inverse_comp_op('/=') -> '==';
-inverse_comp_op('>') -> '=<';
-inverse_comp_op('<') -> '>=';
-inverse_comp_op('>=') -> '<';
-inverse_comp_op('=<') -> '>';
-inverse_comp_op(_) -> none.
-
-%%%
-%%% Evaluation of constant bit fields.
-%%%
-
-is_bs_put({bs_put,_,{bs_put_integer,_,_},_}) -> true;
-is_bs_put({bs_put,_,{bs_put_float,_,_},_}) -> true;
-is_bs_put(_) -> false.
-
-collect_bs_puts(Is) ->
-    collect_bs_puts_1(Is, []).
-    
-collect_bs_puts_1([I|Is]=Is0, Acc) ->
-    case is_bs_put(I) of
-	false -> {reverse(Acc),Is0};
-	true -> collect_bs_puts_1(Is, [I|Acc])
-    end.
-    
-opt_bs_puts(Is) ->
-    opt_bs_1(Is, []).
-
-opt_bs_1([{bs_put,Fail,
-	   {bs_put_float,1,Flags0},[{integer,Sz},Src]}=I0|Is], Acc) ->
-    try eval_put_float(Src, Sz, Flags0) of
-	<<Int:Sz>> ->
-	    Flags = force_big(Flags0),
-	    I = {bs_put,Fail,{bs_put_integer,1,Flags},
-		 [{integer,Sz},{integer,Int}]},
-	    opt_bs_1([I|Is], Acc)
-    catch
-	error:_ ->
-	    opt_bs_1(Is, [I0|Acc])
-    end;
-opt_bs_1([{bs_put,_,{bs_put_integer,1,_},[{integer,8},{integer,_}]}|_]=IsAll,
-	 Acc0) ->
-    {Is,Acc} = bs_collect_string(IsAll, Acc0),
-    opt_bs_1(Is, Acc);
-opt_bs_1([{bs_put,Fail,{bs_put_integer,1,F},[{integer,Sz},{integer,N}]}=I|Is0],
-	 Acc) when Sz > 8 ->
-    case field_endian(F) of
-	big ->
-	    %% We can do this optimization for any field size without risk
-	    %% for code explosion.
-	    case bs_split_int(N, Sz, Fail, Is0) of
-		no_split -> opt_bs_1(Is0, [I|Acc]);
-		Is -> opt_bs_1(Is, Acc)
-	    end;
-	little when Sz < 128 ->
-	    %% We only try to optimize relatively small fields, to avoid
-	    %% an explosion in code size.
-	    <<Int:Sz>> = <<N:Sz/little>>,
-	    Flags = force_big(F),
-	    Is = [{bs_put,Fail,{bs_put_integer,1,Flags},
-		   [{integer,Sz},{integer,Int}]}|Is0],
-	    opt_bs_1(Is, Acc);
-	_ -> 					%native or too wide little field
-	    opt_bs_1(Is0, [I|Acc])
-    end;
-opt_bs_1([{bs_put,Fail,{Op,U,F},[{integer,Sz},Src]}|Is], Acc) when U > 1 ->
-    opt_bs_1([{bs_put,Fail,{Op,1,F},[{integer,U*Sz},Src]}|Is], Acc);
-opt_bs_1([I|Is], Acc) ->
-    opt_bs_1(Is, [I|Acc]);
-opt_bs_1([], Acc) -> reverse(Acc).
-
-eval_put_float(Src, Sz, Flags) when Sz =< 256 -> %Only evaluate if Sz is reasonable.
-    Val = value(Src),
-    case field_endian(Flags) of
-	little -> <<Val:Sz/little-float-unit:1>>;
-	big -> <<Val:Sz/big-float-unit:1>>
-        %% native intentionally not handled here - we can't optimize it.
-    end.
-
-value({integer,I}) -> I;
-value({float,F}) -> F.
-
-bs_collect_string(Is, [{bs_put,_,{bs_put_string,Len,{string,Str}},[]}|Acc]) ->
-    bs_coll_str_1(Is, Len, reverse(Str), Acc);
-bs_collect_string(Is, Acc) ->
-    bs_coll_str_1(Is, 0, [], Acc).
-    
-bs_coll_str_1([{bs_put,_,{bs_put_integer,U,_},[{integer,Sz},{integer,V}]}|Is],
-	      Len, StrAcc, IsAcc) when U*Sz =:= 8 ->
-    Byte = V band 16#FF,
-    bs_coll_str_1(Is, Len+1, [Byte|StrAcc], IsAcc);
-bs_coll_str_1(Is, Len, StrAcc, IsAcc) ->
-    {Is,[{bs_put,{f,0},{bs_put_string,Len,{string,reverse(StrAcc)}},[]}|IsAcc]}.
-
-field_endian({field_flags,F}) -> field_endian_1(F).
-
-field_endian_1([big=E|_]) -> E;
-field_endian_1([little=E|_]) -> E;
-field_endian_1([native=E|_]) -> E;
-field_endian_1([_|Fs]) -> field_endian_1(Fs).
-
-force_big({field_flags,F}) ->
-    {field_flags,force_big_1(F)}.
-
-force_big_1([big|_]=Fs) -> Fs;
-force_big_1([little|Fs]) -> [big|Fs];
-force_big_1([F|Fs]) -> [F|force_big_1(Fs)].
-
-bs_split_int(0, Sz, _, _) when Sz > 64 ->
-    %% We don't want to split in this case because the
-    %% string will consist of only zeroes.
-    no_split;
-bs_split_int(-1, Sz, _, _) when Sz > 64 ->
-    %% We don't want to split in this case because the
-    %% string will consist of only 255 bytes.
-    no_split;
-bs_split_int(N, Sz, Fail, Acc) ->
-    FirstByteSz = case Sz rem 8 of
-		      0 -> 8;
-		      Rem -> Rem
-		  end,
-    bs_split_int_1(N, FirstByteSz, Sz, Fail, Acc).
-
-bs_split_int_1(-1, _, Sz, Fail, Acc) when Sz > 64 ->
-    I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
-	 [{integer,Sz},{integer,-1}]},
-    [I|Acc];
-bs_split_int_1(0, _, Sz, Fail, Acc) when Sz > 64 ->
-    I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
-	 [{integer,Sz},{integer,0}]},
-    [I|Acc];
-bs_split_int_1(N, ByteSz, Sz, Fail, Acc) when Sz > 0 ->
-    Mask = (1 bsl ByteSz) - 1,
-    I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
-	 [{integer,ByteSz},{integer,N band Mask}]},
-    bs_split_int_1(N bsr ByteSz, 8, Sz-ByteSz, Fail, [I|Acc]);
-bs_split_int_1(_, _, _, _, Acc) -> Acc.
-
-
-%%%
-%%% Optimization of new bit syntax matching: get rid
-%%% of redundant bs_restore2/2 instructions across select_val
-%%% instructions, as well as a few other simple peep-hole optimizations.
-%%%
-
-bsm_opt(Is0, Lc0) ->
-    {Is1,D0,Lc} = bsm_scan(Is0, [], Lc0, []),
-    Is2 = case D0 of
-	      [] ->
-		  Is1;
-	     _ ->
-		  D = gb_trees:from_orddict(orddict:from_list(D0)),
-		  bsm_reroute(Is1, D, none, [])
-	 end,
-    Is = beam_clean:bs_clean_saves(Is2),
-    {bsm_opt_2(Is, []),Lc}.
-
-bsm_scan([{label,L}=Lbl,{bs_restore2,_,Save}=R|Is], D0, Lc, Acc0) ->
-    D = [{{L,Save},Lc}|D0],
-    Acc = [{label,Lc},R,Lbl|Acc0],
-    bsm_scan(Is, D, Lc+1, Acc);
-bsm_scan([I|Is], D, Lc, Acc) ->
-    bsm_scan(Is, D, Lc, [I|Acc]);
-bsm_scan([], D, Lc, Acc) ->
-    {reverse(Acc),D,Lc}.
-
-bsm_reroute([{bs_save2,Reg,Save}=I|Is], D, _, Acc) ->
-    bsm_reroute(Is, D, {Reg,Save}, [I|Acc]);
-bsm_reroute([{bs_restore2,Reg,Save}=I|Is], D, _, Acc) ->
-    bsm_reroute(Is, D, {Reg,Save}, [I|Acc]);
-bsm_reroute([{label,_}=I|Is], D, S, Acc) ->
-    bsm_reroute(Is, D, S, [I|Acc]);
-bsm_reroute([{select,select_val,Reg,F0,Lbls0}|Is], D, {_,Save}=S, Acc0) ->
-    [F|Lbls] = bsm_subst_labels([F0|Lbls0], Save, D),
-    Acc = [{select,select_val,Reg,F,Lbls}|Acc0],
-    bsm_reroute(Is, D, S, Acc);
-bsm_reroute([{test,TestOp,F0,TestArgs}=I|Is], D, {_,Save}=S, Acc0) ->
-    F = bsm_subst_label(F0, Save, D),
-    Acc = [{test,TestOp,F,TestArgs}|Acc0],
-    case bsm_not_bs_test(I) of
-	true ->
-	    %% The test instruction will not update the bit offset for the
-	    %% binary being matched. Therefore the save position can be kept.
-	    bsm_reroute(Is, D, S, Acc);
-	false ->
-	    %% The test instruction might update the bit offset. Kill our
-	    %% remembered Save position.
-	    bsm_reroute(Is, D, none, Acc)
-    end;
-bsm_reroute([{test,TestOp,F0,Live,TestArgs,Dst}|Is], D, {_,Save}, Acc0) ->
-    F = bsm_subst_label(F0, Save, D),
-    Acc = [{test,TestOp,F,Live,TestArgs,Dst}|Acc0],
-    %% The test instruction will update the bit offset. Kill our
-    %% remembered Save position.
-    bsm_reroute(Is, D, none, Acc);
-bsm_reroute([{block,[{set,[],[],{alloc,_,_}}]}=Bl,
-	     {bs_context_to_binary,_}=I|Is], D, S, Acc) ->
-    %% To help further bit syntax optimizations.
-    bsm_reroute([I,Bl|Is], D, S, Acc);
-bsm_reroute([I|Is], D, _, Acc) ->
-    bsm_reroute(Is, D, none, [I|Acc]);
-bsm_reroute([], _, _, Acc) -> reverse(Acc).
-
-bsm_opt_2([{test,bs_test_tail2,F,[Ctx,Bits]}|Is],
-	  [{test,bs_skip_bits2,F,[Ctx,{integer,I},Unit,_Flags]}|Acc]) ->
-    bsm_opt_2(Is, [{test,bs_test_tail2,F,[Ctx,Bits+I*Unit]}|Acc]);
-bsm_opt_2([{test,bs_skip_bits2,F,[Ctx,{integer,I1},Unit1,_]}|Is],
-	  [{test,bs_skip_bits2,F,[Ctx,{integer,I2},Unit2,Flags]}|Acc]) ->
-    bsm_opt_2(Is, [{test,bs_skip_bits2,F,
-		    [Ctx,{integer,I1*Unit1+I2*Unit2},1,Flags]}|Acc]);
-bsm_opt_2([I|Is], Acc) ->
-    bsm_opt_2(Is, [I|Acc]);
-bsm_opt_2([], Acc) -> reverse(Acc).
-
-%% bsm_not_bs_test({test,Name,_,Operands}) -> true|false.
-%%  Test whether is the test is a "safe", i.e. does not move the
-%%  bit offset for a binary.
-%%
-%%  'true' means that the test is safe, 'false' that we don't know or
-%%  that the test moves the offset (e.g. bs_get_integer2).
-
-bsm_not_bs_test({test,bs_test_tail2,_,[_,_]}) -> true;
-bsm_not_bs_test(Test) -> beam_utils:is_pure_test(Test).
-
-bsm_subst_labels(Fs, Save, D) ->
-    bsm_subst_labels_1(Fs, Save, D, []).
-
-bsm_subst_labels_1([F|Fs], Save, D, Acc) ->
-    bsm_subst_labels_1(Fs, Save, D, [bsm_subst_label(F, Save, D)|Acc]);
-bsm_subst_labels_1([], _, _, Acc) ->
-    reverse(Acc).
-
-bsm_subst_label({f,Lbl0}=F, Save, D) ->
-    case gb_trees:lookup({Lbl0,Save}, D) of
-	{value,Lbl} -> {f,Lbl};
-	none -> F
-    end;
-bsm_subst_label(Other, _, _) -> Other.
diff --git a/lib/compiler/src/beam_bool.erl b/lib/compiler/src/beam_bool.erl
index cf5455dfde..99e4ccb1e9 100644
--- a/lib/compiler/src/beam_bool.erl
+++ b/lib/compiler/src/beam_bool.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2004-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2004-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -24,8 +25,6 @@
 
 -import(lists, [reverse/1,reverse/2,foldl/3,mapfoldl/3,map/2]).
 
--define(MAXREG, 1024).
-
 -record(st,
 	{next,					%Next label number.
 	 ll					%Live regs at labels.
@@ -126,44 +125,48 @@ bopt_block(Reg, Fail, OldIs, [{block,Bl0}|Acc0], St0) ->
 		%% There was a reference to a boolean expression
 		%% from inside a protected block (try/catch), to
 		%% a boolean expression outside.
-		  throw:protected_barrier ->
+		throw:protected_barrier ->
 		    failed;
 
-		  %% The 'xor' operator was used. We currently don't
-		  %% find it worthwile to translate 'xor' operators
-		  %% (the code would be clumsy).
-		  throw:'xor' ->
+		%% The 'xor' operator was used. We currently don't
+		%% find it worthwile to translate 'xor' operators
+		%% (the code would be clumsy).
+		throw:'xor' ->
 		    failed;
 
-		  %% The block does not contain a boolean expression,
-		  %% but only a call to a guard BIF.
-		  %% For instance: ... when element(1, T) ->
- 		  throw:not_boolean_expr ->
- 		    failed;
-
-		  %% The block contains a 'move' instruction that could
-		  %% not be handled.
- 		  throw:move ->
+		%% The block does not contain a boolean expression,
+		%% but only a call to a guard BIF.
+		%% For instance: ... when element(1, T) ->
+		throw:not_boolean_expr ->
  		    failed;
 
-		  %% The optimization is not safe. (A register
-		  %% used by the instructions following the
-		  %% optimized code is either not assigned a
-		  %% value at all or assigned a different value.)
-		  throw:all_registers_not_killed ->
+		%% The optimization is not safe. (A register
+		%% used by the instructions following the
+		%% optimized code is either not assigned a
+		%% value at all or assigned a different value.)
+		throw:all_registers_not_killed ->
+		    failed;
+		throw:registers_used ->
 		    failed;
-		  throw:registers_used ->
+
+		%% A protected block refered to the value
+		%% returned by another protected block,
+		%% probably because the Core Erlang code
+		%% used nested try/catches in the guard.
+		%% (v3_core never produces nested try/catches
+		%% in guards, so it must have been another
+		%% Core Erlang translator.)
+		throw:protected_violation ->
 		    failed;
 
-		  %% A protected block refered to the value
-		  %% returned by another protected block,
-		  %% probably because the Core Erlang code
-		  %% used nested try/catches in the guard.
-		  %% (v3_core never produces nested try/catches
-		  %% in guards, so it must have been another
-		  %% Core Erlang translator.)
-		  throw:protected_violation ->
+		%% Failed to work out the live registers for a GC
+		%% BIF. For example, if the number of live registers
+		%% needed to be 4 because {x,3} was a source register,
+		%% but {x,2} was not known to be initialized, this
+		%% exception would be thrown.
+		throw:gc_bif_alloc_failure ->
 		    failed
+
 	    end
     end.
 
@@ -205,37 +208,14 @@ ensure_opt_safe(Bl, NewCode, OldIs, Fail, PrecedingCode, St) ->
 	false -> throw(all_registers_not_killed);
 	true -> ok
     end,
-    Same = assigned_same_value(Bl, NewCode),
     MustBeUnused = ordsets:subtract(ordsets:union(NotSet, NewDst),
-				    ordsets:union(MustBeKilled, Same)),
+				    MustBeKilled),
     case none_used(MustBeUnused, OldIs, Fail, St) of
 	false -> throw(registers_used);
 	true -> ok
     end,
     ok.
 
-%% assigned_same_value(OldCode, NewCodeReversed) -> [DestinationRegs]
-%%  Return an ordset with a list of all y registers that are always
-%%  assigned the same value in the old and new code. Currently, we
-%%  are very conservative in that we only consider identical move
-%%  instructions in the same order.
-%%
-assigned_same_value(Old, New) ->
-    case reverse(New) of
-	[{block,Bl}|_] ->
-	    assigned_same_value(Old, Bl, []);
-	_ ->
-	    ordsets:new()
-    end.
-
-assigned_same_value([{set,[{y,_}=D],[S],move}|T1],
-		    [{set,[{y,_}=D],[S],move}|T2], Acc) ->
-    assigned_same_value(T1, T2, [D|Acc]);
-assigned_same_value(_, _, Acc) ->
-    ordsets:from_list(Acc).
-
-update_fail_label([{set,_,_,move}=I|Is], Fail, Acc) ->
-    update_fail_label(Is, Fail, [I|Acc]);
 update_fail_label([{set,Ds,As,{bif,N,{f,_}}}|Is], Fail, Acc) ->
     update_fail_label(Is, Fail, [{set,Ds,As,{bif,N,{f,Fail}}}|Acc]);
 update_fail_label([{set,Ds,As,{alloc,Regs,{gc_bif,N,{f,_}}}}|Is], Fail, Acc) ->
@@ -258,9 +238,9 @@ extend_block(BlAcc0, Fail, [{block,Is0}|OldAcc]) ->
     end;
 extend_block(BlAcc, _, OldAcc) -> {BlAcc,OldAcc}.
 
-extend_block_1([{set,[_],_,{bif,_,{f,Fail}}}=I|Is], Fail, Acc) ->
+extend_block_1([{set,[{x,_}],_,{bif,_,{f,Fail}}}=I|Is], Fail, Acc) ->
     extend_block_1(Is, Fail, [I|Acc]);
-extend_block_1([{set,[_],As,{bif,Bif,_}}=I|Is]=Is0, Fail, Acc) ->
+extend_block_1([{set,[{x,_}],As,{bif,Bif,_}}=I|Is]=Is0, Fail, Acc) ->
     case safe_bool_op(Bif, length(As)) of
 	false -> {Acc,reverse(Is0)};
 	true -> extend_block_1(Is, Fail, [I|Acc])
@@ -304,8 +284,6 @@ split_block_1(Is, Fail, ProhibitFailLabel) ->
 	    end
     end.
 
-split_block_2([{set,_,_,move}=I|Is], Fail, Acc) ->
-    split_block_2(Is, Fail, [I|Acc]);
 split_block_2([{set,[_],_,{bif,_,{f,Fail}}}=I|Is], Fail, Acc) ->
     split_block_2(Is, Fail, [I|Acc]);
 split_block_2([{set,[_],_,{alloc,_,{gc_bif,_,{f,Fail}}}}=I|Is], Fail, Acc) ->
@@ -318,6 +296,8 @@ split_block_label_used([{set,[_],_,{bif,_,{f,Fail}}}|_], Fail) ->
     true;
 split_block_label_used([{set,[_],_,{alloc,_,{gc_bif,_,{f,Fail}}}}|_], Fail) ->
     true;
+split_block_label_used([{set,[_],_,{alloc,_,{put_map,_,{f,Fail}}}}|_], Fail) ->
+    true;
 split_block_label_used([_|Is], Fail) ->
     split_block_label_used(Is, Fail);
 split_block_label_used([], _) -> false.
@@ -331,8 +311,8 @@ dst_regs([{set,[D],_,{bif,_,{f,_}}}|Is], Acc) ->
     dst_regs(Is, [D|Acc]);
 dst_regs([{set,[D],_,{alloc,_,{gc_bif,_,{f,_}}}}|Is], Acc) ->
     dst_regs(Is, [D|Acc]);
-dst_regs([{set,[D],_,move}|Is], Acc) ->
-    dst_regs(Is, [D|Acc]);
+dst_regs([{protected,_,Bl,_}|Is], Acc) ->
+    dst_regs(Bl, dst_regs(Is, Acc));
 dst_regs([_|Is], Acc) ->
     dst_regs(Is, Acc);
 dst_regs([], Acc) -> ordsets:from_list(Acc).
@@ -391,17 +371,14 @@ bopt_tree([{set,_,_,{bif,'xor',_}}|_], _, _) ->
     throw('xor');
 bopt_tree([{protected,[Dst],Code,_}|Is], Forest0, Pre) ->
     ProtForest0 = gb_trees:from_orddict([P || {_,any}=P <- gb_trees:to_list(Forest0)]),
-    {ProtPre,[{_,ProtTree}]} = bopt_tree(Code, ProtForest0, []),
-    Prot = {prot,ProtPre,ProtTree},
-    Forest = gb_trees:enter(Dst, Prot, Forest0),
-    bopt_tree(Is, Forest, Pre);    
-bopt_tree([{set,[Dst],[Src],move}=Move|Is], Forest, Pre) ->
-    case {Src,Dst} of
-	{{tmp,_},_} -> throw(move);
-	{_,{tmp,_}} -> throw(move);
-	_ -> ok
-    end,
-    bopt_tree(Is, Forest, [Move|Pre]);
+    case bopt_tree(Code, ProtForest0, []) of
+        {ProtPre,[{_,ProtTree}]} ->
+            Prot = {prot,ProtPre,ProtTree},
+            Forest = gb_trees:enter(Dst, Prot, Forest0),
+            bopt_tree(Is, Forest, Pre);
+        _Res ->
+            throw(not_boolean_expr)
+    end;
 bopt_tree([{set,[Dst],As,{bif,N,_}}=Bif|Is], Forest0, Pre) ->
     Ar = length(As),
     case safe_bool_op(N, Ar) of
@@ -425,13 +402,17 @@ bopt_tree([], Forest, Pre) ->
 safe_bool_op(N, Ar) ->
     erl_internal:new_type_test(N, Ar) orelse erl_internal:comp_op(N, Ar).
 
+bopt_bool_args([V0,V0], Forest0) ->
+    {V,Forest} = bopt_bool_arg(V0, Forest0),
+    {[V,V],Forest};
 bopt_bool_args(As, Forest) ->
     mapfoldl(fun bopt_bool_arg/2, Forest, As).
 
 bopt_bool_arg({T,_}=R, Forest) when T =:= x; T =:= y; T =:= tmp ->
-    Val = case gb_trees:get(R, Forest) of
-	      any -> {test,is_eq_exact,fail,[R,{atom,true}]};
-	      Val0 -> Val0
+    Val = case gb_trees:lookup(R, Forest) of
+	      {value,any} -> {test,is_eq_exact,fail,[R,{atom,true}]};
+	      {value,Val0} -> Val0;
+              none -> throw(mixed)
 	  end,
     {Val,gb_trees:delete(R, Forest)};
 bopt_bool_arg(Term, Forest) ->
@@ -522,7 +503,9 @@ bopt_cg({prot,Pre0,Tree}, Fail, Rs0, Acc, St0) ->
 bopt_cg({atom,true}, _Fail, _Rs, Acc, St) ->
     {Acc,St};
 bopt_cg({atom,false}, Fail, _Rs, Acc, St) ->
-    {[{jump,{f,Fail}}|Acc],St}.
+    {[{jump,{f,Fail}}|Acc],St};
+bopt_cg(_, _, _, _, _) ->
+    throw(not_boolean_expr).
 
 bopt_cg_not({'and',As0}) ->
     As = [bopt_cg_not(A) || A <- As0],
@@ -535,7 +518,9 @@ bopt_cg_not({'not',Arg}) ->
 bopt_cg_not({test,Test,Fail,As}) ->
     {inverted_test,Test,Fail,As};
 bopt_cg_not({atom,Bool}) when is_boolean(Bool) ->
-    {atom,not Bool}.
+    {atom,not Bool};
+bopt_cg_not(_) ->
+    throw(not_boolean_expr).
 
 bopt_cg_not_not({'and',As}) ->
     {'and',[bopt_cg_not_not(A) || A <- As]};
@@ -565,10 +550,6 @@ free_variables(Is) ->
     E = gb_sets:empty(),
     free_vars_1(Is, E, E, E).
 
-free_vars_1([{set,Ds,As,move}|Is], F0, N0, A) ->
-    F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)),
-    N = gb_sets:union(N0, var_list(Ds)),
-    free_vars_1(Is, F, N, A);
 free_vars_1([{set,Ds,As,{bif,_,_}}|Is], F0, N0, A) ->
     F = gb_sets:union(F0, gb_sets:difference(var_list(As), N0)),
     N = gb_sets:union(N0, var_list(Ds)),
@@ -608,8 +589,6 @@ free_vars_regs(X) -> [{x,X-1}|free_vars_regs(X-1)].
 rename_regs(Is, Regs) ->
     rename_regs(Is, Regs, []).
 
-rename_regs([{set,_,_,move}=I|Is], Regs, Acc) ->
-    rename_regs(Is, Regs, [I|Acc]);
 rename_regs([{set,[Dst0],Ss0,{alloc,_,Info}}|Is], Regs0, Acc) ->
     Live = live_regs(Regs0),
     Ss = rename_sources(Ss0, Regs0),
@@ -651,10 +630,16 @@ put_reg_1(V, [], I) -> [{I,V}].
 fetch_reg(V, [{I,V}|_]) -> {x,I};
 fetch_reg(V, [_|SRs]) -> fetch_reg(V, SRs).
 
-live_regs(Regs) ->
-    foldl(fun ({I,_}, _) ->
-		  I
-	  end, -1, Regs)+1.
+live_regs([{_,reserved}|_]) ->
+    %% We are not sure that this register is initialized, so we must
+    %% abort the optimization.
+    throw(gc_bif_alloc_failure);
+live_regs([{I,_}]) ->
+    I+1;
+live_regs([{_,_}|Regs]) ->
+    live_regs(Regs);
+live_regs([]) ->
+    0.
 
     
 %%%
@@ -707,8 +692,7 @@ ssa_assign({x,_}=R, #ssa{sub=Sub0}=Ssa0) ->
 	    Sub1 = gb_trees:update(R, NewReg, Sub0),
 	    Sub = gb_trees:insert(NewReg, NewReg, Sub1),
 	    Ssa#ssa{sub=Sub}
-    end;
-ssa_assign(_, Ssa) -> Ssa.
+    end.
 
 ssa_sub_list(List, Sub) ->
     [ssa_sub(E, Sub) || E <- List].
@@ -758,6 +742,9 @@ is_not_used(R, Is, Label, #st{ll=Ll}) ->
 initialized_regs(Is) ->
     initialized_regs(Is, ordsets:new()).
 
+initialized_regs([{set,Dst,_Src,{alloc,Live,_}}|_], Regs0) ->
+    Regs = add_init_regs(free_vars_regs(Live), Regs0),
+    add_init_regs(Dst, Regs);
 initialized_regs([{set,Dst,Src,_}|Is], Regs) ->
     initialized_regs(Is, add_init_regs(Dst, add_init_regs(Src, Regs)));
 initialized_regs([{test,_,_,Src}|Is], Regs) ->
diff --git a/lib/compiler/src/beam_bs.erl b/lib/compiler/src/beam_bs.erl
new file mode 100644
index 0000000000..2aed98d4e7
--- /dev/null
+++ b/lib/compiler/src/beam_bs.erl
@@ -0,0 +1,278 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+%% Purpose : Partitions assembly instructions into basic blocks and
+%% optimizes them.
+
+-module(beam_bs).
+
+-export([module/2]).
+-import(lists, [mapfoldl/3,reverse/1]).
+
+module({Mod,Exp,Attr,Fs0,Lc0}, _Opt) ->
+    {Fs,Lc} = mapfoldl(fun function/2, Lc0, Fs0),
+    {ok,{Mod,Exp,Attr,Fs,Lc}}.
+
+function({function,Name,Arity,CLabel,Is0}, Lc0) ->
+    try
+	Is1 = bs_put_opt(Is0),
+	{Is,Lc} = bsm_opt(Is1, Lc0),
+	{{function,Name,Arity,CLabel,Is},Lc}
+    catch
+	Class:Error ->
+	    Stack = erlang:get_stacktrace(),
+	    io:fwrite("Function: ~w/~w\n", [Name,Arity]),
+	    erlang:raise(Class, Error, Stack)
+    end.
+
+%%%
+%%% Evaluation of constant bit fields.
+%%%
+
+bs_put_opt([{bs_put,_,_,_}=I|Is0]) ->
+    {BsPuts0,Is} = collect_bs_puts(Is0, [I]),
+    BsPuts = opt_bs_puts(BsPuts0),
+    BsPuts ++ bs_put_opt(Is);
+bs_put_opt([I|Is]) ->
+    [I|bs_put_opt(Is)];
+bs_put_opt([]) -> [].
+
+collect_bs_puts([{bs_put,_,_,_}=I|Is], Acc) ->
+    collect_bs_puts(Is, [I|Acc]);
+collect_bs_puts([_|_]=Is, Acc) ->
+    {reverse(Acc),Is}.
+
+opt_bs_puts(Is) ->
+    opt_bs_1(Is, []).
+
+opt_bs_1([{bs_put,Fail,
+	   {bs_put_float,1,Flags0},[{integer,Sz},Src]}=I0|Is], Acc) ->
+    try eval_put_float(Src, Sz, Flags0) of
+	<<Int:Sz>> ->
+	    Flags = force_big(Flags0),
+	    I = {bs_put,Fail,{bs_put_integer,1,Flags},
+		 [{integer,Sz},{integer,Int}]},
+	    opt_bs_1([I|Is], Acc)
+    catch
+	error:_ ->
+	    opt_bs_1(Is, [I0|Acc])
+    end;
+opt_bs_1([{bs_put,_,{bs_put_integer,1,_},[{integer,8},{integer,_}]}|_]=IsAll,
+	 Acc0) ->
+    {Is,Acc} = bs_collect_string(IsAll, Acc0),
+    opt_bs_1(Is, Acc);
+opt_bs_1([{bs_put,Fail,{bs_put_integer,1,F},[{integer,Sz},{integer,N}]}=I|Is0],
+	 Acc) when Sz > 8 ->
+    case field_endian(F) of
+	big ->
+	    %% We can do this optimization for any field size without
+	    %% risk for code explosion.
+	    case bs_split_int(N, Sz, Fail, Is0) of
+		no_split -> opt_bs_1(Is0, [I|Acc]);
+		Is -> opt_bs_1(Is, Acc)
+	    end;
+	little when Sz < 128 ->
+	    %% We only try to optimize relatively small fields, to
+	    %% avoid an explosion in code size.
+	    <<Int:Sz>> = <<N:Sz/little>>,
+	    Flags = force_big(F),
+	    Is = [{bs_put,Fail,{bs_put_integer,1,Flags},
+		   [{integer,Sz},{integer,Int}]}|Is0],
+	    opt_bs_1(Is, Acc);
+	_ ->			      %native or too wide little field
+	    opt_bs_1(Is0, [I|Acc])
+    end;
+opt_bs_1([{bs_put,Fail,{Op,U,F},[{integer,Sz},Src]}|Is], Acc) when U > 1 ->
+    opt_bs_1([{bs_put,Fail,{Op,1,F},[{integer,U*Sz},Src]}|Is], Acc);
+opt_bs_1([I|Is], Acc) ->
+    opt_bs_1(Is, [I|Acc]);
+opt_bs_1([], Acc) -> reverse(Acc).
+
+eval_put_float(Src, Sz, Flags) when Sz =< 256 ->
+    %%Only evaluate if Sz is reasonable.
+    Val = value(Src),
+    case field_endian(Flags) of
+	little -> <<Val:Sz/little-float-unit:1>>;
+	big -> <<Val:Sz/big-float-unit:1>>
+        %% native intentionally not handled here - we can't optimize
+        %% it.
+    end.
+
+value({integer,I}) -> I;
+value({float,F}) -> F.
+
+bs_collect_string(Is, [{bs_put,_,{bs_put_string,Len,{string,Str}},[]}|Acc]) ->
+    bs_coll_str_1(Is, Len, reverse(Str), Acc);
+bs_collect_string(Is, Acc) ->
+    bs_coll_str_1(Is, 0, [], Acc).
+
+bs_coll_str_1([{bs_put,_,{bs_put_integer,U,_},[{integer,Sz},{integer,V}]}|Is],
+	      Len, StrAcc, IsAcc) when U*Sz =:= 8 ->
+    Byte = V band 16#FF,
+    bs_coll_str_1(Is, Len+1, [Byte|StrAcc], IsAcc);
+bs_coll_str_1(Is, Len, StrAcc, IsAcc) ->
+    {Is,[{bs_put,{f,0},{bs_put_string,Len,{string,reverse(StrAcc)}},[]}|IsAcc]}.
+
+field_endian({field_flags,F}) -> field_endian_1(F).
+
+field_endian_1([big=E|_]) -> E;
+field_endian_1([little=E|_]) -> E;
+field_endian_1([native=E|_]) -> E;
+field_endian_1([_|Fs]) -> field_endian_1(Fs).
+
+force_big({field_flags,F}) ->
+    {field_flags,force_big_1(F)}.
+
+force_big_1([big|_]=Fs) -> Fs;
+force_big_1([little|Fs]) -> [big|Fs];
+force_big_1([F|Fs]) -> [F|force_big_1(Fs)].
+
+bs_split_int(0, Sz, _, _) when Sz > 64 ->
+    %% We don't want to split in this case because the
+    %% string will consist of only zeroes.
+    no_split;
+bs_split_int(-1, Sz, _, _) when Sz > 64 ->
+    %% We don't want to split in this case because the
+    %% string will consist of only 255 bytes.
+    no_split;
+bs_split_int(N, Sz, Fail, Acc) ->
+    FirstByteSz = case Sz rem 8 of
+		      0 -> 8;
+		      Rem -> Rem
+		  end,
+    bs_split_int_1(N, FirstByteSz, Sz, Fail, Acc).
+
+bs_split_int_1(-1, _, Sz, Fail, Acc) when Sz > 64 ->
+    I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
+	 [{integer,Sz},{integer,-1}]},
+    [I|Acc];
+bs_split_int_1(0, _, Sz, Fail, Acc) when Sz > 64 ->
+    I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
+	 [{integer,Sz},{integer,0}]},
+    [I|Acc];
+bs_split_int_1(N, ByteSz, Sz, Fail, Acc) when Sz > 0 ->
+    Mask = (1 bsl ByteSz) - 1,
+    I = {bs_put,Fail,{bs_put_integer,1,{field_flags,[big]}},
+	 [{integer,ByteSz},{integer,N band Mask}]},
+    bs_split_int_1(N bsr ByteSz, 8, Sz-ByteSz, Fail, [I|Acc]);
+bs_split_int_1(_, _, _, _, Acc) -> Acc.
+
+%%%
+%%% Optimization of bit syntax matching: get rid
+%%% of redundant bs_restore2/2 instructions across select_val
+%%% instructions, as well as a few other simple peep-hole
+%%% optimizations.
+%%%
+
+bsm_opt(Is0, Lc0) ->
+    {Is1,D0,Lc} = bsm_scan(Is0, [], Lc0, []),
+    Is2 = case D0 of
+	      [] ->
+		  %% No bit syntax matching in this function.
+		  Is1;
+	      [_|_] ->
+		  %% Optimize the bit syntax matching.
+		  D = gb_trees:from_orddict(orddict:from_list(D0)),
+		  bsm_reroute(Is1, D, none, [])
+	 end,
+    Is = beam_clean:bs_clean_saves(Is2),
+    {bsm_opt_2(Is, []),Lc}.
+
+bsm_scan([{label,L}=Lbl,{bs_restore2,_,Save}=R|Is], D0, Lc, Acc0) ->
+    D = [{{L,Save},Lc}|D0],
+    Acc = [{label,Lc},R,Lbl|Acc0],
+    bsm_scan(Is, D, Lc+1, Acc);
+bsm_scan([I|Is], D, Lc, Acc) ->
+    bsm_scan(Is, D, Lc, [I|Acc]);
+bsm_scan([], D, Lc, Acc) ->
+    {reverse(Acc),D,Lc}.
+
+bsm_reroute([{bs_save2,Reg,Save}=I|Is], D, _, Acc) ->
+    bsm_reroute(Is, D, {Reg,Save}, [I|Acc]);
+bsm_reroute([{bs_restore2,Reg,Save}=I|Is], D, _, Acc) ->
+    bsm_reroute(Is, D, {Reg,Save}, [I|Acc]);
+bsm_reroute([{label,_}=I|Is], D, S, Acc) ->
+    bsm_reroute(Is, D, S, [I|Acc]);
+bsm_reroute([{select,select_val,Reg,F0,Lbls0}|Is], D, {_,Save}=S, Acc0) ->
+    [F|Lbls] = bsm_subst_labels([F0|Lbls0], Save, D),
+    Acc = [{select,select_val,Reg,F,Lbls}|Acc0],
+    bsm_reroute(Is, D, S, Acc);
+bsm_reroute([{test,TestOp,F0,TestArgs}=I|Is], D, {_,Save}=S, Acc0) ->
+    F = bsm_subst_label(F0, Save, D),
+    Acc = [{test,TestOp,F,TestArgs}|Acc0],
+    case bsm_not_bs_test(I) of
+	true ->
+	    %% The test instruction will not update the bit offset for
+	    %% the binary being matched. Therefore the save position
+	    %% can be kept.
+	    bsm_reroute(Is, D, S, Acc);
+	false ->
+	    %% The test instruction might update the bit offset. Kill
+	    %% our remembered Save position.
+	    bsm_reroute(Is, D, none, Acc)
+    end;
+bsm_reroute([{test,TestOp,F0,Live,TestArgs,Dst}|Is], D, {_,Save}, Acc0) ->
+    F = bsm_subst_label(F0, Save, D),
+    Acc = [{test,TestOp,F,Live,TestArgs,Dst}|Acc0],
+    %% The test instruction will update the bit offset. Kill our
+    %% remembered Save position.
+    bsm_reroute(Is, D, none, Acc);
+bsm_reroute([{block,[{set,[],[],{alloc,_,_}}]}=Bl,
+	     {bs_context_to_binary,_}=I|Is], D, S, Acc) ->
+    %% To help further bit syntax optimizations.
+    bsm_reroute([I,Bl|Is], D, S, Acc);
+bsm_reroute([I|Is], D, _, Acc) ->
+    bsm_reroute(Is, D, none, [I|Acc]);
+bsm_reroute([], _, _, Acc) -> reverse(Acc).
+
+bsm_opt_2([{test,bs_test_tail2,F,[Ctx,Bits]}|Is],
+	  [{test,bs_skip_bits2,F,[Ctx,{integer,I},Unit,_Flags]}|Acc]) ->
+    bsm_opt_2(Is, [{test,bs_test_tail2,F,[Ctx,Bits+I*Unit]}|Acc]);
+bsm_opt_2([{test,bs_skip_bits2,F,[Ctx,{integer,I1},Unit1,_]}|Is],
+	  [{test,bs_skip_bits2,F,[Ctx,{integer,I2},Unit2,Flags]}|Acc]) ->
+    bsm_opt_2(Is, [{test,bs_skip_bits2,F,
+		    [Ctx,{integer,I1*Unit1+I2*Unit2},1,Flags]}|Acc]);
+bsm_opt_2([I|Is], Acc) ->
+    bsm_opt_2(Is, [I|Acc]);
+bsm_opt_2([], Acc) -> reverse(Acc).
+
+%% bsm_not_bs_test({test,Name,_,Operands}) -> true|false.
+%%  Test whether is the test is a "safe", i.e. does not move the
+%%  bit offset for a binary.
+%%
+%%  'true' means that the test is safe, 'false' that we don't know or
+%%  that the test moves the offset (e.g. bs_get_integer2).
+
+bsm_not_bs_test({test,bs_test_tail2,_,[_,_]}) -> true;
+bsm_not_bs_test(Test) -> beam_utils:is_pure_test(Test).
+
+bsm_subst_labels(Fs, Save, D) ->
+    bsm_subst_labels_1(Fs, Save, D, []).
+
+bsm_subst_labels_1([F|Fs], Save, D, Acc) ->
+    bsm_subst_labels_1(Fs, Save, D, [bsm_subst_label(F, Save, D)|Acc]);
+bsm_subst_labels_1([], _, _, Acc) ->
+    reverse(Acc).
+
+bsm_subst_label({f,Lbl0}=F, Save, D) ->
+    case gb_trees:lookup({Lbl0,Save}, D) of
+	{value,Lbl} -> {f,Lbl};
+	none -> F
+    end;
+bsm_subst_label(Other, _, _) -> Other.
diff --git a/lib/compiler/src/beam_bsm.erl b/lib/compiler/src/beam_bsm.erl
index fdfcb08125..286307a4be 100644
--- a/lib/compiler/src/beam_bsm.erl
+++ b/lib/compiler/src/beam_bsm.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2007-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2007-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -20,7 +21,7 @@
 -module(beam_bsm).
 -export([module/2,format_error/1]).
 
--import(lists, [member/2,foldl/3,reverse/1,sort/1,all/2,dropwhile/2]).
+-import(lists, [member/2,foldl/3,reverse/1,sort/1,all/2]).
 
 %%%
 %%% We optimize bit syntax matching where the tail end of a binary is
@@ -209,6 +210,7 @@ btb_reaches_match_2([{call,Arity,{f,Lbl}}|Is], Regs, D) ->
 btb_reaches_match_2([{apply,Arity}|Is], Regs, D) ->
     btb_call(Arity+2, apply, Regs, Is, D);
 btb_reaches_match_2([{call_fun,Live}=I|Is], Regs, D) ->
+    btb_ensure_not_used([{x,Live}], I, Regs),
     btb_call(Live, I, Regs, Is, D);
 btb_reaches_match_2([{make_fun2,_,_,_,Live}|Is], Regs, D) ->
     btb_call(Live, make_fun2, Regs, Is, D);
@@ -241,6 +243,12 @@ btb_reaches_match_2([{bif,_,{f,F},Ss,Dst}=I|Is], Regs0, D0) ->
     Regs = btb_kill([Dst], Regs0),
     D = btb_follow_branch(F, Regs, D0),
     btb_reaches_match_1(Is, Regs, D);
+btb_reaches_match_2([{get_map_elements,{f,F},Src,{list,Ls}}=I|Is], Regs0, D0) ->
+    {Ss,Ds} = beam_utils:split_even(Ls),
+    btb_ensure_not_used([Src|Ss], I, Regs0),
+    Regs = btb_kill(Ds, Regs0),
+    D = btb_follow_branch(F, Regs, D0),
+    btb_reaches_match_1(Is, Regs, D);
 btb_reaches_match_2([{test,bs_start_match2,{f,F},Live,[Ctx,_],Ctx}=I|Is],
 		    Regs0, D0) ->
     CtxRegs = btb_context_regs(Regs0),
@@ -413,7 +421,8 @@ btb_follow_branches([], _, D) -> D.
 
 btb_follow_branch(0, _Regs, D) -> D;
 btb_follow_branch(Lbl, Regs, #btb{ok_br=Br0,index=Li}=D) ->
-    case gb_sets:is_member(Lbl, Br0) of
+    Key = {Lbl,Regs},
+    case gb_sets:is_member(Key, Br0) of
 	true ->
 	    %% We have already followed this branch and it was OK.
 	    D;
@@ -424,7 +433,7 @@ btb_follow_branch(Lbl, Regs, #btb{ok_br=Br0,index=Li}=D) ->
 		btb_reaches_match_1(Is, Regs, D),
 
 	    %% Since we got back, this branch is OK.
-	    D#btb{ok_br=gb_sets:insert(Lbl, Br),must_not_save=MustNotSave,
+	    D#btb{ok_br=gb_sets:insert(Key, Br),must_not_save=MustNotSave,
 		  must_save=MustSave}
     end.
 
@@ -541,16 +550,13 @@ btb_context_regs_1(Regs, N, Tag, Acc) ->
 %%  a binary. MustSave is true if the function may pass the match
 %%  context to the bs_context_to_binary instruction (in which case
 %%  the current position in the binary must have saved into the
-%%  start position using "bs_save_2 Ctx start".
+%%  start position using "bs_save_2 Ctx start").
 
 btb_index(Fs) ->
     btb_index_1(Fs, []).
 
 btb_index_1([{function,_,_,Entry,Is0}|Fs], Acc0) ->
-    [{label,Entry}|Is] =
-	dropwhile(fun({label,L}) when L =:= Entry -> false;
-		     (_) -> true
-		  end, Is0),
+    Is = drop_to_label(Is0, Entry),
     Acc = btb_index_2(Is, Entry, false, Acc0),
     btb_index_1(Fs, Acc);
 btb_index_1([], Acc) -> gb_trees:from_orddict(sort(Acc)).
@@ -565,6 +571,9 @@ btb_index_2(Is0, Entry, _, Acc) ->
 	throw:none -> Acc
     end.
 
+drop_to_label([{label,L}|Is], L) -> Is;
+drop_to_label([_|Is], L) -> drop_to_label(Is, L).
+
 btb_index_find_start_match([{test,_,{f,F},_},{bs_context_to_binary,_}|Is]) ->
     btb_index_find_label(Is, F);
 btb_index_find_start_match(_) ->
@@ -614,7 +623,7 @@ collect_warnings_instr([_|Is], D, Acc) ->
 collect_warnings_instr([], _, Acc) -> Acc.
 
 add_warning(Term, Anno, Ws) ->
-    Line = abs(get_line(Anno)),
+    Line = get_line(Anno),
     File = get_file(Anno),
     [{File,[{Line,?MODULE,Term}]}|Ws].
 
diff --git a/lib/compiler/src/beam_clean.erl b/lib/compiler/src/beam_clean.erl
index e208ffec1f..10805a3c36 100644
--- a/lib/compiler/src/beam_clean.erl
+++ b/lib/compiler/src/beam_clean.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2000-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -86,7 +87,7 @@ add_to_work_list(F, {Fs,Used}=Sets) ->
 	false -> {[F|Fs],sets:add_element(F, Used)}
     end.
 
-
+
 %%%
 %%% Coalesce adjacent labels. Renumber all labels to eliminate gaps.
 %%% This cleanup will slightly reduce file size and slightly speed up loading.
@@ -140,7 +141,7 @@ renumber_labels([{bif,is_record,{f,_},
     renumber_labels(Is, Acc, St);
 renumber_labels([{test,is_record,{f,_}=Fail,
 		  [Term,{atom,Tag}=TagAtom,{integer,Arity}]}|Is0], Acc, St) ->
-    Tmp = {x,1023},
+    Tmp = {x,1022},
     Is = case is_record_tuple(Term, Tag, Arity) of
 	     yes ->
 		 Is0;
@@ -184,30 +185,16 @@ function_replace([{function,Name,Arity,Entry,Asm0}|Fs], Dict, Acc) ->
     function_replace(Fs, Dict, [{function,Name,Arity,Entry,Asm}|Acc]);
 function_replace([], _, Acc) -> Acc.
 
-replace([{test,bs_match_string=Op,{f,Lbl},[Ctx,Bin0]}|Is], Acc, D) ->
-    Bits = bit_size(Bin0),
-    Bin = case Bits rem 8 of
-	      0 -> Bin0;
-	      Rem -> <<Bin0/bitstring,0:(8-Rem)>>
-	  end,
-    I = {test,Op,{f,label(Lbl, D)},[Ctx,Bits,{string,binary_to_list(Bin)}]},
-    replace(Is, [I|Acc], D);
 replace([{test,Test,{f,Lbl},Ops}|Is], Acc, D) ->
     replace(Is, [{test,Test,{f,label(Lbl, D)},Ops}|Acc], D);
 replace([{test,Test,{f,Lbl},Live,Ops,Dst}|Is], Acc, D) ->
     replace(Is, [{test,Test,{f,label(Lbl, D)},Live,Ops,Dst}|Acc], D);
 replace([{select,I,R,{f,Fail0},Vls0}|Is], Acc, D) ->
-    Vls1 = map(fun ({f,L}) -> {f,label(L, D)};
-		   (Other) -> Other end, Vls0),
+    Vls = map(fun ({f,L}) -> {f,label(L, D)};
+		   (Other) -> Other
+	      end, Vls0),
     Fail = label(Fail0, D),
-    case redundant_values(Vls1, Fail, []) of
-	[] ->
-	    %% Oops, no choices left. The loader will not accept that.
-	    %% Convert to a plain jump.
-	    replace(Is, [{jump,{f,Fail}}|Acc], D);
-	Vls ->
-	    replace(Is, [{select,I,R,{f,Fail},Vls}|Acc], D)
-    end;
+    replace(Is, [{select,I,R,{f,Fail},Vls}|Acc], D);
 replace([{'try',R,{f,Lbl}}|Is], Acc, D) ->
     replace(Is, [{'try',R,{f,label(Lbl, D)}}|Acc], D);
 replace([{'catch',R,{f,Lbl}}|Is], Acc, D) ->
@@ -234,6 +221,11 @@ replace([{bs_init,{f,Lbl},Info,Live,Ss,Dst}|Is], Acc, D) when Lbl =/= 0 ->
     replace(Is, [{bs_init,{f,label(Lbl, D)},Info,Live,Ss,Dst}|Acc], D);
 replace([{bs_put,{f,Lbl},Info,Ss}|Is], Acc, D) when Lbl =/= 0 ->
     replace(Is, [{bs_put,{f,label(Lbl, D)},Info,Ss}|Acc], D);
+replace([{put_map=I,{f,Lbl},Op,Src,Dst,Live,List}|Is], Acc, D)
+  when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Op,Src,Dst,Live,List}|Acc], D);
+replace([{get_map_elements=I,{f,Lbl},Src,List}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Src,List}|Acc], D);
 replace([I|Is], Acc, D) ->
     replace(Is, [I|Acc], D);
 replace([], Acc, _) -> Acc.
@@ -243,12 +235,6 @@ label(Old, D) ->
 	{value,Val} -> Val;
 	none -> throw({error,{undefined_label,Old}})
     end.
-	    
-redundant_values([_,{f,Fail}|Vls], Fail, Acc) ->
-    redundant_values(Vls, Fail, Acc);
-redundant_values([Val,Lbl|Vls], Fail, Acc) ->
-    redundant_values(Vls, Fail, [Lbl,Val|Acc]);
-redundant_values([], _, Acc) -> reverse(Acc).
 
 %%%
 %%% Final fixup of bs_start_match2/5,bs_save2/bs_restore2 instructions for
diff --git a/lib/compiler/src/beam_dead.erl b/lib/compiler/src/beam_dead.erl
index b15adfa889..b01f58f683 100644
--- a/lib/compiler/src/beam_dead.erl
+++ b/lib/compiler/src/beam_dead.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2002-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2002-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -21,112 +22,10 @@
 
 -export([module/2]).
 
-%%% The following optimisations are done:
-%%%
-%%% (1) In this code
-%%%
-%%%     	move DeadValue {x,0}
-%%%     	jump L2
-%%%        .
-%%%        .
-%%%        .
-%%%     L2:	move Anything {x,0}
-%%%        .
-%%%        .
-%%%        .
-%%%
-%%%     the first assignment to {x,0} has no effect (is dead),
-%%%     so it can be removed. Besides removing a move instruction,
-%%%     if the move was preceeded by a label, the resulting code
-%%%	will look this
-%%%
-%%%     L1:	jump L2
-%%%        .
-%%%        .
-%%%        .
-%%%     L2:	move Anything {x,0}
-%%%        .
-%%%        .
-%%%        .
-%%%
-%%%	which can be further optimized by the jump optimizer (beam_jump).
-%%%
-%%% (2) In this code
-%%%
-%%%     L1:	move AtomLiteral {x,0}
-%%%     	jump L2
-%%%        .
-%%%        .
-%%%        .
-%%%     L2:	test is_atom FailLabel {x,0}
-%%%    		select_val {x,0}, FailLabel [... AtomLiteral => L3...]
-%%%        .
-%%%        .
-%%%        .
-%%%	L3:	...
-%%%
-%%%     FailLabel: ...
-%%%
-%%%	the first code fragment can be changed to
-%%%
-%%%     L1:	move AtomLiteral {x,0}
-%%%     	jump L3
-%%%
-%%%     If the literal is not included in the table of literals in the
-%%%     select_val instruction, the first code fragment will instead be
-%%%     rewritten as:
-%%%
-%%%     L1:	move AtomLiteral {x,0}
-%%%     	jump FailLabel
-%%%
-%%%	The move instruction will be removed by optimization (1) above,
-%%%	if the code following the L3 label overwrites {x,0}.
-%%%
-%%% 	The code following the L2 label will be kept, but it will be removed later
-%%%	by the jump optimizer.
-%%%
-%%% (3) In this code
-%%%
-%%%     	test is_eq_exact ALabel Src Dst
-%%%     	move Src Dst
-%%%
-%%%	the move instruction can be removed.
-%%%     Same thing for
-%%%
-%%%     	test is_nil ALabel Dst
-%%%     	move [] Dst
-%%%
-%%%
-%%% (4) In this code
-%%%
-%%%    		select_val {x,Reg}, ALabel [... Literal => L1...]
-%%%        .
-%%%        .
-%%%        .
-%%%	L1:	move Literal {x,Reg}
-%%%
-%%%     we can remove the move instruction.
-%%%
-%%% (5) In the following code
-%%%
-%%%     	bif '=:=' Fail Src1 Src2 {x,0}
-%%%    		jump L1
-%%%	   .
-%%%	   .
-%%%	   .
-%%%        L1:	select_val {x,0}, ALabel [... true => L2..., ...false => L3...]
-%%%	   .
-%%%	   .
-%%%	   .
-%%%        L2: ....      L3: ....
-%%%
-%%%  the first two instructions can be replaced with
-%%%
-%%%		test is_eq_exact L3 Src1 Src2
-%%%		jump L2
-%%%
-%%%  provided that {x,0} is killed at both L2 and L3.
-%%%
+%%% Dead code is code that is executed but has no effect. This
+%%% optimization pass either removes dead code or jumps around it,
+%%% potentially making it unreachable and a target for the
+%%% the beam_jump pass.
 
 -import(lists, [mapfoldl/3,reverse/1]).
 
@@ -173,12 +72,39 @@ move_move_into_block([I|Is], Acc) ->
 move_move_into_block([], Acc) -> reverse(Acc).
 
 %%%
-%%% Scan instructions in execution order and remove dead code.
+%%% Scan instructions in execution order and remove redundant 'move'
+%%% instructions. 'move' instructions are redundant if we know that
+%%% the register already contains the value being assigned, as in the
+%%% following code:
+%%%
+%%%           test is_eq_exact SomeLabel Src Dst
+%%%           move Src Dst
+%%%
+%%% or in:
+%%%
+%%%           test is_nil SomeLabel Dst
+%%%           move nil Dst
+%%%
+%%% or in:
+%%%
+%%%           select_val Register FailLabel [... Literal => L1...]
+%%%                      .
+%%%                      .
+%%%                      .
+%%%   L1:     move Literal Register
+%%%
+%%% Also add extra labels to help the second backward pass.
 %%%
 
 forward(Is, Lc) ->
-    forward(Is, gb_trees:empty(), Lc, []).
-
+    forward(Is, #{}, Lc, []).
+
+forward([{move,_,_}=Move|[{label,L}|_]=Is], D, Lc, Acc) ->
+    %% move/2 followed by jump/1 is optimized by backward/3.
+    forward([Move,{jump,{f,L}}|Is], D, Lc, Acc);
+forward([{bif,_,_,_,_}=Bif|[{label,L}|_]=Is], D, Lc, Acc) ->
+    %% bif/4 followed by jump/1 is optimized by backward/3.
+    forward([Bif,{jump,{f,L}}|Is], D, Lc, Acc);
 forward([{block,[]}|Is], D, Lc, Acc) ->
     %% Empty blocks can prevent optimizations.
     forward(Is, D, Lc, Acc);
@@ -190,21 +116,24 @@ forward([{label,Lbl}=LblI,{block,[{set,[Dst],[Lit],move}|BlkIs]}=Blk|Is], D, Lc,
     %% cannot be reached in any other way than through the select_val/3
     %% instruction (i.e. there can be no fallthrough to such label and
     %% it cannot be referenced by, for example, a jump/1 instruction).
-    Block = case gb_trees:lookup({Lbl,Dst}, D) of
-		{value,Lit} -> {block,BlkIs}; %Safe to remove move instruction.
-		_ -> Blk		      %Must keep move instruction.
-	    end,
+    Key = {Lbl,Dst},
+    Block = case D of
+                #{Key := Lit} -> {block,BlkIs}; %Safe to remove move instruction.
+                _ -> Blk                        %Must keep move instruction.
+            end,
     forward([Block|Is], D, Lc, [LblI|Acc]);
 forward([{label,Lbl}=LblI|[{move,Lit,Dst}|Is1]=Is0], D, Lc, Acc) ->
     %% Assumption: The target labels in a select_val/3 instruction
     %% cannot be reached in any other way than through the select_val/3
     %% instruction (i.e. there can be no fallthrough to such label and
     %% it cannot be referenced by, for example, a jump/1 instruction).
-    Is = case gb_trees:lookup({Lbl,Dst}, D) of
-	     {value,Lit} -> Is1;     %Safe to remove move instruction.
-	     _ -> Is0		     %Keep move instruction.
+    Is = case maps:find({Lbl,Dst}, D) of
+	     {ok,Lit} -> Is1;     %Safe to remove move instruction.
+	     _ -> Is0		  %Keep move instruction.
 	 end,
     forward(Is, D, Lc, [LblI|Acc]);
+forward([{test,is_eq_exact,_,[Same,Same]}|Is], D, Lc, Acc) ->
+    forward(Is, D, Lc, Acc);
 forward([{test,is_eq_exact,_,[Dst,Src]}=I,
 	 {block,[{set,[Dst],[Src],move}|Bl]}|Is], D, Lc, Acc) ->
     forward([I,{block,Bl}|Is], D, Lc, Acc);
@@ -215,15 +144,13 @@ forward([{test,is_eq_exact,_,[Dst,Src]}=I,{move,Src,Dst}|Is], D, Lc, Acc) ->
     forward([I|Is], D, Lc, Acc);
 forward([{test,is_nil,_,[Dst]}=I,{move,nil,Dst}|Is], D, Lc, Acc) ->
     forward([I|Is], D, Lc, Acc);
-forward([{test,is_eq_exact,_,_}=I|Is], D, Lc, Acc) ->
-    case Is of
-	[{label,_}|_] -> forward(Is, D, Lc, [I|Acc]);
-	_ -> forward(Is, D, Lc+1, [{label,Lc},I|Acc])
-    end;
-forward([{test,is_ne_exact,_,_}=I|Is], D, Lc, Acc) ->
-    case Is of
-	[{label,_}|_] -> forward(Is, D, Lc, [I|Acc]);
-	_ -> forward(Is, D, Lc+1, [{label,Lc},I|Acc])
+forward([{test,_,_,_}=I|Is]=Is0, D, Lc, Acc) ->
+    %% Help the second, backward pass to by inserting labels after
+    %% relational operators so that they can be skipped if they are
+    %% known to be true.
+    case useful_to_insert_label(Is0) of
+	false -> forward(Is, D, Lc, [I|Acc]);
+	true -> forward(Is, D, Lc+1, [{label,Lc},I|Acc])
     end;
 forward([I|Is], D, Lc, Acc) ->
     forward(Is, D, Lc, [I|Acc]);
@@ -231,17 +158,57 @@ forward([], _, Lc, Acc) -> {Acc,Lc}.
 
 update_value_dict([Lit,{f,Lbl}|T], Reg, D0) ->
     Key = {Lbl,Reg},
-    D = case gb_trees:lookup(Key, D0) of
-	    none -> gb_trees:insert(Key, Lit, D0); %New.
-	    {value,inconsistent} -> D0;		%Inconsistent.
-	    {value,_} -> gb_trees:update(Key, inconsistent, D0)
-	end,
+    D = case D0 of
+            #{Key := inconsistent} -> D0;
+            #{Key := _} -> D0#{Key := inconsistent};
+            _ -> D0#{Key => Lit}
+        end,
     update_value_dict(T, Reg, D);
 update_value_dict([], _, D) -> D.
 
+useful_to_insert_label([_,{label,_}|_]) ->
+    false;
+useful_to_insert_label([{test,Op,_,_}|_]) ->
+    case Op of
+	is_lt -> true;
+	is_ge -> true;
+	is_eq_exact -> true;
+	is_ne_exact -> true;
+	_ -> false
+    end.
+
+%%%
+%%% Scan instructions in reverse execution order and try to
+%%% shortcut branch instructions.
+%%%
+%%% For example, in this code:
+%%%
+%%%             move Literal Register
+%%%             jump L1
+%%%                .
+%%%                .
+%%%                .
+%%%     L1:     test is_{integer,atom} FailLabel Register
+%%%             select_val {x,0} FailLabel [... Literal => L2...]
+%%%                .
+%%%                .
+%%%                .
+%%%     L2:        ...
 %%%
-%%% Scan instructions in reverse execution order and remove dead code.
+%%% the 'selectval' instruction will always transfer control to L2,
+%%% so we can just as well jump to L2 directly by rewriting the
+%%% first part of the sequence like this:
 %%%
+%%%           move Literal Register
+%%%           jump L2
+%%%
+%%% If register Register is killed at label L2, we can remove the
+%%% 'move' instruction, leaving just the 'jump' instruction:
+%%%
+%%%           jump L2
+%%%
+%%% These transformations may leave parts of the code unreachable.
+%%% The beam_jump pass will remove the unreachable code.
 
 backward(Is, D) ->
     backward(Is, D, []).
@@ -272,22 +239,30 @@ backward([{test,is_eq_exact,Fail,[Dst,{integer,Arity}]}=I|
 backward([{label,Lbl}=L|Is], D, Acc) ->
     backward(Is, beam_utils:index_label(Lbl, Acc, D), [L|Acc]);
 backward([{select,select_val,Reg,{f,Fail0},List0}|Is], D, Acc) ->
-    List = shortcut_select_list(List0, Reg, D, []),
+    List1 = shortcut_select_list(List0, Reg, D, []),
     Fail1 = shortcut_label(Fail0, D),
     Fail = shortcut_bs_test(Fail1, Is, D),
-    Sel = {select,select_val,Reg,{f,Fail},List},
-    backward(Is, D, [Sel|Acc]);
-backward([{jump,{f,To0}},{move,Src,Reg}=Move0|Is], D, Acc) ->
-    {To,Move} = case Src of
-		    {atom,Val0} ->
-			To1 = shortcut_select_label(To0, Reg, Val0, D),
-			{To2,Val} = shortcut_boolean_label(To1, Reg, Val0, D),
-			{To2,{move,{atom,Val},Reg}};
-		    _ ->
-			{shortcut_label(To0, D),Move0}
-		end,
+    List = prune_redundant(List1, Fail),
+    case List of
+	[] ->
+	    Jump = {jump,{f,Fail}},
+	    backward([Jump|Is], D, Acc);
+	[V,F] ->
+	    Test = {test,is_eq_exact,{f,Fail},[Reg,V]},
+	    Jump = {jump,F},
+	    backward([Jump,Test|Is], D, Acc);
+	[{atom,B1},F,{atom,B2},F] when B1 =:= not B2 ->
+	    Test = {test,is_boolean,{f,Fail},[Reg]},
+	    Jump = {jump,F},
+	    backward([Jump,Test|Is], D, Acc);
+	[_|_] ->
+	    Sel = {select,select_val,Reg,{f,Fail},List},
+	    backward(Is, D, [Sel|Acc])
+    end;
+backward([{jump,{f,To0}},{move,Src,Reg}=Move|Is], D, Acc) ->
+    To = shortcut_select_label(To0, Reg, Src, D),
     Jump = {jump,{f,To}},
-    case beam_utils:is_killed_at(Reg, To, D) of
+    case is_killed_at(Reg, To, D) of
 	false -> backward([Move|Is], D, [Jump|Acc]);
 	true -> backward([Jump|Is], D, Acc)
     end;
@@ -297,38 +272,69 @@ backward([{jump,{f,To}}=J|[{bif,Op,_,Ops,Reg}|Is]=Is0], D, Acc) ->
     catch
 	throw:not_possible -> backward(Is0, D, [J|Acc])
     end;
+backward([{test,bs_start_match2,F,Live,[R,_]=Args,Ctxt}|Is], D,
+	 [{test,bs_match_string,F,[Ctxt,Bs]},
+	  {test,bs_test_tail2,F,[Ctxt,0]}|Acc0]=Acc) ->
+    {f,To0} = F,
+    To = shortcut_bs_start_match(To0, R, D),
+    case beam_utils:is_killed(Ctxt, Acc0, D) of
+	true ->
+	    Eq = {test,is_eq_exact,{f,To},[R,{literal,Bs}]},
+	    backward(Is, D, [Eq|Acc0]);
+	false ->
+	    I = {test,bs_start_match2,{f,To},Live,Args,Ctxt},
+	    backward(Is, D, [I|Acc])
+    end;
 backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) ->
     To = shortcut_bs_start_match(To0, Src, D),
     I = {test,bs_start_match2,{f,To},Live,Info,Dst},
     backward(Is, D, [I|Acc]);
-backward([{test,is_eq_exact,{f,To0},[Reg,{atom,Val}]=Ops}|Is], D, Acc) ->
-    To1 = shortcut_bs_test(To0, Is, D),
-    To = shortcut_fail_label(To1, Reg, Val, D),
-    I = combine_eqs(To, Ops, D, Acc),
-    backward(Is, D, [I|Acc]);
 backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) ->
     To1 = shortcut_bs_test(To0, Is, D),
     To2 = shortcut_label(To1, D),
+    To3 = shortcut_rel_op(To2, Op, Ops0, D),
+
     %% Try to shortcut a repeated test:
     %%
     %%        test Op {f,Fail1} Operands	test Op {f,Fail2} Operands
     %%        . . .		          ==>   ...
     %% Fail1: test Op {f,Fail2} Operands        Fail1: test Op {f,Fail2} Operands
     %%
-    To = case beam_utils:code_at(To2, D) of
-	     [{test,Op,{f,To3},Ops}|_] ->
+    To = case beam_utils:code_at(To3, D) of
+	     [{test,Op,{f,To4},Ops}|_] ->
 		 case equal_ops(Ops0, Ops) of
-		     true -> To3;
-		     false -> To2
+		     true -> To4;
+		     false -> To3
 		 end;
 	     _Code ->
-		 To2
+		 To3
 	 end,
     I = case Op of
 	    is_eq_exact -> combine_eqs(To, Ops0, D, Acc);
 	    _ -> {test,Op,{f,To},Ops0}
 	end,
-    backward(Is, D, [I|Acc]);
+    case {I,Acc} of
+	{{test,is_atom,Fail,Ops0},[{test,is_boolean,Fail,Ops0}|_]} ->
+	    %% An is_atom test before an is_boolean test (with the
+	    %% same failure label) is redundant.
+	    backward(Is, D, Acc);
+	{{test,is_atom,Fail,[R]},
+	 [{test,is_eq_exact,Fail,[R,{atom,_}]}|_]} ->
+	    %% An is_atom test before a comparison with an atom (with
+	    %% the same failure label) is redundant.
+	    backward(Is, D, Acc);
+	{{test,is_integer,Fail,[R]},
+	 [{test,is_eq_exact,Fail,[R,{integer,_}]}|_]} ->
+	    %% An is_integer test before a comparison with an integer
+	    %% (with the same failure label) is redundant.
+	    backward(Is, D, Acc);
+	{{test,_,_,_},_} ->
+	    %% Still a test instruction. Done.
+	    backward(Is, D, [I|Acc]);
+	{_,_} ->
+	    %% Rewritten to a select_val. Rescan.
+	    backward([I|Is], D, Acc)
+    end;
 backward([{test,Op,{f,To0},Live,Ops0,Dst}|Is], D, Acc) ->
     To1 = shortcut_bs_test(To0, Is, D),
     To2 = shortcut_label(To1, D),
@@ -367,8 +373,8 @@ equal_ops([Op|T0], [Op|T1]) ->
 equal_ops([], []) -> true;
 equal_ops(_, _) -> false.
     
-shortcut_select_list([{_,Val}=Lit,{f,To0}|T], Reg, D, Acc) ->
-    To = shortcut_select_label(To0, Reg, Val, D),
+shortcut_select_list([Lit,{f,To0}|T], Reg, D, Acc) ->
+    To = shortcut_select_label(To0, Reg, Lit, D),
     shortcut_select_list(T, Reg, D, [{f,To},Lit|Acc]);
 shortcut_select_list([], _, _, Acc) -> reverse(Acc).
 
@@ -378,58 +384,35 @@ shortcut_label(To0, D) ->
 	_ -> To0
     end.
 
-shortcut_select_label(To0, Reg, Val, D) ->
-    case beam_utils:code_at(To0, D) of
- 	[{jump,{f,To}}|_] ->
- 	    shortcut_select_label(To, Reg, Val, D);
-	[{test,is_atom,_,[Reg]},{select,select_val,Reg,{f,Fail},Map}|_] ->
-	    To = find_select_val(Map, Val, Fail),
-	    shortcut_select_label(To, Reg, Val, D);
-  	[{test,is_eq_exact,{f,_},[Reg,{atom,Val}]},{label,To}|_] when is_atom(Val) ->
-	    shortcut_select_label(To, Reg, Val, D);
-  	[{test,is_eq_exact,{f,_},[Reg,{atom,Val}]},{jump,{f,To}}|_] when is_atom(Val) ->
-	    shortcut_select_label(To, Reg, Val, D);
-  	[{test,is_eq_exact,{f,To},[Reg,{atom,AnotherVal}]}|_]
-	when is_atom(Val), Val =/= AnotherVal ->
-	    shortcut_select_label(To, Reg, Val, D);
-  	[{test,is_ne_exact,{f,To},[Reg,{atom,Val}]}|_] when is_atom(Val) ->
-	    shortcut_select_label(To, Reg, Val, D);
-  	[{test,is_ne_exact,{f,_},[Reg,{atom,_}]},{label,To}|_] when is_atom(Val) ->
-	    shortcut_select_label(To, Reg, Val, D);
-	[{test,is_tuple,{f,To},[Reg]}|_] when is_atom(Val) ->
-	    shortcut_select_label(To, Reg, Val, D);
-	_ ->
-	    To0
-    end.
+shortcut_select_label(To, Reg, Lit, D) ->
+    shortcut_rel_op(To, is_ne_exact, [Reg,Lit], D).
 
-shortcut_fail_label(To0, Reg, Val, D) ->
-    case beam_utils:code_at(To0, D) of
- 	[{jump,{f,To}}|_] ->
-	    shortcut_fail_label(To, Reg, Val, D);
-  	[{test,is_eq_exact,{f,To},[Reg,{atom,Val}]}|_] when is_atom(Val) ->
-	    shortcut_fail_label(To, Reg, Val, D);
-	_ ->
-	    To0
-    end.
+prune_redundant([_,{f,Fail}|T], Fail) ->
+    prune_redundant(T, Fail);
+prune_redundant([V,F|T], Fail) ->
+    [V,F|prune_redundant(T, Fail)];
+prune_redundant([], _) -> [].
 
-shortcut_boolean_label(To0, Reg, Bool0, D) when is_boolean(Bool0) ->
-    case beam_utils:code_at(To0, D) of
-	[{line,_},{bif,'not',_,[Reg],Reg},{jump,{f,To}}|_] ->
-	    Bool = not Bool0,
-	    {shortcut_select_label(To, Reg, Bool, D),Bool};
-	_ ->
-	    {To0,Bool0}
-    end;
-shortcut_boolean_label(To, _, Bool, _) -> {To,Bool}.
-
-find_select_val([{_,Val},{f,To}|_], Val, _) -> To;
-find_select_val([{_,_}, {f,_}|T], Val, Fail) ->
-    find_select_val(T, Val, Fail);
-find_select_val([], _, Fail) -> Fail.
+%% Replace a comparison operator with a test instruction and a jump.
+%% For example, if we have this code:
+%%
+%%     	  bif '=:=' Fail Src1 Src2 {x,0}
+%%    	  jump L1
+%%           .
+%%           .
+%%           .
+%%   L1:  select_val {x,0} FailLabel [... true => L2..., ...false => L3...]
+%%
+%% the first two instructions can be replaced with
+%%
+%%        test is_eq_exact L3 Src1 Src2
+%%	  jump L2
+%%
+%% provided that {x,0} is killed at both L2 and L3.
 
 replace_comp_op(To, Reg, Op, Ops, D) ->
-    False = comp_op_find_shortcut(To, Reg, false, D),
-    True = comp_op_find_shortcut(To, Reg, true, D),
+    False = comp_op_find_shortcut(To, Reg, {atom,false}, D),
+    True = comp_op_find_shortcut(To, Reg, {atom,true}, D),
     [bif_to_test(Op, Ops, False),{jump,{f,True}}].
 
 comp_op_find_shortcut(To0, Reg, Val, D) ->
@@ -437,7 +420,7 @@ comp_op_find_shortcut(To0, Reg, Val, D) ->
 	To0 ->
 	    not_possible();
 	To ->
-	    case beam_utils:is_killed_at(Reg, To, D) of
+	    case is_killed_at(Reg, To, D) of
 		false -> not_possible();
 		true -> To
 	    end
@@ -461,9 +444,9 @@ not_possible() -> throw(not_possible).
 %%
 %%      is_eq_exact F1 Reg Lit1		    select_val Reg F2 [ Lit1 L1
 %%   L1:                .                                       Lit2 L2 ]
-%%              	.
-%%                	.	     ==>
-%%                	.
+%%                      .
+%%                      .	     ==>
+%%                      .
 %%   F1:  is_eq_exact F2 Reg Lit2          F1: is_eq_exact F2 Reg Lit2
 %%   L2:  ....				   L2:
 %%
@@ -488,31 +471,26 @@ remove_from_list(Lit, [Val,{f,_}=Fail|T]) ->
     [Val,Fail|remove_from_list(Lit, T)];
 remove_from_list(_, []) -> [].
 
-%% shortcut_bs_test(TargetLabel, [Instruction], D) -> TargetLabel'
-%%  Try to shortcut the failure label for a bit syntax matching.
-%%  We know that the binary contains at least Bits bits after
-%%  the latest save point.
+%% shortcut_bs_test(TargetLabel, ReversedInstructions, D) -> TargetLabel'
+%%  Try to shortcut the failure label for bit syntax matching.
 
 shortcut_bs_test(To, Is, D) ->
     shortcut_bs_test_1(beam_utils:code_at(To, D), Is, To, D).
 
-shortcut_bs_test_1([{bs_restore2,Reg,SavePoint}|Is], PrevIs, To, D) ->
-    shortcut_bs_test_2(Is, {Reg,SavePoint}, PrevIs, To, D);
-shortcut_bs_test_1([_|_], _, To, _) -> To.
-
-shortcut_bs_test_2([{label,_}|Is], Save, PrevIs, To, D) ->
-    shortcut_bs_test_2(Is, Save, PrevIs, To, D);
-shortcut_bs_test_2([{test,bs_test_tail2,{f,To},[_,TailBits]}|_],
-		   {Reg,_Point} = RP, PrevIs, To0, D) ->
-    case count_bits_matched(PrevIs, RP, 0) of
+shortcut_bs_test_1([{bs_restore2,Reg,SavePoint},
+		    {label,_},
+		    {test,bs_test_tail2,{f,To},[_,TailBits]}|_],
+		   PrevIs, To0, D) ->
+    case count_bits_matched(PrevIs, {Reg,SavePoint}, 0) of
 	Bits when Bits > TailBits ->
 	    %% This instruction will fail. We know because a restore has been
-	    %% done from the previous point SavePoint in the binary, and we also know
-	    %% that the binary contains at least Bits bits from SavePoint.
+	    %% done from the previous point SavePoint in the binary, and we
+	    %% also know that the binary contains at least Bits bits from
+	    %% SavePoint.
 	    %%
 	    %% Since we will skip a bs_restore2 if we shortcut to label To,
-	    %% we must now make sure that code at To does not depend on the position
-	    %% in the context in any way.
+	    %% we must now make sure that code at To does not depend on
+	    %% the position in the context in any way.
 	    case shortcut_bs_pos_used(To, Reg, D) of
 		false -> To;
 		true -> To0
@@ -520,15 +498,26 @@ shortcut_bs_test_2([{test,bs_test_tail2,{f,To},[_,TailBits]}|_],
 	_Bits ->
 	    To0
     end;
-shortcut_bs_test_2([_|_], _, _, To, _) -> To.
+shortcut_bs_test_1([_|_], _, To, _) -> To.
 
+%% counts_bits_matched(ReversedInstructions, SavePoint, Bits) -> Bits'
+%%  Given a reversed instruction stream, determine the minimum number
+%%  of bits that will be matched by bit syntax instructions up to the
+%%  given save point.
+
+count_bits_matched([{test,bs_get_utf8,{f,_},_,_,_}|Is], SavePoint, Bits) ->
+    count_bits_matched(Is, SavePoint, Bits+8);
+count_bits_matched([{test,bs_get_utf16,{f,_},_,_,_}|Is], SavePoint, Bits) ->
+    count_bits_matched(Is, SavePoint, Bits+16);
+count_bits_matched([{test,bs_get_utf32,{f,_},_,_,_}|Is], SavePoint, Bits) ->
+    count_bits_matched(Is, SavePoint, Bits+32);
 count_bits_matched([{test,_,_,_,[_,Sz,U,{field_flags,_}],_}|Is], SavePoint, Bits) ->
     case Sz of
 	{integer,N} -> count_bits_matched(Is, SavePoint, Bits+N*U);
 	_ -> count_bits_matched(Is, SavePoint, Bits)
     end;
-count_bits_matched([{test,bs_match_string,_,[_,Bits,_]}|Is], SavePoint, Bits0) ->
-    count_bits_matched(Is, SavePoint, Bits0+Bits);
+count_bits_matched([{test,bs_match_string,_,[_,Bs]}|Is], SavePoint, Bits) ->
+    count_bits_matched(Is, SavePoint, Bits+bit_size(Bs));
 count_bits_matched([{test,_,_,_}|Is], SavePoint, Bits) ->
     count_bits_matched(Is, SavePoint, Bits);
 count_bits_matched([{bs_save2,Reg,SavePoint}|_], {Reg,SavePoint}, Bits) ->
@@ -545,20 +534,346 @@ shortcut_bs_pos_used_1(Is, Reg, D) ->
     not beam_utils:is_killed(Reg, Is, D).
 
 %% shortcut_bs_start_match(TargetLabel, Reg) -> TargetLabel
-%%  A failing bs_start_match2 instruction means that the source
-%%  cannot be a binary, so there is no need to jump bs_context_to_binary/1
-%%  or another bs_start_match2 instruction.
+%%  A failing bs_start_match2 instruction means that the source (Reg)
+%%  cannot be a binary. That means that it is safe to skip
+%%  bs_context_to_binary instructions operating on Reg, and
+%%  bs_start_match2 instructions operating on Reg.
 
 shortcut_bs_start_match(To, Reg, D) ->
-    shortcut_bs_start_match_1(beam_utils:code_at(To, D), Reg, To).
+    shortcut_bs_start_match_1(beam_utils:code_at(To, D), Reg, To, D).
+
+shortcut_bs_start_match_1([{bs_context_to_binary,Reg}|Is], Reg, To, D) ->
+    shortcut_bs_start_match_1(Is, Reg, To, D);
+shortcut_bs_start_match_1([{jump,{f,To}}|_], Reg, _, D) ->
+    Code = beam_utils:code_at(To, D),
+    shortcut_bs_start_match_1(Code, Reg, To, D);
+shortcut_bs_start_match_1([{test,bs_start_match2,{f,To},_,[Reg|_],_}|_],
+			  Reg, _, D) ->
+    Code = beam_utils:code_at(To, D),
+    shortcut_bs_start_match_1(Code, Reg, To, D);
+shortcut_bs_start_match_1(_, _, To, _) ->
+    To.
+
+%% shortcut_rel_op(FailLabel, Operator, [Operand], D) -> FailLabel'
+%%  Try to shortcut the given test instruction. Example:
+%%
+%%           is_ge L1 {x,0} 48
+%%     .
+%%     .
+%%     .
+%%     L1:   is_ge L2 {x,0} 65
+%%
+%%  The first test instruction can be rewritten to "is_ge L2 {x,0} 48"
+%%  since the instruction at L1 will also fail.
+%%
+%%  If there are instructions between L1 and the other test instruction
+%%  it may still be possible to do the shortcut. For example:
+%%
+%%     L1:   is_eq_exact L3 {x,0} 92
+%%           is_ge L2 {x,0} 65
+%%
+%%  Since the first test instruction failed, we know that {x,0} must
+%%  be less than 48; therefore, we know that {x,0} cannot be equal to
+%%  92 and the jump to L3 cannot happen.
+
+shortcut_rel_op(To, Op, Ops, D) ->
+    case normalize_op({test,Op,{f,To},Ops}) of
+	{{NormOp,A,B},_} ->
+	    Normalized = {negate_op(NormOp),A,B},
+	    shortcut_rel_op_fp(To, Normalized, D);
+	{_,_} ->
+	    To;
+	error ->
+	    To
+    end.
 
-shortcut_bs_start_match_1([{bs_context_to_binary,Reg}|Is], Reg, To) ->
-    shortcut_bs_start_match_2(Is, Reg, To);
-shortcut_bs_start_match_1(_, _, To) -> To.
+shortcut_rel_op_fp(To0, Normalized, D) ->
+    Code = beam_utils:code_at(To0, D),
+    case shortcut_any_label(Code, Normalized) of
+	error ->
+	    To0;
+	To ->
+	    shortcut_rel_op_fp(To, Normalized, D)
+    end.
 
-shortcut_bs_start_match_2([{jump,{f,To}}|_], _, _) ->
-    To;
-shortcut_bs_start_match_2([{test,bs_start_match2,{f,To},_,[Reg|_],_}|_], Reg, _) ->
-    To;
-shortcut_bs_start_match_2(_Is, _Reg, To) ->
-    To.
+%% shortcut_any_label([Instruction], PrevCondition) -> FailLabel | error
+%%  Using PrevCondition (a previous condition known to be true),
+%%  try to shortcut to another failure label.
+
+shortcut_any_label([{jump,{f,Lbl}}|_], _Prev) ->
+    Lbl;
+shortcut_any_label([{label,Lbl}|_], _Prev) ->
+    Lbl;
+shortcut_any_label([{select,select_val,R,{f,Fail},L}|_], Prev) ->
+    shortcut_selectval(L, R, Fail, Prev);
+shortcut_any_label([I|Is], Prev) ->
+    case normalize_op(I) of
+	error ->
+	    error;
+	{Normalized,Fail} ->
+	    %% We have a relational operator.
+	    case will_succeed(Prev, Normalized) of
+		no ->
+		    %% This test instruction will always branch
+		    %% to Fail.
+		    Fail;
+		yes ->
+		    %% This test instruction will never branch,
+		    %% so we will look at the next instruction.
+		    shortcut_any_label(Is, Prev);
+		maybe ->
+		    %% May or may not branch. From now on, we can only
+		    %% shortcut to the this specific failure label
+		    %% Fail.
+		    shortcut_specific_label(Is, Fail, Prev)
+	    end
+    end.
+
+%% shortcut_specific_label([Instruction], FailLabel, PrevCondition) ->
+%%    FailLabel | error
+%%  We have previously encountered a test instruction that may or
+%%  may not branch to FailLabel. Therefore we are only allowed
+%%  to do the shortcut to the same fail label (FailLabel).
+
+shortcut_specific_label([{label,_}|Is], Fail, Prev) ->
+    shortcut_specific_label(Is, Fail, Prev);
+shortcut_specific_label([{select,select_val,R,{f,F},L}|_], Fail, Prev) ->
+    case shortcut_selectval(L, R, F, Prev) of
+	Fail -> Fail;
+	_ -> error
+    end;
+shortcut_specific_label([I|Is], Fail, Prev) ->
+    case normalize_op(I) of
+	error ->
+	    error;
+	{Normalized,Fail} ->
+	    case will_succeed(Prev, Normalized) of
+		no ->
+		    %% Will branch to FailLabel.
+		    Fail;
+		yes ->
+		    %% Will definitely never branch.
+		    shortcut_specific_label(Is, Fail, Prev);
+		maybe ->
+		    %% May branch, but still OK since it will branch
+		    %% to FailLabel.
+		    shortcut_specific_label(Is, Fail, Prev)
+	    end;
+	{Normalized,_} ->
+	    %% This test instruction will branch to a different
+	    %% fail label, if it branches at all.
+	    case will_succeed(Prev, Normalized) of
+		yes ->
+		    %% Still OK, since the branch will never be
+		    %% taken.
+		    shortcut_specific_label(Is, Fail, Prev);
+		no ->
+		    %% Give up. The branch will definitely be taken
+		    %% to a different fail label.
+		    error;
+		maybe ->
+		    %% Give up. If the branch is taken, it will be
+		    %% to a different fail label.
+		    error
+	    end
+    end.
+
+
+%% shortcut_selectval(List, Reg, Fail, PrevCond) -> FailLabel | error
+%%  Try to shortcut a selectval instruction. A selectval instruction
+%%  is equivalent to the following instruction sequence:
+%%
+%%      is_ne_exact L1 Reg Value1
+%%              .
+%%              .
+%%              .
+%%      is_ne_exact LN Reg ValueN
+%%      jump DefaultFailLabel
+%%
+shortcut_selectval([Val,{f,Lbl}|T], R, Fail, Prev) ->
+    case will_succeed(Prev, {'=/=',R,get_literal(Val)}) of
+	yes -> shortcut_selectval(T, R, Fail, Prev);
+	no -> Lbl;
+	maybe -> error
+    end;
+shortcut_selectval([], _, Fail, _) -> Fail.
+
+%% will_succeed(PrevCondition, Condition) -> yes | no | maybe
+%%  PrevCondition is a condition known to be true. This function
+%%  will tell whether Condition will succeed.
+
+will_succeed({Op1,Reg,A}, {Op2,Reg,B}) ->
+    will_succeed_1(Op1, A, Op2, B);
+will_succeed({'=:=',Reg,{literal,A}}, {TypeTest,Reg}) ->
+    case erlang:TypeTest(A) of
+	false -> no;
+	true -> yes
+    end;
+will_succeed({_,_,_}, maybe) ->
+    maybe;
+will_succeed({_,_,_}, Test) when is_tuple(Test) ->
+    maybe.
+
+will_succeed_1('=:=', A, '<', B) ->
+    if
+	B =< A -> no;
+	true -> yes
+    end;
+will_succeed_1('=:=', A, '=<', B) ->
+    if
+	B < A -> no;
+	true -> yes
+    end;
+will_succeed_1('=:=', A, '=:=', B) ->
+    if
+	A =:= B -> yes;
+	true -> no
+    end;
+will_succeed_1('=:=', A, '=/=', B) ->
+    if
+	A =:= B -> no;
+	true -> yes
+    end;
+will_succeed_1('=:=', A, '>=', B) ->
+    if
+	B > A -> no;
+	true -> yes
+    end;
+will_succeed_1('=:=', A, '>', B) ->
+    if
+	B >= A -> no;
+	true -> yes
+    end;
+
+will_succeed_1('=/=', A, '=/=', B) when A =:= B -> yes;
+will_succeed_1('=/=', A, '=:=', B) when A =:= B -> no;
+
+will_succeed_1('<', A, '=:=', B)  when B >= A -> no;
+will_succeed_1('<', A, '=/=', B)  when B >= A -> yes;
+will_succeed_1('<', A, '<',   B)  when B >= A -> yes;
+will_succeed_1('<', A, '=<',  B)  when B > A  -> yes;
+will_succeed_1('<', A, '>=',  B)  when B > A  -> no;
+will_succeed_1('<', A, '>',   B)  when B >= A -> no;
+
+will_succeed_1('=<', A, '=:=', B) when B > A  -> no;
+will_succeed_1('=<', A, '=/=', B) when B > A  -> yes;
+will_succeed_1('=<', A, '<',   B) when B > A  -> yes;
+will_succeed_1('=<', A, '=<',  B) when B >= A -> yes;
+will_succeed_1('=<', A, '>=',  B) when B > A  -> no;
+will_succeed_1('=<', A, '>',   B) when B >= A -> no;
+
+will_succeed_1('>=', A, '=:=', B) when B < A  -> no;
+will_succeed_1('>=', A, '=/=', B) when B < A  -> yes;
+will_succeed_1('>=', A, '<',   B) when B =< A -> no;
+will_succeed_1('>=', A, '=<',  B) when B < A  -> no;
+will_succeed_1('>=', A, '>=',  B) when B =< A -> yes;
+will_succeed_1('>=', A, '>',   B) when B < A  -> yes;
+
+will_succeed_1('>', A, '=:=', B)  when B =< A -> no;
+will_succeed_1('>', A, '=/=', B)  when B =< A -> yes;
+will_succeed_1('>', A, '<',   B)  when B =< A -> no;
+will_succeed_1('>', A, '=<',  B)  when B < A  -> no;
+will_succeed_1('>', A, '>=',  B)  when B =< A -> yes;
+will_succeed_1('>', A, '>',   B)  when B < A  -> yes;
+
+will_succeed_1(_, _, _, _) -> maybe.
+
+%% normalize_op(Instruction) -> {Normalized,FailLabel} | error
+%%    Normalized = {Operator,Register,Literal} |
+%%                 {TypeTest,Register} |
+%%                 maybe
+%%    Operation = '<' | '=<' | '=:=' | '=/=' | '>=' | '>'
+%%    TypeTest = is_atom | is_integer ...
+%%    Literal = {literal,Term}
+%%
+%%  Normalize a relational operator to facilitate further
+%%  comparisons between operators. Always make the register
+%%  operand the first operand. Thus the following instruction:
+%%
+%%    {test,is_ge,{f,99},{integer,13},{x,0}}
+%%
+%%  will be normalized to:
+%%
+%%    {'=<',{x,0},{literal,13}}
+%%
+%%  NOTE: Bit syntax test instructions are scary. They may change the
+%%  state of match contexts and update registers, so we don't dare
+%%  mess with them.
+
+normalize_op({test,is_ge,{f,Fail},Ops}) ->
+    normalize_op_1('>=', Ops, Fail);
+normalize_op({test,is_lt,{f,Fail},Ops}) ->
+    normalize_op_1('<', Ops, Fail);
+normalize_op({test,is_eq_exact,{f,Fail},Ops}) ->
+    normalize_op_1('=:=', Ops, Fail);
+normalize_op({test,is_ne_exact,{f,Fail},Ops}) ->
+    normalize_op_1('=/=', Ops, Fail);
+normalize_op({test,is_nil,{f,Fail},[R]}) ->
+    normalize_op_1('=:=', [R,nil], Fail);
+normalize_op({test,Op,{f,Fail},[R]}) ->
+    case erl_internal:new_type_test(Op, 1) of
+	true -> {{Op,R},Fail};
+	false -> {maybe,Fail}
+    end;
+normalize_op({test,_,{f,Fail},_}=I) ->
+    case beam_utils:is_pure_test(I) of
+	true -> {maybe,Fail};
+	false -> error
+    end;
+normalize_op(_) ->
+    error.
+
+normalize_op_1(Op, [Op1,Op2], Fail) ->
+    case {get_literal(Op1),get_literal(Op2)} of
+	{error,error} ->
+	    %% Both operands are registers.
+	    {maybe,Fail};
+	{error,Lit} ->
+	    {{Op,Op1,Lit},Fail};
+	{Lit,error} ->
+	    {{turn_op(Op),Op2,Lit},Fail};
+	{_,_} ->
+	    %% Both operands are literals. Can probably only
+	    %% happen if the Core Erlang optimizations passes were
+	    %% turned off, so don't bother trying to do something
+	    %% smart here.
+	    {maybe,Fail}
+    end.
+
+turn_op('<') -> '>';
+turn_op('>=') -> '=<';
+turn_op('=:='=Op) -> Op;
+turn_op('=/='=Op) -> Op.
+
+negate_op('>=') -> '<';
+negate_op('<') -> '>=';
+negate_op('=<') -> '>';
+negate_op('>') -> '=<';
+negate_op('=:=') -> '=/=';
+negate_op('=/=') -> '=:='.
+
+get_literal({atom,Val}) ->
+    {literal,Val};
+get_literal({integer,Val}) ->
+    {literal,Val};
+get_literal({float,Val}) ->
+    {literal,Val};
+get_literal(nil) ->
+    {literal,[]};
+get_literal({literal,_}=Lit) ->
+    Lit;
+get_literal({_,_}) -> error.
+
+
+%%%
+%%% Removing stores to Y registers is not always safe
+%%% if there is an instruction that causes an exception
+%%% within a catch. In practice, there are few or no
+%%% opportunities for removing stores to Y registers anyway
+%%% if sys_core_fold has been run.
+%%%
+
+is_killed_at({x,_}=Reg, Lbl, D) ->
+    beam_utils:is_killed_at(Reg, Lbl, D);
+is_killed_at({y,_}, _, _) ->
+    false.
diff --git a/lib/compiler/src/beam_dict.erl b/lib/compiler/src/beam_dict.erl
index 212b9fb03a..9565ab74c4 100644
--- a/lib/compiler/src/beam_dict.erl
+++ b/lib/compiler/src/beam_dict.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -29,16 +30,24 @@
 
 -type label() :: non_neg_integer().
 
+-type index() :: non_neg_integer().
+
+-type atom_tab()   :: #{atom() => index()}.
+-type import_tab() :: gb_trees:tree(mfa(), index()).
+-type fname_tab()  :: #{Name :: term() => index()}.
+-type line_tab()   :: #{{Fname :: index(), Line :: term()} => index()}.
+-type literal_tab() :: dict:dict(Literal :: term(), index()).
+
 -record(asm,
-	{atoms = gb_trees:empty()   :: gb_tree(),      	%{Atom,Index}
+	{atoms = #{}                :: atom_tab(),
 	 exports = []		    :: [{label(), arity(), label()}],
 	 locals = []		    :: [{label(), arity(), label()}],
-	 imports = gb_trees:empty() :: gb_tree(),      	%{{M,F,A},Index}
+	 imports = gb_trees:empty() :: import_tab(),
 	 strings = <<>>		    :: binary(),	%String pool
-	 lambdas = [],				%[{...}]
-	 literals = dict:new()	    :: dict(),	%Format: {Literal,Number}
-	 fnames = gb_trees:empty()  :: gb_tree(),       %{Name,Index}
-	 lines = gb_trees:empty()   :: gb_tree(),	%{{Fname,Line},Index}
+	 lambdas = {0,[]},				%[{...}]
+	 literals = dict:new()	    :: literal_tab(),
+	 fnames = #{}               :: fname_tab(),
+	 lines = #{}                :: line_tab(),
 	 num_lines = 0		    :: non_neg_integer(), %Number of line instructions
 	 next_import = 0	    :: non_neg_integer(),
 	 string_offset = 0	    :: non_neg_integer(),
@@ -57,7 +66,7 @@ new() ->
 %% Remember the highest opcode.
 -spec opcode(non_neg_integer(), bdict()) -> bdict().
 
-opcode(Op, Dict) when Dict#asm.highest_opcode > Op -> Dict;
+opcode(Op, Dict) when Dict#asm.highest_opcode >= Op -> Dict;
 opcode(Op, Dict) -> Dict#asm{highest_opcode=Op}.
 
 %% Returns the highest opcode encountered.
@@ -69,14 +78,12 @@ highest_opcode(#asm{highest_opcode=Op}) -> Op.
 %%    atom(Atom, Dict) -> {Index,Dict'}
 -spec atom(atom(), bdict()) -> {pos_integer(), bdict()}.
 
-atom(Atom, #asm{atoms=Atoms0}=Dict) when is_atom(Atom) ->
-    case gb_trees:lookup(Atom, Atoms0) of
-	{value,Index} ->
-	    {Index,Dict};
-	none ->
-	    NextIndex = gb_trees:size(Atoms0) + 1,
-	    Atoms = gb_trees:insert(Atom, NextIndex, Atoms0),
-	    {NextIndex,Dict#asm{atoms=Atoms}}
+atom(Atom, #asm{atoms=Atoms}=Dict) when is_atom(Atom) ->
+    case Atoms of
+        #{ Atom := Index} -> {Index,Dict};
+        _ ->
+            NextIndex = maps:size(Atoms) + 1,
+            {NextIndex,Dict#asm{atoms=Atoms#{Atom=>NextIndex}}}
     end.
 
 %% Remembers an exported function.
@@ -138,15 +145,14 @@ string(Str, Dict) when is_list(Str) ->
 -spec lambda(label(), non_neg_integer(), bdict()) ->
         {non_neg_integer(), bdict()}.
 
-lambda(Lbl, NumFree, #asm{lambdas=Lambdas0}=Dict) ->
-    OldIndex = length(Lambdas0),
+lambda(Lbl, NumFree, #asm{lambdas={OldIndex,Lambdas0}}=Dict) ->
     %% Set Index the same as OldIndex.
     Index = OldIndex,
     %% Initialize OldUniq to 0. It will be set to an unique value
     %% based on the MD5 checksum of the BEAM code for the module.
     OldUniq = 0,
     Lambdas = [{Lbl,{OldIndex,Lbl,Index,NumFree,OldUniq}}|Lambdas0],
-    {OldIndex,Dict#asm{lambdas=Lambdas}}.
+    {OldIndex,Dict#asm{lambdas={OldIndex+1,Lambdas}}}.
 
 %% Returns the index for a literal (adding it to the literal table if necessary).
 %%    literal(Literal, Dict) -> {Index,Dict'}
@@ -169,26 +175,22 @@ line([], #asm{num_lines=N}=Dict) ->
     %% No location available. Return the special pre-defined
     %% index 0.
     {0,Dict#asm{num_lines=N+1}};
-line([{location,Name,Line}], #asm{lines=Lines0,num_lines=N}=Dict0) ->
+line([{location,Name,Line}], #asm{lines=Lines,num_lines=N}=Dict0) ->
     {FnameIndex,Dict1} = fname(Name, Dict0),
-    case gb_trees:lookup({FnameIndex,Line}, Lines0) of
-	{value,Index} ->
-	    {Index,Dict1#asm{num_lines=N+1}};
-	none ->
-	    Index = gb_trees:size(Lines0) + 1,
-	    Lines = gb_trees:insert({FnameIndex,Line}, Index, Lines0),
-	    Dict = Dict1#asm{lines=Lines,num_lines=N+1},
-	    {Index,Dict}
+    Key = {FnameIndex,Line},
+    case Lines of
+        #{Key := Index} -> {Index,Dict1#asm{num_lines=N+1}};
+        _ ->
+	    Index = maps:size(Lines) + 1,
+            {Index, Dict1#asm{lines=Lines#{Key=>Index},num_lines=N+1}}
     end.
 
-fname(Name, #asm{fnames=Fnames0}=Dict) ->
-    case gb_trees:lookup(Name, Fnames0) of
-	{value,Index} ->
-	    {Index,Dict};
-	none ->
-	    Index = gb_trees:size(Fnames0),
-	    Fnames = gb_trees:insert(Name, Index, Fnames0),
-	    {Index,Dict#asm{fnames=Fnames}}
+fname(Name, #asm{fnames=Fnames}=Dict) ->
+    case Fnames of
+        #{Name := Index} -> {Index,Dict};
+        _ ->
+            Index = maps:size(Fnames),
+	    {Index,Dict#asm{fnames=Fnames#{Name=>Index}}}
     end.
 
 %% Returns the atom table.
@@ -196,14 +198,12 @@ fname(Name, #asm{fnames=Fnames0}=Dict) ->
 -spec atom_table(bdict()) -> {non_neg_integer(), [[non_neg_integer(),...]]}.
 
 atom_table(#asm{atoms=Atoms}) ->
-    NumAtoms = gb_trees:size(Atoms),
-    Sorted = lists:keysort(2, gb_trees:to_list(Atoms)),
-    Fun = fun({A,_}) ->
-		  L = atom_to_list(A),
-		  [length(L)|L]
-	  end,
-    AtomTab = lists:map(Fun, Sorted),
-    {NumAtoms,AtomTab}.
+    NumAtoms = maps:size(Atoms),
+    Sorted = lists:keysort(2, maps:to_list(Atoms)),
+    {NumAtoms,[begin
+                   L = atom_to_list(A),
+                   [length(L)|L]
+               end || {A,_} <- Sorted]}.
 
 %% Returns the table of local functions.
 %%    local_table(Dict) -> {NumLocals, [{Function, Arity, Label}...]}
@@ -235,13 +235,13 @@ string_table(#asm{strings=Strings,string_offset=Size}) ->
 
 -spec lambda_table(bdict()) -> {non_neg_integer(), [<<_:192>>]}.
 
-lambda_table(#asm{locals=Loc0,lambdas=Lambdas0}) ->
+lambda_table(#asm{locals=Loc0,lambdas={NumLambdas,Lambdas0}}) ->
     Lambdas1 = sofs:relation(Lambdas0),
     Loc = sofs:relation([{Lbl,{F,A}} || {F,A,Lbl} <- Loc0]),
     Lambdas2 = sofs:relative_product1(Lambdas1, Loc),
     Lambdas = [<<F:32,A:32,Lbl:32,Index:32,NumFree:32,OldUniq:32>> ||
 		  {{_,Lbl,Index,NumFree,OldUniq},{F,A}} <- sofs:to_external(Lambdas2)],
-    {length(Lambdas),Lambdas}.
+    {NumLambdas,Lambdas}.
 
 %% Returns the literal table.
 %%    literal_table(Dict) -> {NumLiterals, [<<TermSize>>,TermInExternalFormat]}
@@ -265,11 +265,11 @@ my_term_to_binary(Term) ->
      non_neg_integer(),[{non_neg_integer(),non_neg_integer()}]}.
 
 line_table(#asm{fnames=Fnames0,lines=Lines0,num_lines=NumLineInstrs}) ->
-    NumFnames = gb_trees:size(Fnames0),
-    Fnames1 = lists:keysort(2, gb_trees:to_list(Fnames0)),
+    NumFnames = maps:size(Fnames0),
+    Fnames1 = lists:keysort(2, maps:to_list(Fnames0)),
     Fnames = [Name || {Name,_} <- Fnames1],
-    NumLines = gb_trees:size(Lines0),
-    Lines1 = lists:keysort(2, gb_trees:to_list(Lines0)),
+    NumLines = maps:size(Lines0),
+    Lines1 = lists:keysort(2, maps:to_list(Lines0)),
     Lines = [L || {L,_} <- Lines1],
     {NumLineInstrs,NumFnames,Fnames,NumLines,Lines}.
 
diff --git a/lib/compiler/src/beam_disasm.erl b/lib/compiler/src/beam_disasm.erl
index 1a8bbcee22..c699672db1 100644
--- a/lib/compiler/src/beam_disasm.erl
+++ b/lib/compiler/src/beam_disasm.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2000-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%=======================================================================
@@ -37,7 +38,8 @@
 
 %%-----------------------------------------------------------------------
 
--type literals()     :: 'none' | gb_tree().
+-type index()        :: non_neg_integer().
+-type literals()     :: 'none' | gb_trees:tree(index(), term()).
 -type symbolic_tag() :: 'a' | 'f' | 'h' | 'i' | 'u' | 'x' | 'y' | 'z'.
 -type disasm_tag()   :: symbolic_tag() | 'fr' | 'atom' | 'float' | 'literal'.
 -type disasm_term()  :: 'nil' | {disasm_tag(), _}.
@@ -216,7 +218,8 @@ optional_chunk(F, ChunkTag) ->
 %%-----------------------------------------------------------------------
 
 -type l_info() :: {non_neg_integer(), {_,_,_,_,_,_}}.
--spec beam_disasm_lambdas('none' | binary(), gb_tree()) -> 'none' | [l_info()].
+-spec beam_disasm_lambdas('none' | binary(), gb_trees:tree(index(), _)) ->
+        'none' | [l_info()].
 
 beam_disasm_lambdas(none, _) -> none;
 beam_disasm_lambdas(<<_:32,Tab/binary>>, Atoms) ->
@@ -311,10 +314,7 @@ get_funs({LsR0,[{func_info,[{atom,M}=AtomM,{atom,F}=AtomF,ArityArg]}|Code0]})
   when is_atom(M), is_atom(F) ->
     Arity = resolve_arg_unsigned(ArityArg),
     {LsR,Code,RestCode} = get_fun(Code0, []),
-    Entry = case Code of
-		[{label,[{u,E}]}|_] -> E;
-		_ -> undefined
-	    end,
+    [{label,[{u,Entry}]}|_] = Code,
     [#function{name=F,
 	       arity=Arity,
 	       entry=Entry,
@@ -365,6 +365,14 @@ disasm_instr(B, Bs, Atoms, Literals) ->
 	    disasm_select_inst(select_val, Bs, Atoms, Literals);
 	select_tuple_arity ->
 	    disasm_select_inst(select_tuple_arity, Bs, Atoms, Literals);
+	put_map_assoc ->
+	    disasm_map_inst(put_map_assoc, Arity, Bs, Atoms, Literals);
+	put_map_exact ->
+	    disasm_map_inst(put_map_exact, Arity, Bs, Atoms, Literals);
+	get_map_elements ->
+	    disasm_map_inst(get_map_elements, Arity, Bs, Atoms, Literals);
+	has_map_fields ->
+	    disasm_map_inst(has_map_fields, Arity, Bs, Atoms, Literals);
 	_ ->
 	    try decode_n_args(Arity, Bs, Atoms, Literals) of
 		{Args, RestBs} ->
@@ -395,6 +403,16 @@ disasm_select_inst(Inst, Bs, Atoms, Literals) ->
     {List, RestBs} = decode_n_args(Len, Bs4, Atoms, Literals),
     {{Inst, [X,F,{Z,U,List}]}, RestBs}.
 
+disasm_map_inst(Inst, Arity, Bs0, Atoms, Literals) ->
+    {Args0,Bs1} = decode_n_args(Arity, Bs0, Atoms, Literals),
+    %% no droplast ..
+    [Z|Args1]  = lists:reverse(Args0),
+    Args       = lists:reverse(Args1),
+    {U, Bs2}   = decode_arg(Bs1, Atoms, Literals),
+    {u, Len}   = U,
+    {List, RestBs} = decode_n_args(Len, Bs2, Atoms, Literals),
+    {{Inst, Args ++ [{Z,U,List}]}, RestBs}.
+
 %%-----------------------------------------------------------------------
 %% decode_arg([Byte]) -> {Arg, [Byte]}
 %%
@@ -417,11 +435,12 @@ decode_arg([B|Bs]) ->
 	    decode_int(Tag, B, Bs)
     end.
 
--spec decode_arg([byte(),...], gb_tree(), literals()) -> {disasm_term(), [byte()]}.
+-spec decode_arg([byte(),...], gb_trees:tree(index(), _), literals()) ->
+        {disasm_term(), [byte()]}.
 
 decode_arg([B|Bs0], Atoms, Literals) ->
     Tag = decode_tag(B band 2#111),
-    ?NO_DEBUG('Tag = ~p, B = ~p, Bs = ~p~n', [Tag, B, Bs]),
+    ?NO_DEBUG('Tag = ~p, B = ~p, Bs = ~p~n', [Tag, B, Bs0]),
     case Tag of
 	z ->
 	    decode_z_tagged(Tag, B, Bs0, Literals);
@@ -1009,6 +1028,7 @@ resolve_inst({gc_bif2,Args},Imports,_,_) ->
     [F,Live,Bif,A1,A2,Reg] = resolve_args(Args),
     {extfunc,_Mod,BifName,_Arity} = lookup(Bif+1,Imports),
     {gc_bif,BifName,F,Live,[A1,A2],Reg};
+
 %%
 %% New instruction in R14, gc_bif with 3 arguments
 %%
@@ -1119,6 +1139,29 @@ resolve_inst({line,[Index]},_,_,_) ->
     {line,resolve_arg(Index)};
 
 %%
+%% 17.0
+%%
+resolve_inst({put_map_assoc,Args},_,_,_) ->
+    [FLbl,Src,Dst,{u,N},{{z,1},{u,_Len},List0}] = Args,
+    List = resolve_args(List0),
+    {put_map_assoc,FLbl,Src,Dst,N,{list,List}};
+resolve_inst({put_map_exact,Args},_,_,_) ->
+    [FLbl,Src,Dst,{u,N},{{z,1},{u,_Len},List0}] = Args,
+    List = resolve_args(List0),
+    {put_map_exact,FLbl,Src,Dst,N,{list,List}};
+resolve_inst({is_map=I,Args0},_,_,_) ->
+    [FLbl|Args] = resolve_args(Args0),
+    {test,I,FLbl,Args};
+resolve_inst({has_map_fields,Args0},_,_,_) ->
+    [FLbl,Src,{{z,1},{u,_Len},List0}] = Args0,
+    List = resolve_args(List0),
+    {test,has_map_fields,FLbl,Src,{list,List}};
+resolve_inst({get_map_elements,Args0},_,_,_) ->
+    [FLbl,Src,{{z,1},{u,_Len},List0}] = Args0,
+    List = resolve_args(List0),
+    {get_map_elements,FLbl,Src,{list,List}};
+
+%%
 %% Catches instructions that are not yet handled.
 %%
 resolve_inst(X,_,_,_) -> ?exit({resolve_inst,X}).
diff --git a/lib/compiler/src/beam_disasm.hrl b/lib/compiler/src/beam_disasm.hrl
index c2aca1199e..d968cd9587 100644
--- a/lib/compiler/src/beam_disasm.hrl
+++ b/lib/compiler/src/beam_disasm.hrl
@@ -2,18 +2,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2007-2009. All Rights Reserved.
+%% Copyright Ericsson AB 2007-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -21,7 +22,9 @@
 %%	    the system (e.g. in the translation from Beam to Icode).
 
 %%
-%% XXX: THE FOLLOWING TYPE DECLARATION DOES NOT BELONG HERE...
+%% XXX: THE FOLLOWING TYPE DECLARATION DOES NOT BELONG HERE.
+%%      IT SHOULD BE MOVED TO A FILE THAT DEFINES (AND EXPORTS)
+%%      PROPER TYPES FOR THE SET OF BEAM INSTRUCTIONS.
 %%
 -type beam_instr() :: 'bs_init_writable' | 'fclearerror' | 'if_end'
                     | 'remove_message' | 'return' | 'send' | 'timeout'
@@ -33,7 +36,7 @@
 
 -record(function, {name      :: atom(),
 		   arity     :: byte(),
-		   entry,    %% unused ??
+		   entry     :: beam_lib:label(),    %% unnecessary ?
 		   code = [] :: [beam_instr()]}).
 
 -record(beam_file, {module               :: module(),
diff --git a/lib/compiler/src/beam_except.erl b/lib/compiler/src/beam_except.erl
index e5ec1bd904..4a181c1923 100644
--- a/lib/compiler/src/beam_except.erl
+++ b/lib/compiler/src/beam_except.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2011-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2011-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -131,9 +132,15 @@ translate_exception(_, _, _, _) -> no.
 
 fix_block(Is, 0) ->
     reverse(Is);
-fix_block(Is0, Words) ->
-    [{set,[],[],{alloc,Live,{F1,F2,Needed,F3}}}|Is] = reverse(Is0),
-    [{set,[],[],{alloc,Live,{F1,F2,Needed-Words,F3}}}|Is].
+fix_block(Is, Words) ->
+    reverse(fix_block_1(Is, Words)).
+
+fix_block_1([{set,[],[],{alloc,Live,{F1,F2,Needed0,F3}}}|Is], Words) ->
+    Needed = Needed0 - Words,
+    true = Needed >= 0,				%Assertion.
+    [{set,[],[],{alloc,Live,{F1,F2,Needed,F3}}}|Is];
+fix_block_1([I|Is], Words) ->
+    [I|fix_block_1(Is, Words)].
 
 dig_out_block_fc([{set,[],[],{alloc,Live,_}}|Bl]) ->
     case dig_out_fc(Bl, Live-1, nil) of
diff --git a/lib/compiler/src/beam_flatten.erl b/lib/compiler/src/beam_flatten.erl
index 25428c0c10..36369bd0b4 100644
--- a/lib/compiler/src/beam_flatten.erl
+++ b/lib/compiler/src/beam_flatten.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -51,6 +52,7 @@ norm_block([], Acc) -> Acc.
     
 norm({set,[D],As,{bif,N,F}})      -> {bif,N,F,As,D};
 norm({set,[D],As,{alloc,R,{gc_bif,N,F}}}) -> {gc_bif,N,F,R,As,D};
+norm({set,[D],[],init})           -> {init,D};
 norm({set,[D],[S],move})          -> {move,S,D};
 norm({set,[D],[S],fmove})         -> {fmove,S,D};
 norm({set,[D],[S],fconv})         -> {fconv,S,D};
@@ -60,6 +62,9 @@ norm({set,[],[S],put})            -> {put,S};
 norm({set,[D],[S],{get_tuple_element,I}}) -> {get_tuple_element,S,I,D};
 norm({set,[],[S,D],{set_tuple_element,I}}) -> {set_tuple_element,S,D,I};
 norm({set,[D1,D2],[S],get_list})          -> {get_list,S,D1,D2};
+norm({set,[D],[S|Puts],{alloc,R,{put_map,Op,F}}}) ->
+    {put_map,F,Op,S,D,R,{list,Puts}};
+%% get_map_elements is always handled in beam_split (moved out of block)
 norm({set,[],[],remove_message})   -> remove_message;
 norm({set,[],[],fclearerror}) -> fclearerror;
 norm({set,[],[],fcheckerror}) -> {fcheckerror,{f,0}}.
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl
index b29a3565e4..09cd3aa2d4 100644
--- a/lib/compiler/src/beam_jump.erl
+++ b/lib/compiler/src/beam_jump.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -127,7 +128,7 @@
 %%% on the program state.
 %%% 
 
--import(lists, [reverse/1,reverse/2,foldl/3,dropwhile/2]).
+-import(lists, [reverse/1,reverse/2,foldl/3]).
 
 module({Mod,Exp,Attr,Fs0,Lc}, _Opt) ->
     Fs = [function(F) || F <- Fs0],
@@ -152,20 +153,26 @@ function({function,Name,Arity,CLabel,Asm0}) ->
 share(Is0) ->
     %% We will get more sharing if we never fall through to a label.
     Is = eliminate_fallthroughs(Is0, []),
-    share_1(Is, dict:new(), [], []).
+    share_1(Is, #{}, [], []).
 
 share_1([{label,_}=Lbl|Is], Dict, [], Acc) ->
     share_1(Is, Dict, [], [Lbl|Acc]);
 share_1([{label,L}=Lbl|Is], Dict0, Seq, Acc) ->
-    case dict:find(Seq, Dict0) of
+    case maps:find(Seq, Dict0) of
 	error ->
-	    Dict = dict:store(Seq, L, Dict0),
+	    Dict = maps:put(Seq, L, Dict0),
 	    share_1(Is, Dict, [], [Lbl|Seq ++ Acc]);
 	{ok,Label} ->
 	    share_1(Is, Dict0, [], [Lbl,{jump,{f,Label}}|Acc])
     end;
 share_1([{func_info,_,_,_}=I|Is], _, [], Acc) ->
     reverse(Is, [I|Acc]);
+share_1([{'try',_,_}=I|Is], Dict0, Seq, Acc) ->
+    Dict = clean_non_sharable(Dict0),
+    share_1(Is, Dict, [I|Seq], Acc);
+share_1([{try_case,_}=I|Is], Dict0, Seq, Acc) ->
+    Dict = clean_non_sharable(Dict0),
+    share_1(Is, Dict, [I|Seq], Acc);
 share_1([I|Is], Dict, Seq, Acc) ->
     case is_unreachable_after(I) of
 	false ->
@@ -174,6 +181,24 @@ share_1([I|Is], Dict, Seq, Acc) ->
 	    share_1(Is, Dict, [I], Acc)
     end.
 
+clean_non_sharable(Dict) ->
+    %% We are passing in or out of a 'try' block. Remove
+    %% sequences that should not shared over the boundaries
+    %% of a 'try' block. Since the end of the sequence must match,
+    %% the only possible match between a sequence outside and
+    %% a sequence inside the 'try' block is a sequence that ends
+    %% with an instruction that causes an exception. Any sequence
+    %% that causes an exception must contain a line/1 instruction.
+    maps:filter(fun(K, _V) -> sharable_with_try(K) end, Dict).
+
+sharable_with_try([{line,_}|_]) ->
+    %% This sequence may cause an exception and may potentially
+    %% match a sequence on the other side of the 'try' block
+    %% boundary.
+    false;
+sharable_with_try([_|Is]) ->
+    sharable_with_try(Is);
+sharable_with_try([]) -> true.
 
 %% Eliminate all fallthroughs. Return the result reversed.
 
@@ -202,19 +227,19 @@ is_label(_) -> false.
 move(Is) ->
     move_1(Is, [], []).
 
-move_1([I|Is], End0, Acc0) ->
+move_1([I|Is], Ends, Acc0) ->
     case is_exit_instruction(I) of
 	false ->
-	    move_1(Is, End0, [I|Acc0]);
+	    move_1(Is, Ends, [I|Acc0]);
 	true ->
-	    case extract_seq(Acc0, [I|End0]) of
+	    case extract_seq(Acc0, [I]) of
 		no ->
-		    move_1(Is, End0, [I|Acc0]);
+		    move_1(Is, Ends, [I|Acc0]);
 		{yes,End,Acc} ->
-		    move_1(Is, End, Acc)
+		    move_1(Is, [End|Ends], Acc)
 	    end
     end;
-move_1([], End, Acc) -> reverse(Acc, End).
+move_1([], Ends, Acc) -> reverse(Acc, lists:append(reverse(Ends))).
 
 extract_seq([{line,_}=Line|Is], Acc) ->
     extract_seq(Is, [Line|Acc]);
@@ -241,17 +266,17 @@ extract_seq_1(_, _) -> no.
 %%% (3) (4) (5) (6) Jump and unreachable code optimizations.
 %%%
 
--record(st, {fc,				%Label for function class errors.
-	     entry,				%Entry label (must not be moved).
-	     mlbl,				%Moved labels.
-	     labels				%Set of referenced labels.
-	    }).
+-record(st,
+	{
+	  entry,		     %Entry label (must not be moved).
+	  mlbl,			     %Moved labels.
+	  labels :: cerl_sets:set()  %Set of referenced labels.
+	}).
 
-opt([{label,Fc}|_]=Is0, CLabel) ->
-    Lbls = initial_labels(Is0),
+opt(Is0, CLabel) ->
     find_fixpoint(fun(Is) ->
-			  St = #st{fc=Fc,entry=CLabel,mlbl=dict:new(),
-				   labels=Lbls},
+			  Lbls = initial_labels(Is),
+			  St = #st{entry=CLabel,mlbl=#{},labels=Lbls},
 			  opt(Is, [], St)
 		  end, Is0).
 
@@ -295,24 +320,30 @@ opt([{test,_,{f,_}=Lbl,_,_,_}=I|Is], Acc, St) ->
     opt(Is, [I|Acc], label_used(Lbl, St));
 opt([{select,_,_R,Fail,Vls}=I|Is], Acc, St) ->
     skip_unreachable(Is, [I|Acc], label_used([Fail|Vls], St));
-opt([{label,L}=I|Is], Acc, #st{entry=L}=St) ->
-    %% NEVER move the entry label.
-    opt(Is, [I|Acc], St);
-opt([{label,L1},{jump,{f,L2}}=I|Is], [Prev|Acc], St0) ->
-    St = St0#st{mlbl=dict:append(L2, L1, St0#st.mlbl)},
-    opt([Prev,I|Is], Acc, label_used({f,L2}, St));
 opt([{label,Lbl}=I|Is], Acc, #st{mlbl=Mlbl}=St0) ->
-    case dict:find(Lbl, Mlbl) of
+    case maps:find(Lbl, Mlbl) of
 	{ok,Lbls} ->
 	    %% Essential to remove the list of labels from the dictionary,
 	    %% since we will rescan the inserted labels.  We MUST rescan.
-	    St = St0#st{mlbl=dict:erase(Lbl, Mlbl)},
+	    St = St0#st{mlbl=maps:remove(Lbl, Mlbl)},
 	    insert_labels([Lbl|Lbls], Is, Acc, St);
-	error -> opt(Is, [I|Acc], St0)
+	error ->
+	    opt(Is, [I|Acc], St0)
     end;
-opt([{jump,{f,Lbl}},{label,Lbl}=I|Is], Acc, St) ->
-    opt([I|Is], Acc, St);
-opt([{jump,Lbl}=I|Is], Acc, St) ->
+opt([{jump,{f,_}=X}|[{label,_},{jump,X}|_]=Is], Acc, St) ->
+    opt(Is, Acc, St);
+opt([{jump,{f,Lbl}}|[{label,Lbl}|_]=Is], Acc, St) ->
+    opt(Is, Acc, St);
+opt([{jump,{f,L}=Lbl}=I|Is], Acc0, #st{mlbl=Mlbl0}=St0) ->
+    %% All labels before this jump instruction should now be
+    %% moved to the location of the jump's target.
+    {Lbls,Acc} = collect_labels(Acc0, St0),
+    St = case Lbls of
+	     [] -> St0;
+	     [_|_] ->
+		 Mlbl = maps_append_list(L, Lbls, Mlbl0),
+		 St0#st{mlbl=Mlbl}
+	 end,
     skip_unreachable(Is, [I|Acc], label_used(Lbl, St));
 %% Optimization: quickly handle some common instructions that don't
 %% have any failure labels and where is_unreachable_after(I) =:= false.
@@ -332,22 +363,36 @@ opt([I|Is], Acc, #st{labels=Used0}=St0) ->
 	true  -> skip_unreachable(Is, [I|Acc], St);
 	false -> opt(Is, [I|Acc], St)
     end;
-opt([], Acc, #st{fc=Fc,mlbl=Mlbl}) ->
+opt([], Acc, #st{mlbl=Mlbl}) ->
     Code = reverse(Acc),
-    case dict:find(Fc, Mlbl) of
- 	{ok,Lbls} -> insert_fc_labels(Lbls, Mlbl, Code);
- 	error -> Code
-    end.
+    insert_fc_labels(Code, Mlbl).
 
-insert_fc_labels([L|Ls], Mlbl, Acc0) ->
-    Acc = [{label,L}|Acc0],
-    case dict:find(L, Mlbl) of
+insert_fc_labels([{label,L}=I|Is0], Mlbl) ->
+    case maps:find(L, Mlbl) of
 	error ->
-	    insert_fc_labels(Ls, Mlbl, Acc);
+	    [I|insert_fc_labels(Is0, Mlbl)];
 	{ok,Lbls} ->
-	    insert_fc_labels(Lbls++Ls, Mlbl, Acc)
+	    Is = [{label,Lb} || Lb <- Lbls] ++ Is0,
+	    [I|insert_fc_labels(Is, maps:remove(L, Mlbl))]
     end;
-insert_fc_labels([], _, Acc) -> Acc.
+insert_fc_labels([_|_]=Is, _) -> Is.
+
+maps_append_list(K,Vs,M) ->
+    case M of
+        #{K:=Vs0} -> M#{K:=Vs0++Vs}; % same order as dict
+        _ -> M#{K => Vs}
+    end.
+
+collect_labels(Is, #st{entry=Entry}) ->
+    collect_labels_1(Is, Entry, []).
+
+collect_labels_1([{label,Entry}|_]=Is, Entry, Acc) ->
+    %% Never move the entry label.
+    {Acc,Is};
+collect_labels_1([{label,L}|Is], Entry, Acc) ->
+    collect_labels_1(Is, Entry, [L|Acc]);
+collect_labels_1(Is, _Entry, Acc) ->
+    {Acc,Is}.
 
 %% label_defined(Is, Label) -> true | false.
 %%  Test whether the label Label is defined at the start of the instruction
@@ -394,7 +439,7 @@ skip_unreachable([], Acc, St) ->
 
 %% Add one or more label to the set of used labels.
 
-label_used({f,L}, St) -> St#st{labels=gb_sets:add(L, St#st.labels)};
+label_used({f,L}, St) -> St#st{labels=cerl_sets:add_element(L,St#st.labels)};
 label_used([H|T], St0) -> label_used(T, label_used(H, St0));
 label_used([], St) -> St;
 label_used(_Other, St) -> St.
@@ -402,7 +447,7 @@ label_used(_Other, St) -> St.
 %% Test if label is used.
 
 is_label_used(L, St) ->
-    gb_sets:is_member(L, St#st.labels).
+    cerl_sets:is_element(L, St#st.labels).
 
 %% is_unreachable_after(Instruction) -> boolean()
 %%  Test whether the code after Instruction is unreachable.
@@ -432,27 +477,29 @@ is_exit_instruction(_) -> false.
 %%  (including inside blocks).
 
 is_label_used_in(Lbl, Is) ->
-    is_label_used_in_1(Is, Lbl, gb_sets:empty()).
+    is_label_used_in_1(Is, Lbl, cerl_sets:new()).
 
 is_label_used_in_1([{block,Block}|Is], Lbl, Empty) ->
-    lists:any(fun(I) -> is_label_used_in_2(I, Lbl) end, Block)
+    lists:any(fun(I) -> is_label_used_in_block(I, Lbl) end, Block)
 	orelse is_label_used_in_1(Is, Lbl, Empty);
 is_label_used_in_1([I|Is], Lbl, Empty) ->
     Used = ulbl(I, Empty),
-    gb_sets:is_member(Lbl, Used) orelse is_label_used_in_1(Is, Lbl, Empty);
+    cerl_sets:is_element(Lbl, Used) orelse is_label_used_in_1(Is, Lbl, Empty);
 is_label_used_in_1([], _, _) -> false.
 
-is_label_used_in_2({set,_,_,Info}, Lbl) ->
+is_label_used_in_block({set,_,_,Info}, Lbl) ->
     case Info of
-	{bif,_,{f,F}} -> F =:= Lbl;
-	{alloc,_,{gc_bif,_,{f,F}}} -> F =:= Lbl;
-	{'catch',{f,F}} -> F =:= Lbl;
-	{alloc,_,_} -> false;
-	{put_tuple,_} -> false;
-	{get_tuple_element,_} -> false;
-	{set_tuple_element,_} -> false;
-	{line,_} -> false;
-	_ when is_atom(Info) -> false
+        {bif,_,{f,F}} -> F =:= Lbl;
+        {alloc,_,{gc_bif,_,{f,F}}} -> F =:= Lbl;
+        {alloc,_,{put_map,_,{f,F}}} -> F =:= Lbl;
+        {get_map_elements,{f,F}} -> F =:= Lbl;
+        {try_catch,_,{f,F}} -> F =:= Lbl;
+        {alloc,_,_} -> false;
+        {put_tuple,_} -> false;
+        {get_tuple_element,_} -> false;
+        {set_tuple_element,_} -> false;
+        {line,_} -> false;
+        _ when is_atom(Info) -> false
     end.
 
 %% remove_unused_labels(Instructions0) -> Instructions
@@ -465,13 +512,10 @@ remove_unused_labels(Is) ->
     rem_unused(Is, Used, []).
 
 rem_unused([{label,Lbl}=I|Is0], Used, [Prev|_]=Acc) ->
-    case gb_sets:is_member(Lbl, Used) of
+    case cerl_sets:is_element(Lbl, Used) of
 	false ->
 	    Is = case is_unreachable_after(Prev) of
-		     true ->
-			 dropwhile(fun({label,_}) -> false;
-				      (_) -> true
-				   end, Is0);
+		     true -> drop_upto_label(Is0);
 		     false -> Is0
 		 end,
 	    rem_unused(Is, Used, Acc);
@@ -490,7 +534,11 @@ initial_labels([{line,_}|Is], Acc) ->
 initial_labels([{label,Lbl}|Is], Acc) ->
     initial_labels(Is, [Lbl|Acc]);
 initial_labels([{func_info,_,_,_},{label,Lbl}|_], Acc) ->
-    gb_sets:from_list([Lbl|Acc]).
+    cerl_sets:from_list([Lbl|Acc]).
+
+drop_upto_label([{label,_}|_]=Is) -> Is;
+drop_upto_label([_|Is]) -> drop_upto_label(Is);
+drop_upto_label([]) -> [].
 
 %% ulbl(Instruction, UsedGbSet) -> UsedGbSet'
 %%  Update the gb_set UsedGbSet with any function-local labels
@@ -527,13 +575,17 @@ ulbl({bs_init,Lbl,_,_,_,_}, Used) ->
     mark_used(Lbl, Used);
 ulbl({bs_put,Lbl,_,_}, Used) ->
     mark_used(Lbl, Used);
+ulbl({put_map,Lbl,_Op,_Src,_Dst,_Live,_List}, Used) ->
+    mark_used(Lbl, Used);
+ulbl({get_map_elements,Lbl,_Src,_List}, Used) ->
+    mark_used(Lbl, Used);
 ulbl(_, Used) -> Used.
 
 mark_used({f,0}, Used) -> Used;
-mark_used({f,L}, Used) -> gb_sets:add(L, Used).
+mark_used({f,L}, Used) -> cerl_sets:add_element(L, Used).
 
 mark_used_list([{f,L}|T], Used) ->
-    mark_used_list(T, gb_sets:add(L, Used));
+    mark_used_list(T, cerl_sets:add_element(L, Used));
 mark_used_list([_|T], Used) ->
     mark_used_list(T, Used);
 mark_used_list([], Used) -> Used.
diff --git a/lib/compiler/src/beam_listing.erl b/lib/compiler/src/beam_listing.erl
index 50d1f3cdb1..ce566373bb 100644
--- a/lib/compiler/src/beam_listing.erl
+++ b/lib/compiler/src/beam_listing.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -46,8 +47,8 @@ module(Stream, {Mod,Exp,Attr,Code,NumLabels}) ->
       fun ({function,Name,Arity,Entry,Asm}) ->
 	      io:format(Stream, "\n\n{function, ~w, ~w, ~w}.\n",
 			[Name, Arity, Entry]),
-	      foreach(fun(Op) -> print_op(Stream, Op) end, Asm) end,
-      Code);
+	      io:put_chars(Stream, format_asm(Asm))
+      end, Code);
 module(Stream, {Mod,Exp,Inter}) ->
     %% Other kinds of intermediate formats.
     io:fwrite(Stream, "~w.~n~p.~n", [Mod,Exp]),
@@ -56,10 +57,11 @@ module(Stream, [_|_]=Fs) ->
     %% Form-based abstract format.
     foreach(fun (F) -> io:format(Stream, "~p.\n", [F]) end, Fs).
 
-print_op(Stream, Label) when element(1, Label) == label ->
-    io:format(Stream, "  ~p.\n", [Label]);
-print_op(Stream, Op) ->
-    io:format(Stream, "    ~p.\n", [Op]).
+format_asm([{label,L}|Is]) ->
+    ["  {label,",integer_to_list(L),"}.\n"|format_asm(Is)];
+format_asm([I|Is]) ->
+    [io_lib:format("    ~p", [I]),".\n"|format_asm(Is)];
+format_asm([]) -> [].
 
 function(File, {function,Name,Arity,Args,Body,Vdb,_Anno}) ->
     io:nl(File),
diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl
index 97a8c7ba70..c8bef31824 100644
--- a/lib/compiler/src/beam_peep.erl
+++ b/lib/compiler/src/beam_peep.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2008-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2008-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -64,18 +65,6 @@ function({function,Name,Arity,CLabel,Is0}) ->
 %%      InEncoding =:= latin1, OutEncoding =:= unicode; 
 %%      InEncoding =:= latin1, OutEncoding =:= utf8 ->
 %%
-%% (2) A select_val/4 instruction that only verifies that
-%%     its argument is either 'true' or 'false' can be
-%%     be replaced with an is_boolean/2 instruction. That is:
-%%
-%%          select_val Reg Fail   [ true Next false Next ]
-%%        Next: ...
-%%         
-%%     can be rewritten to
-%%
-%%          is_boolean Fail Reg
-%%        Next: ...
-%%
 
 peep(Is) ->
     peep(Is, gb_sets:empty(), []).
@@ -94,12 +83,19 @@ peep([{gc_bif,_,_,_,_,Dst}=I|Is], SeenTests0, Acc) ->
     %% Kill all remembered tests that depend on the destination register.
     SeenTests = kill_seen(Dst, SeenTests0),
     peep(Is, SeenTests, [I|Acc]);
-peep([{test,is_boolean,{f,Fail},Ops}|_]=Is, SeenTests,
-     [{test,is_atom,{f,Fail},Ops}|Acc]) ->
-    %% The previous is_atom/2 test (with the same failure label) is redundant.
-    %% (If is_boolean(Src) is true, is_atom(Src) is also true, so it is
-    %% OK to still remember that we have seen is_atom/1.)
-    peep(Is, SeenTests, Acc);
+peep([{jump,{f,L}},{label,L}=I|Is], _, Acc) ->
+    %% Sometimes beam_jump has missed this optimization.
+    peep(Is, gb_sets:empty(), [I|Acc]);
+peep([{select,Op,R,F,Vls0}|Is], _, Acc) ->
+    case prune_redundant_values(Vls0, F) of
+	[] ->
+	    %% No values left. Must convert to plain jump.
+	    I = {jump,F},
+	    peep(Is, gb_sets:empty(), [I|Acc]);
+	[_|_]=Vls ->
+	    I = {select,Op,R,F,Vls},
+	    peep(Is, gb_sets:empty(), [I|Acc])
+    end;
 peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) ->
     case beam_utils:is_pure_test(I) of
 	false ->
@@ -108,34 +104,33 @@ peep([{test,Op,_,Ops}=I|Is], SeenTests0, Acc) ->
 	    %% has succeeded.
 	    peep(Is, gb_sets:empty(), [I|Acc]);
 	true ->
-	    Test = {Op,Ops},
-	    case gb_sets:is_element(Test, SeenTests0) of
+	    case is_test_redundant(Op, Ops, SeenTests0) of
 		true ->
-		    %% This test has already succeeded and
+		    %% This test or a similar test has already succeeded and
 		    %% is therefore redundant.
 		    peep(Is, SeenTests0, Acc);
 		false ->
 		    %% Remember that we have seen this test.
+		    Test = {Op,Ops},
 		    SeenTests = gb_sets:insert(Test, SeenTests0),
 		    peep(Is, SeenTests, [I|Acc])
 	    end
     end;
-peep([{select,select_val,Src,Fail,
-       [{atom,false},{f,L},{atom,true},{f,L}]}|
-      [{label,L}|_]=Is], SeenTests, Acc) ->
-    I = {test,is_boolean,Fail,[Src]},
-    peep([I|Is], SeenTests, Acc);
-peep([{select,select_val,Src,Fail,
-       [{atom,true},{f,L},{atom,false},{f,L}]}|
-      [{label,L}|_]=Is], SeenTests, Acc) ->
-    I = {test,is_boolean,Fail,[Src]},
-    peep([I|Is], SeenTests, Acc);
 peep([I|Is], _, Acc) ->
     %% An unknown instruction. Throw away all information we
     %% have collected about test instructions.
     peep(Is, gb_sets:empty(), [I|Acc]);
 peep([], _, Acc) -> reverse(Acc).
 
+is_test_redundant(Op, Ops, Seen) ->
+    gb_sets:is_element({Op,Ops}, Seen) orelse
+	is_test_redundant_1(Op, Ops, Seen).
+
+is_test_redundant_1(is_boolean, [R], Seen) ->
+    gb_sets:is_element({is_eq_exact,[R,{atom,false}]}, Seen) orelse
+	gb_sets:is_element({is_eq_exact,[R,{atom,true}]}, Seen);
+is_test_redundant_1(_, _, _) -> false.
+
 kill_seen(Dst, Seen0) ->
     gb_sets:from_ordset(kill_seen_1(gb_sets:to_list(Seen0), Dst)).
 
@@ -145,3 +140,9 @@ kill_seen_1([{_,Ops}=Test|T], Dst) ->
 	false -> [Test|kill_seen_1(T, Dst)]
     end;
 kill_seen_1([], _) -> [].
+
+prune_redundant_values([_Val,F|Vls], F) ->
+    prune_redundant_values(Vls, F);
+prune_redundant_values([Val,Lbl|Vls], F) ->
+    [Val,Lbl|prune_redundant_values(Vls, F)];
+prune_redundant_values([], _) -> [].
diff --git a/lib/compiler/src/beam_receive.erl b/lib/compiler/src/beam_receive.erl
index 97a9188ee7..89cafe27ce 100644
--- a/lib/compiler/src/beam_receive.erl
+++ b/lib/compiler/src/beam_receive.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2010-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -176,7 +177,8 @@ opt_recv([I|Is], D, R0, L0, Acc) ->
 	    no;
 	false ->
 	    opt_recv(Is, D, R, L, [I|Acc])
-    end.
+    end;
+opt_recv([], _, _, _, _) -> no.
 
 opt_update_regs({block,Bl}, R, L) ->
     {opt_update_regs_bl(Bl, R),L};
diff --git a/lib/compiler/src/beam_reorder.erl b/lib/compiler/src/beam_reorder.erl
new file mode 100644
index 0000000000..6a7c033ec6
--- /dev/null
+++ b/lib/compiler/src/beam_reorder.erl
@@ -0,0 +1,148 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(beam_reorder).
+
+-export([module/2]).
+-import(lists, [member/2,reverse/1]).
+
+module({Mod,Exp,Attr,Fs0,Lc}, _Opt) ->
+    Fs = [function(F) || F <- Fs0],
+    {ok,{Mod,Exp,Attr,Fs,Lc}}.
+
+function({function,Name,Arity,CLabel,Is0}) ->
+    try
+	Is = reorder(Is0),
+	{function,Name,Arity,CLabel,Is}
+    catch
+	Class:Error ->
+	    Stack = erlang:get_stacktrace(),
+	    io:fwrite("Function: ~w/~w\n", [Name,Arity]),
+	    erlang:raise(Class, Error, Stack)
+    end.
+
+%% reorder(Instructions0) -> Instructions
+%%  Reorder instructions before the beam_block pass, because reordering
+%%  will be more cumbersome when the blocks are in place.
+%%
+%%  Execution of get_tuple_element instructions can be delayed until
+%%  they are actually needed. Consider the sequence:
+%%
+%%      get_tuple_element Tuple Pos Dst
+%%      test Test Fail Operands
+%%
+%%  If Dst is killed at label Fail (and not referenced in Operands),
+%%  we can can swap the instructions:
+%%
+%%      test Test Fail Operands
+%%      get_tuple_element Tuple Pos Dst
+%%
+%%  That can be beneficial in two ways: Firstly, if the branch is taken
+%%  we have avoided execution of the get_tuple_element instruction.
+%%  Secondly, even if the branch is not taken, subsequent optimization
+%%  (opt_blocks/1) may be able to change Dst to the final destination
+%%  register and eliminate a 'move' instruction.
+
+reorder(Is) ->
+    D = beam_utils:index_labels(Is),
+    reorder_1(Is, D, []).
+
+reorder_1([{Op,_,_}=TryCatch|[I|Is]=Is0], D, Acc)
+  when Op =:= 'catch'; Op =:= 'try' ->
+    %% Don't allow 'try' or 'catch' instructions to split blocks if
+    %% it can be avoided.
+    case is_safe(I) of
+	false ->
+	    reorder_1(Is0, D, [TryCatch|Acc]);
+	true ->
+	    reorder_1([TryCatch|Is], D, [I|Acc])
+    end;
+reorder_1([{label,L}=I|_], D, Acc) ->
+    Is = beam_utils:code_at(L, D),
+    reorder_1(Is, D, [I|Acc]);
+reorder_1([{test,is_nonempty_list,_,_}=I|Is], D, Acc) ->
+    %% The run-time system may combine the is_nonempty_list test with
+    %% the following get_list instruction.
+    reorder_1(Is, D, [I|Acc]);
+reorder_1([{test,_,_,_}=I,
+	   {select,_,_,_,_}=S|Is], D, Acc) ->
+    %% There is nothing to gain by inserting a get_tuple_element
+    %% instruction between the test instruction and the select
+    %% instruction.
+    reorder_1(Is, D, [S,I|Acc]);
+reorder_1([{test,_,{f,_},[Src|_]}=I|Is], D,
+	  [{get_tuple_element,Src,_,_}|_]=Acc) ->
+    %% We want to avoid code that can confuse beam_validator such as:
+    %%   is_tuple Fail Src
+    %%   test_arity Fail Src Arity
+    %%   is_map Fail Src
+    %%   get_tuple_element Src Pos Dst
+    %% Therefore, don't reorder the instructions in such cases.
+    reorder_1(Is, D, [I|Acc]);
+reorder_1([{test,_,{f,L},Ss}=I|Is0], D0,
+	  [{get_tuple_element,_,_,El}=G|Acc0]=Acc) ->
+    case member(El, Ss) of
+	true ->
+	    reorder_1(Is0, D0, [I|Acc]);
+	false ->
+	    case beam_utils:is_killed_at(El, L, D0) of
+		true ->
+		    Is = [I,G|Is0],
+		    reorder_1(Is, D0, Acc0);
+		false ->
+		    case beam_utils:is_killed(El, Is0, D0) of
+			true ->
+			    Code0 = beam_utils:code_at(L, D0),
+			    Code = [G|Code0],
+			    D = beam_utils:index_label(L, Code, D0),
+			    Is = [I|Is0],
+			    reorder_1(Is, D, Acc0);
+			false ->
+			    reorder_1(Is0, D0, [I|Acc])
+		    end
+	    end
+    end;
+reorder_1([{allocate_zero,N,Live}=I0|Is], D,
+	  [{get_tuple_element,{x,Tup},_,{x,Dst}}=G|Acc]=Acc0) ->
+    case Tup < Dst andalso Dst+1 =:= Live of
+	true ->
+	    %% Move allocation instruction upwards past
+	    %% get_tuple_element instructions to create more
+	    %% opportunities for moving get_tuple_element
+	    %% instructions.
+	    I = {allocate_zero,N,Dst},
+	    reorder_1([I,G|Is], D, Acc);
+	false ->
+	    reorder_1(Is, D, [I0|Acc0])
+    end;
+reorder_1([I|Is], D, Acc) ->
+    reorder_1(Is, D, [I|Acc]);
+reorder_1([], _, Acc) -> reverse(Acc).
+
+%% is_safe(Instruction) -> true|false
+%%  Test whether an instruction is safe (cannot cause an exception).
+
+is_safe({kill,_}) -> true;
+is_safe({move,_,_}) -> true;
+is_safe({put,_}) -> true;
+is_safe({put_list,_,_,_}) -> true;
+is_safe({put_tuple,_,_}) -> true;
+is_safe({test_heap,_,_}) -> true;
+is_safe(_) -> false.
diff --git a/lib/compiler/src/beam_split.erl b/lib/compiler/src/beam_split.erl
index cacaaebffe..c83c686953 100644
--- a/lib/compiler/src/beam_split.erl
+++ b/lib/compiler/src/beam_split.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2011. All Rights Reserved.
+%% Copyright Ericsson AB 2011-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -46,11 +47,20 @@ split_block([{set,[R],[_,_,_]=As,{bif,is_record,{f,Lbl}}}|Is], Bl, Acc) ->
     split_block(Is, [], [{bif,is_record,{f,Lbl},As,R}|make_block(Bl, Acc)]);
 split_block([{set,[R],As,{bif,N,{f,Lbl}=Fail}}|Is], Bl, Acc) when Lbl =/= 0 ->
     split_block(Is, [], [{bif,N,Fail,As,R}|make_block(Bl, Acc)]);
+split_block([{set,[R],As,{bif,raise,{f,_}=Fail}}|Is], Bl, Acc) ->
+    split_block(Is, [], [{bif,raise,Fail,As,R}|make_block(Bl, Acc)]);
 split_block([{set,[R],As,{alloc,Live,{gc_bif,N,{f,Lbl}=Fail}}}|Is], Bl, Acc)
   when Lbl =/= 0 ->
     split_block(Is, [], [{gc_bif,N,Fail,Live,As,R}|make_block(Bl, Acc)]);
-split_block([{set,[R],[],{'catch',L}}|Is], Bl, Acc) ->
-    split_block(Is, [], [{'catch',R,L}|make_block(Bl, Acc)]);
+split_block([{set,[D],[S|Puts],{alloc,R,{put_map,Op,{f,Lbl}=Fail}}}|Is],
+	    Bl, Acc) when Lbl =/= 0 ->
+    split_block(Is, [], [{put_map,Fail,Op,S,D,R,{list,Puts}}|
+			 make_block(Bl, Acc)]);
+split_block([{set,Ds,[S|Ss],{get_map_elements,Fail}}|Is], Bl, Acc) ->
+    Gets = beam_utils:join_even(Ss,Ds),
+    split_block(Is, [], [{get_map_elements,Fail,S,{list,Gets}}|make_block(Bl, Acc)]);
+split_block([{set,[R],[],{try_catch,Op,L}}|Is], Bl, Acc) ->
+    split_block(Is, [], [{Op,R,L}|make_block(Bl, Acc)]);
 split_block([{set,[],[],{line,_}=Line}|Is], Bl, Acc) ->
     split_block(Is, [], [Line|make_block(Bl, Acc)]);
 split_block([I|Is], Bl, Acc) ->
diff --git a/lib/compiler/src/beam_trim.erl b/lib/compiler/src/beam_trim.erl
index fad9c42584..a8dc6805bc 100644
--- a/lib/compiler/src/beam_trim.erl
+++ b/lib/compiler/src/beam_trim.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2007-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2007-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -172,6 +173,10 @@ remap([{bif,Name,Fail,Ss,D}|Is], Map, Acc) ->
 remap([{gc_bif,Name,Fail,Live,Ss,D}|Is], Map, Acc) ->
     I = {gc_bif,Name,Fail,Live,[Map(S) || S <- Ss],Map(D)},
     remap(Is, Map, [I|Acc]);
+remap([{get_map_elements,Fail,M,{list,L0}}|Is], Map, Acc) ->
+    L = [Map(E) || E <- L0],
+    I = {get_map_elements,Fail,Map(M),{list,L}},
+    remap(Is, Map, [I|Acc]);
 remap([{bs_init,Fail,Info,Live,Ss0,Dst0}|Is], Map, Acc) ->
     Ss = [Map(Src) || Src <- Ss0],
     Dst = Map(Dst0),
@@ -275,6 +280,8 @@ frame_size([{kill,_}|Is], Safe) ->
     frame_size(Is, Safe);
 frame_size([{make_fun2,_,_,_,_}|Is], Safe) ->
     frame_size(Is, Safe);
+frame_size([{get_map_elements,{f,L},_,_}|Is], Safe) ->
+    frame_size_branch(L, Is, Safe);
 frame_size([{deallocate,N}|_], _) -> N;
 frame_size([{line,_}|Is], Safe) ->
     frame_size(Is, Safe);
diff --git a/lib/compiler/src/beam_type.erl b/lib/compiler/src/beam_type.erl
index 3b51216a6c..acaf3ede66 100644
--- a/lib/compiler/src/beam_type.erl
+++ b/lib/compiler/src/beam_type.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -22,7 +23,8 @@
 
 -export([module/2]).
 
--import(lists, [foldl/3,reverse/1,filter/2]).
+-import(lists, [filter/2,foldl/3,keyfind/3,member/2,
+		reverse/1,reverse/2,sort/1]).
 
 module({Mod,Exp,Attr,Fs0,Lc}, _Opts) ->
     Fs = [function(F) || F <- Fs0],
@@ -91,8 +93,19 @@ simplify_basic_1([{set,[D],[TupleReg],{get_tuple_element,0}}=I|Is0], Ts0, Acc) -
 	    Ts = update(I, Ts0),
 	    simplify_basic_1(Is0, Ts, [I|Acc])
     end;
-simplify_basic_1([{set,_,_,{'catch',_}}=I|Is], _Ts, Acc) ->
+simplify_basic_1([{set,_,_,{try_catch,_,_}}=I|Is], _Ts, Acc) ->
     simplify_basic_1(Is, tdb_new(), [I|Acc]);
+simplify_basic_1([{test,is_atom,_,[R]}=I|Is], Ts, Acc) ->
+    case tdb_find(R, Ts) of
+	boolean -> simplify_basic_1(Is, Ts, Acc);
+	_ -> simplify_basic_1(Is, Ts, [I|Acc])
+    end;
+simplify_basic_1([{test,is_integer,_,[R]}=I|Is], Ts, Acc) ->
+    case tdb_find(R, Ts) of
+	integer -> simplify_basic_1(Is, Ts, Acc);
+	{integer,_} -> simplify_basic_1(Is, Ts, Acc);
+	_ -> simplify_basic_1(Is, Ts, [I|Acc])
+    end;
 simplify_basic_1([{test,is_tuple,_,[R]}=I|Is], Ts, Acc) ->
     case tdb_find(R, Ts) of
 	{tuple,_,_} -> simplify_basic_1(Is, Ts, Acc);
@@ -106,6 +119,20 @@ simplify_basic_1([{test,test_arity,_,[R,Arity]}=I|Is], Ts0, Acc) ->
 	    Ts = update(I, Ts0),
 	    simplify_basic_1(Is, Ts, [I|Acc])
     end;
+simplify_basic_1([{test,is_map,_,[R]}=I|Is], Ts0, Acc) ->
+    case tdb_find(R, Ts0) of
+	map -> simplify_basic_1(Is, Ts0, Acc);
+	_Other ->
+	    Ts = update(I, Ts0),
+	    simplify_basic_1(Is, Ts, [I|Acc])
+    end;
+simplify_basic_1([{test,is_nonempty_list,_,[R]}=I|Is], Ts0, Acc) ->
+    case tdb_find(R, Ts0) of
+	nonempty_list -> simplify_basic_1(Is, Ts0, Acc);
+	_Other ->
+	    Ts = update(I, Ts0),
+	    simplify_basic_1(Is, Ts, [I|Acc])
+    end;
 simplify_basic_1([{test,is_eq_exact,Fail,[R,{atom,_}=Atom]}=I|Is0], Ts0, Acc0) ->
     Acc = case tdb_find(R, Ts0) of
 	      {atom,_}=Atom -> Acc0;
@@ -122,6 +149,16 @@ simplify_basic_1([{test,is_record,_,[R,{atom,_}=Tag,{integer,Arity}]}=I|Is], Ts0
 	    Ts = update(I, Ts0),
 	    simplify_basic_1(Is, Ts, [I|Acc])
     end;
+simplify_basic_1([{select,select_val,Reg,_,_}=I0|Is], Ts, Acc) ->
+    I = case tdb_find(Reg, Ts) of
+	    {integer,Range} ->
+		simplify_select_val_int(I0, Range);
+	    boolean ->
+		simplify_select_val_bool(I0);
+	    _ ->
+		I0
+	end,
+    simplify_basic_1(Is, tdb_new(), [I|Acc]);
 simplify_basic_1([I|Is], Ts0, Acc) ->
     Ts = update(I, Ts0),
     simplify_basic_1(Is, Ts, [I|Acc]);
@@ -129,19 +166,52 @@ simplify_basic_1([], Ts, Acc) ->
     Is = reverse(Acc),
     {Is,Ts}.
 
+simplify_select_val_int({select,select_val,R,_,L0}=I, {Min,Max}) ->
+    Vs = sort([V || {integer,V} <- L0]),
+    case eq_ranges(Vs, Min, Max) of
+	false -> I;
+	true -> simplify_select_val_1(L0, {integer,Max}, R, [])
+    end.
+
+simplify_select_val_bool({select,select_val,R,_,L}=I) ->
+    Vs = sort([V || {atom,V} <- L]),
+    case Vs of
+	[false,true] ->
+	    simplify_select_val_1(L, {atom,false}, R, []);
+	_ ->
+	    I
+    end.
+
+simplify_select_val_1([Val,F|T], Val, R, Acc) ->
+    L = reverse(Acc, T),
+    {select,select_val,R,F,L};
+simplify_select_val_1([V,F|T], Val, R, Acc) ->
+    simplify_select_val_1(T, Val, R, [F,V|Acc]).
+
+eq_ranges([H], H, H) -> true;
+eq_ranges([H|T], H, Max) -> eq_ranges(T, H+1, Max);
+eq_ranges(_, _, _) -> false.
+
 %% simplify_float([Instruction], TypeDatabase) ->
 %%                 {[Instruction],TypeDatabase'} | not_possible
 %%  Simplify floating point operations in blocks.
 %%
 simplify_float(Is0, Ts0) ->
     {Is1,Ts} = simplify_float_1(Is0, Ts0, [], []),
-    Is2 = flt_need_heap(Is1),
+    Is2 = opt_fmoves(Is1, []),
+    Is3 = flt_need_heap(Is2),
     try
-	{flt_liveness(Is2),Ts}
+	{flt_liveness(Is3),Ts}
     catch
 	throw:not_possible -> not_possible
     end.
 
+simplify_float_1([{set,[],[],fclearerror}|Is], Ts, Rs, Acc) ->
+    simplify_float_1(Is, Ts, Rs, clearerror(Acc));
+simplify_float_1([{set,[],[],fcheckerror}|Is], Ts, Rs, Acc) ->
+    simplify_float_1(Is, Ts, Rs, checkerror(Acc));
+simplify_float_1([{set,[{fr,_}],_,_}=I|Is], Ts, Rs, Acc) ->
+    simplify_float_1(Is, Ts, Rs, [I|Acc]);
 simplify_float_1([{set,[D0],[A0],{alloc,_,{gc_bif,'-',{f,0}}}}=I|Is]=Is0,
 		 Ts0, Rs0, Acc0) ->
     case tdb_find(A0, Ts0) of
@@ -177,19 +247,20 @@ simplify_float_1([{set,[D0],[A0,B0],{alloc,_,{gc_bif,Op0,{f,0}}}}=I|Is]=Is0,
 	    Ts = tdb_update([{D0,float}], Ts0),
 	    simplify_float_1(Is, Ts, Rs, Acc)
     end;
-simplify_float_1([{set,_,_,{'catch',_}}=I|Is]=Is0, _Ts, Rs0, Acc0) ->
+simplify_float_1([{set,_,_,{try_catch,_,_}}=I|Is]=Is0, _Ts, Rs0, Acc0) ->
     Acc = flush_all(Rs0, Is0, Acc0),
     simplify_float_1(Is, tdb_new(), Rs0, [I|Acc]);
 simplify_float_1([{set,_,_,{line,_}}=I|Is], Ts, Rs, Acc) ->
     simplify_float_1(Is, Ts, Rs, [I|Acc]);
+simplify_float_1([I|Is], Ts0, [], Acc) ->
+    Ts = update(I, Ts0),
+    simplify_float_1(Is, Ts, [], [I|Acc]);
 simplify_float_1([I|Is]=Is0, Ts0, Rs0, Acc0) ->
     Ts = update(I, Ts0),
     {Rs,Acc} = flush(Rs0, Is0, Acc0),
     simplify_float_1(Is, Ts, Rs, [I|checkerror(Acc)]);
-simplify_float_1([], Ts, Rs, Acc0) ->
-    Acc = checkerror(Acc0),
-    Is0 = reverse(flush_all(Rs, [], Acc)),
-    Is = opt_fmoves(Is0, []),
+simplify_float_1([], Ts, [], Acc) ->
+    Is = reverse(Acc),
     {Is,Ts}.
 
 coerce_to_float({integer,I}=Int) ->
@@ -224,7 +295,7 @@ clearerror([], OrigIs) -> [{set,[],[],fclearerror}|OrigIs].
 %%  Combine two blocks and eliminate any move instructions that assign
 %%  to registers that are killed later in the block.
 %%
-merge_blocks(B1, [{'%live',_}|B2]) ->
+merge_blocks(B1, [{'%live',_,_}|B2]) ->
     merge_blocks_1(B1++[{set,[],[],stop_here}|B2]).
 
 merge_blocks_1([{set,[],_,stop_here}|Is]) -> Is;
@@ -288,7 +359,7 @@ flt_need_heap_2({set,_,_,{get_tuple_element,_}}, H, Fl) ->
     {[],H,Fl};
 flt_need_heap_2({set,_,_,get_list}, H, Fl) ->
     {[],H,Fl};
-flt_need_heap_2({set,_,_,{'catch',_}}, H, Fl) ->
+flt_need_heap_2({set,_,_,{try_catch,_,_}}, H, Fl) ->
     {[],H,Fl};
 %% All other instructions should cause the insertion of an allocation
 %% instruction if needed.
@@ -309,27 +380,27 @@ build_alloc(Words, Floats) -> {alloc,[{words,Words},{floats,Floats}]}.
 
 %% flt_liveness([Instruction]) -> [Instruction]
 %%  (Re)calculate the number of live registers for each heap allocation
-%%  function. We base liveness of the number of live registers at
-%%  entry to the instruction sequence.
+%%  function. We base liveness of the number of register map at the
+%%  beginning of the instruction sequence.
 %%
 %%  A 'not_possible' term will be thrown if the set of live registers
 %%  is not continous at an allocation function (e.g. if {x,0} and {x,2}
 %%  are live, but not {x,1}).
 
-flt_liveness([{'%live',Live}=LiveInstr|Is]) ->
-    flt_liveness_1(Is, init_regs(Live), [LiveInstr]).
+flt_liveness([{'%live',_Live,Regs}=LiveInstr|Is]) ->
+    flt_liveness_1(Is, Regs, [LiveInstr]).
 
-flt_liveness_1([{set,Ds,Ss,{alloc,_,Alloc}}|Is], Regs0, Acc) ->
-    Live = live_regs(Regs0),
+flt_liveness_1([{set,Ds,Ss,{alloc,Live0,Alloc}}|Is], Regs0, Acc) ->
+    Live = min(Live0, live_regs(Regs0)),
     I = {set,Ds,Ss,{alloc,Live,Alloc}},
-    Regs = foldl(fun(R, A) -> set_live(R, A) end, Regs0, Ds),
+    Regs1 = init_regs(Live),
+    Regs = x_live(Ds, Regs1),
     flt_liveness_1(Is, Regs, [I|Acc]);
 flt_liveness_1([{set,Ds,_,_}=I|Is], Regs0, Acc) ->
-    Regs = foldl(fun(R, A) -> set_live(R, A) end, Regs0, Ds),
-    flt_liveness_1(Is, Regs, [I|Acc]);
-flt_liveness_1([{'%live',_}=I|Is], Regs, Acc) ->
+    Regs = x_live(Ds, Regs0),
     flt_liveness_1(Is, Regs, [I|Acc]);
-flt_liveness_1([], _Regs, Acc) -> reverse(Acc).
+flt_liveness_1([{'%live',_,_}], _Regs, Acc) ->
+    reverse(Acc).
 
 init_regs(Live) ->
     (1 bsl Live) - 1.
@@ -344,20 +415,32 @@ live_regs_1(R, N) ->
 	1 -> live_regs_1(R bsr 1, N+1)
     end.
 
-set_live({x,X}, Regs) -> Regs bor (1 bsl X);
-set_live(_, Regs) -> Regs.
+x_live([{x,N}|Rs], Regs) -> x_live(Rs, Regs bor (1 bsl N));
+x_live([_|Rs], Regs) -> x_live(Rs, Regs);
+x_live([], Regs) -> Regs.
 
 %% update(Instruction, TypeDb) -> NewTypeDb
 %%  Update the type database to account for executing an instruction.
 %%
 %%  First the cases for instructions inside basic blocks.
-update({'%live',_}, Ts) -> Ts;
+update({'%live',_,_}, Ts) -> Ts;
 update({set,[D],[S],move}, Ts) ->
     tdb_copy(S, D, Ts);
 update({set,[D],[{integer,I},Reg],{bif,element,_}}, Ts0) ->
     tdb_update([{Reg,{tuple,I,[]}},{D,kill}], Ts0);
 update({set,[D],[_Index,Reg],{bif,element,_}}, Ts0) ->
     tdb_update([{Reg,{tuple,0,[]}},{D,kill}], Ts0);
+update({set,[D],Args,{bif,N,_}}, Ts0) ->
+    Ar = length(Args),
+    BoolOp = erl_internal:new_type_test(N, Ar) orelse
+	erl_internal:comp_op(N, Ar) orelse
+	erl_internal:bool_op(N, Ar),
+    case BoolOp of
+	true ->
+	    tdb_update([{D,boolean}], Ts0);
+	false ->
+	    tdb_update([{D,kill}], Ts0)
+    end;
 update({set,[D],[S],{get_tuple_element,0}}, Ts) ->
     tdb_update([{D,{tuple_element,S,0}}], Ts);
 update({set,[D],[S],{alloc,_,{gc_bif,float,{f,0}}}}, Ts0) ->
@@ -366,6 +449,13 @@ update({set,[D],[S],{alloc,_,{gc_bif,float,{f,0}}}}, Ts0) ->
 	true ->  tdb_update([{D,float}], Ts0);
 	false -> Ts0
     end;
+update({set,[D],[S1,S2],{alloc,_,{gc_bif,'band',{f,0}}}}, Ts) ->
+    case keyfind(integer, 1, [S1,S2]) of
+	{integer,N} ->
+	    update_band(N, D, Ts);
+	false ->
+	    tdb_update([{D,integer}], Ts)
+    end;
 update({set,[D],[S1,S2],{alloc,_,{gc_bif,'/',{f,0}}}}, Ts0) ->
     %% Make sure we reject non-numeric literals.
     case possibly_numeric(S1) andalso possibly_numeric(S2) of
@@ -373,15 +463,17 @@ update({set,[D],[S1,S2],{alloc,_,{gc_bif,'/',{f,0}}}}, Ts0) ->
 	false -> Ts0
     end;
 update({set,[D],[S1,S2],{alloc,_,{gc_bif,Op,{f,0}}}}, Ts0) ->
-    case arith_op(Op) of
-	no ->
-	    tdb_update([{D,kill}], Ts0);
-	{yes,_} ->
+    case op_type(Op) of
+	integer ->
+	    tdb_update([{D,integer}], Ts0);
+	{float,_} ->
 	    case {tdb_find(S1, Ts0),tdb_find(S2, Ts0)} of
 		{float,_} -> tdb_update([{D,float}], Ts0);
 		{_,float} -> tdb_update([{D,float}], Ts0);
 		{_,_} -> tdb_update([{D,kill}], Ts0)
-	    end
+	    end;
+	unknown ->
+	    tdb_update([{D,kill}], Ts0)
     end;
 update({set,[],_Src,_Op}, Ts0) -> Ts0;
 update({set,[D],_Src,_Op}, Ts0) ->
@@ -396,6 +488,10 @@ update({test,is_float,_Fail,[Src]}, Ts0) ->
     tdb_update([{Src,float}], Ts0);
 update({test,test_arity,_Fail,[Src,Arity]}, Ts0) ->
     tdb_update([{Src,{tuple,Arity,[]}}], Ts0);
+update({test,is_map,_Fail,[Src]}, Ts0) ->
+    tdb_update([{Src,map}], Ts0);
+update({test,is_nonempty_list,_Fail,[Src]}, Ts0) ->
+    tdb_update([{Src,nonempty_list}], Ts0);
 update({test,is_eq_exact,_,[Reg,{atom,_}=Atom]}, Ts) ->
     case tdb_find(Reg, Ts) of
 	error ->
@@ -409,26 +505,72 @@ update({test,is_record,_Fail,[Src,Tag,{integer,Arity}]}, Ts) ->
     tdb_update([{Src,{tuple,Arity,[Tag]}}], Ts);
 update({test,_Test,_Fail,_Other}, Ts) ->
     Ts;
+update({test,bs_get_integer2,_,_,Args,Dst}, Ts) ->
+    tdb_update([{Dst,get_bs_integer_type(Args)}], Ts);
 update({call_ext,Ar,{extfunc,math,Math,Ar}}, Ts) ->
     case is_math_bif(Math, Ar) of
 	true -> tdb_update([{{x,0},float}], Ts);
 	false -> tdb_kill_xregs(Ts)
     end;
 update({call_ext,3,{extfunc,erlang,setelement,3}}, Ts0) ->
-    Op = case tdb_find({x,1}, Ts0) of
-	     error -> kill;
-	     Info -> Info
-	 end,
-    Ts1 = tdb_kill_xregs(Ts0),
-    tdb_update([{{x,0},Op}], Ts1);
+    Ts = tdb_kill_xregs(Ts0),
+    case tdb_find({x,1}, Ts0) of
+	{tuple,Sz,_}=T0 ->
+	    T = case tdb_find({x,0}, Ts0) of
+		    {integer,{I,I}} when I > 1 ->
+			%% First element is not changed. The result
+			%% will have the same type.
+			T0;
+		    _ ->
+			%% Position is 1 or unknown. May change the
+			%% first element of the tuple.
+			{tuple,Sz,[]}
+		end,
+	    tdb_update([{{x,0},T}], Ts);
+	_ ->
+	    Ts
+    end;
 update({call,_Arity,_Func}, Ts) -> tdb_kill_xregs(Ts);
 update({call_ext,_Arity,_Func}, Ts) -> tdb_kill_xregs(Ts);
 update({make_fun2,_,_,_,_}, Ts) -> tdb_kill_xregs(Ts);
 update({line,_}, Ts) -> Ts;
+update({bs_save2,_,_}, Ts) -> Ts;
+update({bs_restore2,_,_}, Ts) -> Ts;
 
 %% The instruction is unknown.  Kill all information.
 update(_I, _Ts) -> tdb_new().
 
+update_band(N, Reg, Ts) ->
+    Type = update_band_1(N, 0),
+    tdb_update([{Reg,Type}], Ts).
+
+update_band_1(N, Bits) when Bits < 64 ->
+    case 1 bsl Bits of
+	P when P =:= N + 1 ->
+	    {integer,{0,N}};
+	P when P > N + 1 ->
+	    integer;
+	_ ->
+	    update_band_1(N, Bits+1)
+    end;
+update_band_1(_, _) ->
+    %% Negative or large positive number. Give up.
+    integer.
+
+get_bs_integer_type([_,{integer,N},U,{field_flags,Fl}])
+  when N*U < 64 ->
+    NumBits = N*U,
+    case member(unsigned, Fl) of
+	true ->
+	    {integer,{0,(1 bsl NumBits)-1}};
+	false ->
+	    %% Signed integer. Don't bother.
+	    integer
+    end;
+get_bs_integer_type(_) ->
+    %% Avoid creating ranges with a huge upper limit.
+    integer.
+
 is_math_bif(cos, 1) -> true;
 is_math_bif(cosh, 1) -> true;
 is_math_bif(sin, 1) -> true;
@@ -445,6 +587,7 @@ is_math_bif(erf, 1) -> true;
 is_math_bif(erfc, 1) -> true;
 is_math_bif(exp, 1) -> true;
 is_math_bif(log, 1) -> true;
+is_math_bif(log2, 1) -> true;
 is_math_bif(log10, 1) -> true;
 is_math_bif(sqrt, 1) -> true;
 is_math_bif(atan2, 2) -> true;
@@ -516,20 +659,31 @@ load_reg(V, Ts, Rs0, Is0) ->
 	    {Rs,Is}
     end.
 
-arith_op('+') -> {yes,fadd};
-arith_op('-') -> {yes,fsub};
-arith_op('*') -> {yes,fmul};
-arith_op('/') -> {yes,fdiv};
-arith_op(_) -> no.
+arith_op(Op) ->
+    case op_type(Op) of
+	{float,Instr} -> {yes,Instr};
+	_ -> no
+    end.
+
+op_type('+') -> {float,fadd};
+op_type('-') -> {float,fsub};
+op_type('*') -> {float,fmul};
+%% '/' and 'band' are specially handled.
+op_type('bor') -> integer;
+op_type('bxor') -> integer;
+op_type('bsl') -> integer;
+op_type('bsr') -> integer;
+op_type('div') -> integer;
+op_type(_) -> unknown.
 
 flush(Rs, [{set,[_],[],{put_tuple,_}}|_]=Is0, Acc0) ->
     Acc = flush_all(Rs, Is0, Acc0),
     {[],Acc};
 flush(Rs0, [{set,Ds,Ss,_Op}|_], Acc0) ->
-    Save = gb_sets:from_list(Ss),
+    Save = cerl_sets:from_list(Ss),
     Acc = save_regs(Rs0, Save, Acc0),
     Rs1 = foldl(fun(S, A) -> mark(S, A, clean) end, Rs0, Ss),
-    Kill = gb_sets:from_list(Ds),
+    Kill = cerl_sets:from_list(Ds),
     Rs = kill_regs(Rs1, Kill),
     {Rs,Acc};
 flush(Rs0, Is, Acc0) ->
@@ -552,7 +706,7 @@ save_regs(Rs, Save, Acc) ->
     foldl(fun(R, A) -> save_reg(R, Save, A) end, Acc, Rs).
 
 save_reg({I,V,dirty}, Save, Acc) ->
-    case gb_sets:is_member(V, Save) of
+    case cerl_sets:is_element(V, Save) of
 	true -> [{set,[V],[{fr,I}],fmove}|checkerror(Acc)];
 	false -> Acc
     end;
@@ -562,7 +716,7 @@ kill_regs(Rs, Kill) ->
     [kill_reg(R, Kill) || R <- Rs].
 
 kill_reg({_,V,_}=R, Kill) ->
-    case gb_sets:is_member(V, Kill) of
+    case cerl_sets:is_element(V, Kill) of
 	true -> free;
 	false -> R
     end;
@@ -589,7 +743,6 @@ checkerror(Is) ->
     checkerror_1(Is, Is).
 
 checkerror_1([{set,[],[],fcheckerror}|_], OrigIs) -> OrigIs;
-checkerror_1([{set,[],[],fclearerror}|_], OrigIs) -> OrigIs;
 checkerror_1([{set,_,_,{bif,fadd,_}}|_], OrigIs) -> checkerror_2(OrigIs);
 checkerror_1([{set,_,_,{bif,fsub,_}}|_], OrigIs) -> checkerror_2(OrigIs);
 checkerror_1([{set,_,_,{bif,fmul,_}}|_], OrigIs) -> checkerror_2(OrigIs);
@@ -600,17 +753,20 @@ checkerror_1([], OrigIs) -> OrigIs.
 
 checkerror_2(OrigIs) -> [{set,[],[],fcheckerror}|OrigIs].
 
-
+
 %%% Routines for maintaining a type database.  The type database 
 %%% associates type information with registers.
 %%%
 %%% {tuple,Size,First} means that the corresponding register contains a
 %%% tuple with *at least* Size elements.  An tuple with unknown
-%%% size is represented as {tuple,0}. First is either [] (meaning that
+%%% size is represented as {tuple,0,[]}. First is either [] (meaning that
 %%% the tuple's first element is unknown) or [FirstElement] (the contents
 %%% of the first element).
 %%%
 %%% 'float' means that the register contains a float.
+%%%
+%%% 'integer' or {integer,{Min,Max}} that the register contains an
+%%% integer.
 
 %% tdb_new() -> EmptyDataBase
 %%  Creates a new, empty type database.
@@ -640,21 +796,45 @@ tdb_copy({Tag,_}=S, D, Ts) when Tag =:= x; Tag =:= y ->
 	error -> orddict:erase(D, Ts);
 	Type -> orddict:store(D, Type, Ts)
     end;
-tdb_copy(Literal, D, Ts) -> orddict:store(D, Literal, Ts).
+tdb_copy(Literal, D, Ts) ->
+    Type = case Literal of
+	       {atom,_} -> Literal;
+	       {float,_} -> float;
+	       {integer,Int} -> {integer,{Int,Int}};
+	       {literal,[_|_]} -> nonempty_list;
+	       {literal,#{}} -> map;
+	       {literal,Tuple} when tuple_size(Tuple) >= 1 ->
+		   Lit = tag_literal(element(1, Tuple)),
+		   {tuple,tuple_size(Tuple),[Lit]};
+	       _ -> term
+	   end,
+    if
+	Type =:= term ->
+	    orddict:erase(D, Ts);
+	true ->
+	    verify_type(Type),
+	    orddict:store(D, Type, Ts)
+    end.
+
+tag_literal(A) when is_atom(A) -> {atom,A};
+tag_literal(F) when is_float(F) -> {float,F};
+tag_literal(I) when is_integer(I) -> {integer,I};
+tag_literal([]) -> nil;
+tag_literal(Lit) -> {literal,Lit}.
 
 %% tdb_update([UpdateOp], Db) -> NewDb
 %%        UpdateOp = {Register,kill}|{Register,NewInfo}
 %%  Updates a type database.  If a 'kill' operation is given, the type
 %%  information for that register will be removed from the database.
 %%  A kill operation takes precedence over other operations for the same
-%%  register (i.e. [{{x,0},kill},{{x,0},{tuple,5}}] means that the
+%%  register (i.e. [{{x,0},kill},{{x,0},{tuple,5,[]}}] means that the
 %%  the existing type information, if any, will be discarded, and the
-%%  the '{tuple,5}' information ignored.
+%%  the '{tuple,5,[]}' information ignored.
 %%
 %%  If NewInfo information is given and there exists information about
 %%  the register, the old and new type information will be merged.
-%%  For instance, {tuple,5} and {tuple,10} will be merged to produce
-%%  {tuple,10}.
+%%  For instance, {tuple,5,_} and {tuple,10,_} will be merged to produce
+%%  {tuple,10,_}.
 
 tdb_update(Uis0, Ts0) ->
     Uis1 = filter(fun ({{x,_},_Op}) -> true;
@@ -665,7 +845,8 @@ tdb_update(Uis0, Ts0) ->
 
 tdb_update1([{Key,kill}|Ops], [{K,_Old}|_]=Db) when Key < K ->
     tdb_update1(remove_key(Key, Ops), Db);
-tdb_update1([{Key,_New}=New|Ops], [{K,_Old}|_]=Db) when Key < K ->
+tdb_update1([{Key,Type}=New|Ops], [{K,_Old}|_]=Db) when Key < K ->
+    verify_type(Type),
     [New|tdb_update1(Ops, Db)];
 tdb_update1([{Key,kill}|Ops], [{Key,_}|Db]) ->
     tdb_update1(remove_key(Key, Ops), Db);
@@ -675,7 +856,8 @@ tdb_update1([{_,_}|_]=Ops, [Old|Db]) ->
     [Old|tdb_update1(Ops, Db)];
 tdb_update1([{Key,kill}|Ops], []) ->
     tdb_update1(remove_key(Key, Ops), []);
-tdb_update1([{_,_}=New|Ops], []) ->
+tdb_update1([{_,Type}=New|Ops], []) ->
+    verify_type(Type),
     [New|tdb_update1(Ops, [])];
 tdb_update1([], Db) -> Db.
 
@@ -700,10 +882,23 @@ merge_type_info({tuple,Sz1,[]}, {tuple,_Sz2,First}=Tuple2) ->
     merge_type_info({tuple,Sz1,First}, Tuple2);
 merge_type_info({tuple,_Sz1,First}=Tuple1, {tuple,Sz2,_}) ->
     merge_type_info(Tuple1, {tuple,Sz2,First});
+merge_type_info(integer, {integer,_}=Int) ->
+    Int;
+merge_type_info({integer,_}=Int, integer) ->
+    Int;
+merge_type_info({integer,{Min1,Max1}}, {integer,{Min2,Max2}}) ->
+    {integer,{max(Min1, Min2),min(Max1, Max2)}};
 merge_type_info(NewType, _) ->
     verify_type(NewType),
     NewType.
 
+verify_type({atom,_}) -> ok;
+verify_type(boolean) -> ok;
+verify_type(integer) -> ok;
+verify_type({integer,{Min,Max}})
+  when is_integer(Min), is_integer(Max) -> ok;
+verify_type(map) -> ok;
+verify_type(nonempty_list) -> ok;
 verify_type({tuple,Sz,[]}) when is_integer(Sz) -> ok;
 verify_type({tuple,Sz,[_]}) when is_integer(Sz) -> ok;
 verify_type({tuple_element,_,_}) -> ok;
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index e9911fefd9..a15ecf633e 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2007-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2007-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -24,7 +25,8 @@
 	 is_not_used/3,is_not_used_at/3,
 	 empty_label_index/0,index_label/3,index_labels/1,
 	 code_at/2,bif_to_test/3,is_pure_test/1,
-	 live_opt/1,delete_live_annos/1,combine_heap_needs/2]).
+	 live_opt/1,delete_live_annos/1,combine_heap_needs/2,
+	 join_even/2,split_even/1]).
 
 -import(lists, [member/2,sort/1,reverse/1,splitwith/2]).
 
@@ -64,8 +66,7 @@ is_killed(R, Is, D) ->
     St = #live{bl=check_killed_block_fun(),lbl=D,res=gb_trees:empty()},
     case check_liveness(R, Is, St) of
 	{killed,_} -> true;
-	{used,_} -> false;
-	{unknown,_} -> false
+	{used,_} -> false
     end.
 
 %% is_killed_at(Reg, Lbl, State) -> true|false
@@ -75,8 +76,7 @@ is_killed_at(R, Lbl, D) when is_integer(Lbl) ->
     St0 = #live{bl=check_killed_block_fun(),lbl=D,res=gb_trees:empty()},
     case check_liveness_at(R, Lbl, St0) of
 	{killed,_} -> true;
-	{used,_} -> false;
-	{unknown,_} -> false
+	{used,_} -> false
     end.
 
 %% is_not_used(Register, [Instruction], State) -> true|false
@@ -90,8 +90,7 @@ is_not_used(R, Is, D) ->
     St = #live{bl=fun check_used_block/3,lbl=D,res=gb_trees:empty()},
     case check_liveness(R, Is, St) of
 	{killed,_} -> true;
-	{used,_} -> false;
-	{unknown,_} -> false
+	{used,_} -> false
     end.
 
 %% is_not_used(Register, [Instruction], State) -> true|false
@@ -105,8 +104,7 @@ is_not_used_at(R, Lbl, D) ->
     St = #live{bl=fun check_used_block/3,lbl=D,res=gb_trees:empty()},
     case check_liveness_at(R, Lbl, St) of
 	{killed,_} -> true;
-	{used,_} -> false;
-	{unknown,_} -> false
+	{used,_} -> false
     end.
 
 %% index_labels(FunctionIs) -> State
@@ -126,8 +124,7 @@ empty_label_index() ->
 %%  Add an index for a label.
 
 index_label(Lbl, Is0, Acc) ->
-    Is = lists:dropwhile(fun({label,_}) -> true;
-			    (_) -> false end, Is0),
+    Is = drop_labels(Is0),
     gb_trees:enter(Lbl, Is, Acc).
 
 
@@ -135,10 +132,7 @@ index_label(Lbl, Is0, Acc) ->
 %%  Retrieve the code at the given label.
 
 code_at(L, Ll) ->
-    case gb_trees:lookup(L, Ll) of
-	{value,Code} -> Code;
-	none -> none
-    end.
+    gb_trees:get(L, Ll).
 
 %% bif_to_test(Bif, [Op], Fail) -> {test,Test,Fail,[Op]}
 %%  Convert a BIF to a test. Fail if not possible.
@@ -152,6 +146,7 @@ bif_to_test(is_function, [_]=Ops, Fail) -> {test,is_function,Fail,Ops};
 bif_to_test(is_function, [_,_]=Ops, Fail) -> {test,is_function2,Fail,Ops};
 bif_to_test(is_integer,  [_]=Ops, Fail) -> {test,is_integer,Fail,Ops};
 bif_to_test(is_list,     [_]=Ops, Fail) -> {test,is_list,Fail,Ops};
+bif_to_test(is_map,      [_]=Ops, Fail) -> {test,is_map,Fail,Ops};
 bif_to_test(is_number,   [_]=Ops, Fail) -> {test,is_number,Fail,Ops};
 bif_to_test(is_pid,      [_]=Ops, Fail) -> {test,is_pid,Fail,Ops};
 bif_to_test(is_port,     [_]=Ops, Fail) -> {test,is_port,Fail,Ops};
@@ -161,10 +156,10 @@ bif_to_test('=<', [A,B], Fail) -> {test,is_ge,Fail,[B,A]};
 bif_to_test('>', [A,B], Fail) -> {test,is_lt,Fail,[B,A]};
 bif_to_test('<', [_,_]=Ops, Fail) -> {test,is_lt,Fail,Ops};
 bif_to_test('>=', [_,_]=Ops, Fail) -> {test,is_ge,Fail,Ops};
-bif_to_test('==', [A,[]], Fail) -> {test,is_nil,Fail,[A]};
+bif_to_test('==', [A,nil], Fail) -> {test,is_nil,Fail,[A]};
 bif_to_test('==', [_,_]=Ops, Fail) -> {test,is_eq,Fail,Ops};
 bif_to_test('/=', [_,_]=Ops, Fail) -> {test,is_ne,Fail,Ops};
-bif_to_test('=:=', [A,[]], Fail) -> {test,is_nil,Fail,[A]};
+bif_to_test('=:=', [A,nil], Fail) -> {test,is_nil,Fail,[A]};
 bif_to_test('=:=', [_,_]=Ops, Fail) -> {test,is_eq_exact,Fail,Ops};
 bif_to_test('=/=', [_,_]=Ops, Fail) -> {test,is_ne_exact,Fail,Ops};
 bif_to_test(is_record, [_,_,_]=Ops, Fail) -> {test,is_record,Fail,Ops}.
@@ -172,8 +167,7 @@ bif_to_test(is_record, [_,_,_]=Ops, Fail) -> {test,is_record,Fail,Ops}.
 
 %% is_pure_test({test,Op,Fail,Ops}) -> true|false.
 %%  Return 'true' if the test instruction does not modify any
-%%  registers and/or bit syntax matching state, nor modifies
-%%  any bit syntax matching state.
+%%  registers and/or bit syntax matching state.
 %%
 is_pure_test({test,is_eq,_,[_,_]}) -> true;
 is_pure_test({test,is_ne,_,[_,_]}) -> true;
@@ -184,6 +178,9 @@ is_pure_test({test,is_lt,_,[_,_]}) -> true;
 is_pure_test({test,is_nil,_,[_]}) -> true;
 is_pure_test({test,is_nonempty_list,_,[_]}) -> true;
 is_pure_test({test,test_arity,_,[_,_]}) -> true;
+is_pure_test({test,has_map_fields,_,[_|_]}) -> true;
+is_pure_test({test,is_bitstr,_,[_]}) -> true;
+is_pure_test({test,is_function2,_,[_,_]}) -> true;
 is_pure_test({test,Op,_,Ops}) -> 
     erl_internal:new_type_test(Op, length(Ops)).
 
@@ -192,7 +189,7 @@ is_pure_test({test,Op,_,Ops}) ->
 %%  Go through the instruction sequence in reverse execution
 %%  order, keep track of liveness and remove 'move' instructions
 %%  whose destination is a register that will not be used.
-%%  Also insert {'%live',Live} annotations at the beginning
+%%  Also insert {'%live',Live,Regs} annotations at the beginning
 %%  and end of each block.
 %%
 live_opt(Is0) ->
@@ -213,7 +210,7 @@ delete_live_annos([{block,Bl0}|Is]) ->
 	[] -> delete_live_annos(Is);
 	[_|_]=Bl -> [{block,Bl}|delete_live_annos(Is)]
     end;
-delete_live_annos([{'%live',_}|Is]) ->
+delete_live_annos([{'%live',_,_}|Is]) ->
     delete_live_annos(Is);
 delete_live_annos([I|Is]) ->
     [I|delete_live_annos(Is)];
@@ -231,21 +228,28 @@ combine_heap_needs(Words, {alloc,Alloc}) when is_integer(Words) ->
 combine_heap_needs(H1, H2) when is_integer(H1), is_integer(H2) ->
     H1+H2.
 
+%% split_even/1
+%% [1,2,3,4,5,6] -> {[1,3,5],[2,4,6]}
+
+split_even(Rs) -> split_even(Rs, [], []).
+
+%% join_even/1
+%% {[1,3,5],[2,4,6]} -> [1,2,3,4,5,6]
+
+join_even([], []) -> [];
+join_even([S|Ss], [D|Ds]) -> [S,D|join_even(Ss, Ds)].
+
 %%%
 %%% Local functions.
 %%%
 
 
-%% check_liveness(Reg, [Instruction], {State,BlockCheckFun}) ->
-%%                      {killed | used | unknown,UpdateState}
-%%  Finds out how Reg is used in the instruction sequence. Returns one of:
-%%    killed - Reg is assigned a new value or killed by an allocation instruction
-%%    used - Reg is used (or possibly referenced by an allocation instruction)
-%%    unknown - not possible to determine (perhaps because of an instruction
-%%              that we don't recognize)
+%% check_liveness(Reg, [Instruction], #live{}) ->
+%%                      {killed | used, #live{}}
+%%  Find out whether Reg is used or killed in instruction sequence.
+%%  'killed' means that Reg is assigned a new value or killed by an
+%%  allocation instruction. 'used' means that Reg is used in some way.
 
-check_liveness(R, [{set,_,_,_}=I|_], St) ->
-    erlang:error(only_allowed_in_blocks, [R,I,St]);
 check_liveness(R, [{block,Blk}|Is], #live{bl=BlockCheck}=St0) ->
     case BlockCheck(R, Blk, St0) of
 	{transparent,St} -> check_liveness(R, Is, St);
@@ -321,8 +325,11 @@ check_liveness(R, [{deallocate,_}|Is], St) ->
 	{y,_} -> {killed,St};
 	_ -> check_liveness(R, Is, St)
     end;
-check_liveness(R, [return|_], St) ->
-    check_liveness_live_ret(R, 1, St);
+check_liveness({x,_}=R, [return|_], St) ->
+    case R of
+	{x,0} -> {used,St};
+	{x,_} -> {killed,St}
+    end;
 check_liveness(R, [{call,Live,_}|Is], St) ->
     case R of
 	{x,X} when X < Live -> {used,St};
@@ -340,14 +347,10 @@ check_liveness(R, [{call_ext,Live,_}=I|Is], St) ->
 		false ->
 		    check_liveness(R, Is, St);
 		true ->
-		    %% We must make sure we don't check beyond this instruction
-		    %% or we will fall through into random unrelated code and
-		    %% get stuck in a loop.
-		    %%
-		    %% We don't want to overwrite a 'catch', so consider this
-		    %% register in use.
-		    %% 
-		    {used,St}
+		    %% We must make sure we don't check beyond this
+		    %% instruction or we will fall through into random
+		    %% unrelated code and get stuck in a loop.
+		    {killed,St}
 	    end
     end;
 check_liveness(R, [{call_fun,Live}|Is], St) ->
@@ -362,11 +365,6 @@ check_liveness(R, [{apply,Args}|Is], St) ->
 	{x,_} -> {killed,St};
 	{y,_} -> check_liveness(R, Is, St)
     end;
-check_liveness({x,R}, [{'%live',Live}|Is], St) ->
-    if
-	R < Live -> check_liveness(R, Is, St);
-	true -> {killed,St}
-    end;
 check_liveness(R, [{bif,Op,{f,Fail},Ss,D}|Is], St0) ->
     case check_liveness_fail(R, Op, Ss, Fail, St0) of
 	{killed,St} = Killed ->
@@ -466,20 +464,54 @@ check_liveness(R, [{loop_rec,{f,_},{x,0}}|_], St) ->
 	{x,_} ->
 	    {killed,St};
 	_ ->
-	    %% y register. Rarely happens. Be very conversative.
-	    {unknown,St}
+	    %% y register. Rarely happens. Be very conversative and
+	    %% assume it's used.
+	    {used,St}
     end;
 check_liveness(R, [{loop_rec_end,{f,Fail}}|_], St) ->
     check_liveness_at(R, Fail, St);
 check_liveness(R, [{line,_}|Is], St) ->
     check_liveness(R, Is, St);
+check_liveness(R, [{get_map_elements,{f,Fail},S,{list,L}}|Is], St0) ->
+    {Ss,Ds} = split_even(L),
+    case member(R, [S|Ss]) of
+	true ->
+	    {used,St0};
+	false ->
+	    case check_liveness_at(R, Fail, St0) of
+		{killed,St}=Killed ->
+		    case member(R, Ds) of
+			true -> Killed;
+			false -> check_liveness(R, Is, St)
+		    end;
+		Other ->
+		    Other
+	    end
+    end;
+check_liveness(R, [{put_map,{f,_},_,Src,_D,Live,{list,_}}|_], St0) ->
+    case R of
+	Src ->
+	    {used,St0};
+	{x,X} when X < Live ->
+	    {used,St0};
+	{x,_} ->
+	    {killed,St0};
+	{y,_} ->
+	    %% Conservatively mark it as used.
+	    {used,St0}
+    end;
+check_liveness(R, [{test_heap,N,Live}|Is], St) ->
+    I = {block,[{set,[],[],{alloc,Live,{nozero,nostack,N,[]}}}]},
+    check_liveness(R, [I|Is], St);
+check_liveness(R, [{allocate_zero,N,Live}|Is], St) ->
+    I = {block,[{set,[],[],{alloc,Live,{zero,N,0,[]}}}]},
+    check_liveness(R, [I|Is], St);
+check_liveness(R, [{get_list,S,D1,D2}|Is], St) ->
+    I = {block,[{set,[D1,D2],[S],get_list}]},
+    check_liveness(R, [I|Is], St);
 check_liveness(_R, Is, St) when is_list(Is) ->
-%%     case Is of
-%% 	[I|_] ->
-%% 	    io:format("~p ~p\n", [_R,I]);
-%% 	_ -> ok
-%%     end,
-    {unknown,St}.
+    %% Not implemented. Conservatively assume that the register is used.
+    {used,St}.
     
 check_liveness_everywhere(R, [{f,Lbl}|T], St0) ->
     case check_liveness_at(R, Lbl, St0) of
@@ -498,7 +530,7 @@ check_liveness_at(R, Lbl, #live{lbl=Ll,res=ResMemorized}=St0) ->
 	none ->
 	    {Res,St} = case gb_trees:lookup(Lbl, Ll) of
 			   {value,Is} -> check_liveness(R, Is, St0);
-			   none -> {unknown,St0}
+			   none -> {used,St0}
 		       end,
 	    {Res,St#live{res=gb_trees:insert(Lbl, Res, St#live.res)}}
     end.
@@ -506,14 +538,6 @@ check_liveness_at(R, Lbl, #live{lbl=Ll,res=ResMemorized}=St0) ->
 check_liveness_ret(R, R, St) -> {used,St};
 check_liveness_ret(_, _, St) -> {killed,St}.
 
-check_liveness_live_ret({x,R}, Live, St) ->
-    if
-	R < Live -> {used,St};
-	true -> {killed,St}
-    end;
-check_liveness_live_ret({y,_}, _, St) ->
-    {killed,St}.
-
 check_liveness_fail(_, _, _, 0, St) ->
     {killed,St};
 check_liveness_fail(R, Op, Args, Fail, St) ->
@@ -550,9 +574,9 @@ check_killed_block(R, [{set,Ds,Ss,_Op}|Is]) ->
 		false -> check_killed_block(R, Is)
 	    end
     end;
-check_killed_block(R, [{'%live',Live}|Is]) ->
+check_killed_block(R, [{'%live',_,Regs}|Is]) ->
     case R of
-	{x,X} when X >= Live -> killed;
+	{x,X} when (Regs bsr X) band 1 =:= 0 -> killed;
 	_ -> check_killed_block(R, Is)
     end;
 check_killed_block(_, []) -> transparent.
@@ -563,8 +587,10 @@ check_killed_block(_, []) -> transparent.
 %%    killed - Reg is assigned a new value or killed by an allocation instruction
 %%    transparent - Reg is neither used nor killed
 %%    used - Reg is explicitly used by an instruction
-%%  
-%%    (Unknown instructions will cause an exception.)
+%%
+%%  '%live' annotations are not allowed.
+%%
+%%  (Unknown instructions will cause an exception.)
 
 check_used_block({x,X}=R, [{set,Ds,Ss,{alloc,Live,Op}}|Is], St) ->
     if 
@@ -573,11 +599,6 @@ check_used_block({x,X}=R, [{set,Ds,Ss,{alloc,Live,Op}}|Is], St) ->
     end;
 check_used_block(R, [{set,Ds,Ss,Op}|Is], St) ->
     check_used_block_1(R, Ss, Ds, Op, Is, St);
-check_used_block(R, [{'%live',Live}|Is], St) ->
-    case R of
-	{x,X} when X >= Live -> {killed,St};
-	_ -> check_used_block(R, Is, St)
-    end;
 check_used_block(_, [], St) -> {transparent,St}.
 
 check_used_block_1(R, Ss, Ds, Op, Is, St0) ->
@@ -608,18 +629,19 @@ is_reg_used_at_1(_, 0, St) ->
 is_reg_used_at_1(R, Lbl, St0) ->
     case check_liveness_at(R, Lbl, St0) of
 	{killed,St} -> {false,St};
-	{used,St} -> {true,St};
-	{unknown,St} -> {true,St}
+	{used,St} -> {true,St}
     end.
 
 index_labels_1([{label,Lbl}|Is0], Acc) ->
-    Is = lists:dropwhile(fun({label,_}) -> true;
-			    (_) -> false end, Is0),
+    Is = drop_labels(Is0),
     index_labels_1(Is0, [{Lbl,Is}|Acc]);
 index_labels_1([_|Is], Acc) ->
     index_labels_1(Is, Acc);
 index_labels_1([], Acc) -> gb_trees:from_orddict(sort(Acc)).
 
+drop_labels([{label,_}|Is]) -> drop_labels(Is);
+drop_labels(Is) -> Is.
+
 %% Help functions for combine_heap_needs.
 
 combine_alloc_lists(Al1, Al2) ->
@@ -674,9 +696,9 @@ live_opt([{test,bs_start_match2,Fail,Live,[Src,_],_}=I|Is], _, D, Acc) ->
 
 %% Other instructions.
 live_opt([{block,Bl0}|Is], Regs0, D, Acc) ->
-    Live0 = {'%live',live_regs(Regs0)},
+    Live0 = {'%live',live_regs(Regs0),Regs0},
     {Bl,Regs} = live_opt_block(reverse(Bl0), Regs0, D, [Live0]),
-    Live = {'%live',live_regs(Regs)},
+    Live = {'%live',live_regs(Regs),Regs},
     live_opt(Is, Regs, D, [{block,[Live|Bl]}|Acc]);
 live_opt([{label,L}=I|Is], Regs, D0, Acc) ->
     D = gb_trees:insert(L, Regs, D0),
@@ -723,11 +745,6 @@ live_opt([{select,_,Src,Fail,List}=I|Is], Regs0, D, Acc) ->
     Regs1 = x_live([Src], Regs0),
     Regs = live_join_labels([Fail|List], D, Regs1),
     live_opt(Is, Regs, D, [I|Acc]);
-live_opt([{'try',_,_}=I|Is], Regs, D, Acc) ->
-    %% If an exeption happens, all x registers will be killed.
-    %% Therefore, we should only base liveness of the code inside
-    %% the try.
-    live_opt(Is, Regs, D, [I|Acc]);
 live_opt([{try_case,_}=I|Is], _, D, Acc) ->
     live_opt(Is, live_call(1), D, [I|Acc]);
 live_opt([{loop_rec,_Fail,_Dst}=I|Is], _, D, Acc) ->
@@ -746,19 +763,23 @@ live_opt([{try_end,_}=I|Is], Regs, D, Acc) ->
     live_opt(Is, Regs, D, [I|Acc]);
 live_opt([{loop_rec_end,_}=I|Is], Regs, D, Acc) ->
     live_opt(Is, Regs, D, [I|Acc]);
+live_opt([{wait_timeout,_,nil}=I|Is], Regs, D, Acc) ->
+    live_opt(Is, Regs, D, [I|Acc]);
 live_opt([{wait_timeout,_,{Tag,_}}=I|Is], Regs, D, Acc) when Tag =/= x ->
     live_opt(Is, Regs, D, [I|Acc]);
 live_opt([{line,_}=I|Is], Regs, D, Acc) ->
     live_opt(Is, Regs, D, [I|Acc]);
 
 %% The following instructions can occur if the "compilation" has been
-%% started from a .S file using the 'asm' option.
+%% started from a .S file using the 'from_asm' option.
 live_opt([{trim,_,_}=I|Is], Regs, D, Acc) ->
     live_opt(Is, Regs, D, [I|Acc]);
-live_opt([{allocate,_,Live}=I|Is], _, D, Acc) ->
-    live_opt(Is, live_call(Live), D, [I|Acc]);
-live_opt([{allocate_heap,_,_,Live}=I|Is], _, D, Acc) ->
-    live_opt(Is, live_call(Live), D, [I|Acc]);
+live_opt([{'%',_}=I|Is], Regs, D, Acc) ->
+    live_opt(Is, Regs, D, [I|Acc]);
+live_opt([{recv_set,_}=I|Is], Regs, D, Acc) ->
+    live_opt(Is, Regs, D, [I|Acc]);
+live_opt([{recv_mark,_}=I|Is], Regs, D, Acc) ->
+    live_opt(Is, Regs, D, [I|Acc]);
 
 live_opt([], _, _, Acc) -> Acc.
 
@@ -822,3 +843,8 @@ x_live([_|Rs], Regs) -> x_live(Rs, Regs);
 x_live([], Regs) -> Regs.
 
 is_live(X, Regs) -> ((Regs bsr X) band 1) =:= 1.
+
+split_even([], Ss, Ds) ->
+    {reverse(Ss),reverse(Ds)};
+split_even([S,D|Rs], Ss, Ds) ->
+    split_even(Rs, [S|Ss], [D|Ds]).
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index eb72290306..4c0cb6780a 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2004-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2004-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 
@@ -22,56 +23,20 @@
 
 %% Avoid warning for local function error/1 clashing with autoimported BIF.
 -compile({no_auto_import,[error/1]}).
--export([file/1, files/1]).
 
 %% Interface for compiler.
 -export([module/2, format_error/1]).
 
 -include("beam_disasm.hrl").
 
--import(lists, [reverse/1,foldl/3,foreach/2,member/2,dropwhile/2]).
-
--define(MAXREG, 1024).
-
-%%-define(DEBUG, 1).
--ifdef(DEBUG).
--define(DBG_FORMAT(F, D), (io:format((F), (D)))).
--else.
--define(DBG_FORMAT(F, D), ok).
--endif.
-
-%%%
-%%% API functions.
-%%%
-
--spec file(file:filename()) -> 'ok' | {'error', term()}.
-
-file(Name) when is_list(Name) ->
-    case case filename:extension(Name) of
-	     ".S" -> s_file(Name);
-	     ".beam" -> beam_file(Name)
-	 end of
-	[] -> ok;
-	Es -> {error,Es}
-    end.
-
--spec files([file:filename()]) -> 'ok'.
-
-files([F|Fs]) ->
-    ?DBG_FORMAT("# Verifying: ~p~n", [F]),
-    case file(F) of
-	ok -> ok;
-	{error,Es} -> 
-	    io:format("~tp:~n~ts~n", [F,format_error(Es)])
-    end,
-    files(Fs);
-files([]) -> ok.
+-import(lists, [reverse/1,foldl/3,foreach/2,dropwhile/2]).
 
 %% To be called by the compiler.
 module({Mod,Exp,Attr,Fs,Lc}=Code, _Opts)
   when is_atom(Mod), is_list(Exp), is_list(Attr), is_integer(Lc) ->
     case validate(Mod, Fs) of
-	[] -> {ok,Code};
+	[] ->
+	    {ok,Code};
 	Es0 ->
 	    Es = [{?MODULE,E} || E <- Es0],
 	    {error,[{atom_to_list(Mod),Es}]}
@@ -79,12 +44,6 @@ module({Mod,Exp,Attr,Fs,Lc}=Code, _Opts)
 
 -spec format_error(term()) -> iolist().
 
-format_error([]) -> [];
-format_error([{{M,F,A},{I,Off,Desc}}|Es]) ->
-    [io_lib:format("  ~p:~p/~p+~p:~n    ~p - ~p~n", 
-		   [M,F,A,Off,I,Desc])|format_error(Es)];
-format_error([Error|Es]) ->
-    [format_error(Error)|format_error(Es)];
 format_error({{_M,F,A},{I,Off,limit}}) ->
     io_lib:format(
       "function ~p/~p+~p:~n"
@@ -103,8 +62,6 @@ format_error({{_M,F,A},{I,Off,Desc}}) ->
       "  Internal consistency check failed - please report this bug.~n"
       "  Instruction: ~p~n"
       "  Error:       ~p:~n", [F,A,Off,I,Desc]);
-format_error({Module,Error}) ->
-    [Module:format_error(Error)];
 format_error(Error) ->
     io_lib:format("~p~n", [Error]).
 
@@ -112,36 +69,6 @@ format_error(Error) ->
 %%% Local functions follow.
 %%% 
 
-s_file(Name) ->
-    {ok,Is} = file:consult(Name),
-    {module,Module} = lists:keyfind(module, 1, Is),
-    Fs = find_functions(Is),
-    validate(Module, Fs).
-
-find_functions(Fs) ->
-    find_functions_1(Fs, none, [], []).
-
-find_functions_1([{function,Name,Arity,Entry}|Is], Func, FuncAcc, Acc0) ->
-    Acc = add_func(Func, FuncAcc, Acc0),
-    find_functions_1(Is, {Name,Arity,Entry}, [], Acc);
-find_functions_1([I|Is], Func, FuncAcc, Acc) ->
-    find_functions_1(Is, Func, [I|FuncAcc], Acc);
-find_functions_1([], Func, FuncAcc, Acc) ->
-    reverse(add_func(Func, FuncAcc, Acc)).
-
-add_func(none, _, Acc) -> Acc;
-add_func({Name,Arity,Entry}, Is, Acc) ->
-    [{function,Name,Arity,Entry,reverse(Is)}|Acc].
-
-beam_file(Name) ->
-    try beam_disasm:file(Name) of
-	{error,beam_lib,Reason} -> [{beam_lib,Reason}];
-	#beam_file{module=Module, code=Code0} ->
-	    Code = normalize_disassembled_code(Code0),
-	    validate(Module, Code)
-    catch _:_ -> [disassembly_failed]
-    end.
-
 %%%
 %%% The validator follows.
 %%%
@@ -196,68 +123,63 @@ validate_0(Module, [{function,Name,Ar,Entry,Code}|Fs], Ft) ->
     try validate_1(Code, Name, Ar, Entry, Ft) of
 	_ -> validate_0(Module, Fs, Ft)
     catch
-	Error ->
+	throw:Error ->
+	    %% Controlled error.
 	    [Error|validate_0(Module, Fs, Ft)];
-	  error:Error ->
-	    [validate_error(Error, Module, Name, Ar)|validate_0(Module, Fs, Ft)]
+	Class:Error ->
+	    %% Crash.
+	    Stack = erlang:get_stacktrace(),
+	    io:fwrite("Function: ~w/~w\n", [Name,Ar]),
+	    erlang:raise(Class, Error, Stack)
     end.
 
--ifdef(DEBUG).
-validate_error(Error, Module, Name, Ar) ->
-    exit(validate_error_1(Error, Module, Name, Ar)).
--else.
-validate_error(Error, Module, Name, Ar) ->
-    validate_error_1(Error, Module, Name, Ar).
--endif.
-validate_error_1(Error, Module, Name, Ar) ->
-    {{Module,Name,Ar},
-     {internal_error,'_',{Error,erlang:get_stacktrace()}}}.
+-type index() :: non_neg_integer().
+-type reg_tab() :: gb_trees:tree(index(), 'none' | {'value', _}).
 
 -record(st,				%Emulation state
-	{x=init_regs(0, term)        :: gb_tree(),	%x register info.
-	 y=init_regs(0, initialized) :: gb_tree(),	%y register info.
+	{x=init_regs(0, term)        :: reg_tab(),%x register info.
+	 y=init_regs(0, initialized) :: reg_tab(),%y register info.
 	 f=init_fregs(),                %
 	 numy=none,			%Number of y registers.
 	 h=0,				%Available heap size.
 	 hf=0,				%Available heap size for floats.
 	 fls=undefined,			%Floating point state.
 	 ct=[],				%List of hot catch/try labels
-	 bsm=undefined,			%Bit syntax matching state.
-	 bits=undefined,	        %Number of bits in bit syntax binary.
 	 setelem=false			%Previous instruction was setelement/3.
 	}).
 
+-type label()        :: integer().
+-type label_set()    :: gb_sets:set(label()).
+-type branched_tab() :: gb_trees:tree(label(), #st{}).
+-type ft_tab()       :: gb_trees:tree().
+
 -record(vst,				%Validator state
 	{current=none              :: #st{} | 'none',	%Current state
-	 branched=gb_trees:empty() :: gb_tree(),	%States at jumps
-	 labels=gb_sets:empty()    :: gb_set(),		%All defined labels
-	 ft=gb_trees:empty()       :: gb_tree()         %Some other functions
+	 branched=gb_trees:empty() :: branched_tab(),	%States at jumps
+	 labels=gb_sets:empty()    :: label_set(),	%All defined labels
+	 ft=gb_trees:empty()       :: ft_tab()          %Some other functions
 	 		% in the module (those that start with bs_start_match2).
 	}).
 
--ifdef(DEBUG).
-print_st(#st{x=Xs,y=Ys,numy=NumY,h=H,ct=Ct}) ->
-    io:format("  #st{x=~p~n"
-	      "      y=~p~n"
-	      "      numy=~p,h=~p,ct=~w~n",
-	      [gb_trees:to_list(Xs),gb_trees:to_list(Ys),NumY,H,Ct]).
--endif.
+%% Match context type.
+-record(ms,
+	{id=make_ref() :: reference(),		%Unique ID.
+	 valid=0 :: non_neg_integer(),		%Valid slots
+	 slots=0 :: non_neg_integer()		%Number of slots
+	}).
 
 validate_1(Is, Name, Arity, Entry, Ft) ->
     validate_2(labels(Is), Name, Arity, Entry, Ft).
 
 validate_2({Ls1,[{func_info,{atom,Mod},{atom,Name},Arity}=_F|Is]},
 	   Name, Arity, Entry, Ft) ->
-    lists:foreach(fun (_L) -> ?DBG_FORMAT("  ~p.~n", [{label,_L}]) end, Ls1),
-    ?DBG_FORMAT("  ~p.~n", [_F]),
     validate_3(labels(Is), Name, Arity, Entry, Mod, Ls1, Ft);
 validate_2({Ls1,Is}, Name, Arity, _Entry, _Ft) ->
     error({{'_',Name,Arity},{first(Is),length(Ls1),illegal_instruction}}).
 
 validate_3({Ls2,Is}, Name, Arity, Entry, Mod, Ls1, Ft) ->
-    lists:foreach(fun (_L) -> ?DBG_FORMAT("  ~p.~n", [{label,_L}]) end, Ls2),
     Offset = 1 + length(Ls1) + 1 + length(Ls2),
-    EntryOK = (Entry =:= undefined) orelse lists:member(Entry, Ls2),
+    EntryOK = lists:member(Entry, Ls2),
     if
 	EntryOK ->
 	    St = init_state(Arity),
@@ -300,7 +222,7 @@ labels_1([{label,L}|Is], R) ->
 labels_1([{line,_}|Is], R) ->
     labels_1(Is, R);
 labels_1(Is, R) ->
-    {lists:reverse(R),Is}.
+    {reverse(R),Is}.
 
 init_state(Arity) ->
     Xs = init_regs(Arity, term),
@@ -325,7 +247,6 @@ valfun([], MFA, _Offset, #vst{branched=Targets0,labels=Labels0}=Vst) ->
 	    error({MFA,Error})
     end;
 valfun([I|Is], MFA, Offset, Vst0) ->
-    ?DBG_FORMAT("    ~p.\n", [I]),
     valfun(Is, MFA, Offset+1,
 	   try
 	       Vst = val_dsetel(I, Vst0),
@@ -343,7 +264,6 @@ valfun_1({label,Lbl}, #vst{current=St0,branched=B,labels=Lbls}=Vst) ->
 valfun_1(_I, #vst{current=none}=Vst) ->
     %% Ignore instructions after erlang:error/1,2, which
     %% the original R10B compiler thought would return.
-    ?DBG_FORMAT("Ignoring ~p\n", [_I]),
     Vst;
 valfun_1({badmatch,Src}, Vst) ->
     assert_term(Src, Vst),
@@ -361,7 +281,7 @@ valfun_1({bs_context_to_binary,Ctx}, #vst{current=#st{x=Xs}}=Vst) ->
     case Ctx of
 	{Tag,X} when Tag =:= x; Tag =:= y ->
 	    Type = case gb_trees:lookup(X, Xs) of
-		       {value,{match_context,_,_}} -> term;
+		       {value,#ms{}} -> term;
 		       _ -> get_term_type(Ctx, Vst)
 		   end,
 	    set_type_reg(Type, Ctx, Vst);
@@ -395,10 +315,6 @@ valfun_1({init,{y,_}=Reg}, Vst) ->
     set_type_y(initialized, Reg, Vst);
 valfun_1({test_heap,Heap,Live}, Vst) ->
     test_heap(Heap, Live, Vst);
-valfun_1({bif,_Op,nofail,Src,Dst}, Vst) ->
-    %% The 'nofail' atom only occurs in disassembled code.
-    validate_src(Src, Vst),
-    set_type_reg(term, Dst, Vst);
 valfun_1({bif,Op,{f,_},Src,Dst}=I, Vst) ->
     case is_bif_safe(Op, length(Src)) of
 	false ->
@@ -424,18 +340,12 @@ valfun_1({put_tuple,Sz,Dst}, Vst0) when is_integer(Sz) ->
 valfun_1({put,Src}, Vst) ->
     assert_term(Src, Vst),
     eat_heap(1, Vst);
-valfun_1({put_string,Sz,_,Dst}, Vst0) when is_integer(Sz) ->
-    Vst = eat_heap(2*Sz, Vst0),
-    set_type_reg(cons, Dst, Vst);
 %% Instructions for optimization of selective receives.
 valfun_1({recv_mark,{f,Fail}}, Vst) when is_integer(Fail) ->
     Vst;
 valfun_1({recv_set,{f,Fail}}, Vst) when is_integer(Fail) ->
     Vst;
 %% Misc.
-valfun_1({'%live',Live}, Vst) ->
-    verify_live(Live, Vst),
-    Vst;
 valfun_1(remove_message, Vst) ->
     Vst;
 valfun_1({'%',_}, Vst) ->
@@ -486,37 +396,33 @@ valfun_1({'try',Dst,{f,Fail}}, Vst0) ->
     Vst = #vst{current=#st{ct=Fails}=St} = 
 	set_type_y({trytag,[Fail]}, Dst, Vst0),
     Vst#vst{current=St#st{ct=[[Fail]|Fails]}};
-valfun_1({catch_end,Reg}, #vst{current=#st{ct=[Fail|Fails]}=St0}=Vst0) ->
+valfun_1({catch_end,Reg}, #vst{current=#st{ct=[Fail|Fails]}}=Vst0) ->
     case get_special_y_type(Reg, Vst0) of
 	{catchtag,Fail} ->
-	    Vst = #vst{current=St} = 
-		set_type_y(initialized_ct, Reg, 
-			   Vst0#vst{current=St0#st{ct=Fails}}),
+	    Vst = #vst{current=St} = set_catch_end(Reg, Vst0),
 	    Xs = gb_trees_from_list([{0,term}]),
-	    Vst#vst{current=St#st{x=Xs,fls=undefined}};
+	    Vst#vst{current=St#st{x=Xs,ct=Fails,fls=undefined}};
 	Type ->
 	    error({bad_type,Type})
     end;
-valfun_1({try_end,Reg}, #vst{current=#st{ct=[Fail|Fails]}=St}=Vst0) ->
+valfun_1({try_end,Reg}, #vst{current=#st{ct=[Fail|Fails]}=St0}=Vst0) ->
     case get_special_y_type(Reg, Vst0) of
 	{trytag,Fail} ->
 	    Vst = case Fail of
 		      [FailLabel] -> branch_state(FailLabel, Vst0);
 		      _ -> Vst0
 		  end,
-	    set_type_reg(initialized_ct, Reg, 
-			 Vst#vst{current=St#st{ct=Fails,fls=undefined}});
+	    St = St0#st{ct=Fails,fls=undefined},
+	    set_catch_end(Reg, Vst#vst{current=St});
 	Type ->
 	    error({bad_type,Type})
     end;
-valfun_1({try_case,Reg}, #vst{current=#st{ct=[Fail|Fails]}=St0}=Vst0) ->
+valfun_1({try_case,Reg}, #vst{current=#st{ct=[Fail|Fails]}}=Vst0) ->
     case get_special_y_type(Reg, Vst0) of
 	{trytag,Fail} ->
-	    Vst = #vst{current=St} = 
-		set_type_y(initialized_ct, Reg, 
-			   Vst0#vst{current=St0#st{ct=Fails}}),
-	    Xs = gb_trees_from_list([{0,{atom,[]}},{1,term},{2,term}]), %XXX
-	    Vst#vst{current=St#st{x=Xs,fls=undefined}};
+	    Vst = #vst{current=St} = set_catch_end(Reg, Vst0),
+	    Xs = gb_trees_from_list([{0,{atom,[]}},{1,term},{2,term}]),
+	    Vst#vst{current=St#st{x=Xs,ct=Fails,fls=undefined}};
 	Type ->
 	    error({bad_type,Type})
     end;
@@ -530,7 +436,7 @@ valfun_2(I, #vst{current=#st{ct=[[Fail]|_]}}=Vst) when is_integer(Fail) ->
     %% Update branched state
     valfun_3(I, branch_state(Fail, Vst));
 valfun_2(_, _) ->
-    error(ambigous_catch_try_state).
+    error(ambiguous_catch_try_state).
 
 %% Handle the remaining floating point instructions here.
 %% Floating point.
@@ -574,6 +480,7 @@ valfun_4({apply,Live}, Vst) ->
 valfun_4({apply_last,Live,_}, Vst) ->
     tail_call(apply, Live+2, Vst);
 valfun_4({call_fun,Live}, Vst) ->
+    validate_src([{x,Live}], Vst),
     call('fun', Live+1, Vst);
 valfun_4({call,Live,Func}, Vst) ->
     call(Func, Live, Vst);
@@ -593,8 +500,6 @@ valfun_4({call_ext_last,Live,Func,StkSize},
     tail_call(Func, Live, Vst);
 valfun_4({call_ext_last,_,_,_}, #vst{current=#st{numy=NumY}}) ->
     error({allocated,NumY});
-valfun_4({make_fun,_,_,Live}, Vst) ->
-    call('fun', Live, Vst);
 valfun_4({make_fun2,_,_,_,Live}, Vst) ->
     call(make_fun, Live, Vst);
 %% Other BIFs
@@ -611,8 +516,9 @@ valfun_4({bif,element,{f,Fail},[Pos,Tuple],Dst}, Vst0) ->
     TupleType = upgrade_tuple_type({tuple,[get_tuple_size(PosType)]}, TupleType0),
     Vst = set_type(TupleType, Tuple, Vst1),
     set_type_reg(term, Dst, Vst);
-valfun_4({raise,{f,_}=Fail,Src,Dst}, Vst) ->
-    valfun_4({bif,raise,Fail,Src,Dst}, Vst);
+valfun_4({bif,raise,{f,0},Src,_Dst}, Vst) ->
+    validate_src(Src, Vst),
+    kill_state(Vst);
 valfun_4({bif,Op,{f,Fail},Src,Dst}, Vst0) ->
     validate_src(Src, Vst0),
     Vst = branch_state(Fail, Vst0),
@@ -628,6 +534,7 @@ valfun_4({gc_bif,Op,{f,Fail},Live,Src,Dst}, #vst{current=St0}=Vst0) ->
     Type = bif_type(Op, Src, Vst),
     set_type_reg(Type, Dst, Vst);
 valfun_4(return, #vst{current=#st{numy=none}}=Vst) ->
+    assert_term({x,0}, Vst),
     kill_state(Vst);
 valfun_4(return, #vst{current=#st{numy=NumY}}) ->
     error({stack_frame,NumY});
@@ -675,7 +582,7 @@ valfun_4({test,bs_start_match2,{f,Fail},Live,[Ctx,NeedSlots],Ctx}, Vst0) ->
     verify_live(Live, Vst0),
     Vst1 = prune_x_regs(Live, Vst0),
     BranchVst = case CtxType of
-		    {match_context,_,_} ->
+		    #ms{} ->
 			%% The failure branch will never be taken when Ctx
 			%% is a match context. Therefore, the type for Ctx
 			%% at the failure label must not be match_context
@@ -728,32 +635,6 @@ valfun_4({bs_save2,Ctx,SavePoint}, Vst) ->
 valfun_4({bs_restore2,Ctx,SavePoint}, Vst) ->
     bsm_restore(Ctx, SavePoint, Vst);
 
-%% Bit syntax instructions.
-valfun_4({bs_start_match,{f,_Fail}=F,Src}, Vst) ->
-    valfun_4({test,bs_start_match,F,[Src]}, Vst);
-valfun_4({test,bs_start_match,{f,Fail},[Src]}, Vst) ->
-    assert_term(Src, Vst),
-    bs_start_match(branch_state(Fail, Vst));
-
-valfun_4({bs_save,SavePoint}, Vst) ->
-    bs_assert_state(Vst),
-    bs_save(SavePoint, Vst);
-valfun_4({bs_restore,SavePoint}, Vst) ->
-    bs_assert_state(Vst),
-    bs_assert_savepoint(SavePoint, Vst),
-    Vst;
-valfun_4({test,bs_skip_bits,{f,Fail},[Src,_,_]}, Vst) ->
-    bs_assert_state(Vst),
-    assert_term(Src, Vst),
-    branch_state(Fail, Vst);
-valfun_4({test,bs_test_tail,{f,Fail},_}, Vst) ->
-    bs_assert_state(Vst),
-    branch_state(Fail, Vst);
-valfun_4({test,_,{f,Fail},[_,_,_,Dst]}, Vst0) ->
-    bs_assert_state(Vst0),
-    Vst = branch_state(Fail, Vst0),
-    set_type_reg({integer,[]}, Dst, Vst);
-
 %% Other test instructions.
 valfun_4({test,is_float,{f,Lbl},[Float]}, Vst) ->
     assert_term(Float, Vst),
@@ -768,6 +649,20 @@ valfun_4({test,is_nonempty_list,{f,Lbl},[Cons]}, Vst) ->
 valfun_4({test,test_arity,{f,Lbl},[Tuple,Sz]}, Vst) when is_integer(Sz) ->
     assert_type(tuple, Tuple, Vst),
     set_type_reg({tuple,Sz}, Tuple, branch_state(Lbl, Vst));
+valfun_4({test,has_map_fields,{f,Lbl},Src,{list,List}}, Vst) ->
+    assert_type(map, Src, Vst),
+    assert_unique_map_keys(List),
+    branch_state(Lbl, Vst);
+valfun_4({test,is_map,{f,Lbl},[Src]}, Vst0) ->
+    Vst = branch_state(Lbl, Vst0),
+    case Src of
+	{Tag,_} when Tag =:= x; Tag =:= y ->
+	    set_type_reg(map, Src, Vst);
+	{literal,Map} when is_map(Map) ->
+	    Vst;
+	_ ->
+	    kill_state(Vst)
+    end;
 valfun_4({test,_Op,{f,Lbl},Src}, Vst) ->
     validate_src(Src, Vst),
     branch_state(Lbl, Vst);
@@ -781,9 +676,6 @@ valfun_4({bs_utf8_size,{f,Fail},A,Dst}, Vst) ->
 valfun_4({bs_utf16_size,{f,Fail},A,Dst}, Vst) ->
     assert_term(A, Vst),
     set_type_reg({integer,[]}, Dst, branch_state(Fail, Vst));
-valfun_4({bs_bits_to_bytes,{f,Fail},Src,Dst}, Vst) ->
-    assert_term(Src, Vst),
-    set_type_reg({integer,[]}, Dst, branch_state(Fail, Vst));
 valfun_4({bs_init2,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     verify_live(Live, Vst0),
     if
@@ -794,8 +686,7 @@ valfun_4({bs_init2,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     end,
     Vst1 = heap_alloc(Heap, Vst0),
     Vst2 = branch_state(Fail, Vst1),
-    Vst3 = prune_x_regs(Live, Vst2),
-    Vst = bs_zero_bits(Vst3),
+    Vst = prune_x_regs(Live, Vst2),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_init_bits,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     verify_live(Live, Vst0),
@@ -807,8 +698,7 @@ valfun_4({bs_init_bits,{f,Fail},Sz,Heap,Live,_,Dst}, Vst0) ->
     end,
     Vst1 = heap_alloc(Heap, Vst0),
     Vst2 = branch_state(Fail, Vst1),
-    Vst3 = prune_x_regs(Live, Vst2),
-    Vst = bs_zero_bits(Vst3),
+    Vst = prune_x_regs(Live, Vst2),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_append,{f,Fail},Bits,Heap,Live,_Unit,Bin,_Flags,Dst}, Vst0) ->
     verify_live(Live, Vst0),
@@ -816,57 +706,84 @@ valfun_4({bs_append,{f,Fail},Bits,Heap,Live,_Unit,Bin,_Flags,Dst}, Vst0) ->
     assert_term(Bin, Vst0),
     Vst1 = heap_alloc(Heap, Vst0),
     Vst2 = branch_state(Fail, Vst1),
-    Vst3 = prune_x_regs(Live, Vst2),
-    Vst = bs_zero_bits(Vst3),
+    Vst = prune_x_regs(Live, Vst2),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_private_append,{f,Fail},Bits,_Unit,Bin,_Flags,Dst}, Vst0) ->
     assert_term(Bits, Vst0),
     assert_term(Bin, Vst0),
-    Vst1 = branch_state(Fail, Vst0),
-    Vst = bs_zero_bits(Vst1),
+    Vst = branch_state(Fail, Vst0),
     set_type_reg(binary, Dst, Vst);
 valfun_4({bs_put_string,Sz,_}, Vst) when is_integer(Sz) ->
     Vst;
-valfun_4({bs_put_binary,{f,Fail},Sz,_,_,Src}=I, Vst0) ->
-    assert_term(Sz, Vst0),
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_binary,{f,Fail},Sz,_,_,Src}, Vst) ->
+    assert_term(Sz, Vst),
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_float,{f,Fail},Sz,_,_,Src}=I, Vst0) ->
-    assert_term(Sz, Vst0),
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_float,{f,Fail},Sz,_,_,Src}, Vst) ->
+    assert_term(Sz, Vst),
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_integer,{f,Fail},Sz,_,_,Src}=I, Vst0) ->
-    assert_term(Sz, Vst0),
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_integer,{f,Fail},Sz,_,_,Src}, Vst) ->
+    assert_term(Sz, Vst),
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_utf8,{f,Fail},_,Src}=I, Vst0) ->
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_utf8,{f,Fail},_,Src}, Vst) ->
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_utf16,{f,Fail},_,Src}=I, Vst0) ->
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_utf16,{f,Fail},_,Src}, Vst) ->
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-valfun_4({bs_put_utf32,{f,Fail},_,Src}=I, Vst0) ->
-    assert_term(Src, Vst0),
-    Vst = bs_align_check(I, Vst0),
+valfun_4({bs_put_utf32,{f,Fail},_,Src}, Vst) ->
+    assert_term(Src, Vst),
     branch_state(Fail, Vst);
-%% Old bit syntax construction (before R10B).
-valfun_4({bs_init,_,_}, Vst) ->
-    bs_zero_bits(Vst);
-valfun_4({bs_need_buf,_}, Vst) -> Vst;
-valfun_4({bs_final,{f,Fail},Dst}, Vst0) ->
-    Vst = branch_state(Fail, Vst0),
-    set_type_reg(binary, Dst, Vst);
-valfun_4({bs_final2,Src,Dst}, Vst0) ->
-    assert_term(Src, Vst0),
-    set_type_reg(binary, Dst, Vst0);
+%% Map instructions.
+valfun_4({put_map_assoc,{f,Fail},Src,Dst,Live,{list,List}}, Vst) ->
+    verify_put_map(Fail, Src, Dst, Live, List, Vst);
+valfun_4({put_map_exact,{f,Fail},Src,Dst,Live,{list,List}}, Vst) ->
+    verify_put_map(Fail, Src, Dst, Live, List, Vst);
+valfun_4({get_map_elements,{f,Fail},Src,{list,List}}, Vst) ->
+    verify_get_map(Fail, Src, List, Vst);
 valfun_4(_, _) ->
     error(unknown_instruction).
 
+verify_get_map(Fail, Src, List, Vst0) ->
+    assert_type(map, Src, Vst0),
+    Vst1 = foldl(fun(D, Vsti) ->
+                         case is_reg_defined(D,Vsti) of
+                             true -> set_type_reg(term,D,Vsti);
+                             false -> Vsti
+                         end
+                 end, Vst0, extract_map_vals(List)),
+    Vst2 = branch_state(Fail, Vst1),
+    Keys = extract_map_keys(List),
+    assert_unique_map_keys(Keys),
+    verify_get_map_pair(List,Vst0,Vst2).
+
+extract_map_vals([_Key,Val|T]) ->
+    [Val|extract_map_vals(T)];
+extract_map_vals([]) -> [].
+
+extract_map_keys([Key,_Val|T]) ->
+    [Key|extract_map_keys(T)];
+extract_map_keys([]) -> [].
+
+verify_get_map_pair([],_,Vst) -> Vst;
+verify_get_map_pair([Src,Dst|Vs],Vst0,Vsti) ->
+    assert_term(Src, Vst0),
+    verify_get_map_pair(Vs,Vst0,set_type_reg(term,Dst,Vsti)).
+
+verify_put_map(Fail, Src, Dst, Live, List, Vst0) ->
+    assert_type(map, Src, Vst0),
+    verify_live(Live, Vst0),
+    verify_y_init(Vst0),
+    foreach(fun (Term) -> assert_term(Term, Vst0) end, List),
+    Vst1 = heap_alloc(0, Vst0),
+    Vst2 = branch_state(Fail, Vst1),
+    Vst = prune_x_regs(Live, Vst2),
+    Keys = extract_map_keys(List),
+    assert_unique_map_keys(Keys),
+    set_type_reg(map, Dst, Vst).
+
 %%
 %% Common code for validating bs_get* instructions.
 %%
@@ -887,15 +804,12 @@ validate_bs_skip_utf(Fail, Ctx, Live, Vst0) ->
     branch_state(Fail, Vst).
 
 %%
-%% Special state handling for setelement/3 and the set_tuple_element/3 instruction.
+%% Special state handling for setelement/3 and set_tuple_element/3 instructions.
 %% A possibility for garbage collection must not occur between setelement/3 and
 %% set_tuple_element/3.
 %%
 val_dsetel({move,_,_}, Vst) ->
     Vst;
-val_dsetel({put_string,0,{string,""},_}, Vst) ->
-    %% An empty string is OK since it doesn't build anything.
-    Vst;
 val_dsetel({call_ext,3,{extfunc,erlang,setelement,3}}, #vst{current=St}=Vst) ->
     Vst#vst{current=St#st{setelem=true}};
 val_dsetel({set_tuple_element,_,_,_}, #vst{current=#st{setelem=false}}) ->
@@ -923,56 +837,86 @@ kill_state_1(Vst) ->
 %%  The stackframe must be initialized.
 %%  The instruction will return to the instruction following the call.
 call(Name, Live, #vst{current=St}=Vst) ->
-    verify_live(Live, Vst),
+    verify_call_args(Name, Live, Vst),
     verify_y_init(Vst),
     case return_type(Name, Vst) of
 	Type when Type =/= exception ->
 	    %% Type is never 'exception' because it has been handled earlier.
 	    Xs = gb_trees_from_list([{0,Type}]),
-	    Vst#vst{current=St#st{x=Xs,f=init_fregs(),bsm=undefined}}
+	    Vst#vst{current=St#st{x=Xs,f=init_fregs()}}
     end.
 
 %% Tail call.
 %%  The stackframe must have a known size and be initialized.
 %%  Does not return to the instruction following the call.
-tail_call(Name, Live, Vst) ->
+tail_call(Name, Live, Vst0) ->
+    verify_y_init(Vst0),
+    Vst = deallocate(Vst0),
     verify_call_args(Name, Live, Vst),
-    verify_y_init(Vst),
     verify_no_ct(Vst),
     kill_state(Vst).
 
 verify_call_args(_, 0, #vst{}) ->
     ok;
 verify_call_args({f,Lbl}, Live, Vst) when is_integer(Live)->
-    Verify = fun(R) ->
-		     case get_move_term_type(R, Vst) of
-			 {match_context,_,_} ->
-			     verify_call_match_context(Lbl, Vst);
-			 _ ->
-			     ok
-		     end
-	     end,
-    verify_call_args_1(Live, Verify, Vst);
+    verify_local_call(Lbl, Live, Vst);
 verify_call_args(_, Live, Vst) when is_integer(Live)->
-    Verify = fun(R) -> get_term_type(R, Vst) end,
-    verify_call_args_1(Live, Verify, Vst);
+    verify_call_args_1(Live, Vst);
 verify_call_args(_, Live, _) ->
     error({bad_number_of_live_regs,Live}).
 
-verify_call_args_1(0, _, _) -> ok;
-verify_call_args_1(N, Verify, Vst) ->
+verify_call_args_1(0, _) -> ok;
+verify_call_args_1(N, Vst) ->
     X = N - 1,
-    Verify({x,X}),
-    verify_call_args_1(X, Verify, Vst).
+    get_term_type({x,X}, Vst),
+    verify_call_args_1(X, Vst).
+
+verify_local_call(Lbl, Live, Vst) ->
+    case all_ms_in_x_regs(Live, Vst) of
+	[{R,Ctx}] ->
+	    %% Verify that there is a suitable bs_start_match2 instruction.
+	    verify_call_match_context(Lbl, R, Vst),
+
+	    %% Since the callee has consumed the match context,
+	    %% there must be no additional copies in Y registers.
+	    #ms{id=Id} = Ctx,
+	    case ms_in_y_regs(Id, Vst) of
+		[] ->
+		    ok;
+		[_|_]=Ys ->
+		    error({multiple_match_contexts,[R|Ys]})
+	    end;
+	[_,_|_]=Xs0 ->
+	    Xs = [R || {R,_} <- Xs0],
+	    error({multiple_match_contexts,Xs});
+	[] ->
+	    ok
+    end.
+
+all_ms_in_x_regs(0, _Vst) ->
+    [];
+all_ms_in_x_regs(Live0, Vst) ->
+    Live = Live0 - 1,
+    R = {x,Live},
+    case get_move_term_type(R, Vst) of
+	#ms{}=M ->
+	    [{R,M}|all_ms_in_x_regs(Live, Vst)];
+	_ ->
+	    all_ms_in_x_regs(Live, Vst)
+    end.
 
-verify_call_match_context(Lbl, #vst{ft=Ft}) ->
+ms_in_y_regs(Id, #vst{current=#st{y=Ys0}}) ->
+    Ys = gb_trees:to_list(Ys0),
+    [Y || {Y,#ms{id=OtherId}} <- Ys, OtherId =:= Id].
+
+verify_call_match_context(Lbl, Ctx, #vst{ft=Ft}) ->
     case gb_trees:lookup(Lbl, Ft) of
 	none ->
 	    error(no_bs_start_match2);
 	{value,[{test,bs_start_match2,_,_,[Ctx,_],Ctx}|_]} ->
 	    ok;
-	{value,[{test,bs_start_match2,_,_,[Bin,_,_],Ctx}|_]} ->
-	    error({binary_and_context_regs_different,Bin,Ctx})
+	{value,[{test,bs_start_match2,_,_,_,_}=I|_]} ->
+	    error({unsuitable_bs_start_match2,I})
     end.
 
 allocate(Zero, Stk, Heap, Live, #vst{current=#st{numy=none}=St}=Vst0) ->
@@ -987,7 +931,7 @@ allocate(_, _, _, _, #vst{current=#st{numy=Numy}}) ->
     error({existing_stack_frame,{size,Numy}}).
 
 deallocate(#vst{current=St}=Vst) ->
-    Vst#vst{current=St#st{y=init_regs(0, initialized),numy=none,bsm=undefined}}.
+    Vst#vst{current=St#st{y=init_regs(0, initialized),numy=none}}.
 
 test_heap(Heap, Live, Vst0) ->
     verify_live(Live, Vst0),
@@ -995,7 +939,7 @@ test_heap(Heap, Live, Vst0) ->
     heap_alloc(Heap, Vst).
 
 heap_alloc(Heap, #vst{current=St0}=Vst) ->
-    St1 = kill_heap_allocation(St0#st{bsm=undefined}),
+    St1 = kill_heap_allocation(St0),
     St = heap_alloc_1(Heap, St1),
     Vst#vst{current=St}.
 
@@ -1056,9 +1000,9 @@ get_fls(#vst{current=#st{fls=Fls}}) when is_atom(Fls) -> Fls.
 
 init_fregs() -> 0.
 
-set_freg({fr,Fr}, #vst{current=#st{f=Fregs0}=St}=Vst)
+set_freg({fr,Fr}=Freg, #vst{current=#st{f=Fregs0}=St}=Vst)
   when is_integer(Fr), 0 =< Fr ->
-    limit_check(Fr),
+    check_limit(Freg),
     Bit = 1 bsl Fr,
     if
 	Fregs0 band Bit =:= 0 ->
@@ -1071,54 +1015,40 @@ set_freg(Fr, _) -> error({bad_target,Fr}).
 assert_freg_set({fr,Fr}=Freg, #vst{current=#st{f=Fregs}})
   when is_integer(Fr), 0 =< Fr ->
     if
-	Fregs band (1 bsl Fr) =/= 0 ->
-	    limit_check(Fr);
-	true -> error({uninitialized_reg,Freg})
+	(Fregs bsr Fr) band 1 =:= 0 ->
+	    error({uninitialized_reg,Freg});
+	true ->
+	    ok
     end;
 assert_freg_set(Fr, _) -> error({bad_source,Fr}).
 
-%%%
-%%% Binary matching.
-%%%
-%%% Possible values for the bsm field (=bit syntax matching state).
-%%%
-%%% undefined 	- Undefined (initial state). No matching instructions allowed.
-%%%		 
-%%% (gb set)	- The gb set contains the defined save points.
-%%%
-%%% The bsm field is reset to 'undefined' by instructions that may cause a
-%%% a garbage collection (might move the binary) and/or context switch
-%%% (may invalidate the save points).
-
-bs_start_match(#vst{current=#st{bsm=undefined}=St}=Vst) ->
-    Vst#vst{current=St#st{bsm=gb_sets:empty()}};
-bs_start_match(Vst) ->
-    %% Must retain save points here - it is possible to restore back
-    %% to a previous binary.
-    Vst.
-
-bs_save(Reg, #vst{current=#st{bsm=Saved}=St}=Vst)
-  when is_integer(Reg), Reg < ?MAXREG  ->
-    Vst#vst{current=St#st{bsm=gb_sets:add(Reg, Saved)}};
-bs_save(_, _) -> error(limit).
-
-bs_assert_savepoint(Reg, #vst{current=#st{bsm=Saved}}) ->
-    case gb_sets:is_member(Reg, Saved) of
-	false -> error({no_save_point,Reg});
-	true -> ok
-    end.
+%%% Maps
 
-bs_assert_state(#vst{current=#st{bsm=undefined}}) ->
-    error(no_bs_match_state);
-bs_assert_state(_) -> ok.
+%% A single item list may be either a list or a register.
+%%
+%% A list with more than item must contain unique literals.
+%%
+%% An empty list is not allowed.
 
+assert_unique_map_keys([]) ->
+    %% There is no reason to use the get_map_elements and
+    %% has_map_fields instructions with empty lists.
+    error(empty_field_list);
+assert_unique_map_keys([_]) ->
+    ok;
+assert_unique_map_keys([_,_|_]=Ls) ->
+    Vs = [get_literal(L) || L <- Ls],
+    case length(Vs) =:= sets:size(sets:from_list(Vs)) of
+	true -> ok;
+	false -> error(keys_not_unique)
+    end.
 
 %%%
 %%% New binary matching instructions.
 %%%
 
 bsm_match_state(Slots) ->
-    {match_context,0,Slots}.
+    #ms{slots=Slots}.
 
 bsm_validate_context(Reg, Vst) ->
     _ = bsm_get_context(Reg, Vst),
@@ -1126,7 +1056,7 @@ bsm_validate_context(Reg, Vst) ->
 
 bsm_get_context({x,X}=Reg, #vst{current=#st{x=Xs}}=_Vst) when is_integer(X) ->
     case gb_trees:lookup(X, Xs) of
-	{value,{match_context,_,_}=Ctx} -> Ctx;
+	{value,#ms{}=Ctx} -> Ctx;
 	_ -> error({no_bsm_context,Reg})
     end;
 bsm_get_context(Reg, _) -> error({bad_source,Reg}).
@@ -1138,8 +1068,8 @@ bsm_save(Reg, {atom,start}, Vst) ->
     Vst;
 bsm_save(Reg, SavePoint, Vst) ->
     case bsm_get_context(Reg, Vst) of
-	{match_context,Bits,Slots} when SavePoint < Slots ->
-	    Ctx = {match_context,Bits bor (1 bsl SavePoint),Slots},
+	#ms{valid=Bits,slots=Slots}=Ctxt0 when SavePoint < Slots ->
+	    Ctx = Ctxt0#ms{valid=Bits bor (1 bsl SavePoint),slots=Slots},
 	    set_type_reg(Ctx, Reg, Vst);
 	_ -> error({illegal_save,SavePoint})
     end.
@@ -1151,63 +1081,15 @@ bsm_restore(Reg, {atom,start}, Vst) ->
     Vst;
 bsm_restore(Reg, SavePoint, Vst) ->
     case bsm_get_context(Reg, Vst) of
-	{match_context,Bits,Slots} when SavePoint < Slots ->
+	#ms{valid=Bits,slots=Slots} when SavePoint < Slots ->
 	    case Bits band (1 bsl SavePoint) of
 		0 -> error({illegal_restore,SavePoint,not_set});
 		_ -> Vst
 	    end;
 	_ -> error({illegal_restore,SavePoint,range})
     end.
-    
 
 %%%
-%%% Validation of alignment in the bit syntax. (Currently, construction only.)
-%%%
-%%% We make sure that the aligned flag is only set when we can be sure of the
-%%% aligment.
-%%%
-
-bs_zero_bits(#vst{current=St}=Vst) ->
-    Vst#vst{current=St#st{bits=0}}.
-
-bs_align_check({bs_put_utf8,_,Flags,_}, #vst{current=#st{}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    Vst;
-bs_align_check({bs_put_utf16,_,Flags,_}, #vst{current=#st{}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    Vst;
-bs_align_check({bs_put_utf32,_,Flags,_}, #vst{current=#st{}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    Vst;
-bs_align_check({_,_,Sz,U,Flags,_}, #vst{current=#st{bits=Bits}=St}=Vst) ->
-    bs_verify_flags(Flags, St),
-    bs_update_bits(Bits, Sz, U, St, Vst).
-
-bs_update_bits(undefined, _, _, _, Vst) -> Vst;
-bs_update_bits(Bits0, {integer,Sz}, U, St, Vst) ->
-    Bits = Bits0 + U*Sz,
-    Vst#vst{current=St#st{bits=Bits}};
-bs_update_bits(_, {atom,all}, _, _, Vst) ->
-    %% A binary will not change the alignment.
-    Vst;
-bs_update_bits(_, _, U, _, Vst) when U rem 8 =:= 0 ->
-    %% Units of 8, 16, and so on will not change the aligment.
-    Vst;
-bs_update_bits(_, _, _, St, Vst) ->
-    %% We can no longer be sure about aligment.
-    Vst#vst{current=St#st{bits=undefined}}.
-
-bs_verify_flags({field_flags,Fl}, #st{bits=Bits}) ->
-    case bs_is_aligned(Fl) of
-	false -> ok;
-	true when is_integer(Bits), Bits rem 8 =:= 0 -> ok;
-	true -> error({aligned_flag_set,{bits,Bits}})
-    end.
-
-bs_is_aligned(Fl) when is_integer(Fl) -> Fl band 1 =:= 1;
-bs_is_aligned(Fl) when is_list(Fl) -> member(aligned, Fl).
-    
-%%%
 %%% Keeping track of types.
 %%%
 
@@ -1215,42 +1097,44 @@ set_type(Type, {x,_}=Reg, Vst) -> set_type_reg(Type, Reg, Vst);
 set_type(Type, {y,_}=Reg, Vst) -> set_type_y(Type, Reg, Vst);
 set_type(_, _, #vst{}=Vst) -> Vst.
 
-set_type_reg(Type, {x,X}, #vst{current=#st{x=Xs}=St}=Vst) 
+set_type_reg(Type, {x,X}=Reg, #vst{current=#st{x=Xs}=St}=Vst)
   when is_integer(X), 0 =< X ->
-    limit_check(X),
+    check_limit(Reg),
     Vst#vst{current=St#st{x=gb_trees:enter(X, Type, Xs)}};
 set_type_reg(Type, Reg, Vst) ->
     set_type_y(Type, Reg, Vst).
 
-set_type_y(Type, {y,Y}=Reg, #vst{current=#st{y=Ys0,numy=NumY}=St}=Vst) 
+set_type_y(Type, {y,Y}=Reg, #vst{current=#st{y=Ys0}=St}=Vst)
   when is_integer(Y), 0 =< Y ->
-    limit_check(Y),
-    case {Y,NumY} of
-	{_,none} ->
-	    error({no_stack_frame,Reg});
-	{_,_} when Y > NumY ->
-	    error({y_reg_out_of_range,Reg,NumY});
-	{_,_} ->
-	    Ys = if  Type =:= initialized_ct ->
-			 gb_trees:enter(Y, initialized, Ys0);
-		     true ->
-			 case gb_trees:lookup(Y, Ys0) of
-			     none -> 
-				 gb_trees:insert(Y, Type, Ys0);
-			     {value,uinitialized} ->
-				 gb_trees:insert(Y, Type, Ys0);
-			     {value,{catchtag,_}=Tag} ->
-				 error(Tag);
-			     {value,{trytag,_}=Tag} ->
-				 error(Tag);
-			     {value,_} ->
-				 gb_trees:update(Y, Type, Ys0)
-			 end
-		 end,
-	    Vst#vst{current=St#st{y=Ys}}
-    end;
+    check_limit(Reg),
+    Ys = case gb_trees:lookup(Y, Ys0) of
+	     none ->
+		 error({invalid_store,Reg,Type});
+	     {value,{catchtag,_}=Tag} ->
+		 error(Tag);
+	     {value,{trytag,_}=Tag} ->
+		 error(Tag);
+	     {value,_} ->
+		 gb_trees:update(Y, Type, Ys0)
+	 end,
+    Vst#vst{current=St#st{y=Ys}};
 set_type_y(Type, Reg, #vst{}) -> error({invalid_store,Reg,Type}).
 
+set_catch_end({y,Y}, #vst{current=#st{y=Ys0}=St}=Vst) ->
+    Ys = gb_trees:update(Y, initialized, Ys0),
+    Vst#vst{current=St#st{y=Ys}}.
+
+
+is_reg_defined({x,_}=Reg, Vst) -> is_type_defined_x(Reg, Vst);
+is_reg_defined({y,_}=Reg, Vst) -> is_type_defined_y(Reg, Vst);
+is_reg_defined(V, #vst{}) -> error({not_a_register, V}).
+
+is_type_defined_x({x,X}, #vst{current=#st{x=Xs}}) ->
+    gb_trees:is_defined(X,Xs).
+
+is_type_defined_y({y,Y}, #vst{current=#st{y=Ys}}) ->
+    gb_trees:is_defined(Y,Ys).
+
 assert_term(Src, Vst) ->
     get_term_type(Src, Vst),
     ok.
@@ -1278,7 +1162,7 @@ assert_term(Src, Vst) ->
 %%			Thus 'exception' is never stored as type descriptor
 %%			for a register.
 %%
-%% {match_context,_,_}	A matching context for bit syntax matching. We do allow
+%% #ms{}	        A match context for bit syntax matching. We do allow
 %%			it to moved/to from stack, but otherwise it must only
 %%			be accessed by bit syntax matching instructions.
 %%
@@ -1311,6 +1195,8 @@ assert_term(Src, Vst) ->
 %%
 %% number		Integer or Float of unknown value
 %%
+%% map			Map.
+%%
 
 assert_type(WantedType, Term, Vst) ->
     assert_type(WantedType, get_term_type(Term, Vst)).
@@ -1318,16 +1204,20 @@ assert_type(WantedType, Term, Vst) ->
 assert_type(Correct, Correct) -> ok;
 assert_type(float, {float,_}) -> ok;
 assert_type(tuple, {tuple,_}) -> ok;
+assert_type(tuple, {literal,Tuple}) when is_tuple(Tuple) -> ok;
 assert_type({tuple_element,I}, {tuple,[Sz]})
   when 1 =< I, I =< Sz ->
     ok;
 assert_type({tuple_element,I}, {tuple,Sz})
   when is_integer(Sz), 1 =< I, I =< Sz ->
     ok;
+assert_type({tuple_element,I}, {literal,Lit}) when I =< tuple_size(Lit) ->
+    ok;
+assert_type(cons, {literal,[_|_]}) ->
+    ok;
 assert_type(Needed, Actual) ->
     error({bad_type,{needed,Needed},{actual,Actual}}).
 
-
 %% upgrade_tuple_type(NewTupleType, OldType) -> TupleType.
 %%  upgrade_tuple_type/2 is used when linear code finds out more and
 %%  more information about a tuple type, so that the type gets more
@@ -1379,7 +1269,7 @@ get_term_type(Src, Vst) ->
 	initialized -> error({unassigned,Src});
 	{catchtag,_} -> error({catchtag,Src});
 	{trytag,_} -> error({trytag,Src});
-	{match_context,_,_} -> error({match_context,Src});
+	#ms{} -> error({match_context,Src});
 	Type -> Type
     end.
 
@@ -1393,6 +1283,7 @@ get_term_type_1(nil=T, _) -> T;
 get_term_type_1({atom,A}=T, _) when is_atom(A) -> T;
 get_term_type_1({float,F}=T, _) when is_float(F) -> T;
 get_term_type_1({integer,I}=T, _) when is_integer(I) -> T;
+get_term_type_1({literal,Map}, _) when is_map(Map) -> map;
 get_term_type_1({literal,_}=T, _) -> T;
 get_term_type_1({x,X}=Reg, #vst{current=#st{x=Xs}}) when is_integer(X) ->
     case gb_trees:lookup(X, Xs) of
@@ -1408,6 +1299,15 @@ get_term_type_1({y,Y}=Reg, #vst{current=#st{y=Ys}}) when is_integer(Y) ->
 get_term_type_1(Src, _) -> error({bad_source,Src}).
 
 
+%% get_literal(Src) -> literal_value().
+get_literal(nil) -> [];
+get_literal({atom,A}) when is_atom(A) -> A;
+get_literal({float,F}) when is_float(F) -> F;
+get_literal({integer,I}) when is_integer(I) -> I;
+get_literal({literal,L}) -> L;
+get_literal(T) -> error({not_literal,T}).
+
+
 branch_arities([], _, #vst{}=Vst) -> Vst;
 branch_arities([Sz,{f,L}|T], Tuple, #vst{current=St}=Vst0) 
   when is_integer(Sz) ->
@@ -1438,14 +1338,13 @@ merge_states(L, St, Branched) when L =/= 0 ->
 	{value,OtherSt} -> merge_states_1(St, OtherSt)
     end.
 
-merge_states_1(#st{x=Xs0,y=Ys0,numy=NumY0,h=H0,ct=Ct0,bsm=Bsm0}=St,
-	       #st{x=Xs1,y=Ys1,numy=NumY1,h=H1,ct=Ct1,bsm=Bsm1}) ->
+merge_states_1(#st{x=Xs0,y=Ys0,numy=NumY0,h=H0,ct=Ct0},
+	       #st{x=Xs1,y=Ys1,numy=NumY1,h=H1,ct=Ct1}) ->
     NumY = merge_stk(NumY0, NumY1),
     Xs = merge_regs(Xs0, Xs1),
     Ys = merge_y_regs(Ys0, Ys1),
     Ct = merge_ct(Ct0, Ct1),
-    Bsm = merge_bsm(Bsm0, Bsm1),
-    St#st{x=Xs,y=Ys,numy=NumY,h=min(H0, H1),ct=Ct,bsm=Bsm}.
+    #st{x=Xs,y=Ys,numy=NumY,h=min(H0, H1),ct=Ct}.
 
 merge_stk(S, S) -> S;
 merge_stk(_, _) -> undecided.
@@ -1475,20 +1374,24 @@ merge_regs_1([], [_|_]) -> [];
 merge_regs_1([_|_], []) -> [].
 
 merge_y_regs(Rs0, Rs1) ->
-    Rs = merge_y_regs_1(gb_trees:to_list(Rs0), gb_trees:to_list(Rs1)),
-    gb_trees_from_list(Rs).
+    case {gb_trees:size(Rs0),gb_trees:size(Rs1)} of
+	{Sz0,Sz1} when Sz0 < Sz1 ->
+	    merge_y_regs_1(Sz0-1, Rs1, Rs0);
+	{_,Sz1} ->
+	    merge_y_regs_1(Sz1-1, Rs0, Rs1)
+    end.
 
-merge_y_regs_1([Same|Rs1], [Same|Rs2]) ->
-    [Same|merge_y_regs_1(Rs1, Rs2)];
-merge_y_regs_1([{R1,_}|Rs1], [{R2,_}|_]=Rs2) when R1 < R2 ->
-    [{R1,uninitialized}|merge_y_regs_1(Rs1, Rs2)];
-merge_y_regs_1([{R1,_}|_]=Rs1, [{R2,_}|Rs2]) when R1 > R2 ->
-    [{R2,uninitialized}|merge_y_regs_1(Rs1, Rs2)];
-merge_y_regs_1([{R,Type1}|Rs1], [{R,Type2}|Rs2]) ->
-    [{R,merge_types(Type1, Type2)}|merge_y_regs_1(Rs1, Rs2)];
-merge_y_regs_1([], []) -> [];
-merge_y_regs_1([], [_|_]=Rs) -> Rs;
-merge_y_regs_1([_|_]=Rs, []) -> Rs.
+merge_y_regs_1(Y, S, Regs0) when Y >= 0 ->
+    Type0 = gb_trees:get(Y, Regs0),
+    case gb_trees:get(Y, S) of
+	Type0 ->
+	    merge_y_regs_1(Y-1, S, Regs0);
+	Type1 ->
+	    Type = merge_types(Type0, Type1),
+	    Regs = gb_trees:update(Y, Type, Regs0),
+	    merge_y_regs_1(Y-1, S, Regs)
+    end;
+merge_y_regs_1(_, _, Regs) -> Regs.
 
 %% merge_types(Type1, Type2) -> Type
 %%  Return the most specific type possible.
@@ -1518,20 +1421,17 @@ merge_types(bool, {atom,A}) ->
     merge_bool(A);
 merge_types({atom,A}, bool) ->
     merge_bool(A);
-merge_types({match_context,B0,Slots},{match_context,B1,Slots}) ->
-    {match_context,B0 bor B1,Slots};
-merge_types({match_context,_,_}=M, _) ->
+merge_types(#ms{id=Id,valid=B0,slots=Slots}=M,
+	    #ms{id=Id,valid=B1,slots=Slots}) ->
+    M#ms{valid=B0 bor B1,slots=Slots};
+merge_types(#ms{}=M, _) ->
     M;
-merge_types(_, {match_context,_,_}=M) ->
+merge_types(_, #ms{}=M) ->
     M;
 merge_types(T1, T2) when T1 =/= T2 ->
     %% Too different. All we know is that the type is a 'term'.
     term.
 
-merge_bsm(undefined, _) -> undefined;
-merge_bsm(_, undefined) -> undefined;
-merge_bsm(Bsm0, Bsm1) -> gb_sets:intersection(Bsm0, Bsm1).
-
 tuple_sz([Sz]) -> Sz;
 tuple_sz(Sz) -> Sz.
 
@@ -1638,6 +1538,7 @@ bif_type(is_float, [_], _) -> bool;
 bif_type(is_function, [_], _) -> bool;
 bif_type(is_integer, [_], _) -> bool;
 bif_type(is_list, [_], _) -> bool;
+bif_type(is_map, [_], _) -> bool;
 bif_type(is_number, [_], _) -> bool;
 bif_type(is_pid, [_], _) -> bool;
 bif_type(is_port, [_], _) -> bool;
@@ -1649,7 +1550,6 @@ bif_type(node, [_], _) -> {atom,[]};
 bif_type(hd, [_], _) -> term;
 bif_type(tl, [_], _) -> term;
 bif_type(get, [_], _) -> term;
-bif_type(raise, [_,_], _) -> exception;
 bif_type(Bif, _, _) when is_atom(Bif) -> term.
 
 is_bif_safe('/=', 2) -> true;
@@ -1663,10 +1563,12 @@ is_bif_safe('>=', 2) -> true;
 is_bif_safe(is_atom, 1) -> true;
 is_bif_safe(is_boolean, 1) -> true;
 is_bif_safe(is_binary, 1) -> true;
+is_bif_safe(is_bitstring, 1) -> true;
 is_bif_safe(is_float, 1) -> true;
 is_bif_safe(is_function, 1) -> true;
 is_bif_safe(is_integer, 1) -> true;
 is_bif_safe(is_list, 1) -> true;
+is_bif_safe(is_map, 1) -> true;
 is_bif_safe(is_number, 1) -> true;
 is_bif_safe(is_pid, 1) -> true;
 is_bif_safe(is_port, 1) -> true;
@@ -1692,8 +1594,12 @@ return_type_1(erlang, setelement, 3, Vst) ->
     Tuple = {x,1},
     TupleType =
 	case get_term_type(Tuple, Vst) of
-	    {tuple,_}=TT -> TT;
-	    _ -> {tuple,[0]}
+	    {tuple,_}=TT ->
+		TT;
+	    {literal,Lit} when is_tuple(Lit) ->
+		{tuple,tuple_size(Lit)};
+	    _ ->
+		{tuple,[0]}
 	end,
     case get_term_type({x,0}, Vst) of
 	{integer,[]} -> TupleType;
@@ -1709,8 +1615,6 @@ return_type_1(M, F, A, _) when is_atom(M), is_atom(F), is_integer(A), A >= 0 ->
 
 return_type_erl(exit, 1) -> exception;
 return_type_erl(throw, 1) -> exception;
-return_type_erl(fault, 1) -> exception;
-return_type_erl(fault, 2) -> exception;
 return_type_erl(error, 1) -> exception;
 return_type_erl(error, 2) -> exception;
 return_type_erl(F, A) when is_atom(F), is_integer(A), A >= 0 -> term.
@@ -1731,6 +1635,7 @@ return_type_math(erf, 1) -> {float,[]};
 return_type_math(erfc, 1) -> {float,[]};
 return_type_math(exp, 1) -> {float,[]};
 return_type_math(log, 1) -> {float,[]};
+return_type_math(log2, 1) -> {float,[]};
 return_type_math(log10, 1) -> {float,[]};
 return_type_math(sqrt, 1) -> {float,[]};
 return_type_math(atan2, 2) -> {float,[]};
@@ -1738,66 +1643,19 @@ return_type_math(pow, 2) -> {float,[]};
 return_type_math(pi, 0) -> {float,[]};
 return_type_math(F, A) when is_atom(F), is_integer(A), A >= 0 -> term.
 
-limit_check(Num) when is_integer(Num), Num >= ?MAXREG ->
-    error(limit);
-limit_check(_) -> ok.
+check_limit({x,X}) when is_integer(X), X < 1023 ->
+    %% Note: x(1023) is reserved for use by the BEAM loader.
+    ok;
+check_limit({y,Y}) when is_integer(Y), Y < 1024 ->
+    ok;
+check_limit({fr,Fr}) when is_integer(Fr), Fr < 1024 ->
+    ok;
+check_limit(_) ->
+    error(limit).
 
 min(A, B) when is_integer(A), is_integer(B), A < B -> A;
 min(A, B) when is_integer(A), is_integer(B) -> B.
 
 gb_trees_from_list(L) -> gb_trees:from_orddict(lists:sort(L)).
 
--ifdef(DEBUG).
-error(Error) -> exit(Error).
--else.
 error(Error) -> throw(Error).
--endif.
-
-
-%%%
-%%% Rewrite disassembled code to the same format as we used internally
-%%% to not have to worry later.
-%%%
-
-normalize_disassembled_code(Fs) ->
-    Index = ndc_index(Fs, []),
-    ndc(Fs, Index, []).
-
-ndc_index([{function,Name,Arity,Entry,_Code}|Fs], Acc) ->
-    ndc_index(Fs, [{{Name,Arity},Entry}|Acc]);
-ndc_index([], Acc) ->
-    gb_trees:from_orddict(lists:sort(Acc)).
-
-ndc([{function,Name,Arity,Entry,Code0}|Fs], D, Acc) ->
-    Code = ndc_1(Code0, D, []),
-    ndc(Fs, D, [{function,Name,Arity,Entry,Code}|Acc]);
-ndc([], _, Acc) -> reverse(Acc).
-    
-ndc_1([{call=Op,A,{_,F,A}}|Is], D, Acc) ->
-    ndc_1(Is, D, [{Op,A,{f,gb_trees:get({F,A}, D)}}|Acc]);
-ndc_1([{call_only=Op,A,{_,F,A}}|Is], D, Acc) ->
-    ndc_1(Is, D, [{Op,A,{f,gb_trees:get({F,A}, D)}}|Acc]);
-ndc_1([{call_last=Op,A,{_,F,A},Sz}|Is], D, Acc) ->
-    ndc_1(Is, D, [{Op,A,{f,gb_trees:get({F,A}, D)},Sz}|Acc]);
-ndc_1([{arithbif,Op,F,Src,Dst}|Is], D, Acc) ->
-    ndc_1(Is, D, [{bif,Op,F,Src,Dst}|Acc]);
-ndc_1([{arithfbif,Op,F,Src,Dst}|Is], D, Acc) ->
-    ndc_1(Is, D, [{bif,Op,F,Src,Dst}|Acc]);
-ndc_1([{test,bs_start_match2=Op,F,[A1,Live,A3,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3],Dst}|Acc]);
-ndc_1([{test,bs_get_binary2=Op,F,[A1,Live,A3,A4,A5,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3,A4,A5],Dst}|Acc]);
-ndc_1([{test,bs_get_float2=Op,F,[A1,Live,A3,A4,A5,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3,A4,A5],Dst}|Acc]);
-ndc_1([{test,bs_get_integer2=Op,F,[A1,Live,A3,A4,A5,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3,A4,A5],Dst}|Acc]);
-ndc_1([{test,bs_get_utf8=Op,F,[A1,Live,A3,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3],Dst}|Acc]);
-ndc_1([{test,bs_get_utf16=Op,F,[A1,Live,A3,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3],Dst}|Acc]);
-ndc_1([{test,bs_get_utf32=Op,F,[A1,Live,A3,Dst]}|Is], D, Acc) ->
-    ndc_1(Is, D, [{test,Op,F,Live,[A1,A3],Dst}|Acc]);
-ndc_1([I|Is], D, Acc) ->
-    ndc_1(Is, D, [I|Acc]);
-ndc_1([], _, Acc) ->
-    reverse(Acc).
diff --git a/lib/compiler/src/beam_z.erl b/lib/compiler/src/beam_z.erl
index 8c6b0c916d..6c7f8543c2 100644
--- a/lib/compiler/src/beam_z.erl
+++ b/lib/compiler/src/beam_z.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2012. All Rights Reserved.
+%% Copyright Ericsson AB 2012-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -23,6 +24,8 @@
 
 -export([module/2]).
 
+-import(lists, [dropwhile/2]).
+
 module({Mod,Exp,Attr,Fs0,Lc}, _Opt) ->
     Fs = [function(F) || F <- Fs0],
     {ok,{Mod,Exp,Attr,Fs,Lc}}.
@@ -50,6 +53,16 @@ undo_renames([{call,A,F},return|Is]) ->
     [{call_only,A,F}|undo_renames(Is)];
 undo_renames([{call_ext,A,F},return|Is]) ->
     [{call_ext_only,A,F}|undo_renames(Is)];
+undo_renames([{bif,raise,_,_,_}=I|Is0]) ->
+    %% A minor optimization. Done here because:
+    %%  (1) beam_jump may move or share 'raise' instructions, and that
+    %%      may confuse beam_validator.
+    %%  (2) beam_trim cannot do its optimization if the 'deallocate'
+    %%      instruction after 'raise' has been removed.
+    Is = dropwhile(fun({label,_}) -> false;
+		      (_) -> true
+		   end, Is0),
+    [I|undo_renames(Is)];
 undo_renames([I|Is]) ->
     [undo_rename(I)|undo_renames(Is)];
 undo_renames([]) -> [].
@@ -74,6 +87,21 @@ undo_rename({bs_init,F,{I,Extra,U,Flags},Live,[Sz,Src],Dst}) ->
     {I,F,Sz,Extra,Live,U,Src,Flags,Dst};
 undo_rename({bs_init,_,bs_init_writable=I,_,_,_}) ->
     I;
+undo_rename({test,bs_match_string=Op,F,[Ctx,Bin0]}) ->
+    Bits = bit_size(Bin0),
+    Bin = case Bits rem 8 of
+	      0 -> Bin0;
+	      Rem -> <<Bin0/bitstring,0:(8-Rem)>>
+	  end,
+    {test,Op,F,[Ctx,Bits,{string,binary_to_list(Bin)}]};
+undo_rename({put_map,Fail,assoc,S,D,R,L}) ->
+    {put_map_assoc,Fail,S,D,R,L};
+undo_rename({put_map,Fail,exact,S,D,R,L}) ->
+    {put_map_exact,Fail,S,D,R,L};
+undo_rename({test,has_map_fields,Fail,[Src|List]}) ->
+    {test,has_map_fields,Fail,Src,{list,List}};
+undo_rename({get_map_elements,Fail,Src,{list,List}}) ->
+    {get_map_elements,Fail,Src,{list,List}};
 undo_rename({select,I,Reg,Fail,List}) ->
     {I,Reg,Fail,{list,List}};
 undo_rename(I) -> I.
diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl
index 4b74d60e9f..61abae344c 100644
--- a/lib/compiler/src/cerl.erl
+++ b/lib/compiler/src/cerl.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2001-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 
@@ -120,15 +121,28 @@
 	 update_c_bitstr/5, update_c_bitstr/6, ann_c_bitstr/5,
 	 ann_c_bitstr/6, is_c_bitstr/1, bitstr_val/1, bitstr_size/1,
 	 bitstr_bitsize/1, bitstr_unit/1, bitstr_type/1,
-	 bitstr_flags/1]).
-
--export_type([c_binary/0, c_call/0, c_clause/0, c_cons/0, c_fun/0, c_literal/0,
-              c_module/0, c_tuple/0, c_values/0, c_var/0, cerl/0, var_name/0]).
-
-%%
-%% needed by the include file below -- do not move
-%%
--type var_name() :: integer() | atom() | {atom(), integer()}.
+	 bitstr_flags/1,
+
+	 %% keep map exports here for now
+	 c_map_pattern/1,
+	 is_c_map/1,
+	 is_c_map_pattern/1,
+	 map_es/1,
+	 map_arg/1,
+	 update_c_map/3,
+	 c_map/1, is_c_map_empty/1,
+	 ann_c_map/2, ann_c_map/3,
+	 ann_c_map_pattern/2,
+	 map_pair_op/1,map_pair_key/1,map_pair_val/1,
+	 update_c_map_pair/4,
+	 c_map_pair/2, c_map_pair_exact/2,
+	 ann_c_map_pair/4
+     ]).
+
+-export_type([c_binary/0, c_bitstr/0, c_call/0, c_clause/0, c_cons/0, c_fun/0,
+	      c_let/0, c_literal/0, c_map/0, c_map_pair/0,
+	      c_module/0, c_tuple/0,
+	      c_values/0, c_var/0, cerl/0, var_name/0]).
 
 -include("core_parse.hrl").
 
@@ -145,6 +159,8 @@
 -type c_let()     :: #c_let{}.
 -type c_letrec()  :: #c_letrec{}.
 -type c_literal() :: #c_literal{}.
+-type c_map()     :: #c_map{}.
+-type c_map_pair() :: #c_map_pair{}.
 -type c_module()  :: #c_module{}.
 -type c_primop()  :: #c_primop{}.
 -type c_receive() :: #c_receive{}.
@@ -155,11 +171,14 @@
 -type c_var()     :: #c_var{}.
 
 -type cerl() :: c_alias()  | c_apply()  | c_binary()  | c_bitstr()
-              | c_call()   | c_case()   | c_catch()   | c_clause() | c_cons()
+              | c_call()   | c_case()   | c_catch()   | c_clause()  | c_cons()
               | c_fun()    | c_let()    | c_letrec()  | c_literal()
-              | c_module() | c_primop() | c_receive() | c_seq()
+	      | c_map()    | c_map_pair()
+	      | c_module() | c_primop() | c_receive() | c_seq()
               | c_try()    | c_tuple()  | c_values()  | c_var().
 
+-type var_name() :: integer() | atom() | {atom(), integer()}.
+
 %% =====================================================================
 %% Representation (general)
 %%
@@ -191,13 +210,15 @@
 %%    <td>call</td>
 %%    <td>case</td>
 %%    <td>catch</td>
-%%  </tr><tr>
 %%    <td>clause</td>
+%%  </tr><tr>
 %%    <td>cons</td>
 %%    <td>fun</td>
 %%    <td>let</td>
 %%    <td>letrec</td>
 %%    <td>literal</td>
+%%    <td>map</td>
+%%    <td>map_pair</td>
 %%    <td>module</td>
 %%  </tr><tr>
 %%    <td>primop</td>
@@ -237,7 +258,7 @@
 %% @see c_primop/2
 %% @see c_receive/1
 %% @see c_seq/2
-%% @see c_try/3
+%% @see c_try/5
 %% @see c_tuple/1
 %% @see c_values/1
 %% @see c_var/1
@@ -248,10 +269,10 @@
 %% @see subtrees/1
 %% @see meta/1
 
--type ctype() :: 'alias'   | 'apply'  | 'binary' | 'bitrst'  | 'call'  | 'case'
-               | 'catch'   | 'clause' | 'cons'   | 'fun'     | 'let'  | 'letrec'
-               | 'literal' | 'module' | 'primop' | 'receive' | 'seq'   | 'try' 
-               | 'tuple'   | 'values' |  'var'.
+-type ctype() :: 'alias'   | 'apply'  | 'binary' | 'bitrst' | 'call' | 'case'
+               | 'catch'   | 'clause' | 'cons'   | 'fun'    | 'let'  | 'letrec'
+               | 'literal' | 'map'  | 'map_pair' | 'module' | 'primop'
+               | 'receive' | 'seq'    | 'try'    | 'tuple'  | 'values' | 'var'.
 
 -spec type(cerl()) -> ctype().
 
@@ -268,6 +289,8 @@ type(#c_fun{}) -> 'fun';
 type(#c_let{}) -> 'let';
 type(#c_letrec{}) -> letrec;
 type(#c_literal{}) -> literal;
+type(#c_map{}) -> map;
+type(#c_map_pair{}) -> map_pair;
 type(#c_module{}) -> module;
 type(#c_primop{}) -> primop;
 type(#c_receive{}) -> 'receive';
@@ -414,6 +437,8 @@ is_literal_term([H | T]) ->
 is_literal_term(T) when is_tuple(T) ->
     is_literal_term_list(tuple_to_list(T));
 is_literal_term(B) when is_bitstring(B) -> true;
+is_literal_term(M) when is_map(M) ->
+    is_literal_term_list(maps:to_list(M));
 is_literal_term(_) ->
     false.
 
@@ -1433,7 +1458,7 @@ is_proper_list(_) ->
 %% X4]</code>.
 %%
 %% @see c_cons/2
-%% @see c_nil/1
+%% @see c_nil/0
 %% @see is_c_list/1
 %% @see list_length/1
 %% @see make_list/2
@@ -1464,7 +1489,7 @@ abstract_list([]) ->
 %% efficient.</p>
 %%
 %% @see c_cons/2
-%% @see c_nil/1
+%% @see c_nil/0
 %% @see is_c_list/1
 %% @see list_elements/1
 
@@ -1558,6 +1583,133 @@ ann_make_list(_, [], Node) ->
 
 
 %% ---------------------------------------------------------------------
+%% maps
+
+%% @spec is_c_map(Node::cerl()) -> boolean()
+%%
+%% @doc Returns <code>true</code> if <code>Node</code> is an abstract
+%% map constructor, otherwise <code>false</code>.
+
+-spec is_c_map(cerl()) -> boolean().
+
+is_c_map(#c_map{}) ->
+    true;
+is_c_map(#c_literal{val = V}) when is_map(V) ->
+    true;
+is_c_map(_) ->
+    false.
+
+-spec map_es(c_map() | c_literal()) -> [c_map_pair()].
+
+map_es(#c_literal{anno=As,val=M}) when is_map(M) ->
+    [ann_c_map_pair(As,
+                    #c_literal{anno=As,val='assoc'},
+                    #c_literal{anno=As,val=K},
+                    #c_literal{anno=As,val=V}) || {K,V} <- maps:to_list(M)];
+map_es(#c_map{es = Es}) ->
+    Es.
+
+-spec map_arg(c_map() | c_literal()) -> c_map() | c_literal().
+
+map_arg(#c_literal{anno=As,val=M}) when is_map(M) ->
+    #c_literal{anno=As,val=#{}};
+map_arg(#c_map{arg=M}) ->
+    M.
+
+-spec c_map([c_map_pair()]) -> c_map().
+
+c_map(Pairs) ->
+    ann_c_map([], Pairs).
+
+-spec c_map_pattern([c_map_pair()]) -> c_map().
+
+c_map_pattern(Pairs) ->
+    #c_map{es=Pairs, is_pat=true}.
+
+-spec ann_c_map_pattern([term()], [c_map_pair()]) -> c_map().
+
+ann_c_map_pattern(As, Pairs) ->
+    #c_map{anno=As, es=Pairs, is_pat=true}.
+
+-spec is_c_map_empty(c_map() | c_literal()) -> boolean().
+
+is_c_map_empty(#c_map{ es=[] }) -> true;
+is_c_map_empty(#c_literal{val=M}) when is_map(M),map_size(M) =:= 0 -> true;
+is_c_map_empty(_) -> false.
+
+-spec is_c_map_pattern(c_map()) -> boolean().
+
+is_c_map_pattern(#c_map{is_pat=IsPat}) ->
+    IsPat.
+
+-spec ann_c_map([term()], [c_map_pair()]) -> c_map() | c_literal().
+
+ann_c_map(As, Es) ->
+    ann_c_map(As, #c_literal{val=#{}}, Es).
+
+-spec ann_c_map([term()], c_map() | c_literal(), [c_map_pair()]) -> c_map() | c_literal().
+
+ann_c_map(As,#c_literal{val=M},Es) when is_map(M) ->
+    fold_map_pairs(As,Es,M);
+ann_c_map(As,M,Es) ->
+    #c_map{arg=M, es=Es, anno=As }.
+
+fold_map_pairs(As,[],M) -> #c_literal{anno=As,val=M};
+%% M#{ K => V}
+fold_map_pairs(As,[#c_map_pair{op=#c_literal{val=assoc},key=Ck,val=Cv}=E|Es],M) ->
+    case is_lit_list([Ck,Cv]) of
+	true ->
+	    [K,V] = lit_list_vals([Ck,Cv]),
+	    fold_map_pairs(As,Es,maps:put(K,V,M));
+	false ->
+	    #c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
+    end;
+%% M#{ K := V}
+fold_map_pairs(As,[#c_map_pair{op=#c_literal{val=exact},key=Ck,val=Cv}=E|Es],M) ->
+    case is_lit_list([Ck,Cv]) of
+	true ->
+	    [K,V] = lit_list_vals([Ck,Cv]),
+	    case maps:is_key(K,M) of
+		true -> fold_map_pairs(As,Es,maps:put(K,V,M));
+		false ->
+		    #c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
+	    end;
+	false ->
+	    #c_map{arg=#c_literal{val=M,anno=As}, es=[E|Es], anno=As }
+    end.
+
+-spec update_c_map(c_map(), cerl(), [cerl()]) -> c_map() | c_literal().
+
+update_c_map(#c_map{is_pat=true}=Old, M, Es) ->
+    Old#c_map{arg=M, es=Es};
+update_c_map(#c_map{is_pat=false}=Old, M, Es) ->
+    ann_c_map(get_ann(Old), M, Es).
+
+map_pair_key(#c_map_pair{key=K}) -> K.
+map_pair_val(#c_map_pair{val=V}) -> V.
+map_pair_op(#c_map_pair{op=Op}) -> Op.
+
+-spec c_map_pair(cerl(), cerl()) -> c_map_pair().
+
+c_map_pair(Key,Val) ->
+    #c_map_pair{op=#c_literal{val=assoc},key=Key,val=Val}.
+
+-spec c_map_pair_exact(cerl(), cerl()) -> c_map_pair().
+
+c_map_pair_exact(Key,Val) ->
+    #c_map_pair{op=#c_literal{val=exact},key=Key,val=Val}.
+
+-spec ann_c_map_pair([term()], cerl(), cerl(), cerl()) ->
+        c_map_pair().
+
+ann_c_map_pair(As,Op,K,V) ->
+    #c_map_pair{op=Op, key = K, val=V, anno = As}.
+
+update_c_map_pair(Old,Op,K,V) ->
+    #c_map_pair{op=Op, key=K, val=V, anno = get_ann(Old)}.
+
+
+%% ---------------------------------------------------------------------
 
 %% @spec c_tuple(Elements::[cerl()]) -> cerl()
 %%
@@ -1803,7 +1955,7 @@ is_c_var(_) ->
     false.
 
 
-%% @spec c_fname(Name::atom(), Arity::integer()) -> cerl()
+%% @spec c_fname(Name::atom(), Arity::arity()) -> cerl()
 %% @equiv c_var({Name, Arity})
 %% @see fname_id/1
 %% @see fname_arity/1
@@ -1811,18 +1963,18 @@ is_c_var(_) ->
 %% @see ann_c_fname/3
 %% @see update_c_fname/3
 
--spec c_fname(atom(), non_neg_integer()) -> c_var().
+-spec c_fname(atom(), arity()) -> c_var().
 
 c_fname(Atom, Arity) ->
     c_var({Atom, Arity}).
 
 
-%% @spec ann_c_fname(As::[term()], Name::atom(), Arity::integer()) ->
+%% @spec ann_c_fname(As::[term()], Name::atom(), Arity::arity()) ->
 %%           cerl()
 %% @equiv ann_c_var(As, {Atom, Arity})
 %% @see c_fname/2
 
--spec ann_c_fname([term()], atom(), non_neg_integer()) -> c_var().
+-spec ann_c_fname([term()], atom(), arity()) -> c_var().
 
 ann_c_fname(As, Atom, Arity) ->
     ann_c_var(As, {Atom, Arity}).
@@ -1840,13 +1992,13 @@ update_c_fname(#c_var{name = {_, Arity}, anno = As}, Atom) ->
     #c_var{name = {Atom, Arity}, anno = As}.
 
 
-%% @spec update_c_fname(Old::cerl(), Name::atom(), Arity::integer()) ->
+%% @spec update_c_fname(Old::cerl(), Name::atom(), Arity::arity()) ->
 %%           cerl()
 %% @equiv update_c_var(Old, {Atom, Arity})
 %% @see update_c_fname/2
 %% @see c_fname/2
 
--spec update_c_fname(c_var(), atom(), integer()) -> c_var().
+-spec update_c_fname(c_var(), atom(), arity()) -> c_var().
 
 update_c_fname(Node, Atom, Arity) ->
     update_c_var(Node, {Atom, Arity}).
@@ -1859,7 +2011,7 @@ update_c_fname(Node, Atom, Arity) ->
 %%
 %% @see c_fname/2
 %% @see c_var/1
-%% @see c_var_name/1
+%% @see var_name/1
 
 -spec is_c_fname(cerl()) -> boolean().
 
@@ -1895,14 +2047,14 @@ fname_id(#c_var{name={A,_}}) ->
     A.
 
 
-%% @spec fname_arity(cerl()) -> byte()
+%% @spec fname_arity(cerl()) -> arity()
 %%
 %% @doc Returns the arity part of an abstract function name variable.
 %%
 %% @see fname_id/1
 %% @see c_fname/2
 
--spec fname_arity(c_var()) -> byte().
+-spec fname_arity(c_var()) -> arity().
 
 fname_arity(#c_var{name={_,N}}) ->
     N.
@@ -2348,7 +2500,7 @@ fun_body(Node) ->
     Node#c_fun.body.
 
 
-%% @spec fun_arity(Node::cerl()) -> integer()
+%% @spec fun_arity(Node::cerl()) -> arity()
 %%
 %% @doc Returns the number of parameter subtrees of an abstract
 %% fun-expression.
@@ -2359,7 +2511,7 @@ fun_body(Node) ->
 %% @see c_fun/2
 %% @see fun_vars/1
 
--spec fun_arity(c_fun()) -> non_neg_integer().
+-spec fun_arity(c_fun()) -> arity().
 
 fun_arity(Node) ->
     length(fun_vars(Node)).
@@ -2945,9 +3097,15 @@ pat_vars(Node, Vs) ->
 	    pat_vars(cons_hd(Node), pat_vars(cons_tl(Node), Vs));
 	tuple ->
 	    pat_list_vars(tuple_es(Node), Vs);
+	map ->
+	    pat_list_vars(map_es(Node), Vs);
+	map_pair ->
+	    %% map_pair_key is not a pattern var, excluded
+	    pat_list_vars([map_pair_op(Node),map_pair_val(Node)],Vs);
 	binary ->
 	    pat_list_vars(binary_segments(Node), Vs);
 	bitstr ->
+	    %% bitstr_size is not a pattern var, excluded
 	    pat_vars(bitstr_val(Node), Vs);
 	alias ->
 	    pat_vars(alias_pat(Node), [alias_var(Node) | Vs])
@@ -3260,7 +3418,7 @@ apply_args(Node) ->
     Node#c_apply.args.
 
 
-%% @spec apply_arity(Node::cerl()) -> integer()
+%% @spec apply_arity(Node::cerl()) -> arity()
 %%
 %% @doc Returns the number of argument subtrees of an abstract
 %% function application.
@@ -3272,7 +3430,7 @@ apply_args(Node) ->
 %% @see c_apply/2
 %% @see apply_args/1
 
--spec apply_arity(c_apply()) -> non_neg_integer().
+-spec apply_arity(c_apply()) -> arity().
 
 apply_arity(Node) ->
     length(apply_args(Node)).
@@ -3378,7 +3536,7 @@ call_args(Node) ->
     Node#c_call.args.
 
 
-%% @spec call_arity(Node::cerl()) -> integer()
+%% @spec call_arity(Node::cerl()) -> arity()
 %%
 %% @doc Returns the number of argument subtrees of an abstract
 %% inter-module call.
@@ -3390,7 +3548,7 @@ call_args(Node) ->
 %% @see c_call/3
 %% @see call_args/1
 
--spec call_arity(c_call()) -> non_neg_integer().
+-spec call_arity(c_call()) -> arity().
 
 call_arity(Node) ->
     length(call_args(Node)).
@@ -3482,7 +3640,7 @@ primop_args(Node) ->
     Node#c_primop.args.
 
 
-%% @spec primop_arity(Node::cerl()) -> integer()
+%% @spec primop_arity(Node::cerl()) -> arity()
 %%
 %% @doc Returns the number of argument subtrees of an abstract
 %% primitive operation call.
@@ -3494,7 +3652,7 @@ primop_args(Node) ->
 %% @see c_primop/2
 %% @see primop_args/1
 
--spec primop_arity(c_primop()) -> non_neg_integer().
+-spec primop_arity(c_primop()) -> arity().
 
 primop_arity(Node) ->
     length(primop_args(Node)).
@@ -3531,7 +3689,7 @@ c_try(Expr, Vs, Body, Evs, Handler) ->
 %% @spec ann_c_try(As::[term()], Expression::cerl(),
 %%                 Variables::[cerl()], Body::cerl(),
 %%                 EVars::[cerl()], Handler::cerl()) -> cerl()
-%% @see c_try/3
+%% @see c_try/5
 
 -spec ann_c_try([term()], cerl(), [cerl()], cerl(), [cerl()], cerl()) ->
         c_try().
@@ -3544,7 +3702,7 @@ ann_c_try(As, Expr, Vs, Body, Evs, Handler) ->
 %% @spec update_c_try(Old::cerl(), Expression::cerl(),
 %%                    Variables::[cerl()], Body::cerl(),
 %%                    EVars::[cerl()], Handler::cerl()) -> cerl()
-%% @see c_try/3
+%% @see c_try/5
 
 -spec update_c_try(c_try(), cerl(), [cerl()], cerl(), [cerl()], cerl()) ->
         c_try().
@@ -3559,7 +3717,7 @@ update_c_try(Node, Expr, Vs, Body, Evs, Handler) ->
 %% @doc Returns <code>true</code> if <code>Node</code> is an abstract
 %% try-expression, otherwise <code>false</code>.
 %%
-%% @see c_try/3
+%% @see c_try/5
 
 -spec is_c_try(cerl()) -> boolean().
 
@@ -3573,7 +3731,7 @@ is_c_try(_) ->
 %%
 %% @doc Returns the expression subtree of an abstract try-expression.
 %%
-%% @see c_try/3
+%% @see c_try/5
 
 -spec try_arg(c_try()) -> cerl().
 
@@ -3586,7 +3744,7 @@ try_arg(Node) ->
 %% @doc Returns the list of success variable subtrees of an abstract
 %% try-expression.
 %%
-%% @see c_try/3
+%% @see c_try/5
 
 -spec try_vars(c_try()) -> [cerl()].
 
@@ -3598,7 +3756,7 @@ try_vars(Node) ->
 %%
 %% @doc Returns the success body subtree of an abstract try-expression.
 %%
-%% @see c_try/3
+%% @see c_try/5
 
 -spec try_body(c_try()) -> cerl().
 
@@ -3611,7 +3769,7 @@ try_body(Node) ->
 %% @doc Returns the list of exception variable subtrees of an abstract
 %% try-expression.
 %%
-%% @see c_try/3
+%% @see c_try/5
 
 -spec try_evars(c_try()) -> [cerl()].
 
@@ -3624,7 +3782,7 @@ try_evars(Node) ->
 %% @doc Returns the exception body subtree of an abstract
 %% try-expression.
 %%
-%% @see c_try/3
+%% @see c_try/5
 
 -spec try_handler(c_try()) -> cerl().
 
@@ -3646,7 +3804,7 @@ try_handler(Node) ->
 %% @see update_c_catch/2
 %% @see is_c_catch/1
 %% @see catch_body/1
-%% @see c_try/3
+%% @see c_try/5
 
 -spec c_catch(cerl()) -> c_catch().
 
@@ -3803,7 +3961,6 @@ data_type(#c_cons{}) ->
 data_type(#c_tuple{}) ->
     tuple.
 
-
 %% @spec data_es(Node::cerl()) -> [cerl()]
 %%
 %% @doc Returns the list of subtrees of a data constructor node. If
@@ -3835,7 +3992,6 @@ data_es(#c_cons{hd = H, tl = T}) ->
 data_es(#c_tuple{es = Es}) ->
     Es.
 
-
 %% @spec data_arity(Node::cerl()) -> integer()
 %%
 %% @doc Returns the number of subtrees of a data constructor
@@ -3892,7 +4048,6 @@ ann_make_data(As, {atomic, V}, []) -> #c_literal{val = V, anno = As};
 ann_make_data(As, cons, [H, T]) -> ann_c_cons(As, H, T);
 ann_make_data(As, tuple, Es) -> ann_c_tuple(As, Es).
 
-
 %% @spec update_data(Old::cerl(), Type::dtype(),
 %%                   Elements::[cerl()]) -> cerl()
 %% @see make_data/2
@@ -4022,6 +4177,10 @@ subtrees(T) ->
 		    [[cons_hd(T)], [cons_tl(T)]];
 		tuple ->
 		    [tuple_es(T)];
+		map ->
+		    [map_es(T)];
+		map_pair ->
+		    [[map_pair_op(T)],[map_pair_key(T)],[map_pair_val(T)]];
 		'let' ->
 		    [let_vars(T), [let_arg(T)], [let_body(T)]];
 		seq ->
@@ -4143,6 +4302,9 @@ ann_make_tree(As, bitstr, [[V],[S],[U],[T],[Fs]]) ->
     ann_c_bitstr(As, V, S, U, T, Fs);
 ann_make_tree(As, cons, [[H], [T]]) -> ann_c_cons(As, H, T);
 ann_make_tree(As, tuple, [Es]) -> ann_c_tuple(As, Es);
+ann_make_tree(As, map, [Es]) -> ann_c_map(As, Es);
+ann_make_tree(As, map, [[A], Es]) -> ann_c_map(As, A, Es);
+ann_make_tree(As, map_pair, [[Op], [K], [V]]) -> ann_c_map_pair(As, Op, K, V);
 ann_make_tree(As, 'let', [Vs, [A], [B]]) -> ann_c_let(As, Vs, A, B);
 ann_make_tree(As, seq, [[A], [B]]) -> ann_c_seq(As, A, B);
 ann_make_tree(As, apply, [[Op], Es]) -> ann_c_apply(As, Op, Es);
@@ -4272,12 +4434,8 @@ meta_1(cons, Node) ->
     %% we get exactly one element, we generate a 'c_cons' call
     %% instead of 'make_list' to reconstruct the node.
     case split_list(Node) of
-	{[H], none} ->
-	    meta_call(c_cons, [meta(H), meta(c_nil())]);
 	{[H], Node1} ->
 	    meta_call(c_cons, [meta(H), meta(Node1)]);
-	{L, none} ->
-	    meta_call(make_list, [make_list(meta_list(L))]);
 	{L, Node1} ->
 	    meta_call(make_list,
 		      [make_list(meta_list(L)), meta(Node1)])
@@ -4364,8 +4522,6 @@ split_list(Node, L) ->
     case type(Node) of
 	cons when A =:= [] ->
 	    split_list(cons_tl(Node), [cons_hd(Node) | L]);
-	nil when A =:= [] ->
-	    {lists:reverse(L), none};
 	_ ->
 	    {lists:reverse(L), Node}
     end.
diff --git a/lib/compiler/src/cerl_clauses.erl b/lib/compiler/src/cerl_clauses.erl
index 99fa8dd9d5..805095e30c 100644
--- a/lib/compiler/src/cerl_clauses.erl
+++ b/lib/compiler/src/cerl_clauses.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2001-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 
@@ -354,6 +355,29 @@ match(P, E, Bs) ->
 			    {false, Bs}
 		    end
 	    end;
+	map ->
+	    %% The most we can do is to say "definitely no match" if a
+	    %% map pattern is matched against non-map data.
+	    case E of
+		any ->
+		    {false, Bs};
+		_ ->
+		    case type(E) of
+			literal ->
+			    case is_map(concrete(E)) of
+				false ->
+				    none;
+				true ->
+				    {false, Bs}
+			    end;
+			cons ->
+			    none;
+			tuple ->
+			    none;
+			_ ->
+			    {false, Bs}
+		    end
+	    end;
 	_ ->
 	    match_1(P, E, Bs)
     end.
diff --git a/lib/compiler/src/cerl_inline.erl b/lib/compiler/src/cerl_inline.erl
index 2e7554c1ff..2a8cf2e758 100644
--- a/lib/compiler/src/cerl_inline.erl
+++ b/lib/compiler/src/cerl_inline.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2001-2012. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -42,7 +43,7 @@
 	       bitstr_flags/1, binary_segments/1, update_c_alias/3,
 	       update_c_apply/3, update_c_binary/2, update_c_bitstr/6,
 	       update_c_call/4, update_c_case/3, update_c_catch/2,
-	       update_c_clause/4, c_fun/2, c_int/1, c_let/3,
+	       update_c_clause/4, c_fun/2, c_int/1, c_let/3, ann_c_let/4,
 	       update_c_let/4, update_c_letrec/3, update_c_module/5,
 	       update_c_primop/3, update_c_receive/4, update_c_seq/3,
 	       c_seq/2, update_c_try/6, c_tuple/1, update_c_values/2,
@@ -51,8 +52,8 @@
 	       catch_body/1, clause_body/1, clause_guard/1,
 	       clause_pats/1, clause_vars/1, concrete/1, cons_hd/1,
 	       cons_tl/1, data_arity/1, data_es/1, data_type/1,
-	       fun_body/1, fun_vars/1, get_ann/1, int_val/1,
-	       is_c_atom/1, is_c_cons/1, is_c_fun/1, is_c_int/1,
+	       fname_arity/1, fun_body/1, fun_vars/1, get_ann/1, int_val/1,
+	       is_c_atom/1, is_c_cons/1, is_c_fname/1, is_c_int/1,
 	       is_c_list/1, is_c_seq/1, is_c_tuple/1, is_c_var/1,
 	       is_data/1, is_literal/1, is_literal_term/1, let_arg/1,
 	       let_body/1, let_vars/1, letrec_body/1, letrec_defs/1,
@@ -63,7 +64,11 @@
 	       receive_clauses/1, receive_timeout/1, seq_arg/1,
 	       seq_body/1, set_ann/2, try_arg/1, try_body/1, try_vars/1,
 	       try_evars/1, try_handler/1, tuple_es/1, tuple_arity/1,
-	       type/1, values_es/1, var_name/1]).
+	       type/1, values_es/1, var_name/1,
+	       map_arg/1, map_es/1, update_c_map/3,
+	       update_c_map_pair/4,
+	       map_pair_op/1, map_pair_key/1, map_pair_val/1
+	   ]).
 
 -import(lists, [foldl/3, foldr/3, mapfoldl/3, reverse/1]).
 
@@ -128,6 +133,8 @@ weight(call) -> 3;      % Assume remote-calls as efficient as `apply'.
 weight(primop) -> 2;    % Assume more efficient than `apply'.
 weight(binary) -> 4;    % Initialisation base cost.
 weight(bitstr) -> 3;    % Coding/decoding a value; like a primop.
+weight(map) -> 4;       % Initialisation base cost.
+weight(map_pair) -> 3;  % Coding/decoding a value; like a primop.
 weight(module) -> 1.    % Like a letrec with a constant body
 
 %% These "reference" structures are used for variables and function
@@ -333,6 +340,8 @@ i(E, Ctxt, Ren, Env, S0) ->
                     i_catch(E, Ctxt, Ren, Env, S);
 		binary ->
 		    i_binary(E, Ren, Env, S);
+		map ->
+		    i_map(E, Ctxt, Ren, Env, S);
                 module ->
                     i_module(E, Ctxt, Ren, Env, S)
             end
@@ -437,15 +446,14 @@ i_var_1(R, Opnd, Ctxt, Env, S) ->
 	    residualize_var(R, S);
 	false ->
 	    S1 = st__mark_inner_pending(L, S),
-	    case catch {ok, visit(Opnd, S1)} of
-		{ok, {E, S2}} ->
+	    try visit(Opnd, S1) of
+		{E, S2} ->
 		    %% Note that we pass the current environment and
 		    %% context to `copy', but not the current renaming.
 		    S3 = st__clear_inner_pending(L, S2),
-		    copy(R, Opnd, E, Ctxt, Env, S3);
-		{'EXIT', X} ->
-		    exit(X);
-		X ->
+		    copy(R, Opnd, E, Ctxt, Env, S3)
+	    catch
+		throw:X ->
  		    %% If we use destructive update for the
  		    %% `inner-pending' flag, we must make sure to clear
  		    %% it also if we make a nonlocal return.
@@ -1022,8 +1030,17 @@ i_apply(E, Ctxt, Ren, Env, S) ->
 					visit_and_count_size(Opnd, S)
 				end,
 				S3, Opnds),
-	    N = apply_size(length(Es)),
-            {update_c_apply(E, E1, Es), count_size(N, S4)}
+            Arity = length(Es),
+            E2 = case is_c_fname(E1) andalso length(Es) =/= fname_arity(E1) of
+                     true ->
+                         V = new_var(Env),
+                         ann_c_let(get_ann(E), [V], E1,
+				   update_c_apply(E, V, Es));
+                     false ->
+                         update_c_apply(E, E1, Es)
+                 end,
+            N = apply_size(Arity),
+            {E2, count_size(N, S4)}
     end.
 
 apply_size(A) ->
@@ -1111,8 +1128,8 @@ i_call_3(M, F, As, E, Ctxt, Env, S) ->
     %% Note that we extract the results of argument expessions here; the
     %% expressions could still be sequences with side effects.
     Vs = [concrete(result(A)) || A <- As],
-    case catch {ok, apply(atom_val(M), atom_val(F), Vs)} of
-	{ok, V} ->
+    try apply(atom_val(M), atom_val(F), Vs) of
+	V ->
 	    %% Evaluation completed normally - try to turn the result
 	    %% back into a syntax tree (representing a literal).
 	    case is_literal_term(V) of
@@ -1125,8 +1142,9 @@ i_call_3(M, F, As, E, Ctxt, Env, S) ->
 		false ->
 		    %% The result could not be represented as a literal.
 		    i_call_4(M, F, As, E, Ctxt, Env, S)
-	    end;
-	_ ->
+	    end
+    catch
+	error:_ ->
 	    %% The evaluation attempt did not complete normally.
 	    i_call_4(M, F, As, E, Ctxt, Env, S)
     end.
@@ -1324,6 +1342,25 @@ i_bitstr(E, Ren, Env, S) ->
     S3 = count_size(weight(bitstr), S2),
     {update_c_bitstr(E, Val, Size, Unit, Type, Flags), S3}.
 
+i_map(E, Ctx, Ren, Env, S0) ->
+    %% Visit the segments for value.
+    {M1, S1} = i(map_arg(E), value, Ren, Env, S0),
+    {Es, S2} = mapfoldl(fun (E, S) ->
+		i_map_pair(E, Ctx, Ren, Env, S)
+	end, S1, map_es(E)),
+    S3 = count_size(weight(map), S2),
+    {update_c_map(E, M1,Es), S3}.
+
+i_map_pair(E, Ctx, Ren, Env, S0) ->
+    %% It is not necessary to visit the Op field
+    %% since it is always a literal.
+    {Key, S1} = i(map_pair_key(E), value, Ren, Env, S0),
+    {Val, S2} = i(map_pair_val(E), Ctx, Ren, Env, S1),
+    Op = map_pair_op(E),
+    S3 = count_size(weight(map_pair), S2),
+    {update_c_map_pair(E, Op, Key, Val), S3}.
+
+
 %% This is a simplified version of `i_pattern', for lists of parameter
 %% variables only. It does not modify the state.
 
@@ -1383,6 +1420,12 @@ i_pattern(E, Ren, Env, Ren0, Env0, S) ->
 				S, binary_segments(E)),
 	    S2 = count_size(weight(binary), S1),
 	    {update_c_binary(E, Es), S2};
+	map ->
+	    {Es, S1} = mapfoldl(fun (E, S) ->
+			i_map_pair_pattern(E, Ren, Env, Ren0, Env0, S)
+		end, S, map_es(E)),
+	    S2 = count_size(weight(map), S1),
+	    {update_c_map(E, map_arg(E), Es), S2};
 	_ ->
 	    case is_literal(E) of
 		true ->
@@ -1416,6 +1459,15 @@ i_bitstr_pattern(E, Ren, Env, Ren0, Env0, S) ->
     S3 = count_size(weight(bitstr), S2),
     {update_c_bitstr(E, Val, Size, Unit, Type, Flags), S3}.
 
+i_map_pair_pattern(E, Ren, Env, Ren0, Env0, S) ->
+    %% It is not necessary to visit the Op it is always a literal.
+    %% Key is an expression
+    {Key, S1} = i(map_pair_key(E), value, Ren0, Env0, S),
+    {Val, S2} = i_pattern(map_pair_val(E), Ren, Env, Ren0, Env0, S1),
+    Op = map_pair_op(E), %% should be 'exact' literal
+    S3 = count_size(weight(map_pair), S2),
+    {update_c_map_pair(E, Op, Key, Val), S3}.
+
 
 %% ---------------------------------------------------------------------
 %% Other central inlining functions
@@ -1578,7 +1630,7 @@ make_let_binding_1(R, E, S) ->
 %%  completely.
 
 copy(R, Opnd, E, Ctxt, Env, S) ->
-    case is_c_var(E) of
+    case is_c_var(E) andalso not is_c_fname(E) of
         true ->
 	    %% The operand reduces to another variable - get its
 	    %% ref-structure and attempt to propagate further.
@@ -1628,12 +1680,12 @@ copy_var(R, Ctxt, Env, S) ->
     end.
 
 copy_1(R, Opnd, E, Ctxt, Env, S) ->
-    %% Fun-expression (lambdas) are a bit special; they are copyable,
-    %% but should preferably not be duplicated, so they should not be
-    %% copy propagated except into application contexts, where they can
-    %% be inlined.
-    case is_c_fun(E) of
-        true ->
+    case type(E) of
+        'fun' ->
+            %% Fun-expression (lambdas) are a bit special; they are copyable,
+            %% but should preferably not be duplicated, so they should not be
+            %% copy propagated except into application contexts, where they can
+            %% be inlined.
             case Ctxt of
                 #app{} ->
                     %% First test if the operand is "outer-pending"; if
@@ -1649,7 +1701,28 @@ copy_1(R, Opnd, E, Ctxt, Env, S) ->
                 _ ->
                     residualize_var(R, S)
             end;
-        false ->
+        var ->
+            %% Variables at this point only refer to local functions; they are
+            %% copyable but can't appear in guards, so they should not be
+            %% copy propagated except into application contexts, where they can
+            %% be inlined.
+            case Ctxt of
+                #app{} ->
+                    %% First test if the operand is "outer-pending"; if
+                    %% so, don't inline.
+                    case st__test_outer_pending(Opnd#opnd.loc, S) of
+                        false ->
+                            R1 = env__get(var_name(E), Opnd#opnd.env),
+                            copy_var(R1, Ctxt, Env, S);
+                        true ->
+                            %% Cyclic reference forced inlining to stop
+                            %% (avoiding infinite unfolding).
+                            residualize_var(R, S)
+                    end;
+                _ ->
+                    residualize_var(R, S)
+            end;
+        _ ->
             %% We have no other cases to handle here
             residualize_var(R, S)
     end.
@@ -1664,12 +1737,11 @@ copy_1(R, Opnd, E, Ctxt, Env, S) ->
 
 copy_inline(R, Opnd, E, Ctxt, Env, S) ->
     S1 = st__mark_outer_pending(Opnd#opnd.loc, S),
-    case catch {ok, copy_inline_1(R, E, Ctxt, Env, S1)} of
-        {ok, {E1, S2}} ->
-            {E1, st__clear_outer_pending(Opnd#opnd.loc, S2)};
-        {'EXIT', X} ->
-            exit(X);
-        X ->
+    try copy_inline_1(R, E, Ctxt, Env, S1) of
+        {E1, S2} ->
+            {E1, st__clear_outer_pending(Opnd#opnd.loc, S2)}
+    catch
+        throw:X ->
  	    %% If we use destructive update for the `outer-pending'
  	    %% flag, we must make sure to clear it upon a nonlocal
  	    %% return.
@@ -1686,19 +1758,16 @@ copy_inline_1(R, E, Ctxt, Env, S) ->
             copy_inline_2(R, E, Ctxt, Env, S);
         false ->
             S1 = new_active_effort(get_effort_limit(S), S),
-            case catch {ok, copy_inline_2(R, E, Ctxt, Env, S1)} of
-                {ok, {E1, S2}} ->
+            try copy_inline_2(R, E, Ctxt, Env, S1) of
+                {E1, S2} ->
                     %% Revert to the old effort counter.
-                    {E1, revert_effort(S, S2)};
-                {counter_exceeded, effort, _} ->
+                    {E1, revert_effort(S, S2)}
+	    catch
+                throw:{counter_exceeded, effort, _} ->
                     %% Aborted this inlining attempt because too much
                     %% effort was spent. Residualize the variable and
                     %% revert to the previous state.
-                    residualize_var(R, S);
-                {'EXIT', X} ->
-                    exit(X);
-                X ->
-                    throw(X)
+                    residualize_var(R, S)
             end
     end.
 
@@ -1724,11 +1793,12 @@ copy_inline_2(R, E, Ctxt, Env, S) ->
     %% close to zero at this point. (This is an extension to the
     %% original algorithm.)
     S1 = new_active_size(Limit + apply_size(length(Ctxt#app.opnds)), S),
-    case catch {ok, inline(E, Ctxt, ren__identity(), Env, S1)} of
-        {ok, {E1, S2}} ->
+    try inline(E, Ctxt, ren__identity(), Env, S1) of
+        {E1, S2} ->
             %% Revert to the old size counter.
-            {E1, revert_size(S, S2)};
-        {counter_exceeded, size, S2} ->
+            {E1, revert_size(S, S2)}
+    catch
+        throw:{counter_exceeded, size, S2} ->
             %% Aborted this inlining attempt because it got too big.
             %% Residualize the variable and revert to the old size
             %% counter. (It is important that we do not also revert the
@@ -1741,11 +1811,7 @@ copy_inline_2(R, E, Ctxt, Env, S) ->
   	    %% must make sure to clear the flags of any nested
   	    %% app-contexts upon aborting; see `inline' for details.
  	    S4 = reset_nested_apps(Ctxt, S3),    % for effect
-            residualize_var(R, S4);
-        {'EXIT', X} ->
-            exit(X);
-        X ->
-            throw(X)
+            residualize_var(R, S4)
     end.
 
 reset_nested_apps(#app{ctxt = Ctxt, loc = L}, S) ->
diff --git a/lib/compiler/src/cerl_sets.erl b/lib/compiler/src/cerl_sets.erl
new file mode 100644
index 0000000000..0361186713
--- /dev/null
+++ b/lib/compiler/src/cerl_sets.erl
@@ -0,0 +1,207 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2000-2015. All Rights Reserved.
+%% 
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(cerl_sets).
+
+%% Standard interface.
+-export([new/0,is_set/1,size/1,to_list/1,from_list/1]).
+-export([is_element/2,add_element/2,del_element/2]).
+-export([union/2,union/1,intersection/2,intersection/1]).
+-export([is_disjoint/2]).
+-export([subtract/2,is_subset/2]).
+-export([fold/3,filter/2]).
+
+-export_type([set/0, set/1]).
+
+%%------------------------------------------------------------------------------
+
+-type set() :: set(_).
+-opaque set(Element) :: #{Element => 'ok'}.
+
+%%------------------------------------------------------------------------------
+
+%% new() -> Set
+-spec new() -> set().
+
+new() -> #{}.
+
+%% is_set(Set) -> boolean().
+%%  Return 'true' if Set is a set of elements, else 'false'.
+-spec is_set(Set) -> boolean() when
+      Set :: term().
+
+is_set(S) when is_map(S) -> true;
+is_set(_) -> false.
+
+%% size(Set) -> int().
+%%  Return the number of elements in Set.
+-spec size(Set) -> non_neg_integer() when
+      Set :: set().
+
+size(S) -> maps:size(S).
+
+%% to_list(Set) -> [Elem].
+%%  Return the elements in Set as a list.
+-spec to_list(Set) -> List when
+      Set :: set(Element),
+      List :: [Element].
+
+to_list(S) -> maps:keys(S).
+
+%% from_list([Elem]) -> Set.
+%%  Build a set from the elements in List.
+-spec from_list(List) -> Set when
+      List :: [Element],
+      Set :: set(Element).
+from_list(Ls) -> maps:from_list([{K,ok}||K<-Ls]).
+
+%% is_element(Element, Set) -> boolean().
+%%  Return 'true' if Element is an element of Set, else 'false'.
+-spec is_element(Element, Set) -> boolean() when
+      Set :: set(Element).
+
+is_element(E,S) ->
+    case S of
+        #{E := _} -> true;
+        _ -> false
+    end.
+
+%% add_element(Element, Set) -> Set.
+%%  Return Set with Element inserted in it.
+-spec add_element(Element, Set1) -> Set2 when
+      Set1 :: set(Element),
+      Set2 :: set(Element).
+
+add_element(E,S) -> S#{E=>ok}.
+
+-spec del_element(Element, Set1) -> Set2 when
+      Set1 :: set(Element),
+      Set2 :: set(Element).
+
+%% del_element(Element, Set) -> Set.
+%%  Return Set but with Element removed.
+del_element(E,S) -> maps:remove(E,S).
+
+%% union(Set1, Set2) -> Set
+%%  Return the union of Set1 and Set2.
+-spec union(Set1, Set2) -> Set3 when
+      Set1 :: set(Element),
+      Set2 :: set(Element),
+      Set3 :: set(Element).
+
+union(S1,S2) -> maps:merge(S1,S2).
+
+%% union([Set]) -> Set
+%%  Return the union of the list of sets.
+-spec union(SetList) -> Set when
+      SetList :: [set(Element)],
+      Set :: set(Element).
+
+union([S1,S2|Ss]) ->
+    union1(union(S1, S2), Ss);
+union([S]) -> S;
+union([]) -> new().
+
+union1(S1, [S2|Ss]) ->
+    union1(union(S1, S2), Ss);
+union1(S1, []) -> S1.
+
+%% intersection(Set1, Set2) -> Set.
+%%  Return the intersection of Set1 and Set2.
+-spec intersection(Set1, Set2) -> Set3 when
+      Set1 :: set(Element),
+      Set2 :: set(Element),
+      Set3 :: set(Element).
+
+intersection(S1, S2) ->
+    filter(fun (E) -> is_element(E, S1) end, S2).
+
+%% intersection([Set]) -> Set.
+%%  Return the intersection of the list of sets.
+-spec intersection(SetList) -> Set when
+      SetList :: [set(Element),...],
+      Set :: set(Element).
+
+intersection([S1,S2|Ss]) ->
+    intersection1(intersection(S1, S2), Ss);
+intersection([S]) -> S.
+
+intersection1(S1, [S2|Ss]) ->
+    intersection1(intersection(S1, S2), Ss);
+intersection1(S1, []) -> S1.
+
+%% is_disjoint(Set1, Set2) -> boolean().
+%%  Check whether Set1 and Set2 are disjoint.
+-spec is_disjoint(Set1, Set2) -> boolean() when
+      Set1 :: set(Element),
+      Set2 :: set(Element).
+
+is_disjoint(S1, S2) when map_size(S1) < map_size(S2) ->
+    fold(fun (_, false) -> false;
+	     (E, true) -> not is_element(E, S2)
+	 end, true, S1);
+is_disjoint(S1, S2) ->
+    fold(fun (_, false) -> false;
+	     (E, true) -> not is_element(E, S1)
+	 end, true, S2).
+
+%% subtract(Set1, Set2) -> Set.
+%%  Return all and only the elements of Set1 which are not also in
+%%  Set2.
+-spec subtract(Set1, Set2) -> Set3 when
+      Set1 :: set(Element),
+      Set2 :: set(Element),
+      Set3 :: set(Element).
+
+subtract(S1, S2) ->
+    filter(fun (E) -> not is_element(E, S2) end, S1).
+
+%% is_subset(Set1, Set2) -> boolean().
+%%  Return 'true' when every element of Set1 is also a member of
+%%  Set2, else 'false'.
+-spec is_subset(Set1, Set2) -> boolean() when
+      Set1 :: set(Element),
+      Set2 :: set(Element).
+
+is_subset(S1, S2) ->
+    fold(fun (E, Sub) -> Sub andalso is_element(E, S2) end, true, S1).
+
+%% fold(Fun, Accumulator, Set) -> Accumulator.
+%%  Fold function Fun over all elements in Set and return Accumulator.
+-spec fold(Function, Acc0, Set) -> Acc1 when
+      Function :: fun((Element, AccIn) -> AccOut),
+      Set :: set(Element),
+      Acc0 :: Acc,
+      Acc1 :: Acc,
+      AccIn :: Acc,
+      AccOut :: Acc.
+
+fold(F, Init, D) ->
+    lists:foldl(fun(E,Acc) -> F(E,Acc) end,Init,maps:keys(D)).
+
+%% filter(Fun, Set) -> Set.
+%%  Filter Set with Fun.
+-spec filter(Pred, Set1) -> Set2 when
+      Pred :: fun((Element) -> boolean()),
+      Set1 :: set(Element),
+      Set2 :: set(Element).
+
+filter(F, D) ->
+    maps:from_list(lists:filter(fun({K,_}) -> F(K) end, maps:to_list(D))).
diff --git a/lib/compiler/src/cerl_trees.erl b/lib/compiler/src/cerl_trees.erl
index 1e3755025f..b3decbec1f 100644
--- a/lib/compiler/src/cerl_trees.erl
+++ b/lib/compiler/src/cerl_trees.erl
@@ -1,32 +1,33 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2001-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 
 %% @doc Basic functions on Core Erlang abstract syntax trees.
 %%
 %% <p>Syntax trees are defined in the module <a
-%% href=""><code>cerl</code></a>.</p>
+%% href="cerl"><code>cerl</code></a>.</p>
 %%
 %% @type cerl() = cerl:cerl()
 
 -module(cerl_trees).
 
 -export([depth/1, fold/3, free_variables/1, get_label/1, label/1, label/2, 
-	 map/2, mapfold/3, size/1, variables/1]).
+	 map/2, mapfold/3, mapfold/4, size/1, variables/1]).
 
 -import(cerl, [alias_pat/1, alias_var/1, ann_c_alias/3, ann_c_apply/3,
 	       ann_c_binary/2, ann_c_bitstr/6, ann_c_call/4,
@@ -55,7 +56,16 @@
 	       update_c_let/4, update_c_letrec/3, update_c_module/5,
 	       update_c_primop/3, update_c_receive/4, update_c_seq/3,
 	       update_c_try/6, update_c_tuple/2, update_c_tuple_skel/2,
-	       update_c_values/2, values_es/1, var_name/1]).
+	       update_c_values/2, values_es/1, var_name/1,
+
+	       map_arg/1, map_es/1,
+	       ann_c_map/3,
+	       update_c_map/3,
+	       is_c_map_pattern/1, ann_c_map_pattern/2,
+	       map_pair_key/1,map_pair_val/1,map_pair_op/1,
+	       ann_c_map_pair/4,
+	       update_c_map_pair/4
+	   ]).
 
 
 %% ---------------------------------------------------------------------
@@ -129,6 +139,12 @@ map_1(F, T) ->
 			       map(F, cons_tl(T)));
  	tuple ->
 	    update_c_tuple_skel(T, map_list(F, tuple_es(T)));
+ 	map ->
+	    update_c_map(T, map(F, map_arg(T)), map_list(F, map_es(T)));
+	map_pair ->
+	    update_c_map_pair(T, map(F, map_pair_op(T)),
+                                 map(F, map_pair_key(T)),
+                                 map(F, map_pair_val(T)));
  	'let' ->
 	    update_c_let(T, map_list(F, let_vars(T)),
 			 map(F, let_arg(T)),
@@ -235,6 +251,14 @@ fold_1(F, S, T) ->
 	    fold(F, fold(F, S, cons_hd(T)), cons_tl(T));
 	tuple ->
 	    fold_list(F, S, tuple_es(T));
+	map ->
+	    fold_list(F, S, map_es(T));
+	map_pair ->
+	    fold(F,
+		fold(F,
+		    fold(F, S, map_pair_op(T)),
+		    map_pair_key(T)),
+		map_pair_val(T));
  	'let' ->
 	    fold(F, fold(F, fold_list(F, S, let_vars(T)),
 			 let_arg(T)),
@@ -317,127 +341,162 @@ fold_pairs(_, S, []) ->
 %% starting with the given value <code>Initial</code>, while doing a
 %% post-order traversal of the tree, much like <code>fold/3</code>.
 %%
+%% This is the same as mapfold/4, with an identity function as the
+%% pre-operation.
+%%
 %% @see map/2
 %% @see fold/3
+%% @see mapfold/4
 
 -spec mapfold(fun((cerl:cerl(), term()) -> {cerl:cerl(), term()}),
 	      term(), cerl:cerl()) -> {cerl:cerl(), term()}.
 
 mapfold(F, S0, T) ->
+  mapfold(fun(T0, A) -> {T0, A} end, F, S0, T).
+
+
+%% @spec mapfold(Pre, Post, Initial::term(), Tree::cerl()) ->
+%%           {cerl(), term()}
+%%
+%%    Pre = Post = (cerl(), term()) -> {cerl(), term()}
+%%
+%% @doc Does a combined map/fold operation on the nodes of the
+%% tree. It begins by calling <code>Pre</code> on the tree, using the
+%% <code>Initial</code> value. It then deconstructs the top node of
+%% the returned tree and recurses on the children, using the returned
+%% value as the new initial and carrying the returned values from one
+%% call to the next. Finally it reassembles the top node from the
+%% children, calls <code>Post</code> on it and returns the result.
+
+-spec mapfold(fun((cerl:cerl(), term()) -> {cerl:cerl(), term()}),
+              fun((cerl:cerl(), term()) -> {cerl:cerl(), term()}),
+	      term(), cerl:cerl()) -> {cerl:cerl(), term()}.
+
+mapfold(Pre, Post, S00, T0) ->
+    {T, S0} = Pre(T0, S00),
     case type(T) of
  	literal ->
 	    case concrete(T) of
 		[_ | _] ->
-		    {T1, S1} = mapfold(F, S0, cons_hd(T)),
-		    {T2, S2} = mapfold(F, S1, cons_tl(T)),
-		    F(update_c_cons(T, T1, T2), S2);
+		    {T1, S1} = mapfold(Pre, Post, S0, cons_hd(T)),
+		    {T2, S2} = mapfold(Pre, Post, S1, cons_tl(T)),
+		    Post(update_c_cons(T, T1, T2), S2);
 		V when tuple_size(V) > 0 ->
-		    {Ts, S1} = mapfold_list(F, S0, tuple_es(T)),
-		    F(update_c_tuple(T, Ts), S1);
+		    {Ts, S1} = mapfold_list(Pre, Post, S0, tuple_es(T)),
+		    Post(update_c_tuple(T, Ts), S1);
 		_ ->
-		    F(T, S0)
+		    Post(T, S0)
 	    end;
  	var ->
- 	    F(T, S0);
+	    Post(T, S0);
 	values ->
-	    {Ts, S1} = mapfold_list(F, S0, values_es(T)),
- 	    F(update_c_values(T, Ts), S1);
+	    {Ts, S1} = mapfold_list(Pre, Post, S0, values_es(T)),
+	    Post(update_c_values(T, Ts), S1);
 	cons ->
-	    {T1, S1} = mapfold(F, S0, cons_hd(T)),
-	    {T2, S2} = mapfold(F, S1, cons_tl(T)),
-	    F(update_c_cons_skel(T, T1, T2), S2);
+	    {T1, S1} = mapfold(Pre, Post, S0, cons_hd(T)),
+	    {T2, S2} = mapfold(Pre, Post, S1, cons_tl(T)),
+	    Post(update_c_cons_skel(T, T1, T2), S2);
  	tuple ->
-	    {Ts, S1} = mapfold_list(F, S0, tuple_es(T)),
-	    F(update_c_tuple_skel(T, Ts), S1);
+	    {Ts, S1} = mapfold_list(Pre, Post, S0, tuple_es(T)),
+	    Post(update_c_tuple_skel(T, Ts), S1);
+	map ->
+	    {M , S1} = mapfold(Pre, Post, S0, map_arg(T)),
+	    {Ts, S2} = mapfold_list(Pre, Post, S1, map_es(T)),
+	    Post(update_c_map(T, M, Ts), S2);
+	map_pair ->
+	    {Op,  S1} = mapfold(Pre, Post, S0, map_pair_op(T)),
+	    {Key, S2} = mapfold(Pre, Post, S1, map_pair_key(T)),
+	    {Val, S3} = mapfold(Pre, Post, S2, map_pair_val(T)),
+	    Post(update_c_map_pair(T,Op,Key,Val), S3);
  	'let' ->
-	    {Vs, S1} = mapfold_list(F, S0, let_vars(T)),
-	    {A, S2} = mapfold(F, S1, let_arg(T)),
-	    {B, S3} = mapfold(F, S2, let_body(T)),
-	    F(update_c_let(T, Vs, A, B), S3);
+	    {Vs, S1} = mapfold_list(Pre, Post, S0, let_vars(T)),
+	    {A, S2} = mapfold(Pre, Post, S1, let_arg(T)),
+	    {B, S3} = mapfold(Pre, Post, S2, let_body(T)),
+	    Post(update_c_let(T, Vs, A, B), S3);
 	seq ->
-	    {A, S1} = mapfold(F, S0, seq_arg(T)),
-	    {B, S2} = mapfold(F, S1, seq_body(T)),
- 	    F(update_c_seq(T, A, B), S2);
+	    {A, S1} = mapfold(Pre, Post, S0, seq_arg(T)),
+	    {B, S2} = mapfold(Pre, Post, S1, seq_body(T)),
+	    Post(update_c_seq(T, A, B), S2);
  	apply ->
-	    {E, S1} = mapfold(F, S0, apply_op(T)),
-	    {As, S2} = mapfold_list(F, S1, apply_args(T)),
-	    F(update_c_apply(T, E, As), S2);
+	    {E, S1} = mapfold(Pre, Post, S0, apply_op(T)),
+	    {As, S2} = mapfold_list(Pre, Post, S1, apply_args(T)),
+	    Post(update_c_apply(T, E, As), S2);
  	call ->
-	    {M, S1} = mapfold(F, S0, call_module(T)),
-	    {N, S2} = mapfold(F, S1, call_name(T)),
-	    {As, S3} = mapfold_list(F, S2, call_args(T)),
- 	    F(update_c_call(T, M, N, As), S3);
+	    {M, S1} = mapfold(Pre, Post, S0, call_module(T)),
+	    {N, S2} = mapfold(Pre, Post, S1, call_name(T)),
+	    {As, S3} = mapfold_list(Pre, Post, S2, call_args(T)),
+	    Post(update_c_call(T, M, N, As), S3);
  	primop ->
-	    {N, S1} = mapfold(F, S0, primop_name(T)),
-	    {As, S2} = mapfold_list(F, S1, primop_args(T)),
-	    F(update_c_primop(T, N, As), S2);
+	    {N, S1} = mapfold(Pre, Post, S0, primop_name(T)),
+	    {As, S2} = mapfold_list(Pre, Post, S1, primop_args(T)),
+	    Post(update_c_primop(T, N, As), S2);
  	'case' ->
-	    {A, S1} = mapfold(F, S0, case_arg(T)),
-	    {Cs, S2} = mapfold_list(F, S1, case_clauses(T)),
- 	    F(update_c_case(T, A, Cs), S2);
+	    {A, S1} = mapfold(Pre, Post, S0, case_arg(T)),
+	    {Cs, S2} = mapfold_list(Pre, Post, S1, case_clauses(T)),
+	    Post(update_c_case(T, A, Cs), S2);
  	clause ->
-	    {Ps, S1} = mapfold_list(F, S0, clause_pats(T)),
-	    {G, S2} = mapfold(F, S1, clause_guard(T)),
-	    {B, S3} = mapfold(F, S2, clause_body(T)),
-	    F(update_c_clause(T, Ps, G, B), S3);
+	    {Ps, S1} = mapfold_list(Pre, Post, S0, clause_pats(T)),
+	    {G, S2} = mapfold(Pre, Post, S1, clause_guard(T)),
+	    {B, S3} = mapfold(Pre, Post, S2, clause_body(T)),
+	    Post(update_c_clause(T, Ps, G, B), S3);
  	alias ->
-	    {V, S1} = mapfold(F, S0, alias_var(T)),
-	    {P, S2} = mapfold(F, S1, alias_pat(T)),
-	    F(update_c_alias(T, V, P), S2);
+	    {V, S1} = mapfold(Pre, Post, S0, alias_var(T)),
+	    {P, S2} = mapfold(Pre, Post, S1, alias_pat(T)),
+	    Post(update_c_alias(T, V, P), S2);
  	'fun' ->
-	    {Vs, S1} = mapfold_list(F, S0, fun_vars(T)),
-	    {B, S2} = mapfold(F, S1, fun_body(T)),
-	    F(update_c_fun(T, Vs, B), S2);
+	    {Vs, S1} = mapfold_list(Pre, Post, S0, fun_vars(T)),
+	    {B, S2} = mapfold(Pre, Post, S1, fun_body(T)),
+	    Post(update_c_fun(T, Vs, B), S2);
  	'receive' ->
-	    {Cs, S1} = mapfold_list(F, S0, receive_clauses(T)),
-	    {E, S2} = mapfold(F, S1, receive_timeout(T)),
-	    {A, S3} = mapfold(F, S2, receive_action(T)),
-	    F(update_c_receive(T, Cs, E, A), S3);
+	    {Cs, S1} = mapfold_list(Pre, Post, S0, receive_clauses(T)),
+	    {E, S2} = mapfold(Pre, Post, S1, receive_timeout(T)),
+	    {A, S3} = mapfold(Pre, Post, S2, receive_action(T)),
+	    Post(update_c_receive(T, Cs, E, A), S3);
  	'try' ->
-	    {E, S1} = mapfold(F, S0, try_arg(T)),
-	    {Vs, S2} = mapfold_list(F, S1, try_vars(T)),
-	    {B, S3} = mapfold(F, S2, try_body(T)),
-	    {Evs, S4} = mapfold_list(F, S3, try_evars(T)),
-	    {H, S5} = mapfold(F, S4, try_handler(T)),
-	    F(update_c_try(T, E, Vs, B, Evs, H), S5);
+	    {E, S1} = mapfold(Pre, Post, S0, try_arg(T)),
+	    {Vs, S2} = mapfold_list(Pre, Post, S1, try_vars(T)),
+	    {B, S3} = mapfold(Pre, Post, S2, try_body(T)),
+	    {Evs, S4} = mapfold_list(Pre, Post, S3, try_evars(T)),
+	    {H, S5} = mapfold(Pre, Post, S4, try_handler(T)),
+	    Post(update_c_try(T, E, Vs, B, Evs, H), S5);
  	'catch' ->
-	    {B, S1} = mapfold(F, S0, catch_body(T)),
-	    F(update_c_catch(T, B), S1);
+	    {B, S1} = mapfold(Pre, Post, S0, catch_body(T)),
+	    Post(update_c_catch(T, B), S1);
 	binary ->
-	    {Ds, S1} = mapfold_list(F, S0, binary_segments(T)),
-	    F(update_c_binary(T, Ds), S1);
+	    {Ds, S1} = mapfold_list(Pre, Post, S0, binary_segments(T)),
+	    Post(update_c_binary(T, Ds), S1);
 	bitstr ->
-	    {Val, S1} = mapfold(F, S0, bitstr_val(T)),
-	    {Size, S2} = mapfold(F, S1, bitstr_size(T)),
-	    {Unit, S3} = mapfold(F, S2, bitstr_unit(T)),
-	    {Type, S4} = mapfold(F, S3, bitstr_type(T)),
-	    {Flags, S5} = mapfold(F, S4, bitstr_flags(T)),
-	    F(update_c_bitstr(T, Val, Size, Unit, Type, Flags), S5);
+	    {Val, S1} = mapfold(Pre, Post, S0, bitstr_val(T)),
+	    {Size, S2} = mapfold(Pre, Post, S1, bitstr_size(T)),
+	    {Unit, S3} = mapfold(Pre, Post, S2, bitstr_unit(T)),
+	    {Type, S4} = mapfold(Pre, Post, S3, bitstr_type(T)),
+	    {Flags, S5} = mapfold(Pre, Post, S4, bitstr_flags(T)),
+	    Post(update_c_bitstr(T, Val, Size, Unit, Type, Flags), S5);
 	letrec ->
-	    {Ds, S1} = mapfold_pairs(F, S0, letrec_defs(T)),
-	    {B, S2} = mapfold(F, S1, letrec_body(T)),
-	    F(update_c_letrec(T, Ds, B), S2);
+	    {Ds, S1} = mapfold_pairs(Pre, Post, S0, letrec_defs(T)),
+	    {B, S2} = mapfold(Pre, Post, S1, letrec_body(T)),
+	    Post(update_c_letrec(T, Ds, B), S2);
 	module ->
-	    {N, S1} = mapfold(F, S0, module_name(T)),
-	    {Es, S2} = mapfold_list(F, S1, module_exports(T)),
-	    {As, S3} = mapfold_pairs(F, S2, module_attrs(T)),
-	    {Ds, S4} = mapfold_pairs(F, S3, module_defs(T)),
-	    F(update_c_module(T, N, Es, As, Ds), S4)
+	    {N, S1} = mapfold(Pre, Post, S0, module_name(T)),
+	    {Es, S2} = mapfold_list(Pre, Post, S1, module_exports(T)),
+	    {As, S3} = mapfold_pairs(Pre, Post, S2, module_attrs(T)),
+	    {Ds, S4} = mapfold_pairs(Pre, Post, S3, module_defs(T)),
+	    Post(update_c_module(T, N, Es, As, Ds), S4)
     end.
 
-mapfold_list(F, S0, [T | Ts]) ->
-    {T1, S1} = mapfold(F, S0, T),
-    {Ts1, S2} = mapfold_list(F, S1, Ts),
+mapfold_list(Pre, Post, S0, [T | Ts]) ->
+    {T1, S1} = mapfold(Pre, Post, S0, T),
+    {Ts1, S2} = mapfold_list(Pre, Post, S1, Ts),
     {[T1 | Ts1], S2};
-mapfold_list(_, S, []) ->
+mapfold_list(_, _, S, []) ->
     {[], S}.
 
-mapfold_pairs(F, S0, [{T1, T2} | Ps]) ->
-    {T3, S1} = mapfold(F, S0, T1),
-    {T4, S2} = mapfold(F, S1, T2),
-    {Ps1, S3} = mapfold_pairs(F, S2, Ps),
+mapfold_pairs(Pre, Post, S0, [{T1, T2} | Ps]) ->
+    {T3, S1} = mapfold(Pre, Post, S0, T1),
+    {T4, S2} = mapfold(Pre, Post, S1, T2),
+    {Ps1, S3} = mapfold_pairs(Pre, Post, S2, Ps),
     {[{T3, T4} | Ps1], S3};
-mapfold_pairs(_, S, []) ->
+mapfold_pairs(_, _, S, []) ->
     {[], S}.
 
 
@@ -488,6 +547,10 @@ variables(T, S) ->
 			  variables(cons_tl(T), S));
 	tuple ->
 	    vars_in_list(tuple_es(T), S);
+	map ->
+	    vars_in_list([map_arg(T)|map_es(T)], S);
+	map_pair ->
+	    vars_in_list([map_pair_op(T),map_pair_key(T),map_pair_val(T)], S);
 	'let' ->
 	    Vs = variables(let_body(T), S),
 	    Vs1 = var_list_names(let_vars(T)),
@@ -604,8 +667,8 @@ vars_in_list([], _, A) ->
 vars_in_defs(Ds, S) ->
     vars_in_defs(Ds, S, []).
 
-vars_in_defs([{_, F} | Ds], S, A) ->
-    vars_in_defs(Ds, S, ordsets:union(variables(F, S), A));
+vars_in_defs([{_, Post} | Ds], S, A) ->
+    vars_in_defs(Ds, S, ordsets:union(variables(Post, S), A));
 vars_in_defs([], _, A) ->
     A.
 
@@ -667,13 +730,14 @@ label(T, N, Env) ->
 	    %% Constant literals are not labeled.
 	    {T, N};
 	var ->
-	    case dict:find(var_name(T), Env) of
-		{ok, L} ->
-		    {As, _} = label_ann(T, L),
-		    N1 = N;
-		error ->
-		    {As, N1} = label_ann(T, N)
-	    end,
+            {As, N1} =
+                case dict:find(var_name(T), Env) of
+		    {ok, L} ->
+		        {A, _} = label_ann(T, L),
+		        {A, N};
+                    error ->
+		        label_ann(T, N)
+                end,
 	    {set_ann(T, As), N1};
 	values ->
 	    {Ts, N1} = label_list(values_es(T), N, Env),
@@ -688,6 +752,24 @@ label(T, N, Env) ->
 	    {Ts, N1} = label_list(tuple_es(T), N, Env),
 	    {As, N2} = label_ann(T, N1),
 	    {ann_c_tuple_skel(As, Ts), N2};
+ 	map ->
+	    case is_c_map_pattern(T) of
+		false ->
+		    {M,  N1} = label(map_arg(T), N, Env),
+		    {Ts, N2} = label_list(map_es(T), N1, Env),
+		    {As, N3} = label_ann(T, N2),
+		    {ann_c_map(As, M, Ts), N3};
+		true ->
+		    {Ts, N1} = label_list(map_es(T), N, Env),
+		    {As, N2} = label_ann(T, N1),
+		    {ann_c_map_pattern(As, Ts), N2}
+	    end;
+	map_pair ->
+	    {Op,  N1} = label(map_pair_op(T), N, Env),
+	    {Key, N2} = label(map_pair_key(T), N1, Env),
+	    {Val, N3} = label(map_pair_val(T), N2, Env),
+	    {As,  N4} = label_ann(T, N3),
+	    {ann_c_map_pair(As,Op,Key,Val), N4};
  	'let' ->
 	    {A, N1} = label(let_arg(T), N, Env),
 	    {Vs, N2, Env1} = label_vars(let_vars(T), N1, Env),
diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index 2ca403de54..82ff8a95f3 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2015. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -25,6 +26,7 @@
 -export([forms/1,forms/2,noenv_forms/2]).
 -export([output_generated/1,noenv_output_generated/1]).
 -export([options/0]).
+-export([env_compiler_options/0]).
 
 %% Erlc interface.
 -export([compile/3,compile_beam/3,compile_asm/3,compile_core/3]).
@@ -39,13 +41,19 @@
 
 %%----------------------------------------------------------------------
 
+-type abstract_code() :: [erl_parse:abstract_form()].
+
 -type option() :: atom() | {atom(), term()} | {'d', atom(), term()}.
 
--type err_info() :: {erl_scan:line(), module(), term()}. %% ErrorDescriptor
+-type err_info() :: {erl_anno:line() | 'none',
+		     module(), term()}. %% ErrorDescriptor
 -type errors()   :: [{file:filename(), [err_info()]}].
 -type warnings() :: [{file:filename(), [err_info()]}].
 -type mod_ret()  :: {'ok', module()}
                   | {'ok', module(), cerl:c_module()} %% with option 'to_core'
+                  | {'ok',                            %% with option 'to_pp'
+                     module() | [],                   %% module() if 'to_exp'
+                     abstract_code()}
                   | {'ok', module(), warnings()}.
 -type bin_ret()  :: {'ok', module(), binary()}
                   | {'ok', module(), binary(), warnings()}.
@@ -76,7 +84,11 @@ file(File, Opts) when is_list(Opts) ->
 file(File, Opt) ->
     file(File, [Opt|?DEFAULT_OPTIONS]).
 
-forms(File) -> forms(File, ?DEFAULT_OPTIONS).
+-spec forms(abstract_code()) -> comp_ret().
+
+forms(Forms) -> forms(Forms, ?DEFAULT_OPTIONS).
+
+-spec forms(abstract_code(), [option()] | option()) -> comp_ret().
 
 forms(Forms, Opts) when is_list(Opts) ->
     do_compile({forms,Forms}, [binary|Opts++env_default_opts()]);
@@ -104,6 +116,8 @@ noenv_file(File, Opts) when is_list(Opts) ->
 noenv_file(File, Opt) ->
     noenv_file(File, [Opt|?DEFAULT_OPTIONS]).
 
+-spec noenv_forms(abstract_code(), [option()] | option()) -> comp_ret().
+
 noenv_forms(Forms, Opts) when is_list(Opts) ->
     do_compile({forms,Forms}, [binary|Opts]);
 noenv_forms(Forms, Opt) when is_atom(Opt) ->
@@ -118,6 +132,14 @@ noenv_output_generated(Opts) ->
 	end, Passes).
 
 %%
+%% Retrieve ERL_COMPILER_OPTIONS as a list of terms
+%%
+
+-spec env_compiler_options() -> [term()].
+
+env_compiler_options() -> env_default_opts().
+
+%%
 %%  Local functions
 %%
 
@@ -131,7 +153,8 @@ env_default_opts() ->
 	Str when is_list(Str) ->
 	    case erl_scan:string(Str) of
 		{ok,Tokens,_} ->
-		    case erl_parse:parse_term(Tokens ++ [{dot, 1}]) of
+                    Dot = {dot, erl_anno:new(1)},
+		    case erl_parse:parse_term(Tokens ++ [Dot]) of
 			{ok,List} when is_list(List) -> List;
 			{ok,Term} -> [Term];
 			{error,_Reason} ->
@@ -229,12 +252,27 @@ format_error({undef_parse_transform,M}) ->
 format_error({core_transform,M,R}) ->
     io_lib:format("error in core transform '~s': ~tp", [M, R]);
 format_error({crash,Pass,Reason}) ->
-    io_lib:format("internal error in ~p;\ncrash reason: ~tp", [Pass,Reason]);
+    io_lib:format("internal error in ~p;\ncrash reason: ~ts", [Pass,format_error_reason(Reason)]);
 format_error({bad_return,Pass,Reason}) ->
-    io_lib:format("internal error in ~p;\nbad return value: ~tp", [Pass,Reason]);
+    io_lib:format("internal error in ~p;\nbad return value: ~ts", [Pass,format_error_reason(Reason)]);
 format_error({module_name,Mod,Filename}) ->
-    io_lib:format("Module name '~s' does not match file name '~ts'",
-		  [Mod,Filename]).
+    io_lib:format("Module name '~s' does not match file name '~ts'", [Mod,Filename]);
+format_error(reparsing_invalid_unicode) ->
+    "Non-UTF-8 character(s) detected, but no encoding declared. Encode the file in UTF-8 or add \"%% coding: latin-1\" at the beginning of the file. Retrying with latin-1 encoding.".
+
+format_error_reason({Reason, Stack}) when is_list(Stack) ->
+    StackFun = fun
+	(escript, run,      2) -> true;
+	(escript, start,    1) -> true;
+	(init,    start_it, 1) -> true;
+	(init,    start_em, 1) -> true;
+	(_Mod, _Fun, _Arity)   -> false
+    end,
+    FormatFun = fun (Term, _) -> io_lib:format("~tp", [Term]) end,
+    [io_lib:format("~tp", [Reason]),"\n\n",
+     lib:format_stacktrace(1, Stack, StackFun, FormatFun)];
+format_error_reason(Reason) ->
+    io_lib:format("~tp", [Reason]).
 
 %% The compile state record.
 -record(compile, {filename="" :: file:filename(),
@@ -269,11 +307,20 @@ internal_comp(Passes, File, Suffix, St0) ->
     St1 = St0#compile{filename=File, dir=Dir, base=Base,
 		      ifile=erlfile(Dir, Base, Suffix),
 		      ofile=objfile(Base, St0)},
-    Run = case member(time, St1#compile.options) of
-	      true  ->
-		  io:format("Compiling ~tp\n", [File]),
-		  fun run_tc/2;
-	      false -> fun({_Name,Fun}, St) -> catch Fun(St) end
+    Opts = St1#compile.options,
+    Run0 = case member(time, Opts) of
+	       true  ->
+		   io:format("Compiling ~tp\n", [File]),
+		   fun run_tc/2;
+	       false -> fun({_Name,Fun}, St) -> catch Fun(St) end
+	   end,
+    Run = case keyfind(eprof, 1, Opts) of
+	      {eprof,EprofPass} ->
+		  fun(P, St) ->
+			  run_eprof(P, EprofPass, St)
+		  end;
+	      false ->
+		  Run0
 	  end,
     case fold_comp(Passes, Run, St1) of
 	{ok,St2} -> comp_ret_ok(St2);
@@ -304,17 +351,26 @@ fold_comp([{Name,Pass}|Ps], Run, St0) ->
 fold_comp([], _Run, St) -> {ok,St}.
 
 run_tc({Name,Fun}, St) ->
-    Before0 = statistics(runtime),
+    T1 = erlang:monotonic_time(),
     Val = (catch Fun(St)),
-    After0 = statistics(runtime),
-    {Before_c, _} = Before0,
-    {After_c, _} = After0,
+    T2 = erlang:monotonic_time(),
+    Elapsed = erlang:convert_time_unit(T2 - T1, native, milli_seconds),
     Mem0 = erts_debug:flat_size(Val)*erlang:system_info(wordsize),
     Mem = lists:flatten(io_lib:format("~.1f kB", [Mem0/1024])),
-    io:format(" ~-30s: ~10.2f s ~12s\n",
-	      [Name,(After_c-Before_c) / 1000,Mem]),
+    io:format(" ~-30s: ~10.3f s ~12s\n",
+	      [Name,Elapsed/1000,Mem]),
     Val.
 
+run_eprof({Name,Fun}, Name, St) ->
+    io:format("~p: Running eprof\n", [Name]),
+    c:appcall(tools, eprof, start_profiling, [[self()]]),
+    Val = (catch Fun(St)),
+    c:appcall(tools, eprof, stop_profiling, []),
+    c:appcall(tools, eprof, analyze, []),
+    Val;
+run_eprof({_,Fun}, _, St) ->
+    catch Fun(St).
+
 comp_ret_ok(#compile{code=Code,warnings=Warn0,module=Mod,options=Opts}=St) ->
     case werror(St) of
         true ->
@@ -415,8 +471,6 @@ pass(from_core) ->
     {".core",[?pass(parse_core)|core_passes()]};
 pass(from_asm) ->
     {".S",[?pass(beam_consult_asm)|asm_passes()]};
-pass(asm) ->
-    pass(from_asm);
 pass(from_beam) ->
     {".beam",[?pass(read_beam_file)|binary_passes()]};
 pass(_) -> none.
@@ -592,7 +646,7 @@ standard_passes() ->
      {iff,'to_exp',{done,"E"}},
 
      %% Conversion to Core Erlang.
-     ?pass(core_module),
+     {pass,v3_core},
      {iff,'dcore',{listing,"core"}},
      {iff,'to_core0',{done,"core"}}
      | core_passes()].
@@ -604,10 +658,12 @@ core_passes() ->
       [{unless,no_copt,
        [{core_old_inliner,fun test_old_inliner/1,fun core_old_inliner/1},
 	{iff,doldinline,{listing,"oldinline"}},
-	?pass(core_fold_module),
+	{pass,sys_core_fold},
+	{iff,dcorefold,{listing,"corefold"}},
 	{core_inline_module,fun test_core_inliner/1,fun core_inline_module/1},
 	{iff,dinline,{listing,"inline"}},
-	{core_fold_after_inline,fun test_core_inliner/1,fun core_fold_module/1},
+        {core_fold_after_inlining,fun test_any_inliner/1,
+         fun core_fold_module_after_inlining/1},
 	?pass(core_transforms)]},
        {iff,dcopt,{listing,"copt"}},
        {iff,'to_core',{done,"core"}}]}
@@ -615,14 +671,14 @@ core_passes() ->
 
 kernel_passes() ->
     %% Destructive setelement/3 optimization and core lint.
-    [?pass(core_dsetel_module),
+    [{pass,sys_core_dsetel},
      {iff,dsetel,{listing,"dsetel"}},
 
      {iff,clint,?pass(core_lint_module)},
      {iff,core,?pass(save_core_code)},
 
      %% Kernel Erlang and code generation.
-     ?pass(kernel_module),
+     {pass,v3_kernel},
      {iff,dkern,{listing,"kernel"}},
      {iff,'to_kernel',{done,"kernel"}},
      {pass,v3_life},
@@ -635,11 +691,16 @@ asm_passes() ->
     %% Assembly level optimisations.
     [{delay,
       [{pass,beam_a},
+       {iff,da,{listing,"a"}},
        {unless,no_postopt,
-	[{pass,beam_block},
+	[{unless,no_reorder,{pass,beam_reorder}},
+	 {iff,dre,{listing,"reorder"}},
+	 {pass,beam_block},
 	 {iff,dblk,{listing,"block"}},
 	 {unless,no_except,{pass,beam_except}},
 	 {iff,dexcept,{listing,"except"}},
+	 {unless,no_bs_opt,{pass,beam_bs}},
+	 {iff,dbs,{listing,"bs"}},
 	 {unless,no_bopt,{pass,beam_bool}},
 	 {iff,dbool,{listing,"bool"}},
 	 {unless,no_topt,{pass,beam_type}},
@@ -667,6 +728,7 @@ asm_passes() ->
        {iff,no_postopt,[{pass,beam_clean}]},
 
        {pass,beam_z},
+       {iff,dz,{listing,"z"}},
        {iff,dopt,{listing,"optimize"}},
        {iff,'S',{listing,"S"}},
        {iff,'to_asm',{done,"S"}}]},
@@ -773,20 +835,59 @@ no_native_compilation(BeamFile, #compile{options=Opts0}) ->
 	_ -> false
     end.
 
-parse_module(St) ->
-    Opts = St#compile.options,
-    Cwd = ".",
-    IncludePath = [Cwd, St#compile.dir|inc_paths(Opts)],
-    R =  epp:parse_file(St#compile.ifile, IncludePath, pre_defs(Opts)),
+parse_module(St0) ->
+    case do_parse_module(utf8, St0) of
+	{ok,_}=Ret ->
+	    Ret;
+	{error,_}=Ret ->
+	    Ret;
+	{invalid_unicode,File,Line} ->
+	    case do_parse_module(latin1, St0) of
+		{ok,St} ->
+		    Es = [{File,[{Line,?MODULE,reparsing_invalid_unicode}]}],
+		    {ok,St#compile{warnings=Es++St#compile.warnings}};
+		{error,St} ->
+		    Es = [{File,[{Line,?MODULE,reparsing_invalid_unicode}]}],
+		    {error,St#compile{errors=Es++St#compile.errors}}
+	    end
+    end.
+
+do_parse_module(DefEncoding, #compile{ifile=File,options=Opts,dir=Dir}=St) ->
+    R = epp:parse_file(File,
+		       [{includes,[".",Dir|inc_paths(Opts)]},
+			{macros,pre_defs(Opts)},
+			{default_encoding,DefEncoding},
+			extra]),
     case R of
-	{ok,Forms} ->
-            Encoding = epp:read_encoding(St#compile.ifile),
-	    {ok,St#compile{code=Forms,encoding=Encoding}};
+	{ok,Forms,Extra} ->
+	    Encoding = proplists:get_value(encoding, Extra),
+	    case find_invalid_unicode(Forms, File) of
+		none ->
+		    {ok,St#compile{code=Forms,encoding=Encoding}};
+		{invalid_unicode,_,_}=Ret ->
+		    case Encoding of
+			none ->
+			    Ret;
+			_ ->
+			    {ok,St#compile{code=Forms,encoding=Encoding}}
+		    end
+	    end;
 	{error,E} ->
 	    Es = [{St#compile.ifile,[{none,?MODULE,{epp,E}}]}],
 	    {error,St#compile{errors=St#compile.errors ++ Es}}
     end.
 
+find_invalid_unicode([H|T], File0) ->
+    case H of
+	{attribute,_,file,{File,_}} ->
+	    find_invalid_unicode(T, File);
+	{error,{Line,file_io_server,invalid_unicode}} ->
+	    {invalid_unicode,File0,Line};
+	_Other ->
+	    find_invalid_unicode(T, File0)
+    end;
+find_invalid_unicode([], _) -> none.
+
 parse_core(St) ->
     case file:read_file(St#compile.ifile) of
 	{ok,Bin} ->
@@ -846,28 +947,35 @@ transform_module(#compile{options=Opt,code=Code0}=St0) ->
 
 foldl_transform(St, [T|Ts]) ->
     Name = "transform " ++ atom_to_list(T),
-    Fun = fun(S) -> T:parse_transform(S#compile.code, S#compile.options) end,
-    Run = case member(time, St#compile.options) of
-	      true  -> fun run_tc/2;
-	      false -> fun({_Name,F}, S) -> catch F(S) end
-	  end,
-    case Run({Name, Fun}, St) of
-	{error,Es,Ws} ->
-	    {error,St#compile{warnings=St#compile.warnings ++ Ws,
-			      errors=St#compile.errors ++ Es}};
-	{'EXIT',{undef,_}} ->
-	    Es = [{St#compile.ifile,[{none,compile,
-				      {undef_parse_transform,T}}]}],
-	    {error,St#compile{errors=St#compile.errors ++ Es}};
-	{'EXIT',R} ->
-	    Es = [{St#compile.ifile,[{none,compile,{parse_transform,T,R}}]}],
-	    {error,St#compile{errors=St#compile.errors ++ Es}};
-	{warning, Forms, Ws} ->
-	    foldl_transform(
-	      St#compile{code=Forms,
-			 warnings=St#compile.warnings ++ Ws}, Ts);
-	Forms ->
-	    foldl_transform(St#compile{code=Forms}, Ts)
+    case code:ensure_loaded(T) =:= {module,T} andalso
+                erlang:function_exported(T, parse_transform, 2) of
+        true ->
+            Fun = fun(S) ->
+                         T:parse_transform(S#compile.code, S#compile.options)
+                  end,
+            Run = case member(time, St#compile.options) of
+                      true  -> fun run_tc/2;
+                      false -> fun({_Name,F}, S) -> catch F(S) end
+                  end,
+            case Run({Name, Fun}, St) of
+                {error,Es,Ws} ->
+                    {error,St#compile{warnings=St#compile.warnings ++ Ws,
+                                      errors=St#compile.errors ++ Es}};
+                {'EXIT',R} ->
+                    Es = [{St#compile.ifile,[{none,compile,
+                                              {parse_transform,T,R}}]}],
+                    {error,St#compile{errors=St#compile.errors ++ Es}};
+                {warning, Forms, Ws} ->
+                    foldl_transform(
+                      St#compile{code=Forms,
+                                 warnings=St#compile.warnings ++ Ws}, Ts);
+                Forms ->
+                    foldl_transform(St#compile{code=Forms}, Ts)
+            end;
+        false ->
+            Es = [{St#compile.ifile,[{none,compile,
+                                      {undef_parse_transform,T}}]}],
+            {error,St#compile{errors=St#compile.errors ++ Es}}
     end;
 foldl_transform(St, []) -> {ok,St}.
 
@@ -1121,13 +1229,11 @@ expand_module(#compile{code=Code,options=Opts0}=St0) ->
     Opts = expand_opts(Opts1),
     {ok,St0#compile{module=Mod,options=Opts,code={Mod,Exp,Forms}}}.
 
-core_module(#compile{code=Code0,options=Opts}=St) ->
-    {ok,Code,Ws} = v3_core:module(Code0, Opts),
-    {ok,St#compile{code=Code,warnings=St#compile.warnings ++ Ws}}.
-
-core_fold_module(#compile{code=Code0,options=Opts,warnings=Warns}=St) ->
-    {ok,Code,Ws} = sys_core_fold:module(Code0, Opts),
-    {ok,St#compile{code=Code,warnings=Warns ++ Ws}}.
+core_fold_module_after_inlining(#compile{code=Code0,options=Opts}=St) ->
+    %% Inlining may produce code that generates spurious warnings.
+    %% Ignore all warnings.
+    {ok,Code,_Ws} = sys_core_fold:module(Code0, Opts),
+    {ok,St#compile{code=Code}}.
 
 test_old_inliner(#compile{options=Opts}) ->
     %% The point of this test is to avoid loading the old inliner
@@ -1147,6 +1253,9 @@ test_core_inliner(#compile{options=Opts}) ->
 		end, Opts)
     end.
 
+test_any_inliner(St) ->
+    test_old_inliner(St) orelse test_core_inliner(St).
+
 core_old_inliner(#compile{code=Code0,options=Opts}=St) ->
     {ok,Code} = sys_core_inline:module(Code0, Opts),
     {ok,St#compile{code=Code}}.
@@ -1155,14 +1264,6 @@ core_inline_module(#compile{code=Code0,options=Opts}=St) ->
     Code = cerl_inline:core_transform(Code0, Opts),
     {ok,St#compile{code=Code}}.
 
-core_dsetel_module(#compile{code=Code0,options=Opts}=St) ->
-    {ok,Code} = sys_core_dsetel:module(Code0, Opts),
-    {ok,St#compile{code=Code}}.
-
-kernel_module(#compile{code=Code0,options=Opts}=St) ->
-    {ok,Code,Ws} = v3_kernel:module(Code0, Opts),
-    {ok,St#compile{code=Code,warnings=St#compile.warnings ++ Ws}}.
-
 save_abstract_code(#compile{ifile=File}=St) ->
     case abstract_code(St) of
 	{ok,Code} ->
@@ -1171,7 +1272,8 @@ save_abstract_code(#compile{ifile=File}=St) ->
 	    {error,St#compile{errors=St#compile.errors ++ [{File,Es}]}}
     end.
 
-abstract_code(#compile{code=Code,options=Opts,ofile=OFile}) ->
+abstract_code(#compile{code=Code0,options=Opts,ofile=OFile}) ->
+    Code = erl_parse:anno_to_term(Code0),
     Abstr = erlang:term_to_binary({raw_abstract_v1,Code}, [compressed]),
     case member(encrypt_debug_info, Opts) of
 	true ->
@@ -1224,26 +1326,18 @@ generate_key(String) when is_list(String) ->
 encrypt({des3_cbc=Type,Key,IVec,BlockSize}, Bin0) ->
     Bin1 = case byte_size(Bin0) rem BlockSize of
 	       0 -> Bin0;
-	       N -> list_to_binary([Bin0,random_bytes(BlockSize-N)])
+	       N -> list_to_binary([Bin0,crypto:strong_rand_bytes(BlockSize-N)])
 	   end,
     Bin = crypto:block_encrypt(Type, Key, IVec, Bin1),
     TypeString = atom_to_list(Type),
     list_to_binary([0,length(TypeString),TypeString,Bin]).
 
-random_bytes(N) ->
-    {A,B,C} = now(),
-    _ = random:seed(A, B, C),
-    random_bytes_1(N, []).
-
-random_bytes_1(0, Acc) -> Acc;
-random_bytes_1(N, Acc) -> random_bytes_1(N-1, [random:uniform(255)|Acc]).
-
 save_core_code(St) ->
     {ok,St#compile{core_code=cerl:from_records(St#compile.code)}}.
 
 beam_asm(#compile{ifile=File,code=Code0,
 		  abstract_code=Abst,mod_options=Opts0}=St) ->
-    Source = filename:absname(File),
+    Source = paranoid_absname(File),
     Opts1 = lists:map(fun({debug_info_key,_}) -> {debug_info_key,'********'};
 			 (Other) -> Other
 		      end, Opts0),
@@ -1252,6 +1346,16 @@ beam_asm(#compile{ifile=File,code=Code0,
 	{ok,Code} -> {ok,St#compile{code=Code,abstract_code=[]}}
     end.
 
+paranoid_absname(""=File) ->
+    File;
+paranoid_absname(File) ->
+    case file:get_cwd() of
+	{ok,Cwd} ->
+	    filename:absname(File, Cwd);
+	_ ->
+	    File
+    end.
+
 test_native(#compile{options=Opts}) ->
     %% This test is done late, in case some other option has turned off native.
     %% 'native' given on the command line can be overridden by
@@ -1290,10 +1394,10 @@ native_compile_1(St) ->
 	{error,R} ->
 	    case IgnoreErrors of
 		true ->
-		    Ws = [{St#compile.ifile,[{?MODULE,{native,R}}]}],
+		    Ws = [{St#compile.ifile,[{none,?MODULE,{native,R}}]}],
 		    {ok,St#compile{warnings=St#compile.warnings ++ Ws}};
 		false ->
-		    Es = [{St#compile.ifile,[{?MODULE,{native,R}}]}],
+		    Es = [{St#compile.ifile,[{none,?MODULE,{native,R}}]}],
 		    {error,St#compile{errors=St#compile.errors ++ Es}}
 	    end
     catch
@@ -1302,7 +1406,7 @@ native_compile_1(St) ->
 	    case IgnoreErrors of
 		true ->
 		    Ws = [{St#compile.ifile,
-			   [{?MODULE,{native_crash,R,Stk}}]}],
+			   [{none,?MODULE,{native_crash,R,Stk}}]}],
 		    {ok,St#compile{warnings=St#compile.warnings ++ Ws}};
 		false ->
 		    erlang:raise(Class, R, Stk)
@@ -1349,7 +1453,7 @@ save_binary(#compile{module=Mod,ofile=Outfile,
 		    save_binary_1(St);
 		_ ->
 		    Es = [{St#compile.ofile,
-			   [{?MODULE,{module_name,Mod,Base}}]}],
+			   [{none,?MODULE,{module_name,Mod,Base}}]}],
 		    {error,St#compile{errors=St#compile.errors ++ Es}}
 	    end
     end.
@@ -1363,20 +1467,20 @@ save_binary_1(St) ->
 		ok ->
 		    {ok,St};
 		{error,RenameError} ->
-		    Es0 = [{Ofile,[{?MODULE,{rename,Tfile,Ofile,
-					     RenameError}}]}],
+		    Es0 = [{Ofile,[{none,?MODULE,{rename,Tfile,Ofile,
+						  RenameError}}]}],
 		    Es = case file:delete(Tfile) of
 			     ok -> Es0;
 			     {error,DeleteError} ->
 				 Es0 ++
 				     [{Ofile,
-				       [{?MODULE,{delete_temp,Tfile,
-						  DeleteError}}]}]
+				       [{none,?MODULE,{delete_temp,Tfile,
+						       DeleteError}}]}]
 			 end,
 		    {error,St#compile{errors=St#compile.errors ++ Es}}
 	    end;
 	{error,_Error} ->
-	    Es = [{Tfile,[{compile,write_error}]}],
+	    Es = [{Tfile,[{none,compile,write_error}]}],
 	    {error,St#compile{errors=St#compile.errors ++ Es}}
     end.
 
@@ -1419,6 +1523,9 @@ report_warnings(#compile{options=Opts,warnings=Ws0}) ->
 	false -> ok
     end.
 
+format_message(F, P, [{none,Mod,E}|Es]) ->
+    M = {none,io_lib:format("~ts: ~s~ts\n", [F,P,Mod:format_error(E)])},
+    [M|format_message(F, P, Es)];
 format_message(F, P, [{{Line,Column}=Loc,Mod,E}|Es]) ->
     M = {{F,Loc},io_lib:format("~ts:~w:~w ~s~ts\n",
                                 [F,Line,Column,P,Mod:format_error(E)])},
@@ -1428,12 +1535,17 @@ format_message(F, P, [{Line,Mod,E}|Es]) ->
                                 [F,Line,P,Mod:format_error(E)])},
     [M|format_message(F, P, Es)];
 format_message(F, P, [{Mod,E}|Es]) ->
+    %% Not documented and not expected to be used any more, but
+    %% keep a while just in case.
     M = {none,io_lib:format("~ts: ~s~ts\n", [F,P,Mod:format_error(E)])},
     [M|format_message(F, P, Es)];
 format_message(_, _, []) -> [].
 
 %% list_errors(File, ErrorDescriptors) -> ok
 
+list_errors(F, [{none,Mod,E}|Es]) ->
+    io:fwrite("~ts: ~ts\n", [F,Mod:format_error(E)]),
+    list_errors(F, Es);
 list_errors(F, [{{Line,Column},Mod,E}|Es]) ->
     io:fwrite("~ts:~w:~w: ~ts\n", [F,Line,Column,Mod:format_error(E)]),
     list_errors(F, Es);
@@ -1441,6 +1553,8 @@ list_errors(F, [{Line,Mod,E}|Es]) ->
     io:fwrite("~ts:~w: ~ts\n", [F,Line,Mod:format_error(E)]),
     list_errors(F, Es);
 list_errors(F, [{Mod,E}|Es]) ->
+    %% Not documented and not expected to be used any more, but
+    %% keep a while just in case.
     io:fwrite("~ts: ~ts\n", [F,Mod:format_error(E)]),
     list_errors(F, Es);
 list_errors(_F, []) -> ok.
@@ -1525,11 +1639,8 @@ output_encoding(F, #compile{encoding = Encoding}) ->
     ok = io:setopts(F, [{encoding, Encoding}]),
     ok = io:fwrite(F, <<"%% ~s\n">>, [epp:encoding_to_string(Encoding)]).
 
-restore_expanded_types("P", Fs) ->
-    epp:restore_typed_record_fields(Fs);
 restore_expanded_types("E", {M,I,Fs0}) ->
-    Fs1 = restore_expand_module(Fs0),
-    Fs = epp:restore_typed_record_fields(Fs1),
+    Fs = restore_expand_module(Fs0),
     {M,I,Fs};
 restore_expanded_types(_Ext, Code) -> Code.
 
@@ -1541,11 +1652,13 @@ restore_expand_module([{attribute,Line,spec,[Arg]}|Fs]) ->
     [{attribute,Line,spec,Arg}|restore_expand_module(Fs)];
 restore_expand_module([{attribute,Line,callback,[Arg]}|Fs]) ->
     [{attribute,Line,callback,Arg}|restore_expand_module(Fs)];
+restore_expand_module([{attribute,Line,record,[R]}|Fs]) ->
+    [{attribute,Line,record,R}|restore_expand_module(Fs)];
 restore_expand_module([F|Fs]) ->
     [F|restore_expand_module(Fs)];
 restore_expand_module([]) -> [].
 
-
+
 -spec options() -> 'ok'.
 
 options() ->
@@ -1582,11 +1695,12 @@ help([_|T]) ->
 help(_) ->
     ok.
 
-
+
 %% compile(AbsFileName, Outfilename, Options)
 %%   Compile entry point for erl_compile.
 
 compile(File0, _OutFile, Options) ->
+    pre_load(),
     File = shorten_filename(File0),
     case file(File, make_erl_options(Options)) of
 	{ok,_Mod} -> ok;
@@ -1602,7 +1716,7 @@ compile_beam(File0, _OutFile, Opts) ->
 
 compile_asm(File0, _OutFile, Opts) ->
     File = shorten_filename(File0),
-    case file(File, [asm|make_erl_options(Opts)]) of
+    case file(File, [from_asm|make_erl_options(Opts)]) of
 	{ok,_Mod} -> ok;
 	Other -> Other
     end.
@@ -1651,3 +1765,47 @@ make_erl_options(Opts) ->
 	end,
     Options ++ [report_errors, {cwd, Cwd}, {outdir, Outdir}|
 	        [{i, Dir} || Dir <- Includes]] ++ Specific.
+
+pre_load() ->
+    L = [beam_a,
+	 beam_asm,
+	 beam_block,
+	 beam_bool,
+	 beam_bs,
+	 beam_bsm,
+	 beam_clean,
+	 beam_dead,
+	 beam_dict,
+	 beam_except,
+	 beam_flatten,
+	 beam_jump,
+	 beam_opcodes,
+	 beam_peep,
+	 beam_receive,
+	 beam_reorder,
+	 beam_split,
+	 beam_trim,
+	 beam_type,
+	 beam_utils,
+	 beam_validator,
+	 beam_z,
+	 cerl,
+	 cerl_clauses,
+	 cerl_sets,
+	 cerl_trees,
+	 core_lib,
+	 epp,
+	 erl_bifs,
+	 erl_expand_records,
+	 erl_lint,
+	 erl_parse,
+	 erl_scan,
+	 sys_core_dsetel,
+	 sys_core_fold,
+	 sys_pre_expand,
+	 v3_codegen,
+	 v3_core,
+	 v3_kernel,
+	 v3_life],
+    _ = code:ensure_modules_loaded(L),
+    ok.
diff --git a/lib/compiler/src/compiler.app.src b/lib/compiler/src/compiler.app.src
index 8775c84698..1fd7800e85 100644
--- a/lib/compiler/src/compiler.app.src
+++ b/lib/compiler/src/compiler.app.src
@@ -1,18 +1,19 @@
 % This is an -*- erlang -*- file.
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 
@@ -24,6 +25,7 @@
 	     beam_asm,
 	     beam_block,
 	     beam_bool,
+	     beam_bs,
 	     beam_bsm,
 	     beam_clean,
 	     beam_dead,
@@ -36,6 +38,7 @@
 	     beam_opcodes,
 	     beam_peep,
 	     beam_receive,
+	     beam_reorder,
 	     beam_split,
 	     beam_trim,
 	     beam_type,
@@ -45,6 +48,7 @@
 	     cerl,
 	     cerl_clauses,
 	     cerl_inline,
+             cerl_sets,
 	     cerl_trees,
 	     compile,
 	     core_scan,
@@ -56,6 +60,7 @@
 	     rec_env,
 	     sys_core_dsetel,
 	     sys_core_fold,
+	     sys_core_fold_lists,
 	     sys_core_inline,
 	     sys_pre_attributes,
 	     sys_pre_expand,
@@ -67,4 +72,6 @@
 	    ]},
   {registered, []},
   {applications, [kernel, stdlib]},
-  {env, []}]}.
+  {env, []},
+  {runtime_dependencies, ["stdlib-2.5","kernel-4.0","hipe-3.12","erts-7.0",
+			  "crypto-3.6"]}]}.
diff --git a/lib/compiler/src/compiler.appup.src b/lib/compiler/src/compiler.appup.src
index 54a63833e6..e9db37e203 100644
--- a/lib/compiler/src/compiler.appup.src
+++ b/lib/compiler/src/compiler.appup.src
@@ -1 +1,22 @@
-{"%VSN%",[],[]}.
+%% -*- erlang -*-
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2014-2016. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+{"%VSN%",
+ [{<<".*">>,[{restart_application, compiler}]}],
+ [{<<".*">>,[{restart_application, compiler}]}]
+}.
diff --git a/lib/compiler/src/core_lib.erl b/lib/compiler/src/core_lib.erl
index 824be9ff7f..c1806272bd 100644
--- a/lib/compiler/src/core_lib.erl
+++ b/lib/compiler/src/core_lib.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2000-2009. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -20,71 +21,16 @@
 
 -module(core_lib).
 
--export([get_anno/1,set_anno/2]).
--export([is_literal/1,is_literal_list/1]).
--export([literal_value/1]).
 -export([make_values/1]).
 -export([is_var_used/2]).
 
 -include("core_parse.hrl").
 
-%%
-%% Generic get/set annotation that should be used only with cerl() structures.
-%%
--spec get_anno(cerl:cerl()) -> term().
-
-get_anno(C) -> element(2, C).
-
--spec set_anno(cerl:cerl(), term()) -> cerl:cerl().
-
-set_anno(C, A) -> setelement(2, C, A).
-
--spec is_literal(cerl:cerl()) -> boolean().
-
-is_literal(#c_literal{}) -> true;
-is_literal(#c_cons{hd=H,tl=T}) ->
-    is_literal(H) andalso is_literal(T);
-is_literal(#c_tuple{es=Es}) -> is_literal_list(Es);
-is_literal(#c_binary{segments=Es}) -> is_lit_bin(Es);
-is_literal(_) -> false.
-
--spec is_literal_list([cerl:cerl()]) -> boolean().
-
-is_literal_list(Es) -> lists:all(fun is_literal/1, Es).
-
-is_lit_bin(Es) ->
-    lists:all(fun (#c_bitstr{val=E,size=S}) ->
-		      is_literal(E) andalso is_literal(S)
-	      end, Es).
-
-%% Return the value of LitExpr.
--spec literal_value(cerl:c_literal() | cerl:c_binary() |
-		    cerl:c_cons() | cerl:c_tuple()) -> term().
-
-literal_value(#c_literal{val=V}) -> V;
-literal_value(#c_binary{segments=Es}) ->
-    list_to_binary([literal_value_bin(Bit) || Bit <- Es]);
-literal_value(#c_cons{hd=H,tl=T}) ->
-    [literal_value(H)|literal_value(T)];
-literal_value(#c_tuple{es=Es}) ->
-    list_to_tuple(literal_value_list(Es)).
-
-literal_value_list(Vals) -> [literal_value(V) || V <- Vals].
-
-literal_value_bin(#c_bitstr{val=Val,size=Sz,unit=U,type=T,flags=Fs}) ->
-    %% We will only handle literals constructed by make_literal/1.
-    %% Could be made more general in the future if the need arises.
-    8 = literal_value(Sz),
-    1 = literal_value(U),
-    integer = literal_value(T),
-    [unsigned,big] = literal_value(Fs),
-    literal_value(Val).
-
 %% Make a suitable values structure, expr or values, depending on Expr.
 -spec make_values([cerl:cerl()] | cerl:cerl()) -> cerl:cerl().
 
 make_values([E]) -> E;
-make_values([H|_]=Es) -> #c_values{anno=get_anno(H),es=Es};
+make_values([H|_]=Es) -> #c_values{anno=cerl:get_ann(H),es=Es};
 make_values([]) -> #c_values{es=[]};
 make_values(E) -> E.
 
@@ -105,6 +51,10 @@ vu_expr(V, #c_cons{hd=H,tl=T}) ->
     vu_expr(V, H) orelse vu_expr(V, T);
 vu_expr(V, #c_tuple{es=Es}) ->
     vu_expr_list(V, Es);
+vu_expr(V, #c_map{arg=M,es=Es}) ->
+    vu_expr(V, M) orelse vu_expr_list(V, Es);
+vu_expr(V, #c_map_pair{key=Key,val=Val}) ->
+    vu_expr_list(V, [Key,Val]);
 vu_expr(V, #c_binary{segments=Ss}) ->
     vu_seg_list(V, Ss);
 vu_expr(V, #c_fun{vars=Vs,body=B}) ->
@@ -201,6 +151,8 @@ vu_pattern(V, #c_tuple{es=Es}, St) ->
     vu_pattern_list(V, Es, St);
 vu_pattern(V, #c_binary{segments=Ss}, St) ->
     vu_pat_seg_list(V, Ss, St);
+vu_pattern(V, #c_map{es=Es}, St) ->
+    vu_map_pairs(V, Es, St);
 vu_pattern(V, #c_alias{var=Var,pat=P}, St0) ->
     case vu_pattern(V, Var, St0) of
 	{true,_}=St1 -> St1;
@@ -223,6 +175,18 @@ vu_pat_seg_list(V, Ss, St) ->
 			end
 		end, St, Ss).
 
+vu_map_pairs(V, [#c_map_pair{key=Key,val=Pat}|T], St0) ->
+    case vu_expr(V, Key) of
+	true ->
+	    {true,false};
+	false ->
+	    case vu_pattern(V, Pat, St0) of
+		{true,_}=St -> St;
+		St -> vu_map_pairs(V, T, St)
+	    end
+    end;
+vu_map_pairs(_, [], St) -> St.
+
 -spec vu_var_list(cerl:var_name(), [cerl:c_var()]) -> boolean().
 
 vu_var_list(V, Vs) ->
diff --git a/lib/compiler/src/core_lint.erl b/lib/compiler/src/core_lint.erl
index 1e8983f594..7d3513c0ba 100644
--- a/lib/compiler/src/core_lint.erl
+++ b/lib/compiler/src/core_lint.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2015. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -33,9 +34,6 @@
 %% Values only as multiple values/variables/patterns.
 %% Return same number of values as requested
 %% Correct number of arguments
-%%
-%% Checks to add:
-%%
 %% Consistency of values/variables
 %% Consistency of function return values/calls.
 %%
@@ -68,14 +66,14 @@
                   | {'undefined_function', fa(), fa()}
                   | {'tail_segment_not_at_end', fa()}.
 
--type error()    :: {module(), err_desc()}.
+-type error()    :: {'none', module(), err_desc()}.
 -type warning()  :: {module(), term()}.
 
 %%-----------------------------------------------------------------------
 %% Define the lint state record.
 
 -record(lint, {module       :: module(),		% Current module
-	       func         :: fa(),			% Current function
+	       func         :: fa() | 'undefined',	% Current function
 	       errors  = [] :: [error()],		% Errors
 	       warnings= [] :: [warning()]}).		% Warnings
 
@@ -162,7 +160,7 @@ return_status(St) ->
 %% add_warning(ErrorDescriptor, State) -> State'
 %%  Note that we don't use line numbers here.
 
-add_error(E, St) -> St#lint{errors=[{?MODULE,E}|St#lint.errors]}.
+add_error(E, St) -> St#lint{errors=[{none,?MODULE,E}|St#lint.errors]}.
 
 %%add_warning(W, St) -> St#lint{warnings=[{none,core_lint,W}|St#lint.warnings]}.
 
@@ -176,7 +174,7 @@ check_exports(Es, St) ->
     end.
 
 check_attrs(As, St) ->
-    case all(fun ({#c_literal{},V}) -> core_lib:is_literal(V);
+    case all(fun ({#c_literal{},#c_literal{}}) -> true;
 		 (_) -> false
 	     end, As) of
 	true -> St;
@@ -211,7 +209,7 @@ functions(Fs, Def, St0) ->
 function({#c_var{name={_,_}},B}, Def, St) ->
     %% Body must be a fun!
     case B of
-	#c_fun{} -> expr(B, Def, any, St);
+	#c_fun{} -> expr(B, Def, 1, St);
 	_ -> add_error({illegal_expr,St#lint.func}, St)
     end.
 
@@ -247,26 +245,43 @@ gbody(E, Def, Rt, St0) ->
 	false -> St1
     end.
 
-gexpr(#c_var{name=N}, Def, _Rt, St) when is_atom(N); is_integer(N) ->
-    expr_var(N, Def, St);
-gexpr(#c_literal{}, _Def, _Rt, St) -> St;
-gexpr(#c_cons{hd=H,tl=T}, Def, _Rt, St) ->
-    gexpr_list([H,T], Def, St);
-gexpr(#c_tuple{es=Es}, Def, _Rt, St) ->
-    gexpr_list(Es, Def, St);
-gexpr(#c_binary{segments=Ss}, Def, _Rt, St) ->
-    gbitstr_list(Ss, Def, St);
+gexpr(#c_var{name=N}, Def, Rt, St) when is_atom(N); is_integer(N) ->
+    return_match(Rt, 1, expr_var(N, Def, St));
+gexpr(#c_literal{}, _Def, Rt, St) ->
+    return_match(Rt, 1, St);
+gexpr(#c_cons{hd=H,tl=T}, Def, Rt, St) ->
+    return_match(Rt, 1, gexpr_list([H,T], Def, St));
+gexpr(#c_tuple{es=Es}, Def, Rt, St) ->
+    return_match(Rt, 1, gexpr_list(Es, Def, St));
+gexpr(#c_map{es=Es}, Def, Rt, St) ->
+    return_match(Rt, 1, gexpr_list(Es, Def, St));
+gexpr(#c_map_pair{key=K,val=V}, Def, Rt, St) ->
+    return_match(Rt, 1, gexpr_list([K,V], Def, St));
+gexpr(#c_binary{segments=Ss}, Def, Rt, St) ->
+    return_match(Rt, 1, gbitstr_list(Ss, Def, St));
 gexpr(#c_seq{arg=Arg,body=B}, Def, Rt, St0) ->
-    St1 = gexpr(Arg, Def, any, St0),		%Ignore values
-    gbody(B, Def, Rt, St1);
+    St1 = gexpr(Arg, Def, 1, St0),
+    return_match(Rt, 1, gbody(B, Def, Rt, St1));
 gexpr(#c_let{vars=Vs,arg=Arg,body=B}, Def, Rt, St0) ->
     St1 = gbody(Arg, Def, let_varcount(Vs), St0), %This is a guard body
     {Lvs,St2} = variable_list(Vs, St1),
     gbody(B, union(Lvs, Def), Rt, St2);
-gexpr(#c_call{module=#c_literal{val=erlang},
-	      name=#c_literal{},
-	      args=As}, Def, 1, St) ->
-    gexpr_list(As, Def, St);
+gexpr(#c_call{module=#c_literal{val=erlang},name=#c_literal{val=is_record},
+              args=[Arg,#c_literal{val=Tag},#c_literal{val=Size}]},
+      Def, Rt, St) when is_atom(Tag), is_integer(Size) ->
+    return_match(Rt, 1, gexpr(Arg, Def, 1, St));
+gexpr(#c_call{module=#c_literal{val=erlang},name=#c_literal{val=is_record}},
+      _Def, Rt, St) ->
+    return_match(Rt, 1, add_error({illegal_guard,St#lint.func}, St));
+gexpr(#c_call{module=#c_literal{val=erlang},name=#c_literal{val=Name},args=As},
+      Def, Rt, St0) when is_atom(Name) ->
+    St1 = return_match(Rt, 1, St0),
+    case is_guard_bif(Name, length(As)) of
+        true ->
+            gexpr_list(As, Def, St1);
+        false ->
+            add_error({illegal_guard,St1#lint.func}, St1)
+    end;
 gexpr(#c_primop{name=#c_literal{val=A},args=As}, Def, _Rt, St0) when is_atom(A) ->
     gexpr_list(As, Def, St0);
 gexpr(#c_try{arg=E,vars=[#c_var{name=X}],body=#c_var{name=X},
@@ -278,6 +293,7 @@ gexpr(#c_case{arg=Arg,clauses=Cs}, Def, Rt, St0) ->
     St1 = gbody(Arg, Def, PatCount, St0),
     clauses(Cs, Def, PatCount, Rt, St1);
 gexpr(_Core, _, _, St) ->
+    %%io:fwrite("clint gexpr: ~p~n", [_Core]),
     add_error({illegal_guard,St#lint.func}, St).
 
 %% gexpr_list([Expr], Defined, State) -> State.
@@ -293,21 +309,35 @@ gbitstr_list(Es, Def, St0) ->
 gbitstr(#c_bitstr{val=V,size=S}, Def, St) ->
     gexpr_list([V,S], Def, St).
 
+%% is_guard_bif(Name, Arity) -> Boolean.
+
+is_guard_bif(Name, Arity) ->
+    erl_internal:guard_bif(Name, Arity)
+        orelse erl_internal:arith_op(Name, Arity)
+        orelse erl_internal:bool_op(Name, Arity)
+        orelse erl_internal:comp_op(Name, Arity).
+
 %% expr(Expr, Defined, RetCount, State) -> State.
 
-expr(#c_var{name={_,_}=FA}, Def, _Rt, St) ->
-    expr_fname(FA, Def, St);
-expr(#c_var{name=N}, Def, _Rt, St) -> expr_var(N, Def, St);
-expr(#c_literal{}, _Def, _Rt, St) -> St;
-expr(#c_cons{hd=H,tl=T}, Def, _Rt, St) ->
-    expr_list([H,T], Def, St);
-expr(#c_tuple{es=Es}, Def, _Rt, St) ->
-    expr_list(Es, Def, St);
-expr(#c_binary{segments=Ss}, Def, _Rt, St) ->
-    bitstr_list(Ss, Def, St);
+expr(#c_var{name={_,_}=FA}, Def, Rt, St) ->
+    return_match(Rt, 1, expr_fname(FA, Def, St));
+expr(#c_var{name=N}, Def, Rt, St) ->
+    return_match(Rt, 1, expr_var(N, Def, St));
+expr(#c_literal{}, _Def, Rt, St) ->
+    return_match(Rt, 1, St);
+expr(#c_cons{hd=H,tl=T}, Def, Rt, St) ->
+    return_match(Rt, 1, expr_list([H,T], Def, St));
+expr(#c_tuple{es=Es}, Def, Rt, St) ->
+    return_match(Rt, 1, expr_list(Es, Def, St));
+expr(#c_map{es=Es}, Def, Rt, St) ->
+    return_match(Rt, 1, expr_list(Es, Def, St));
+expr(#c_map_pair{key=K,val=V}, Def, Rt, St) ->
+    return_match(Rt, 1, expr_list([K,V], Def, St));
+expr(#c_binary{segments=Ss}, Def, Rt, St) ->
+    return_match(Rt, 1, bitstr_list(Ss, Def, St));
 expr(#c_fun{vars=Vs,body=B}, Def, Rt, St0) ->
     {Vvs,St1} = variable_list(Vs, St0),
-    return_match(Rt, 1, body(B, union(Vvs, Def), any, St1));
+    return_match(Rt, 1, body(B, union(Vvs, Def), 1, St1));
 expr(#c_seq{arg=Arg,body=B}, Def, Rt, St0) ->
     St1 = expr(Arg, Def, 1, St0),
     body(B, Def, Rt, St1);
@@ -333,15 +363,26 @@ expr(#c_receive{clauses=Cs,timeout=T,action=A}, Def, Rt, St0) ->
     St1 = expr(T, Def, 1, St0),
     St2 = body(A, Def, Rt, St1),
     clauses(Cs, Def, 1, Rt, St2);
-expr(#c_apply{op=Op,args=As}, Def, _Rt, St0) ->
+expr(#c_apply{op=Op,args=As}, Def, Rt, St0) ->
     St1 = apply_op(Op, Def, length(As), St0),
-    expr_list(As, Def, St1);
+    return_match(Rt, 1, expr_list(As, Def, St1));
+expr(#c_call{module=#c_literal{val=erlang},name=#c_literal{val=Name},args=As},
+     Def, Rt, St0) when is_atom(Name) ->
+    St1 = expr_list(As, Def, St0),
+    case erl_bifs:is_exit_bif(erlang, Name, length(As)) of
+        true -> St1;
+        false -> return_match(Rt, 1, St1)
+    end;
 expr(#c_call{module=M,name=N,args=As}, Def, _Rt, St0) ->
     St1 = expr(M, Def, 1, St0),
     St2 = expr(N, Def, 1, St1),
     expr_list(As, Def, St2);
-expr(#c_primop{name=#c_literal{val=A},args=As}, Def, _Rt, St0) when is_atom(A) ->
-    expr_list(As, Def, St0);
+expr(#c_primop{name=#c_literal{val=A},args=As}, Def, Rt, St0) when is_atom(A) ->
+    St1 = expr_list(As, Def, St0),
+    case A of
+        match_fail -> St1;
+        _ -> return_match(Rt, 1, St1)
+    end;
 expr(#c_catch{body=B}, Def, Rt, St) ->
     return_match(Rt, 1, body(B, Def, 1, St));
 expr(#c_try{arg=A,vars=Vs,body=B,evars=Evs,handler=H}, Def, Rt, St0) ->
@@ -355,7 +396,7 @@ expr(#c_try{arg=A,vars=Vs,body=B,evars=Evs,handler=H}, Def, Rt, St0) ->
     {Ens,St5} = variable_list(Evs, St4),
     body(H, union(Ens, Def), Rt, St5);
 expr(_Other, _, _, St) ->
-    %%io:fwrite("clint: ~p~n", [_Other]),
+    %%io:fwrite("clint expr: ~p~n", [_Other]),
     add_error({illegal_expr,St#lint.func}, St).
 
 %% expr_list([Expr], Defined, State) -> State.
@@ -454,13 +495,19 @@ pattern(#c_cons{hd=H,tl=T}, Def, Ps, St) ->
     pattern_list([H,T], Def, Ps, St);
 pattern(#c_tuple{es=Es}, Def, Ps, St) ->
     pattern_list(Es, Def, Ps, St);
+pattern(#c_map{es=Es}, Def, Ps, St) ->
+    pattern_list(Es, Def, Ps, St);
+pattern(#c_map_pair{op=#c_literal{val=exact},key=K,val=V},Def,Ps,St) ->
+    pattern_list([K,V],Def,Ps,St);
 pattern(#c_binary{segments=Ss}, Def, Ps, St0) ->
     St = pat_bin_tail_check(Ss, St0),
     pat_bin(Ss, Def, Ps, St);
 pattern(#c_alias{var=V,pat=P}, Def, Ps, St0) ->
     {Vvs,St1} = variable(V, Ps, St0),
     pattern(P, Def, union(Vvs, Ps), St1);
-pattern(_, _, Ps, St) -> {Ps,add_error({not_pattern,St#lint.func}, St)}.
+pattern(_Other, _, Ps, St) ->
+    %%io:fwrite("clint pattern: ~p~n", [_Other]),
+    {Ps,add_error({not_pattern,St#lint.func}, St)}.
 
 pat_var(N, _Def, Ps, St) ->
     case is_element(N, Ps) of
diff --git a/lib/compiler/src/core_parse.hrl b/lib/compiler/src/core_parse.hrl
index 0b8f4d8895..83a6f0179c 100644
--- a/lib/compiler/src/core_parse.hrl
+++ b/lib/compiler/src/core_parse.hrl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -34,7 +35,7 @@
 -record(c_apply, {anno=[], op,		% op :: Tree,
 		  args}).		% args :: [Tree]
 
--record(c_binary, {anno=[], segments}).	% segments :: [#c_bitstr{}]
+-record(c_binary, {anno=[], segments :: [cerl:c_bitstr()]}).
 
 -record(c_bitstr, {anno=[], val,        % val :: Tree,
 		   size,		% size :: Tree,
@@ -70,6 +71,16 @@
 
 -record(c_literal, {anno=[], val}).	% val :: literal()
 
+-record(c_map, {anno=[],
+		arg=#c_literal{val=#{}} :: cerl:c_var() | cerl:c_literal(),
+		es :: [cerl:c_map_pair()],
+		is_pat=false :: boolean()}).
+
+-record(c_map_pair, {anno=[],
+	             op :: #c_literal{val::'assoc'} | #c_literal{val::'exact'},
+		     key,
+		     val}).
+
 -record(c_module, {anno=[], name,	% name :: Tree,
 		   exports,		% exports :: [Tree],
 		   attrs,		% attrs :: [#c_def{}],
diff --git a/lib/compiler/src/core_parse.yrl b/lib/compiler/src/core_parse.yrl
index 4e98a8c2da..8028aa99bb 100644
--- a/lib/compiler/src/core_parse.yrl
+++ b/lib/compiler/src/core_parse.yrl
@@ -1,18 +1,19 @@
 %% -*-Erlang-*-
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -21,6 +22,8 @@
 %% Have explicit productions for annotated phrases named anno_XXX.
 %% This just does an XXX and adds the annotation.
 
+Expect 0.
+
 Nonterminals
 
 module_definition module_export module_attribute module_defs
@@ -44,9 +47,14 @@ receive_expr timeout try_expr
 sequence catch_expr
 variable clause clause_pattern
 
-annotation anno_fun anno_expression anno_expressions
+map_expr anno_map_expr map_pairs anno_map_pair map_pair map_pair_assoc map_pair_exact
+map_pattern map_pair_patterns map_pair_pattern
+
+annotation anno_atom anno_fun anno_expression anno_expressions
 anno_variable anno_variables anno_pattern anno_patterns
 anno_function_name
+anno_literal
+anno_segment anno_segment_pattern
 anno_clause anno_clauses.
 
 Terminals
@@ -54,6 +62,7 @@ Terminals
 %% Separators
 
 '(' ')' '{' '}' '[' ']' '|' ',' '->' '=' '/' '<' '>' ':' '-|' '#'
+'~' '=>' ':='
 
 %% Keywords (atoms are assumed to always be single-quoted).
 
@@ -83,7 +92,7 @@ module_definition ->
 module_definition ->
     '(' 'module' atom module_export module_attribute module_defs 'end'
 	'-|' annotation ')' :
-	#c_module{anno='$9',name=tok_val('$3'),exports='$4',
+        #c_module{anno='$9',name=#c_literal{val=tok_val('$3')},exports='$4',
 		  attrs='$5',defs='$6'}.
 
 module_export -> '[' ']' : [].
@@ -92,7 +101,7 @@ module_export -> '[' exported_names ']' : '$2'.
 exported_names -> exported_name ',' exported_names : ['$1' | '$3'].
 exported_names -> exported_name : ['$1'].
 
-exported_name -> function_name : '$1'.
+exported_name -> anno_function_name : '$1'.
 
 module_attribute -> 'attributes' '[' ']' : [].
 module_attribute -> 'attributes' '[' attribute_list ']' : '$3'.
@@ -100,8 +109,16 @@ module_attribute -> 'attributes' '[' attribute_list ']' : '$3'.
 attribute_list -> attribute ',' attribute_list : ['$1' | '$3'].
 attribute_list -> attribute : ['$1'].
 
-attribute -> atom '=' literal :
-	{#c_literal{val=tok_val('$1')},'$3'}.
+attribute -> anno_atom '=' anno_literal :
+	{'$1','$3'}.
+
+anno_atom -> atom :
+         cerl:c_atom(tok_val('$1')).
+anno_atom -> '(' atom '-|' annotation ')' :
+         cerl:ann_c_atom('$4', tok_val('$2')).
+
+anno_literal -> literal : '$1'.
+anno_literal -> '(' literal '-|' annotation ')' : cerl:set_ann('$2', '$4').
 
 module_defs -> function_definitions : '$1'.
 
@@ -118,7 +135,7 @@ function_definition ->
 	{'$1','$3'}.
 
 anno_fun -> '(' fun_expr '-|' annotation ')' :
-	core_lib:set_anno('$2', '$4').
+	cerl:set_ann('$2', '$4').
 anno_fun -> fun_expr : '$1'.
 
 %% Constant terms for annotations and attributes.
@@ -157,7 +174,7 @@ tail_constant -> ',' constant tail_constant : ['$2'|'$3'].
 %%  ( ( V -| <anno> ) = ( {a} -| <anno> ) -| <anno> )
 
 anno_pattern -> '(' other_pattern '-|' annotation ')' :
-	core_lib:set_anno('$2', '$4').
+	cerl:set_ann('$2', '$4').
 anno_pattern -> other_pattern : '$1'.
 anno_pattern -> anno_variable : '$1'.
 
@@ -166,6 +183,7 @@ anno_patterns -> anno_pattern : ['$1'].
 
 other_pattern -> atomic_pattern : '$1'.
 other_pattern -> tuple_pattern : '$1'.
+other_pattern -> map_pattern : '$1'.
 other_pattern -> cons_pattern : '$1'.
 other_pattern -> binary_pattern : '$1'.
 other_pattern -> anno_variable '=' anno_pattern :
@@ -176,21 +194,41 @@ atomic_pattern -> atomic_literal : '$1'.
 tuple_pattern -> '{' '}' : c_tuple([]).
 tuple_pattern -> '{' anno_patterns '}' : c_tuple('$2').
 
+map_pattern -> '~' '{' '}' '~' : c_map_pattern([]).
+map_pattern -> '~' '{' map_pair_patterns '}' '~' :
+		   c_map_pattern('$3').
+map_pattern -> '~' '{' map_pair_patterns '|' anno_map_expr '}' '~' :
+		   ann_c_map_pattern('$5', '$3').
+
+map_pair_patterns -> map_pair_pattern : ['$1'].
+map_pair_patterns -> map_pair_pattern ',' map_pair_patterns : ['$1' | '$3'].
+
+map_pair_pattern -> anno_expression ':=' anno_pattern :
+			#c_map_pair{op=#c_literal{val=exact},
+				    key='$1',val='$3'}.
+map_pair_pattern -> '(' anno_expression ':=' anno_pattern '-|' annotation ')' :
+			#c_map_pair{anno='$6',op=#c_literal{val=exact},
+				    key='$2',val='$4'}.
+
 cons_pattern -> '[' anno_pattern tail_pattern :
-		    #c_cons{hd='$2',tl='$3'}.
+		    c_cons('$2', '$3').
 
 tail_pattern -> ']' : #c_literal{val=[]}.
 tail_pattern -> '|' anno_pattern ']' : '$2'.
 tail_pattern -> ',' anno_pattern tail_pattern :
-		    #c_cons{hd='$2',tl='$3'}.
+		    c_cons('$2', '$3').
 
 binary_pattern -> '#' '{' '}' '#' : #c_binary{segments=[]}.
 binary_pattern -> '#' '{' segment_patterns '}' '#' : #c_binary{segments='$3'}.
 
-segment_patterns -> segment_pattern ',' segment_patterns : ['$1' | '$3'].
-segment_patterns -> segment_pattern : ['$1'].
+segment_patterns -> anno_segment_pattern ',' segment_patterns : ['$1' | '$3'].
+segment_patterns -> anno_segment_pattern : ['$1'].
 
-segment_pattern -> '#' '<' anno_pattern '>' '(' anno_patterns ')':
+anno_segment_pattern -> segment_pattern : '$1'.
+anno_segment_pattern -> '(' segment_pattern '-|' annotation ')' :
+      cerl:set_ann('$2', '$4').
+
+segment_pattern -> '#' '<' anno_pattern '>' '(' anno_expressions ')':
 	case '$6' of
 	    [S,U,T,Fs] ->
 		#c_bitstr{val='$3',size=S,unit=U,type=T,flags=Fs};
@@ -206,7 +244,7 @@ anno_variables -> anno_variable : ['$1'].
 
 anno_variable -> variable : '$1'.
 anno_variable -> '(' variable '-|' annotation ')' :
-	core_lib:set_anno('$2', '$4').
+	cerl:set_ann('$2', '$4').
 
 %% Expressions
 %%  Must split expressions into two levels as nested value expressions
@@ -214,7 +252,7 @@ anno_variable -> '(' variable '-|' annotation ')' :
 
 anno_expression -> expression : '$1'.
 anno_expression -> '(' expression '-|' annotation ')' :
-	core_lib:set_anno('$2', '$4').
+	cerl:set_ann('$2', '$4').
 
 anno_expressions -> anno_expression ',' anno_expressions : ['$1' | '$3'].
 anno_expressions -> anno_expression : ['$1'].
@@ -240,6 +278,7 @@ single_expression -> primop_expr : '$1'.
 single_expression -> try_expr : '$1'.
 single_expression -> sequence : '$1'.
 single_expression -> catch_expr : '$1'.
+single_expression -> map_expr : '$1'.
 
 literal -> atomic_literal : '$1'.
 literal -> tuple_literal : '$1'.
@@ -262,11 +301,33 @@ cons_literal -> '[' literal tail_literal : c_cons('$2', '$3').
 
 tail_literal -> ']' : #c_literal{val=[]}.
 tail_literal -> '|' literal ']' : '$2'.
-tail_literal -> ',' literal tail_literal : #c_cons{hd='$2',tl='$3'}.
+tail_literal -> ',' literal tail_literal : c_cons('$2', '$3').
 
 tuple -> '{' '}' : c_tuple([]).
 tuple -> '{' anno_expressions '}' : c_tuple('$2').
 
+map_expr -> '~' '{' '}' '~' : c_map([]).
+map_expr -> '~' '{' map_pairs '}' '~' : c_map('$3').
+map_expr -> '~' '{' map_pairs '|' anno_variable '}' '~' : ann_c_map([], '$5', '$3').
+map_expr -> '~' '{' map_pairs '|' anno_map_expr '}' '~' : ann_c_map([], '$5', '$3').
+
+anno_map_expr -> map_expr : '$1'.
+anno_map_expr -> '(' map_expr '-|' annotation ')' : cerl:set_ann('$2', '$4').
+
+map_pairs -> anno_map_pair : ['$1'].
+map_pairs -> anno_map_pair ',' map_pairs : ['$1' | '$3'].
+
+anno_map_pair -> map_pair : '$1'.
+anno_map_pair -> '(' map_pair '-|' annotation ')' : cerl:set_ann('$2', '$4').
+
+map_pair -> map_pair_assoc : '$1'.
+map_pair -> map_pair_exact : '$1'.
+
+map_pair_assoc -> anno_expression '=>' anno_expression :
+		#c_map_pair{op=#c_literal{val=assoc},key='$1',val='$3'}.
+map_pair_exact -> anno_expression ':=' anno_expression :
+		#c_map_pair{op=#c_literal{val=exact},key='$1',val='$3'}.
+
 cons -> '[' anno_expression tail : c_cons('$2', '$3').
 
 tail -> ']' : #c_literal{val=[]}.
@@ -274,10 +335,13 @@ tail -> '|' anno_expression ']' : '$2'.
 tail -> ',' anno_expression tail : c_cons('$2', '$3').
 
 binary -> '#' '{' '}' '#' : #c_literal{val = <<>>}.
-binary -> '#' '{' segments '}' '#' : #c_binary{segments='$3'}.
+binary -> '#' '{' segments '}' '#' : make_binary('$3').
+
+segments -> anno_segment ',' segments : ['$1' | '$3'].
+segments -> anno_segment : ['$1'].
 
-segments -> segment ',' segments : ['$1' | '$3'].
-segments -> segment : ['$1'].
+anno_segment -> segment : '$1'.
+anno_segment -> '(' segment '-|' annotation ')' : cerl:set_ann('$2', '$4').
 
 segment -> '#' '<' anno_expression '>' '(' anno_expressions ')':
 	case '$6' of
@@ -293,7 +357,7 @@ function_name -> atom '/' integer :
 
 anno_function_name -> function_name : '$1'.
 anno_function_name -> '(' function_name '-|' annotation ')' :
-	core_lib:set_anno('$2', '$4').
+	cerl:set_ann('$2', '$4').
 
 let_vars -> anno_variable : ['$1'].
 let_vars -> '<' '>' : [].
@@ -321,7 +385,7 @@ anno_clauses -> anno_clause : ['$1'].
 
 anno_clause -> clause : '$1'.
 anno_clause -> '(' clause '-|' annotation ')' :
-	core_lib:set_anno('$2', '$4').
+	cerl:set_ann('$2', '$4').
 
 clause -> clause_pattern 'when' anno_expression '->' anno_expression :
 	#c_clause{pats='$1',guard='$3',body='$5'}.
@@ -377,7 +441,56 @@ Erlang code.
 
 -include("core_parse.hrl").
 
--import(cerl, [c_cons/2,c_tuple/1]).
+-import(cerl, [ann_c_map/3,ann_c_map_pattern/2,c_cons/2,c_map/1,
+	       c_map_pattern/1,c_tuple/1]).
 
 tok_val(T) -> element(3, T).
 tok_line(T) -> element(2, T).
+
+%% make_binary([#c_bitstr{}]) -> #c_binary{} | #c_literal{}
+%%  Create either #c_binary{} or #c_literal{} from the binary segments.
+%%  In certain contexts, such as keys for maps, only literals and
+%%  variables are allowed, so we must not create a #c_binary{}
+%%  record in those situation.
+%%
+%%  To keep this function simple, we use a crude heuristic. We will
+%%  assume that Core Erlang has been produced by core_pp. If the
+%%  segments *could* have been output from a literal binary by
+%%  core_pp, we will create a #c_literal{}. Otherwise we will create a
+%%  #c_binary{} record.
+
+make_binary(Segs) ->
+    try make_lit_bin(<<>>, Segs) of
+	Bs when is_bitstring(Bs) ->
+	    #c_literal{val=Bs}
+    catch
+	throw:impossible ->
+	    #c_binary{segments=Segs}
+    end.
+
+make_lit_bin(Acc, [#c_bitstr{val=I0,size=Sz0,unit=U0,type=Type0,flags=F0}|T]) ->
+    I = get_lit_val(I0),
+    Sz = get_lit_val(Sz0),
+    U = get_lit_val(U0),
+    Type = get_lit_val(Type0),
+    F = get_lit_val(F0),
+    if
+	is_integer(I), U =:= 1, Type =:= integer, F =:= [unsigned,big] ->
+	    ok;
+	true ->
+	    throw(impossible)
+    end,
+    if
+	Sz =< 8, T =:= [] ->
+	    <<Acc/binary,I:Sz>>;
+	Sz =:= 8 ->
+	    make_lit_bin(<<Acc/binary,I:8>>, T);
+	true ->
+	    throw(impossible)
+    end;
+make_lit_bin(Acc, []) -> Acc.
+
+get_lit_val(#c_literal{val=Val}) -> Val;
+get_lit_val(_) -> throw(impossible).
+
+%% vim: syntax=erlang
diff --git a/lib/compiler/src/core_pp.erl b/lib/compiler/src/core_pp.erl
index 1f91a52be3..67209d06be 100644
--- a/lib/compiler/src/core_pp.erl
+++ b/lib/compiler/src/core_pp.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -20,7 +21,7 @@
 
 -module(core_pp).
 
--export([format/1]).
+-export([format/1,format_all/1]).
 
 -include("core_parse.hrl").
 
@@ -32,25 +33,35 @@
 %%	Prettyprint-formats (naively) an abstract Core Erlang syntax
 %%	tree.
 
--record(ctxt, {class = term    :: 'clause' | 'def' | 'expr' | 'term',
-	       indent = 0      :: integer(),
+-record(ctxt, {indent = 0      :: integer(),
 	       item_indent = 2 :: integer(),
 	       body_indent = 4 :: integer(),
-	       tab_width = 8   :: non_neg_integer(),
-	       line = 0        :: integer()}).
+	       line = 0        :: integer(),
+	       clean = true    :: boolean()}).
+
+-define(TAB_WIDTH, 8).
 
 -spec format(cerl:cerl()) -> iolist().
 
 format(Node) ->
     format(Node, #ctxt{}).
 
-maybe_anno(Node, Fun, Ctxt) ->
-    As = core_lib:get_anno(Node),
-    case get_line(As) of
+-spec format_all(cerl:cerl()) -> iolist().
+
+format_all(Node) ->
+    format(Node, #ctxt{clean=false}).
+
+maybe_anno(Node, Fun, #ctxt{clean=false}=Ctxt) ->
+    As = cerl:get_ann(Node),
+    maybe_anno(Node, Fun, Ctxt, As);
+maybe_anno(Node, Fun, #ctxt{clean=true}=Ctxt) ->
+    As0 = cerl:get_ann(Node),
+    case get_line(As0) of
 	none ->
-	    maybe_anno(Node, Fun, Ctxt, As);
+	    maybe_anno(Node, Fun, Ctxt, As0);
   	Line ->
-	    if  Line > Ctxt#ctxt.line ->
+	    As = strip_line(As0),
+	    if Line > Ctxt#ctxt.line ->
 		    [io_lib:format("%% Line ~w",[Line]),
 		     nl_indent(Ctxt),
 		     maybe_anno(Node, Fun, Ctxt#ctxt{line = Line}, As)
@@ -60,22 +71,22 @@ maybe_anno(Node, Fun, Ctxt) ->
 	    end
     end.
 
-maybe_anno(Node, Fun, Ctxt, As) ->
-    case strip_line(As) of
-	[] ->
-	    Fun(Node, Ctxt);
-	List ->
-	    Ctxt1 = add_indent(Ctxt, 2),
-	    Ctxt2 = add_indent(Ctxt1, 3),
-	    ["( ",
-	     Fun(Node, Ctxt1),
-	     nl_indent(Ctxt1),
-	     "-| ",format_anno(List, Ctxt2)," )"
-	    ]
-    end.
+maybe_anno(Node, Fun, Ctxt, []) ->
+    Fun(Node, Ctxt);
+maybe_anno(Node, Fun, Ctxt, List) ->
+    Ctxt1 = add_indent(Ctxt, 2),
+    Ctxt2 = add_indent(Ctxt1, 3),
+    ["( ",
+     Fun(Node, Ctxt1),
+     nl_indent(Ctxt1),
+     "-| ",format_anno(List, Ctxt2)," )"
+    ].
 
 format_anno([_|_]=List, Ctxt) ->
     [$[,format_anno_list(List, Ctxt),$]];
+format_anno({file,Name}, _Ctxt) ->
+    %% Optimization: Reduces file size considerably.
+    io_lib:format("{'file',~p}", [Name]);
 format_anno(Tuple, Ctxt) when is_tuple(Tuple) ->
     [${,format_anno_list(tuple_to_list(Tuple), Ctxt),$}];
 format_anno(Val, Ctxt) when is_atom(Val) ->
@@ -118,6 +129,13 @@ format_1(#c_literal{val=Tuple}, Ctxt) when is_tuple(Tuple) ->
 format_1(#c_literal{anno=A,val=Bitstring}, Ctxt) when is_bitstring(Bitstring) ->
     Segs = segs_from_bitstring(Bitstring),
     format_1(#c_binary{anno=A,segments=Segs}, Ctxt);
+format_1(#c_literal{anno=A,val=M},Ctxt) when is_map(M) ->
+    Pairs = maps:to_list(M),
+    Op = #c_literal{val=assoc},
+    Cpairs = [#c_map_pair{op=Op,
+			  key=#c_literal{val=K},
+			  val=#c_literal{val=V}} || {K,V} <- Pairs],
+    format_1(#c_map{anno=A,arg=#c_literal{val=#{}},es=Cpairs},Ctxt);
 format_1(#c_var{name={I,A}}, _) ->
     [core_atom(I),$/,integer_to_list(A)];
 format_1(#c_var{name=V}, _) ->
@@ -161,6 +179,22 @@ format_1(#c_tuple{es=Es}, Ctxt) ->
      format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
      $}
     ];
+format_1(#c_map{arg=#c_literal{anno=[],val=M},es=Es}, Ctxt)
+  when is_map(M), map_size(M) =:= 0 ->
+    ["~{",
+     format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
+     "}~"
+    ];
+format_1(#c_map{arg=Var,es=Es}, Ctxt) ->
+    ["~{",
+     format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
+     "|",format(Var, add_indent(Ctxt, 1)),
+     "}~"
+    ];
+format_1(#c_map_pair{op=#c_literal{val=assoc},key=K,val=V}, Ctxt) ->
+    format_map_pair("=>", K, V, Ctxt);
+format_1(#c_map_pair{op=#c_literal{val=exact},key=K,val=V}, Ctxt) ->
+    format_map_pair(":=", K, V, Ctxt);
 format_1(#c_cons{hd=H,tl=T}, Ctxt) ->
     Txt = ["["|format(H, add_indent(Ctxt, 1))],
     [Txt|format_list_tail(T, add_indent(Ctxt, width(Txt, Ctxt)))];
@@ -169,9 +203,16 @@ format_1(#c_values{es=Es}, Ctxt) ->
 format_1(#c_alias{var=V,pat=P}, Ctxt) ->
     Txt = [format(V, Ctxt)|" = "],
     [Txt|format(P, add_indent(Ctxt, width(Txt, Ctxt)))];
-format_1(#c_let{vars=Vs0,arg=A,body=B}, Ctxt) ->
-    Vs = [core_lib:set_anno(V, []) || V <- Vs0],
-    case is_simple_term(A) of
+format_1(#c_let{anno=Anno0,vars=Vs0,arg=A0,body=B}, #ctxt{clean=Clean}=Ctxt) ->
+    {Vs,A,Anno} = case Clean of
+		      false ->
+			  {Vs0,A0,Anno0};
+		      true ->
+			  {[cerl:set_ann(V, []) || V <- Vs0],
+			   cerl:set_ann(A0, []),
+			   []}
+		  end,
+    case is_simple_term(A) andalso Anno =:= [] of
 	false ->
 	    Ctxt1 = add_indent(Ctxt, Ctxt#ctxt.body_indent),
 	    ["let ",
@@ -188,7 +229,7 @@ format_1(#c_let{vars=Vs0,arg=A,body=B}, Ctxt) ->
 	    ["let ",
 	     format_values(Vs, add_indent(Ctxt, 4)),
 	     " = ",
-	     format(core_lib:set_anno(A, []), Ctxt1),
+	     format(A, Ctxt1),
 	     nl_indent(Ctxt),
 	     "in  "
 	     | format(B, add_indent(Ctxt, 4))
@@ -295,35 +336,30 @@ format_1(#c_module{name=N,exports=Es,attrs=As,defs=Ds}, Ctxt) ->
     [Mod," [",
      format_vseq(Es,
 		 "", ",",
-		 add_indent(set_class(Ctxt, term), width(Mod, Ctxt)+2),
+		 add_indent(Ctxt, width(Mod, Ctxt)+2),
 		 fun format/2),
      "]",
      nl_indent(Ctxt),
      "    attributes [",
      format_vseq(As,
 		 "", ",",
-		 add_indent(set_class(Ctxt, def), 16),
+		 add_indent(Ctxt, 16),
 		 fun format_def/2),
      "]",
      nl_indent(Ctxt),
      format_funcs(Ds, Ctxt),
      nl_indent(Ctxt)
      | "end"
-    ];
-format_1(Type, _) ->
-    ["** Unsupported type: ",
-     io_lib:write(Type)
-     | " **"
     ].
 
 format_funcs(Fs, Ctxt) ->
     format_vseq(Fs,
 		"", "",
-		set_class(Ctxt, def),
+		Ctxt,
 		fun format_def/2).
 
 format_def({N,V}, Ctxt0) ->
-    Ctxt1 = add_indent(set_class(Ctxt0, expr), Ctxt0#ctxt.body_indent),
+    Ctxt1 = add_indent(Ctxt0, Ctxt0#ctxt.body_indent),
     [format(N, Ctxt0),
      " =",
      nl_indent(Ctxt1)
@@ -336,7 +372,10 @@ format_values(Vs, Ctxt) ->
      format_hseq(Vs, ",", add_indent(Ctxt, 1), fun format/2),
      $>].
 
-format_bitstr(#c_bitstr{val=V,size=S,unit=U,type=T,flags=Fs}, Ctxt0) ->
+format_bitstr(Node, Ctxt) ->
+    maybe_anno(Node, fun do_format_bitstr/2, Ctxt).
+
+do_format_bitstr(#c_bitstr{val=V,size=S,unit=U,type=T,flags=Fs}, Ctxt0) ->
     Vs = [S, U, T, Fs],
     Ctxt1 = add_indent(Ctxt0, 2),
     Val = format(V, Ctxt1),
@@ -344,8 +383,7 @@ format_bitstr(#c_bitstr{val=V,size=S,unit=U,type=T,flags=Fs}, Ctxt0) ->
     ["#<", Val, ">(", format_hseq(Vs,",", Ctxt2, fun format/2), $)].
 
 format_clauses(Cs, Ctxt) ->
-    format_vseq(Cs, "", "", set_class(Ctxt, clause),
-		fun format_clause/2).
+    format_vseq(Cs, "", "", Ctxt, fun format_clause/2).
 
 format_clause(Node, Ctxt) ->
     maybe_anno(Node, fun format_clause_1/2, Ctxt).
@@ -357,15 +395,13 @@ format_clause_1(#c_clause{pats=Ps,guard=G,body=B}, Ctxt) ->
      case is_trivial_guard(G) of
 	 true ->
 	     [" when ",
-	      format_guard(G, add_indent(set_class(Ctxt, expr),
-					 width(Ptxt, Ctxt) + 6))];
+	      format_guard(G, add_indent(Ctxt, width(Ptxt, Ctxt) + 6))];
 	 false ->
 	     [nl_indent(Ctxt2), "when ",
 	      format_guard(G, add_indent(Ctxt2, 2))]
      end++
      " ->",
-     nl_indent(Ctxt2)
-     | format(B, set_class(Ctxt2, expr))
+     nl_indent(Ctxt2) | format(B, Ctxt2)
     ].
 
 is_trivial_guard(#c_literal{val=Val}) when is_atom(Val) -> true;
@@ -417,46 +453,55 @@ format_list_tail(#c_cons{anno=[],hd=H,tl=T}, Ctxt) ->
 format_list_tail(Tail, Ctxt) ->
     ["|",format(Tail, add_indent(Ctxt, 1)),"]"].
 
-indent(Ctxt) -> indent(Ctxt#ctxt.indent, Ctxt).
+format_map_pair(Op, K, V, Ctxt0) ->
+    Ctxt1 = add_indent(Ctxt0, 1),
+    Txt = format(K, Ctxt1),
+    Ctxt2 = add_indent(Ctxt0, width(Txt, Ctxt1)),
+    [Txt,Op,format(V, Ctxt2)].
 
-indent(N, _) when N =< 0 -> "";
-indent(N, Ctxt) ->
-    T = Ctxt#ctxt.tab_width,
-    string:chars($\t, N div T, string:chars($\s, N rem T)).
+indent(#ctxt{indent=N}) ->
+    if
+	N =< 0 ->
+	    "";
+	true ->
+	    string:chars($\t, N div ?TAB_WIDTH, spaces(N rem ?TAB_WIDTH))
+    end.
 
 nl_indent(Ctxt) -> [$\n|indent(Ctxt)].
 
+spaces(0) -> "";
+spaces(1) -> " ";
+spaces(2) -> "  ";
+spaces(3) -> "   ";
+spaces(4) -> "    ";
+spaces(5) -> "     ";
+spaces(6) -> "      ";
+spaces(7) -> "       ".
 
+%% Undo indentation done by nl_indent/1.
 unindent(T, Ctxt) ->
-    unindent(T, Ctxt#ctxt.indent, Ctxt, []).
+    unindent(T, Ctxt#ctxt.indent, []).
 
-unindent(T, N, _, C) when N =< 0 ->
+unindent(T, N, C) when N =< 0 ->
     [T|C];
-unindent([$\s|T], N, Ctxt, C) ->
-    unindent(T, N - 1, Ctxt, C);
-unindent([$\t|T], N, Ctxt, C) ->
-    Tab = Ctxt#ctxt.tab_width,
+unindent([$\s|T], N, C) ->
+    unindent(T, N - 1, C);
+unindent([$\t|T], N, C) ->
+    Tab = ?TAB_WIDTH,
     if N >= Tab ->
-	    unindent(T, N - Tab, Ctxt, C);
+	    unindent(T, N - Tab, C);
        true ->
-	    unindent([string:chars($\s, Tab - N)|T], 0, Ctxt, C)
+	    unindent([spaces(Tab - N)|T], 0, C)
     end;
-unindent([L|T], N, Ctxt, C) when is_list(L) ->
-    unindent(L, N, Ctxt, [T|C]);
-unindent([H|T], _, _, C) ->
-    [H|[T|C]];
-unindent([], N, Ctxt, [H|T]) ->
-    unindent(H, N, Ctxt, T);
-unindent([], _, _, []) -> [].
+unindent([L|T], N, C) when is_list(L) ->
+    unindent(L, N, [T|C]).
 
 
 width(Txt, Ctxt) ->
-    try width(Txt, 0, Ctxt, [])
-    catch error:_ -> exit({bad_text,Txt})
-    end.
+    width(Txt, 0, Ctxt, []).
 
 width([$\t|T], A, Ctxt, C) ->
-    width(T, A + Ctxt#ctxt.tab_width, Ctxt, C);
+    width(T, A + ?TAB_WIDTH, Ctxt, C);
 width([$\n|T], _, Ctxt, C) ->
     width(unindent([T|C], Ctxt), Ctxt);
 width([H|T], A, Ctxt, C) when is_list(H) ->
@@ -470,14 +515,9 @@ width([], A, _, []) -> A.
 add_indent(Ctxt, Dx) ->
     Ctxt#ctxt{indent = Ctxt#ctxt.indent + Dx}.
 
-set_class(Ctxt, Class) ->
-    Ctxt#ctxt{class = Class}.
-
 core_atom(A) -> io_lib:write_string(atom_to_list(A), $').
 
 
-is_simple_term(#c_values{es=Es}) ->
-    length(Es) < 3 andalso lists:all(fun is_simple_term/1, Es);
 is_simple_term(#c_tuple{es=Es}) ->
     length(Es) < 4 andalso lists:all(fun is_simple_term/1, Es);
 is_simple_term(#c_var{}) -> true;
diff --git a/lib/compiler/src/core_scan.erl b/lib/compiler/src/core_scan.erl
index 0ca2f57dde..11b52f6c5f 100644
--- a/lib/compiler/src/core_scan.erl
+++ b/lib/compiler/src/core_scan.erl
@@ -1,19 +1,19 @@
-%% -*- coding: utf-8 -*-
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2000-2012. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -96,7 +96,7 @@ format_error(Other) -> io_lib:write(Other).
 
 string_thing($') -> "atom";    %' stupid emacs
 string_thing($") -> "string".  %" stupid emacs
-
+
 %% Re-entrant pre-scanner.
 %%
 %% If the input list of characters is insufficient to build a term the
@@ -214,7 +214,7 @@ pre_comment(eof, Sofar, Pos) ->
 
 pre_error(E, Epos, Pos) ->
     {error,{Epos,core_scan,E}, Pos}.
-
+
 %% scan(CharList, StartPos)
 %%  This takes a list of characters and tries to tokenise them.
 %%
@@ -272,6 +272,10 @@ scan1("->" ++ Cs, Toks, Pos) ->
     scan1(Cs, [{'->',Pos}|Toks], Pos);
 scan1("-|" ++ Cs, Toks, Pos) ->
     scan1(Cs, [{'-|',Pos}|Toks], Pos);
+scan1(":=" ++ Cs, Toks, Pos) ->
+    scan1(Cs, [{':=',Pos}|Toks], Pos);
+scan1("=>" ++ Cs, Toks, Pos) ->
+    scan1(Cs, [{'=>',Pos}|Toks], Pos);
 scan1([C|Cs], Toks, Pos) ->				%Punctuation character
     P = list_to_atom([C]),
     scan1(Cs, [{P,Pos}|Toks], Pos);
diff --git a/lib/compiler/src/erl_bifs.erl b/lib/compiler/src/erl_bifs.erl
index 3ad3c8c690..6b2d781a76 100644
--- a/lib/compiler/src/erl_bifs.erl
+++ b/lib/compiler/src/erl_bifs.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2001-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -91,6 +92,7 @@ is_pure(erlang, is_float, 1) -> true;
 is_pure(erlang, is_function, 1) -> true;
 is_pure(erlang, is_integer, 1) -> true;
 is_pure(erlang, is_list, 1) -> true;
+is_pure(erlang, is_map, 1) -> true;
 is_pure(erlang, is_number, 1) -> true;
 is_pure(erlang, is_pid, 1) -> true;
 is_pure(erlang, is_port, 1) -> true;
@@ -133,6 +135,7 @@ is_pure(math, erf, 1) -> true;
 is_pure(math, erfc, 1) -> true;
 is_pure(math, exp, 1) -> true;
 is_pure(math, log, 1) -> true;
+is_pure(math, log2, 1) -> true;
 is_pure(math, log10, 1) -> true;
 is_pure(math, pow, 2) -> true;
 is_pure(math, sin, 1) -> true;
diff --git a/lib/compiler/src/genop.tab b/lib/compiler/src/genop.tab
index 75ac91907a..dcbdeb32e6 100644..100755
--- a/lib/compiler/src/genop.tab
+++ b/lib/compiler/src/genop.tab
@@ -1,18 +1,19 @@
 #
 # %CopyrightBegin%
 #
-# Copyright Ericsson AB 1998-2011. All Rights Reserved.
+# Copyright Ericsson AB 1998-2016. All Rights Reserved.
 #
-# The contents of this file are subject to the Erlang Public License,
-# Version 1.1, (the "License"); you may not use this file except in
-# compliance with the License. You should have received a copy of the
-# Erlang Public License along with this software. If not, it can be
-# retrieved online at http://www.erlang.org/.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# Software distributed under the License is distributed on an "AS IS"
-# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-# the License for the specific language governing rights and limitations
-# under the License.
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 #
 # %CopyrightEnd%
 #
@@ -23,49 +24,152 @@ BEAM_FORMAT_NUMBER=0
 # arity or semantics, the format number above must be bumped.
 #
 
+## @spec label Lbl
+## @doc Specify a module local label.
+##      Label gives this code address a name (Lbl) and marks the start of
+##      a basic block.
 1: label/1
+
+## @spec func_info M F A
+## @doc Define a function M:F/A
 2: func_info/3
+
 3: int_code_end/0
 
 #
 # Function and BIF calls.
 #
+
+## @spec call Arity Label
+## @doc Call the function at Label.
+##      Save the next instruction as the return address in the CP register.
 4: call/2
+
+## @spec call_last Arity Label Deallocate
+## @doc Deallocate and do a tail recursive call to the function at Label.
+##      Do not update the CP register.
+##      Before the call deallocate Deallocate words of stack.
 5: call_last/3
+
+## @spec call_only Arity Label
+## @doc Do a tail recursive call to the function at Label.
+##      Do not update the CP register.
 6: call_only/2
 
+## @spec call_ext Arity Destination
+## @doc Call the function of arity Arity pointed to by Destination.
+##      Save the next instruction as the return address in the CP register.
 7: call_ext/2
+
+## @spec call_ext_last Arity Destination Deallocate
+## @doc Deallocate and do a tail call to function of arity Arity
+##      pointed to by Destination.
+##      Do not update the CP register.
+##      Deallocate Deallocate words from the stack before the call.
 8: call_ext_last/3
 
+## @spec bif0 Bif Reg
+## @doc Call the bif Bif and store the result in Reg.
 9: bif0/2
+
+## @spec bif1 Lbl Bif Arg Reg
+## @doc Call the bif Bif with the argument Arg, and store the result in Reg.
+##      On failure jump to Lbl.
 10: bif1/4
+
+## @spec bif2 Lbl Bif Arg1 Arg2 Reg
+## @doc Call the bif Bif with the arguments Arg1 and Arg2,
+##      and store the result in Reg.
+##      On failure jump to Lbl.
 11: bif2/5
 
 #
 # Allocating, deallocating and returning.
 #
+
+## @spec allocate StackNeed Live
+## @doc Allocate space for StackNeed words on the stack. If a GC is needed
+##      during allocation there are Live number of live X registers.
+##      Also save the continuation pointer (CP) on the stack.
 12: allocate/2
+
+## @spec allocate_heap StackNeed HeapNeed Live
+## @doc Allocate space for StackNeed words on the stack and ensure there is
+##      space for HeapNeed words on the heap. If a GC is needed
+##      save Live number of X registers.
+##      Also save the continuation pointer (CP) on the stack.
 13: allocate_heap/3
+
+## @spec allocate_zero StackNeed Live
+## @doc Allocate space for StackNeed words on the stack. If a GC is needed
+##      during allocation there are Live number of live X registers.
+##      Clear the new stack words. (By writing NIL.)
+##      Also save the continuation pointer (CP) on the stack.
 14: allocate_zero/2
+
+## @spec allocate_heap_zero StackNeed HeapNeed Live
+## @doc Allocate space for StackNeed words on the stack and HeapNeed words
+##      on the heap. If a GC is needed
+##      during allocation there are Live number of live X registers.
+##      Clear the new stack words. (By writing NIL.)
+##      Also save the continuation pointer (CP) on the stack.
 15: allocate_heap_zero/3
+
+## @spec test_heap HeapNeed Live
+## @doc Ensure there is space for HeapNeed words on the heap. If a GC is needed
+##      save Live number of X registers.
 16: test_heap/2
+
+## @spec init N
+## @doc  Clear the Nth stack word. (By writing NIL.)
 17: init/1
+
+## @spec deallocate N
+## @doc  Restore the continuation pointer (CP) from the stack and deallocate
+##       N+1 words from the stack (the + 1 is for the CP).
 18: deallocate/1
+
+## @spec return
+## @doc  Return to the address in the continuation pointer (CP).
 19: return/0
 
 #
 # Sending & receiving.
 #
+## @spec send
+## @doc  Send argument in x(1) as a message to the destination process in x(0).
+##       The message in x(1) ends up as the result of the send in x(0).
 20: send/0
+
+## @spec remove_message
+## @doc  Unlink the current message from the message queue and store a
+##       pointer to the message in x(0). Remove any timeout.
 21: remove_message/0
+
+## @spec timeout
+## @doc  Reset the save point of the mailbox and clear the timeout flag.
 22: timeout/0
+
+## @spec loop_rec Label Source
+## @doc  Loop over the message queue, if it is empty jump to Label.
 23: loop_rec/2
+
+## @spec loop_rec_end Label
+## @doc  Advance the save pointer to the next message and jump back to Label.
 24: loop_rec_end/1
+
+## @spec wait Label
+## @doc  Suspend the processes and set the entry point to the beginning of the
+##       receive loop at Label.
 25: wait/1
+
+## @spec wait_timeout Lable Time
+## @doc  Sets up a timeout of Time milliseconds and saves the address of the
+##       following instruction as the entry point if the timeout triggers.
 26: wait_timeout/2
 
 #
-# Arithmethic opcodes.
+# Arithmetic opcodes.
 #
 27: -m_plus/4
 28: -m_minus/4
@@ -83,36 +187,106 @@ BEAM_FORMAT_NUMBER=0
 #
 # Comparision operators.
 #
+
+## @spec is_lt Lbl Arg1 Arg2
+## @doc Compare two terms and jump to Lbl if Arg1 is not less than Arg2.
 39: is_lt/3
+
+## @spec is_ge Lbl Arg1 Arg2
+## @doc Compare two terms and jump to Lbl if Arg1 is less than Arg2.
 40: is_ge/3
+
+## @spec is_eq Lbl Arg1 Arg2
+## @doc Compare two terms and jump to Lbl if Arg1 is not (numerically) equal to Arg2.
 41: is_eq/3
+
+## @spec is_ne Lbl Arg1 Arg2
+## @doc Compare two terms and jump to Lbl if Arg1 is (numerically) equal to Arg2.
 42: is_ne/3
+
+## @spec is_eq_exact Lbl Arg1 Arg2
+## @doc Compare two terms and jump to Lbl if Arg1 is not exactly equal to Arg2.
 43: is_eq_exact/3
+
+## @spec is_ne_exact Lbl Arg1 Arg2
+## @doc Compare two terms and jump to Lbl if Arg1 is exactly equal to Arg2.
 44: is_ne_exact/3
 
 #
 # Type tests.
 #
+
+## @spec is_integer Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not an integer.
 45: is_integer/2
+
+## @spec is_float Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a float.
 46: is_float/2
+
+## @spec is_number Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a number.
 47: is_number/2
+
+## @spec is_atom Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not an atom.
 48: is_atom/2
+
+## @spec is_pid Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a pid.
 49: is_pid/2
+
+## @spec is_reference Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a reference.
 50: is_reference/2
+
+## @spec is_port Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a port.
 51: is_port/2
+
+## @spec is_nil Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not nil.
 52: is_nil/2
+
+## @spec is_binary Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a binary.
 53: is_binary/2
+
 54: -is_constant/2
+
+## @spec is_list Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a cons or nil.
 55: is_list/2
+
+## @spec is_nonempty_list Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a cons.
 56: is_nonempty_list/2
+
+## @spec is_tuple Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a tuple.
 57: is_tuple/2
+
+## @spec test_arity Lbl Arg1 Arity
+## @doc Test the arity of (the tuple in) Arg1 and jump
+## to Lbl if it is not equal to Arity.
 58: test_arity/3
 
 #
 # Indexing & jumping.
 #
+
+## @spec select_val Arg FailLabel Destinations
+## @doc Jump to the destination label corresponding to Arg
+##      in the Destinations list, if no arity matches, jump to FailLabel.
 59: select_val/3
+
+## @spec select_tuple_arity Tuple FailLabel Destinations
+## @doc Check the arity of the tuple Tuple and jump to the corresponding
+##      destination label, if no arity matches, jump to FailLabel.
 60: select_tuple_arity/3
+
+## @spec jump Label
+## @doc Jump to Label.
 61: jump/1
 
 #
@@ -124,9 +298,26 @@ BEAM_FORMAT_NUMBER=0
 #
 # Moving, extracting, modifying.
 #
+
+## @spec move Source Destination
+## @doc Move the source Source (a literal or a register) to
+##      the destination register Destination.
 64: move/2
+
+## @spec get_list  Source Head Tail
+## @doc  Get the head and tail (or car and cdr) parts of a list
+##       (a cons cell) from Source and put them into the registers
+##       Head and Tail.
 65: get_list/3
+
+## @spec get_tuple_element Source Element Destination
+## @doc  Get element number Element from the tuple in Source and put
+##       it in the destination register Destination.
 66: get_tuple_element/3
+
+## @spec set_tuple_element NewElement Tuple Position
+## @doc  Update the element at position Position of the tuple Tuple
+##       with the new element NewElement.
 67: set_tuple_element/3
 
 #
@@ -147,13 +338,26 @@ BEAM_FORMAT_NUMBER=0
 #
 # 'fun' support.
 #
+## @spec call_fun Arity
+## @doc Call a fun of arity Arity. Assume arguments in
+##      registers x(0) to x(Arity-1) and that the fun is in x(Arity).
+##      Save the next instruction as the return address in the CP register.
 75: call_fun/1
+
 76: -make_fun/3
+
+## @spec is_function Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a
+##      function (i.e. fun or closure).
 77: is_function/2
 
 #
 # Late additions to R5.
 #
+
+## @spec call_ext_only Arity Label
+##      Do a tail recursive call to the function at Label.
+##      Do not update the CP register.
 78: call_ext_only/2
 
 #
@@ -212,9 +416,14 @@ BEAM_FORMAT_NUMBER=0
 111: bs_add/5
 112: apply/1
 113: apply_last/2
+## @spec is_boolean Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a Boolean.
 114: is_boolean/2
 
 # New instructions in R10B-6.
+## @spec is_function2 Lbl Arg1 Arity
+## @doc Test the type of Arg1 and jump to Lbl if it is not a
+##      function of arity Arity.
 115: is_function2/3
 
 # New bit syntax matching in R11B.
@@ -229,7 +438,20 @@ BEAM_FORMAT_NUMBER=0
 123: bs_restore2/2
 
 # New GC bifs introduced in R11B.
+
+## @spec gc_bif1 Lbl Live Bif Arg Reg
+## @doc Call the bif Bif with the argument Arg, and store the result in Reg.
+##      On failure jump to Lbl.
+##      Do a garbage collection if necessary to allocate space on the heap
+##      for the result (saving Live number of X registers).
 124: gc_bif1/5
+
+## @spec gc_bif2 Lbl Live Bif Arg1 Arg2 Reg
+## @doc Call the bif Bif with the arguments Arg1 and Arg2,
+##      and store the result in Reg.
+##      On failure jump to Lbl.
+##      Do a garbage collection if necessary to allocate space on the heap
+##      for the result (saving Live number of X registers).
 125: gc_bif2/6
 
 # Experimental new bit_level bifs introduced in R11B.
@@ -241,6 +463,8 @@ BEAM_FORMAT_NUMBER=0
 128: -put_literal/2
 
 # R11B-5
+## @spec is_bitstr Lbl Arg1
+## @doc Test the type of Arg1 and jump to Lbl if it is not a bit string.
 129: is_bitstr/2
 
 # R12B
@@ -250,7 +474,12 @@ BEAM_FORMAT_NUMBER=0
 133: bs_init_writable/0
 134: bs_append/8
 135: bs_private_append/6
+
+## @spec trim N Remaining
+## @doc Reduce the stack usage by N words,
+##      keeping the CP on the top of the stack.
 136: trim/2
+
 137: bs_init_bits/6
 
 # R12B-5
@@ -277,10 +506,34 @@ BEAM_FORMAT_NUMBER=0
 
 # R14A
 
+## @spec recv_mark Label
+## @doc  Save the end of the message queue and the address of
+##       the label Label so that a recv_set instruction can start
+##       scanning the inbox from this position.
 150: recv_mark/1
+
+## @spec recv_set Label
+## @doc Check that the saved mark points to Label and set the
+##      save pointer in the message queue to the last position
+##      of the message queue saved by the recv_mark instruction.
 151: recv_set/1
+
+## @spec gc_bif3 Lbl Live Bif Arg1 Arg2 Arg3 Reg
+## @doc Call the bif Bif with the arguments Arg1, Arg2 and Arg3,
+##      and store the result in Reg.
+##      On failure jump to Lbl.
+##      Do a garbage collection if necessary to allocate space on the heap
+##      for the result (saving Live number of X registers).
 152: gc_bif3/7
 
 # R15A
 
 153: line/1
+
+# R17
+
+154: put_map_assoc/5
+155: put_map_exact/5
+156: is_map/2
+157: has_map_fields/3
+158: get_map_elements/3
diff --git a/lib/compiler/src/rec_env.erl b/lib/compiler/src/rec_env.erl
index 31a1f8b0b7..cdc513e57c 100644
--- a/lib/compiler/src/rec_env.erl
+++ b/lib/compiler/src/rec_env.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2001-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -21,8 +22,7 @@
 %% @doc Abstract environments, supporting self-referential bindings and
 %% automatic new-key generation.
 
-%% The current implementation is based on Erlang standard library
-%% dictionaries.
+%% The current implementation is based on Erlang standard library maps.
 
 %%% -define(DEBUG, true).
 
@@ -61,7 +61,7 @@ test_0(Type, N) ->
     io:fwrite("\ncalls: ~w.\n", [get(new_key_calls)]),
     io:fwrite("\nretries: ~w.\n", [get(new_key_retries)]),
     io:fwrite("\nmax: ~w.\n", [get(new_key_max)]),
-    dict:to_list(element(1,Env)).
+    maps:to_list(element(1,Env)).
 
 test_1(integer = Type, N, Env) when is_integer(N), N > 0 ->
     Key = new_key(Env),
@@ -72,20 +72,20 @@ test_1({custom, F} = Type, N, Env) when is_integer(N), N > 0 ->
 test_1(_,0, Env) ->
     Env.
 -endif.
+%%@clear
 
 
 %% Representation:
 %%
 %%	environment() = [Mapping]
 %%
-%%      Mapping = {map, Dict} | {rec, Dict, Dict}
-%%	Dict = dict:dictionary()
+%%      Mapping = {map, map()} | {rec, map(), map()}
 %%
-%% An empty environment is a list containing a single `{map, Dict}'
+%% An empty environment is a list containing a single `{map, map()}'
 %% element - empty lists are not valid environments. To find a key in an
 %% environment, it is searched for in each mapping in the list, in
 %% order, until it the key is found in some mapping, or the end of the
-%% list is reached. In a 'rec' mapping, we keep the original dictionary
+%% list is reached. In a 'rec' mapping, we keep the original map
 %% together with a version where entries may have been deleted - this
 %% makes it possible to garbage collect the entire 'rec' mapping when
 %% all its entries are unused (for example, by being shadowed by later
@@ -95,7 +95,7 @@ test_1(_,0, Env) ->
 %% =====================================================================
 %% @type environment(). An abstract environment.
 
--type mapping()     :: {'map', dict()} | {'rec', dict(), dict()}.
+-type mapping()     :: {'map', map()} | {'rec', map(), map()}.
 -type environment() :: [mapping(),...].
 
 %% =====================================================================
@@ -106,7 +106,7 @@ test_1(_,0, Env) ->
 -spec empty() -> environment().
 
 empty() ->
-    [{map, dict:new()}].
+    [{map, #{}}].
 
 
 %% =====================================================================
@@ -117,14 +117,14 @@ empty() ->
 
 -spec is_empty(environment()) -> boolean().
 
-is_empty([{map, Dict} | Es]) ->
-    N = dict:size(Dict),
+is_empty([{map, Map} | Es]) ->
+    N = map_size(Map),
     if N =/= 0 -> false;
        Es =:= [] -> true;
        true -> is_empty(Es)
     end;
-is_empty([{rec, Dict, _} | Es]) ->
-    N = dict:size(Dict),
+is_empty([{rec, Map, _} | Es]) ->
+    N = map_size(Map),
     if N =/= 0 -> false;
        Es =:= [] -> true;
        true -> is_empty(Es)
@@ -144,12 +144,12 @@ is_empty([{rec, Dict, _} | Es]) ->
 size(Env) ->
     env_size(Env).
 
-env_size([{map, Dict}]) ->
-    dict:size(Dict);
-env_size([{map, Dict} | Env]) ->
-    dict:size(Dict) + env_size(Env);
-env_size([{rec, Dict, _Dict0} | Env]) ->
-    dict:size(Dict) + env_size(Env).
+env_size([{map, Map}]) ->
+    map_size(Map);
+env_size([{map, Map} | Env]) ->
+    map_size(Map) + env_size(Env);
+env_size([{rec, Map, _Map0} | Env]) ->
+    map_size(Map) + env_size(Env).
 
 
 %% =====================================================================
@@ -163,8 +163,8 @@ env_size([{rec, Dict, _Dict0} | Env]) ->
 
 -spec is_defined(term(), environment()) -> boolean().
 
-is_defined(Key, [{map, Dict} | Env]) ->
-    case dict:is_key(Key, Dict) of
+is_defined(Key, [{map, Map} | Env]) ->
+    case maps:is_key(Key, Map) of
 	true ->
 	    true;
 	false when Env =:= [] ->
@@ -172,8 +172,8 @@ is_defined(Key, [{map, Dict} | Env]) ->
 	false ->
 	    is_defined(Key, Env)
     end;
-is_defined(Key, [{rec, Dict, _Dict0} | Env]) ->
-    dict:is_key(Key, Dict) orelse is_defined(Key, Env).
+is_defined(Key, [{rec, Map, _Map0} | Env]) ->
+    maps:is_key(Key, Map) orelse is_defined(Key, Env).
 
 
 %% =====================================================================
@@ -186,12 +186,12 @@ is_defined(Key, [{rec, Dict, _Dict0} | Env]) ->
 keys(Env) ->
     lists:sort(keys(Env, [])).
 
-keys([{map, Dict}], S) ->
-    dict:fetch_keys(Dict) ++ S;
-keys([{map, Dict} | Env], S) ->
-    keys(Env, dict:fetch_keys(Dict) ++ S);
-keys([{rec, Dict, _Dict0} | Env], S) ->
-    keys(Env, dict:fetch_keys(Dict) ++ S).
+keys([{map, Map}], S) ->
+    maps:keys(Map) ++ S;
+keys([{map, Map} | Env], S) ->
+    keys(Env, maps:keys(Map) ++ S);
+keys([{rec, Map, _Map0} | Env], S) ->
+    keys(Env, maps:keys(Map) ++ S).
 
 
 %% =====================================================================
@@ -210,12 +210,12 @@ keys([{rec, Dict, _Dict0} | Env], S) ->
 to_list(Env) ->
     lists:sort(to_list(Env, [])).
 
-to_list([{map, Dict}], S) ->
-    dict:to_list(Dict) ++ S;
-to_list([{map, Dict} | Env], S) ->
-    to_list(Env, dict:to_list(Dict) ++ S);
-to_list([{rec, Dict, _Dict0} | Env], S) ->
-    to_list(Env, dict:to_list(Dict) ++ S).
+to_list([{map, Map}], S) ->
+    maps:to_list(Map) ++ S;
+to_list([{map, Map} | Env], S) ->
+    to_list(Env, maps:to_list(Map) ++ S);
+to_list([{rec, Map, _Map0} | Env], S) ->
+    to_list(Env, maps:to_list(Map) ++ S).
 
 
 %% =====================================================================
@@ -234,12 +234,12 @@ to_list([{rec, Dict, _Dict0} | Env], S) ->
 
 -spec bind(term(), term(), environment()) -> environment().
 
-bind(Key, Value, [{map, Dict}]) ->
-    [{map, dict:store(Key, Value, Dict)}];
-bind(Key, Value, [{map, Dict} | Env]) ->
-    [{map, dict:store(Key, Value, Dict)} | delete_any(Key, Env)];
+bind(Key, Value, [{map, Map}]) ->
+    [{map, maps:put(Key, Value, Map)}];
+bind(Key, Value, [{map, Map} | Env]) ->
+    [{map, maps:put(Key, Value, Map)} | delete_any(Key, Env)];
 bind(Key, Value, Env) ->
-    [{map, dict:store(Key, Value, dict:new())} | delete_any(Key, Env)].
+    [{map, maps:put(Key, Value, #{})} | delete_any(Key, Env)].
 
 
 %% =====================================================================
@@ -257,17 +257,17 @@ bind(Key, Value, Env) ->
 
 -spec bind_list([term()], [term()], environment()) -> environment().
 
-bind_list(Ks, Vs, [{map, Dict}]) ->
-    [{map, store_list(Ks, Vs, Dict)}];
-bind_list(Ks, Vs, [{map, Dict} | Env]) ->
-    [{map, store_list(Ks, Vs, Dict)} | delete_list(Ks, Env)];
+bind_list(Ks, Vs, [{map, Map}]) ->
+    [{map, store_list(Ks, Vs, Map)}];
+bind_list(Ks, Vs, [{map, Map} | Env]) ->
+    [{map, store_list(Ks, Vs, Map)} | delete_list(Ks, Env)];
 bind_list(Ks, Vs, Env) ->
-    [{map, store_list(Ks, Vs, dict:new())} | delete_list(Ks, Env)].
+    [{map, store_list(Ks, Vs, #{})} | delete_list(Ks, Env)].
 
-store_list([K | Ks], [V | Vs], Dict) ->
-    store_list(Ks, Vs, dict:store(K, V, Dict));
-store_list([], _, Dict) ->
-    Dict.
+store_list([K | Ks], [V | Vs], Map) ->
+    store_list(Ks, Vs, maps:put(K, V, Map));
+store_list([], _, Map) ->
+    Map.
 
 delete_list([K | Ks], Env) ->
     delete_list(Ks, delete_any(K, Env));
@@ -296,48 +296,40 @@ delete_any(Key, Env) ->
 
 -spec delete(term(), environment()) -> environment().
 
-delete(Key, [{map, Dict} = E | Env]) ->
-    case dict:is_key(Key, Dict) of
-	true ->
-	    [{map, dict:erase(Key, Dict)} | Env];
-	false ->
+delete(Key, [{map, Map} = E | Env]) ->
+    case maps:take(Key, Map) of
+	{_, Map1} ->
+	    [{map, Map1} | Env];
+	error ->
 	    delete_1(Key, Env, E)
     end;
-delete(Key, [{rec, Dict, Dict0} = E | Env]) ->
-    case dict:is_key(Key, Dict) of
-	true ->
-	    %% The Dict0 component must be preserved as it is until all
-	    %% keys in Dict have been deleted.
-	    Dict1 = dict:erase(Key, Dict),
-	    case dict:size(Dict1) of
-		0 ->
-		    Env;    % the whole {rec,...} is now garbage
-		_ ->
-		    [{rec, Dict1, Dict0} | Env]
-	    end;
-	false ->
+delete(Key, [{rec, Map, Map0} = E | Env]) ->
+    case maps:take(Key, Map) of
+	{_, Map1} when map_size(Map1) =:= 0 ->
+	    Env; % the whole {rec,...} is now garbage
+	%% The Map0 component must be preserved as it is until all
+	%% keys in Map have been deleted.
+	{_, Map1} ->
+	    [{rec, Map1, Map0} | Env];
+	error ->
 	    [E | delete(Key, Env)]
     end.
 
 %% This is just like above, except we pass on the preceding 'map'
 %% mapping in the list to enable merging when removing 'rec' mappings.
 
-delete_1(Key, [{rec, Dict, Dict0} = E | Env], E1) ->
-    case dict:is_key(Key, Dict) of
-	true ->
-	    Dict1 = dict:erase(Key, Dict),
-	    case dict:size(Dict1) of
-		0 ->
-		    concat(E1, Env);
-		_ ->
-		    [E1, {rec, Dict1, Dict0} | Env]
-	    end;
-	false ->
+delete_1(Key, [{rec, Map, Map0} = E | Env], E1) ->
+    case maps:take(Key, Map) of
+	{_, Map1} when map_size(Map1) =:= 0 ->
+	    concat(E1, Env);
+	{_, Map1} ->
+	    [E1, {rec, Map1, Map0} | Env];
+	error ->
 	    [E1, E | delete(Key, Env)]
     end.
 
-concat({map, D1}, [{map, D2} | Env]) ->
-    [dict:merge(fun (_K, V1, _V2) -> V1 end, D1, D2) | Env];
+concat({map, M1}, [{map, M2} | Env]) ->
+    [maps:merge(M2, M1) | Env];
 concat(E1, Env) ->
     [E1 | Env].
 
@@ -390,15 +382,15 @@ bind_recursive([], [], _, Env) ->
     Env;
 bind_recursive(Ks, Vs, F, Env) ->
     F1 = fun (V) ->
-		 fun (Dict) -> F(V, [{rec, Dict, Dict} | Env]) end
+		 fun (Map) -> F(V, [{rec, Map, Map} | Env]) end
 	 end,
-    Dict = bind_recursive_1(Ks, Vs, F1, dict:new()),
-    [{rec, Dict, Dict} | Env].
+    Map = bind_recursive_1(Ks, Vs, F1, #{}),
+    [{rec, Map, Map} | Env].
 
-bind_recursive_1([K | Ks], [V | Vs], F, Dict) ->
-    bind_recursive_1(Ks, Vs, F, dict:store(K, F(V), Dict));
-bind_recursive_1([], [], _, Dict) ->
-    Dict.
+bind_recursive_1([K | Ks], [V | Vs], F, Map) ->
+    bind_recursive_1(Ks, Vs, F, maps:put(K, F(V), Map));
+bind_recursive_1([], [], _, Map) ->
+    Map.
 
 
 %% =====================================================================
@@ -414,8 +406,8 @@ bind_recursive_1([], [], _, Dict) ->
 
 -spec lookup(term(), environment()) -> 'error' | {'ok', term()}.
 
-lookup(Key, [{map, Dict} | Env]) ->
-    case dict:find(Key, Dict) of
+lookup(Key, [{map, Map} | Env]) ->
+    case maps:find(Key, Map) of
 	{ok, _}=Value ->
 	    Value;
 	error when Env =:= [] ->
@@ -423,10 +415,10 @@ lookup(Key, [{map, Dict} | Env]) ->
 	error ->
 	    lookup(Key, Env)
     end;
-lookup(Key, [{rec, Dict, Dict0} | Env]) ->
-    case dict:find(Key, Dict) of
+lookup(Key, [{rec, Map, Map0} | Env]) ->
+    case maps:find(Key, Map) of
 	{ok, F} ->
-	    {ok, F(Dict0)};
+	    {ok, F(Map0)};
 	error ->
 	    lookup(Key, Env)
     end.
@@ -596,7 +588,17 @@ start_range(Env) ->
 %% (pseudo-)randomly distributed over the range.
 
 generate(_N, Range) ->
-    random:uniform(Range).    % works well
+    %% We must use the same sequence of random variables to ensure
+    %% that two compilations of the same source code generates the
+    %% same BEAM code.
+    case rand:export_seed() of
+	undefined ->
+	    _ = rand:seed(exsplus, {1,42,2053}),
+	    ok;
+	_ ->
+	    ok
+    end,
+    rand:uniform(Range).			% works well
 
 
 %% =====================================================================
diff --git a/lib/compiler/src/sys_core_dsetel.erl b/lib/compiler/src/sys_core_dsetel.erl
index f6696992b9..bd3eeae238 100644
--- a/lib/compiler/src/sys_core_dsetel.erl
+++ b/lib/compiler/src/sys_core_dsetel.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2002-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2002-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -71,7 +72,7 @@ module(M0, _Options) ->
     {ok,M}.
 
 visit_module(#c_module{defs=Ds0}=R) ->
-    Env = dict:new(),
+    Env = #{},
     Ds = visit_module_1(Ds0, Env, []),
     R#c_module{defs=Ds}.
 
@@ -94,14 +95,23 @@ visit(Env, #c_var{name={_,_}}=R) ->
     {R, Env};
 visit(Env0, #c_var{name=X}=R) ->
     %% There should not be any free variables. If there are,
-    %% the next line will cause an exception.
-    {ok, N} = dict:find(X, Env0),
-    {R, dict:store(X, N+1, Env0)};
+    %% the case will fail with an exception.
+    case Env0 of
+	#{X:=N} ->
+	    {R, Env0#{X:=N+1}}
+    end;
 visit(Env, #c_literal{}=R) ->
     {R, Env};
 visit(Env0, #c_tuple{es=Es0}=R) ->
     {Es1,Env1} = visit_list(Env0, Es0),
     {R#c_tuple{es=Es1}, Env1};
+visit(Env0, #c_map{es=Es0}=R) ->
+    {Es1,Env1} = visit_list(Env0, Es0),
+    {R#c_map{es=Es1}, Env1};
+visit(Env0, #c_map_pair{key=K0,val=V0}=R) ->
+    {K,Env1} = visit(Env0, K0),
+    {V,Env2} = visit(Env1, V0),
+    {R#c_map_pair{key=K,val=V}, Env2};
 visit(Env0, #c_cons{hd=H0,tl=T0}=R) ->
     {H1,Env1} = visit(Env0, H0),
     {T1,Env2} = visit(Env1, T0),
@@ -195,7 +205,7 @@ bind_vars(Vs, Env) ->
     bind_vars(Vs, Env, []).
 
 bind_vars([#c_var{name=X}|Vs], Env0, Xs)->
-    bind_vars(Vs, dict:store(X, 0, Env0), [X|Xs]);
+    bind_vars(Vs, Env0#{X=>0}, [X|Xs]);
 bind_vars([], Env,Xs) ->
     {Xs, Env}.
 
@@ -209,9 +219,14 @@ visit_pats([], Env, Vs) ->
     {Vs, Env}.
 
 visit_pat(Env0, #c_var{name=V}, Vs) ->
-    {[V|Vs], dict:store(V, 0, Env0)};
+    {[V|Vs], Env0#{V=>0}};
 visit_pat(Env0, #c_tuple{es=Es}, Vs) ->
     visit_pats(Es, Env0, Vs);
+visit_pat(Env0, #c_map{es=Es}, Vs) ->
+    visit_pats(Es, Env0, Vs);
+visit_pat(Env0, #c_map_pair{op=#c_literal{val=exact},key=V,val=K}, Vs0) ->
+    {Vs1, Env1} = visit_pat(Env0, V, Vs0),
+    visit_pat(Env1, K, Vs1);
 visit_pat(Env0, #c_cons{hd=H,tl=T}, Vs0) ->
     {Vs1, Env1} = visit_pat(Env0, H, Vs0),
     visit_pat(Env1, T, Vs1);
@@ -222,23 +237,25 @@ visit_pat(Env0, #c_bitstr{val=Val,size=Sz}, Vs0) ->
 	case Sz of
 	    #c_var{name=V} ->
 		%% We don't tolerate free variables.
-		{ok, N} = dict:find(V, Env0),
-		{Vs0, dict:store(V, N+1, Env0)};
+		case Env0 of
+		    #{V:=N} ->
+			{Vs0, Env0#{V:=N+1}}
+		end;
 	    _ ->
 		visit_pat(Env0, Sz, Vs0)
 	end,
     visit_pat(Env1, Val, Vs1);
 visit_pat(Env0, #c_alias{pat=P,var=#c_var{name=V}}, Vs) ->
-    visit_pat(dict:store(V, 0, Env0), P, [V|Vs]);
+    visit_pat(Env0#{V=>0}, P, [V|Vs]);
 visit_pat(Env, #c_literal{}, Vs) ->
     {Vs, Env}.
 
 restore_vars([V|Vs], Env0, Env1) ->
-    case dict:find(V, Env0) of
-	{ok, N} ->
-	    restore_vars(Vs, Env0, dict:store(V, N, Env1));
-	error ->
-	    restore_vars(Vs, Env0, dict:erase(V, Env1))
+    case Env0 of
+	#{V:=N} ->
+	    restore_vars(Vs, Env0, Env1#{V=>N});
+	_ ->
+	    restore_vars(Vs, Env0, maps:remove(V, Env1))
     end;
 restore_vars([], _, Env1) ->
     Env1.
@@ -336,8 +353,8 @@ is_safe(#c_literal{}) -> true;
 is_safe(_) -> false.
 
 is_single_use(V, Env) ->
-    case dict:find(V, Env) of
-	{ok, 1} ->
+    case Env of
+	#{V:=1} ->
 	    true;
 	_ ->
 	    false
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index cda3f7d81e..e0de50f3ae 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -70,9 +71,10 @@
 -export([module/2,format_error/1]).
 
 -import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,all/2,any/2,
-		reverse/1,reverse/2,member/2,nth/2,flatten/1]).
+		reverse/1,reverse/2,member/2,nth/2,flatten/1,
+		unzip/1,keyfind/3]).
 
--import(cerl, [ann_c_cons/3,ann_c_tuple/2]).
+-import(cerl, [ann_c_cons/3,ann_c_map/3,ann_c_tuple/2]).
 
 -include("core_parse.hrl").
 
@@ -91,10 +93,14 @@
 -endif.
 
 %% Variable value info.
--record(sub, {v=[],				%Variable substitutions
-	      s=[],				%Variables in scope
-	      t=[],				%Types
-	      in_guard=false}).			%In guard or not.
+-record(sub, {v=[],                                 %Variable substitutions
+              s=cerl_sets:new() :: cerl_sets:set(), %Variables in scope
+              t=#{} :: map(),                       %Types
+              in_guard=false}).                     %In guard or not.
+
+-type type_info() :: cerl:cerl() | 'bool' | 'integer'.
+-type yes_no_maybe() :: 'yes' | 'no' | 'maybe'.
+-type sub() :: #sub{}.
 
 -spec module(cerl:c_module(), [compile:option()]) ->
 	{'ok', cerl:c_module(), [_]}.
@@ -246,6 +252,16 @@ expr(#c_tuple{anno=Anno,es=Es0}=Tuple, Ctxt, Sub) ->
 	value ->
 	    ann_c_tuple(Anno, Es)
     end;
+expr(#c_map{anno=Anno,arg=V0,es=Es0}=Map, Ctxt, Sub) ->
+    Es = pair_list(Es0, Ctxt, Sub),
+    case Ctxt of
+	effect ->
+	    add_warning(Map, useless_building),
+	    expr(make_effect_seq(Es, Sub), Ctxt, Sub);
+	value ->
+	    V = expr(V0, Ctxt, Sub),
+	    ann_c_map(Anno,V,Es)
+    end;
 expr(#c_binary{segments=Ss}=Bin0, Ctxt, Sub) ->
     %% Warn for useless building, but always build the binary
     %% anyway to preserve a possible exception.
@@ -261,7 +277,7 @@ expr(#c_fun{}=Fun, effect, _) ->
     add_warning(Fun, useless_building),
     void();
 expr(#c_fun{vars=Vs0,body=B0}=Fun, Ctxt0, Sub0) ->
-    {Vs1,Sub1} = pattern_list(Vs0, Sub0),
+    {Vs1,Sub1} = var_list(Vs0, Sub0),
     Ctxt = case Ctxt0 of
 	       {letrec,Ctxt1} -> Ctxt1;
 	       value -> value
@@ -283,7 +299,8 @@ expr(#c_seq{arg=Arg0,body=B0}=Seq0, Ctxt, Sub) ->
 		false -> Seq0#c_seq{arg=Arg,body=B1}
 	    end
     end;
-expr(#c_let{}=Let, Ctxt, Sub) ->
+expr(#c_let{}=Let0, Ctxt, Sub) ->
+    Let = opt_case_in_let(Let0),
     case simplify_let(Let, Sub) of
 	impossible ->
 	    %% The argument for the let is "simple", i.e. has no
@@ -295,32 +312,83 @@ expr(#c_let{}=Let, Ctxt, Sub) ->
 	    %% Now recursively re-process the new expression.
 	    expr(Expr, Ctxt, sub_new_preserve_types(Sub))
     end;
+expr(#c_letrec{body=#c_var{}}=Letrec, effect, _Sub) ->
+    %% This is named fun in an 'effect' context. Warn and ignore.
+    add_warning(Letrec, useless_building),
+    void();
 expr(#c_letrec{defs=Fs0,body=B0}=Letrec, Ctxt, Sub) ->
     Fs1 = map(fun ({Name,Fb}) ->
 		      {Name,expr(Fb, {letrec,Ctxt}, Sub)}
 	      end, Fs0),
-    B1 = body(B0, value, Sub),
+    B1 = body(B0, Ctxt, Sub),
     Letrec#c_letrec{defs=Fs1,body=B1};
 expr(#c_case{}=Case0, Ctxt, Sub) ->
+    %% Ideally, the compiler should only emit warnings when there is
+    %% a real mistake in the code being compiled. We use the follow
+    %% heuristics in an attempt to approach that ideal:
+    %%
+    %% * If the guard for a clause always fails, we will emit a
+    %%   warning.
+    %%
+    %% * If a case expression is a literal, we will emit no warnings
+    %%   for clauses that will not match or for clauses that are
+    %%   shadowed after a clause that will always match. That means
+    %%   that code such as:
+    %%
+    %%      case ?DEBUG of
+    %%         false -> ok;
+    %%         true -> ...
+    %%      end
+    %%
+    %%   (where ?DEBUG expands to either 'true' or 'false') will not
+    %%   produce any warnings.
+    %%
+    %% * If the case expression is not literal, warnings will be
+    %%   emitted for every clause that don't match and for all
+    %%   clauses following a clause that will always match.
+    %%
+    %% * If no clause will ever match, there will be a warning
+    %%   (in addition to any warnings that may have been emitted
+    %%   according to the rules above).
+    %%
     case opt_bool_case(Case0) of
 	#c_case{arg=Arg0,clauses=Cs0}=Case1 ->
 	    Arg1 = body(Arg0, value, Sub),
-	    {Arg2,Cs1} = case_opt(Arg1, Cs0),
-	    Cs2 = clauses(Arg2, Cs1, Case1, Ctxt, Sub),
-	    Case = eval_case(Case1#c_case{arg=Arg2,clauses=Cs2}, Sub),
-	    bsm_an(Case);
+	    LitExpr = cerl:is_literal(Arg1),
+	    {Arg2,Cs1} = case_opt(Arg1, Cs0, Sub),
+	    Cs2 = clauses(Arg2, Cs1, Ctxt, Sub, LitExpr),
+	    Case = Case1#c_case{arg=Arg2,clauses=Cs2},
+	    warn_no_clause_match(Case1, Case),
+	    Expr = eval_case(Case, Sub),
+            case move_case_into_arg(Case, Sub) of
+                impossible ->
+                    bsm_an(Expr);
+                Other ->
+                    expr(Other, Ctxt, sub_new_preserve_types(Sub))
+            end;
 	Other ->
 	    expr(Other, Ctxt, Sub)
     end;
 expr(#c_receive{clauses=Cs0,timeout=T0,action=A0}=Recv, Ctxt, Sub) ->
-    Cs1 = clauses(#c_var{name='_'}, Cs0, Recv, Ctxt, Sub), %This is all we know
+    Cs1 = clauses(#c_var{name='_'}, Cs0, Ctxt, Sub, false),
     T1 = expr(T0, value, Sub),
     A1 = body(A0, Ctxt, Sub),
     Recv#c_receive{clauses=Cs1,timeout=T1,action=A1};
-expr(#c_apply{op=Op0,args=As0}=App, _, Sub) ->
+expr(#c_apply{anno=Anno,op=Op0,args=As0}=App, _, Sub) ->
     Op1 = expr(Op0, value, Sub),
     As1 = expr_list(As0, value, Sub),
-    App#c_apply{op=Op1,args=As1};
+    case Op1 of
+	#c_var{} ->
+	    App#c_apply{op=Op1,args=As1};
+	_ ->
+	    add_warning(App, invalid_call),
+	    Err = #c_call{anno=Anno,
+			  module=#c_literal{val=erlang},
+			  name=#c_literal{val=error},
+			  args=[#c_tuple{es=[#c_literal{val='badfun'},
+					     Op1]}]},
+	    make_effect_seq(As1++[Err], Sub)
+    end;
 expr(#c_call{module=M0,name=N0}=Call0, Ctxt, Sub) ->
     M1 = expr(M0, value, Sub),
     N1 = expr(N0, value, Sub),
@@ -363,13 +431,13 @@ expr(#c_try{anno=A,arg=E0,vars=Vs0,body=B0,evars=Evs0,handler=H0}=Try, _, Sub0)
     %% Here is the general try/catch construct outside of guards.
     %% We can remove try if the value is simple and replace it with a let.
     E1 = body(E0, value, Sub0),
-    {Vs1,Sub1} = pattern_list(Vs0, Sub0),
+    {Vs1,Sub1} = var_list(Vs0, Sub0),
     B1 = body(B0, value, Sub1),
     case is_safe_simple(E1, Sub0) of
 	true ->
 	    expr(#c_let{anno=A,vars=Vs1,arg=E1,body=B1}, value, Sub0);
 	false ->
-	    {Evs1,Sub2} = pattern_list(Evs0, Sub0),
+	    {Evs1,Sub2} = var_list(Evs0, Sub0),
 	    H1 = body(H0, value, Sub2),
 	    Try#c_try{arg=E1,vars=Vs1,body=B1,evars=Evs1,handler=H1}
     end.
@@ -377,6 +445,16 @@ expr(#c_try{anno=A,arg=E0,vars=Vs0,body=B0,evars=Evs0,handler=H0}=Try, _, Sub0)
 expr_list(Es, Ctxt, Sub) ->
     [expr(E, Ctxt, Sub) || E <- Es].
 
+pair_list(Es, Ctxt, Sub) ->
+    [pair(E, Ctxt, Sub) || E <- Es].
+
+pair(#c_map_pair{key=K,val=V}, effect, Sub) ->
+    make_effect_seq([K,V], Sub);
+pair(#c_map_pair{key=K0,val=V0}=Pair, value=Ctxt, Sub) ->
+    K = expr(K0, Ctxt, Sub),
+    V = expr(V0, Ctxt, Sub),
+    Pair#c_map_pair{key=K,val=V}.
+
 bitstr_list(Es, Sub) ->
     [bitstr(E, Sub) || E <- Es].
 
@@ -402,10 +480,7 @@ is_safe_simple(#c_call{module=#c_literal{val=erlang},
     case erl_internal:bool_op(Name, NumArgs) of
 	true ->
 	    %% Boolean operators are safe if the arguments are boolean.
-	    all(fun(#c_var{name=V}) -> is_boolean_type(V, Sub);
-		   (#c_literal{val=Lit}) -> is_boolean(Lit);
-		   (_) -> false
-		end, Args);
+	    all(fun(C) -> is_boolean_type(C, Sub) =:= yes end, Args);
 	false ->
 	    %% We need a rather complicated test to ensure that
 	    %% we only allow safe calls that are allowed in a guard.
@@ -620,23 +695,15 @@ count_bits_1(Int, Bits) -> count_bits_1(Int bsr 64, Bits+64).
 %%  a rewritten expression consisting of a sequence of
 %%  the arguments only is returned.
 
-useless_call(effect, #c_call{anno=Anno,
-			     module=#c_literal{val=Mod},
+useless_call(effect, #c_call{module=#c_literal{val=Mod},
 			     name=#c_literal{val=Name},
 			     args=Args}=Call) ->
     A = length(Args),
     case erl_bifs:is_safe(Mod, Name, A) of
 	false ->
 	    case erl_bifs:is_pure(Mod, Name, A) of
-		true ->
-		    case member(result_not_wanted, Anno) of
-			false ->
-			    add_warning(Call, result_ignored);
-			true ->
-			    ok
-		    end;
-		false ->
-		    ok
+		true -> add_warning(Call, result_ignored);
+		false -> ok
 	    end,
 	    no;
 	true ->
@@ -646,7 +713,7 @@ useless_call(effect, #c_call{anno=Anno,
 useless_call(_, _) -> no.
 
 %% make_effect_seq([Expr], Sub) -> #c_seq{}|void()
-%%  Convert a list of epressions evaluated in effect context to a chain of
+%%  Convert a list of expressions evaluated in effect context to a chain of
 %%  #c_seq{}. The body in the innermost #c_seq{} will be void().
 %%  Anything that will not have any effect will be thrown away.
 
@@ -662,385 +729,23 @@ make_effect_seq([], _) -> void().
 call(#c_call{args=As}=Call, #c_literal{val=M}=M0, #c_literal{val=N}=N0, Sub) ->
     case get(no_inline_list_funcs) of
   	true ->
- 	    call_0(Call, M0, N0, As, Sub);
+	    call_1(Call, M0, N0, As, Sub);
   	false ->
-  	    call_1(Call, M, N, As, Sub)
+	    case sys_core_fold_lists:call(Call, M, N, As) of
+		none ->
+		    call_1(Call, M, N, As, Sub);
+		Core ->
+		    expr(Core, Sub)
+	    end
+
       end;
 call(#c_call{args=As}=Call, M, N, Sub) ->
-    call_0(Call, M, N, As, Sub).
+    call_1(Call, M, N, As, Sub).
 
-call_0(Call, M, N, As0, Sub) ->
+call_1(Call, M, N, As0, Sub) ->
     As1 = expr_list(As0, value, Sub),
     fold_call(Call#c_call{args=As1}, M, N, As1, Sub).
 
-%% We inline some very common higher order list operations.
-%% We use the same evaluation order as the library function.
-
-call_1(#c_call{anno=Anno}, lists, all, [Arg1,Arg2], Sub) ->
-    Loop = #c_var{name={'lists^all',1}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    Err1 = #c_tuple{es=[#c_literal{val='case_clause'}, X]},
-    CC1 = #c_clause{pats=[#c_literal{val=true}], guard=#c_literal{val=true},
-		    body=#c_apply{anno=Anno, op=Loop, args=[Xs]}},
-    CC2 = #c_clause{pats=[#c_literal{val=false}], guard=#c_literal{val=true},
-		    body=#c_literal{val=false}},
-    CC3 = #c_clause{pats=[X], guard=#c_literal{val=true},
-		    body=match_fail(Anno, Err1)},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_case{arg=#c_apply{anno=Anno, op=F, args=[X]},
-				clauses = [CC1, CC2, CC3]}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=1}]},
-		   body=#c_literal{val=true}},
-    Err2 = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^all',1}}|Anno], Err2)},
-    Fun = #c_fun{vars=[Xs],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, any, [Arg1,Arg2], Sub) ->
-    Loop = #c_var{name={'lists^any',1}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    Err1 = #c_tuple{es=[#c_literal{val='case_clause'}, X]},
-    CC1 = #c_clause{pats=[#c_literal{val=true}], guard=#c_literal{val=true},
-		    body=#c_literal{val=true}},
-    CC2 = #c_clause{pats=[#c_literal{val=false}], guard=#c_literal{val=true},
-		    body=#c_apply{anno=Anno, op=Loop, args=[Xs]}},
-    CC3 = #c_clause{pats=[X], guard=#c_literal{val=true},
-		    body=match_fail(Anno, Err1)},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_case{arg=#c_apply{anno=Anno, op=F, args=[X]},
-				clauses = [CC1, CC2, CC3]}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=1}]},
-		   body=#c_literal{val=false}},
-    Err2 = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^any',1}}|Anno], Err2)},
-    Fun = #c_fun{vars=[Xs],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, foreach, [Arg1,Arg2], Sub) ->
-    Loop = #c_var{name={'lists^foreach',1}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_seq{arg=#c_apply{anno=Anno, op=F, args=[X]},
-			       body=#c_apply{anno=Anno, op=Loop, args=[Xs]}}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=1}]},
-		   body=#c_literal{val=ok}},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^foreach',1}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, map, [Arg1,Arg2], Sub) ->
-    Loop = #c_var{name={'lists^map',1}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    H = #c_var{name='H'},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_let{vars=[H], arg=#c_apply{anno=Anno,
-						      op=F,
-						      args=[X]},
-			       body=#c_cons{hd=H,
-					    anno=[compiler_generated],
-					    tl=#c_apply{anno=Anno,
-							op=Loop,
-							args=[Xs]}}}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=1}]},
-		   body=#c_literal{val=[]}},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^map',1}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, flatmap, [Arg1,Arg2], Sub) ->
-    Loop = #c_var{name={'lists^flatmap',1}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    H = #c_var{name='H'},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_let{vars=[H],
-			       arg=#c_apply{anno=Anno, op=F, args=[X]},
-			       body=#c_call{anno=[compiler_generated|Anno],
-					    module=#c_literal{val=erlang},
-					    name=#c_literal{val='++'},
-					    args=[H,
-						  #c_apply{anno=Anno,
-							   op=Loop,
-							   args=[Xs]}]}}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=1}]},
-		   body=#c_literal{val=[]}},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^flatmap',1}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, filter, [Arg1,Arg2], Sub) ->
-    Loop = #c_var{name={'lists^filter',1}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    B = #c_var{name='B'},
-    Err1 = #c_tuple{es=[#c_literal{val='case_clause'}, X]},
-    CC1 = #c_clause{pats=[#c_literal{val=true}], guard=#c_literal{val=true},
-		    body=#c_cons{anno=[compiler_generated], hd=X, tl=Xs}},
-    CC2 = #c_clause{pats=[#c_literal{val=false}], guard=#c_literal{val=true},
-		    body=Xs},
-    CC3 = #c_clause{pats=[X], guard=#c_literal{val=true},
-		    body=match_fail(Anno, Err1)},
-    Case = #c_case{arg=B, clauses = [CC1, CC2, CC3]},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_let{vars=[B],
-			       arg=#c_apply{anno=Anno, op=F, args=[X]},
-			       body=#c_let{vars=[Xs],
-					   arg=#c_apply{anno=Anno,
-							op=Loop,
-							args=[Xs]},
-					   body=Case}}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=1}]},
-		   body=#c_literal{val=[]}},
-    Err2 = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^filter',1}}|Anno], Err2)},
-    Fun = #c_fun{vars=[Xs],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}},
-    Sub);
-call_1(#c_call{anno=Anno}, lists, foldl, [Arg1,Arg2,Arg3], Sub) ->
-    Loop = #c_var{name={'lists^foldl',2}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    A = #c_var{name='A'},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_apply{anno=Anno,
-				 op=Loop,
-				 args=[Xs, #c_apply{anno=Anno,
-						    op=F,
-						    args=[X, A]}]}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=2}]},
-		   body=A},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, A, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^foldl',2}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs, A],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, A, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L, A]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, foldr, [Arg1,Arg2,Arg3], Sub) ->
-    Loop = #c_var{name={'lists^foldr',2}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    A = #c_var{name='A'},
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=#c_apply{anno=Anno,
-				 op=F,
-				 args=[X, #c_apply{anno=Anno,
-						   op=Loop,
-						   args=[Xs, A]}]}},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=2}]},
-		   body=A},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, A, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^foldr',2}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs, A],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, A, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-			       body=#c_apply{anno=Anno, op=Loop, args=[L, A]}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, mapfoldl, [Arg1,Arg2,Arg3], Sub) ->
-    Loop = #c_var{name={'lists^mapfoldl',2}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    Avar = #c_var{name='A'},
-    Match =
-	fun (A, P, E) ->
-		C1 = #c_clause{pats=[P], guard=#c_literal{val=true}, body=E},
-		Err = #c_tuple{es=[#c_literal{val='badmatch'}, X]},
-		C2 = #c_clause{pats=[X], guard=#c_literal{val=true},
-			       body=match_fail(Anno, Err)},
-		#c_case{arg=A, clauses=[C1, C2]}
-	end,
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-		   body=Match(#c_apply{anno=Anno, op=F, args=[X, Avar]},
-			      #c_tuple{es=[X, Avar]},
-%%% Tuple passing version
-			      Match(#c_apply{anno=Anno,
-					     op=Loop,
-					     args=[Xs, Avar]},
-				    #c_tuple{es=[Xs, Avar]},
-				    #c_tuple{anno=[compiler_generated],
-					     es=[#c_cons{anno=[compiler_generated],
-							 hd=X, tl=Xs},
-						 Avar]})
-%%% Multiple-value version
-%%% 			      #c_let{vars=[Xs,A],
-%%% 				     %% The tuple here will be optimised
-%%% 				     %% away later; no worries.
-%%% 				     arg=#c_apply{op=Loop, args=[Xs, A]},
-%%% 				     body=#c_values{es=[#c_cons{hd=X, tl=Xs},
-%%% 							A]}}
-			     )},
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=2}]},
-%%% Tuple passing version
-		   body=#c_tuple{anno=[compiler_generated],
-				 es=[#c_literal{val=[]}, Avar]}},
-%%% Multiple-value version
-%%% 		   body=#c_values{es=[#c_literal{val=[]}, A]}},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Avar, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^mapfoldl',2}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs, Avar],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, Avar, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-%%% Tuple passing version
-			       body=#c_apply{anno=Anno,
-					     op=Loop,
-					     args=[L, Avar]}}},
-%%% Multiple-value version
-%%% 			       body=#c_let{vars=[Xs, A],
-%%% 					   arg=#c_apply{op=Loop,
-%%% 							args=[L, A]},
-%%% 					   body=#c_tuple{es=[Xs, A]}}}},
-	 Sub);
-call_1(#c_call{anno=Anno}, lists, mapfoldr, [Arg1,Arg2,Arg3], Sub) ->
-    Loop = #c_var{name={'lists^mapfoldr',2}},
-    F = #c_var{name='F'},
-    Xs = #c_var{name='Xs'},
-    X = #c_var{name='X'},
-    Avar = #c_var{name='A'},
-    Match =
-	fun (A, P, E) ->
-		C1 = #c_clause{pats=[P], guard=#c_literal{val=true}, body=E},
-		Err = #c_tuple{es=[#c_literal{val='badmatch'}, X]},
-		C2 = #c_clause{pats=[X], guard=#c_literal{val=true},
-			       body=match_fail(Anno, Err)},
-		#c_case{arg=A, clauses=[C1, C2]}
-	end,
-    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
-%%% Tuple passing version
-		   body=Match(#c_apply{anno=Anno,
-				       op=Loop,
-				       args=[Xs, Avar]},
-			      #c_tuple{es=[Xs, Avar]},
-			      Match(#c_apply{anno=Anno, op=F, args=[X, Avar]},
-				    #c_tuple{es=[X, Avar]},
-				    #c_tuple{anno=[compiler_generated],
-					     es=[#c_cons{anno=[compiler_generated],
-							 hd=X, tl=Xs}, Avar]}))
-%%% Multiple-value version
-%%% 		   body=#c_let{vars=[Xs,A],
-%%% 			       %% The tuple will be optimised away
-%%% 			       arg=#c_apply{op=Loop, args=[Xs, A]},
-%%% 			       body=Match(#c_apply{op=F, args=[X, A]},
-%%% 					  #c_tuple{es=[X, A]},
-%%% 					  #c_values{es=[#c_cons{hd=X, tl=Xs},
-%%% 						        A]})}
-		  },
-    C2 = #c_clause{pats=[#c_literal{val=[]}],
-		   guard=#c_call{module=#c_literal{val=erlang},
-				 name=#c_literal{val=is_function},
-				 args=[F, #c_literal{val=2}]},
-%%% Tuple passing version
-		   body=#c_tuple{anno=[compiler_generated],
-				 es=[#c_literal{val=[]}, Avar]}},
-%%% Multiple-value version
-%%% 		   body=#c_values{es=[#c_literal{val=[]}, A]}},
-    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Avar, Xs]},
-    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
-		   body=match_fail([{function_name,{'lists^mapfoldr',2}}|Anno], Err)},
-    Fun = #c_fun{vars=[Xs, Avar],
-		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
-    L = #c_var{name='L'},
-    expr(#c_let{vars=[F, Avar, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
-		body=#c_letrec{defs=[{Loop,Fun}],
-%%% Tuple passing version
-			       body=#c_apply{anno=Anno,
-					     op=Loop,
-					     args=[L, Avar]}}},
-%%% Multiple-value version
-%%% 			       body=#c_let{vars=[Xs, A],
-%%% 					   arg=#c_apply{op=Loop,
-%%% 							args=[L, A]},
-%%% 					   body=#c_tuple{es=[Xs, A]}}}},
-	 Sub);
-call_1(#c_call{module=M, name=N}=Call, _, _, As, Sub) ->
-    call_0(Call, M, N, As, Sub).
-
-match_fail(Anno, Arg) ->
-    #c_primop{anno=Anno,
-	      name=#c_literal{val='match_fail'},
-	      args=[Arg]}.
-
 %% fold_call(Call, Mod, Name, Args, Sub) -> Expr.
 %%  Try to safely evaluate the call.  Just try to evaluate arguments,
 %%  do the call and convert return values to literals.  If this
@@ -1065,29 +770,33 @@ fold_call_1(Call, Mod, Name, Args, Sub) ->
 	true -> fold_call_2(Call, Mod, Name, Args, Sub)
     end.
 
-fold_call_2(Call, Module, Name, Args0, Sub) ->
-    try
-	Args = [core_lib:literal_value(A) || A <- Args0],
-	try apply(Module, Name, Args) of
-	    Val ->
-		case cerl:is_literal_term(Val) of
-		    true ->
-			#c_literal{val=Val};
-		    false ->
-			%% Successful evaluation, but it was not
-			%% possible to express the computed value as a literal.
-			Call
-		end
-	catch
-	    error:Reason ->
-		%% Evaluation of the function failed. Warn and replace
-		%% the call with a call to erlang:error/1.
-		eval_failure(Call, Reason)
-	end
+fold_call_2(Call, Module, Name, Args, Sub) ->
+    case all(fun cerl:is_literal/1, Args) of
+	true ->
+	    %% All arguments are literals.
+	    fold_lit_args(Call, Module, Name, Args);
+	false ->
+	    %% At least one non-literal argument.
+	    fold_non_lit_args(Call, Module, Name, Args, Sub)
+    end.
+
+fold_lit_args(Call, Module, Name, Args0) ->
+    Args = [cerl:concrete(A) || A <- Args0],
+    try apply(Module, Name, Args) of
+	Val ->
+	    case cerl:is_literal_term(Val) of
+		true ->
+		    cerl:ann_abstract(cerl:get_ann(Call), Val);
+		false ->
+		    %% Successful evaluation, but it was not possible
+		    %% to express the computed value as a literal.
+		    Call
+	    end
     catch
-	error:_ ->
-	    %% There was at least one non-literal argument.
-	    fold_non_lit_args(Call, Module, Name, Args0, Sub)
+	error:Reason ->
+	    %% Evaluation of the function failed. Warn and replace
+	    %% the call with a call to erlang:error/1.
+	    eval_failure(Call, Reason)
     end.
 
 %% fold_non_lit_args(Call, Module, Name, Args, Sub) -> Expr.
@@ -1126,41 +835,53 @@ fold_non_lit_args(Call, _, _, _, _) -> Call.
 %% Evaluate a relational operation using type information.
 eval_rel_op(Call, Op, [#c_var{name=V},#c_var{name=V}], _) ->
     Bool = erlang:Op(same, same),
-    #c_literal{anno=core_lib:get_anno(Call),val=Bool};
-eval_rel_op(Call, '=:=', [#c_var{name=V}=Var,#c_literal{val=true}], Sub) ->
+    #c_literal{anno=cerl:get_ann(Call),val=Bool};
+eval_rel_op(Call, '=:=', [Term,#c_literal{val=true}], Sub) ->
     %% BoolVar =:= true  ==>  BoolVar
-    case is_boolean_type(V, Sub) of
-	true -> Var;
-	false -> Call
+    case is_boolean_type(Term, Sub) of
+	yes -> Term;
+	maybe -> Call;
+	no -> #c_literal{val=false}
     end;
-eval_rel_op(Call, '==', Ops, _Sub) ->
-    case is_exact_eq_ok(Ops) of
+eval_rel_op(Call, '==', Ops, Sub) ->
+    case is_exact_eq_ok(Ops, Sub) of
 	true ->
-	    Name = #c_literal{anno=core_lib:get_anno(Call),val='=:='},
+	    Name = #c_literal{anno=cerl:get_ann(Call),val='=:='},
 	    Call#c_call{name=Name};
 	false ->
 	    Call
     end;
-eval_rel_op(Call, '/=', Ops, _Sub) ->
-    case is_exact_eq_ok(Ops) of
+eval_rel_op(Call, '/=', Ops, Sub) ->
+    case is_exact_eq_ok(Ops, Sub) of
 	true ->
-	    Name = #c_literal{anno=core_lib:get_anno(Call),val='=/='},
+	    Name = #c_literal{anno=cerl:get_ann(Call),val='=/='},
 	    Call#c_call{name=Name};
 	false ->
 	    Call
     end;
 eval_rel_op(Call, _, _, _) -> Call.
 
-is_exact_eq_ok([#c_literal{val=Lit}|_]) ->
+is_exact_eq_ok([A,B]=L, Sub) ->
+    case is_int_type(A, Sub) =:= yes andalso is_int_type(B, Sub) =:= yes of
+	true -> true;
+	false -> is_exact_eq_ok_1(L)
+    end.
+
+is_exact_eq_ok_1([#c_literal{val=Lit}|_]) ->
     is_non_numeric(Lit);
-is_exact_eq_ok([_|T]) ->
-    is_exact_eq_ok(T);
-is_exact_eq_ok([]) -> false.
+is_exact_eq_ok_1([_|T]) ->
+    is_exact_eq_ok_1(T);
+is_exact_eq_ok_1([]) -> false.
 
 is_non_numeric([H|T]) ->
     is_non_numeric(H) andalso is_non_numeric(T);
 is_non_numeric(Tuple) when is_tuple(Tuple) ->
     is_non_numeric_tuple(Tuple, tuple_size(Tuple));
+is_non_numeric(Map) when is_map(Map) ->
+    %% Note that 17.x and 18.x compare keys in different ways.
+    %% Be very conservative -- require that both keys and values
+    %% are non-numeric.
+    is_non_numeric(maps:to_list(Map));
 is_non_numeric(Num) when is_number(Num) ->
     false;
 is_non_numeric(_) -> true.
@@ -1174,40 +895,31 @@ is_non_numeric_tuple(_Tuple, 0) -> true.
 %% there must be at least one non-literal argument (i.e.
 %% there is no need to handle the case that all argments
 %% are literal).
-eval_bool_op(Call, 'and', [#c_literal{val=true},#c_var{name=V}=Res], Sub) ->
-    case is_boolean_type(V, Sub) of
-	true -> Res;
-	false-> Call
-    end;
-eval_bool_op(Call, 'and', [#c_var{name=V}=Res,#c_literal{val=true}], Sub) ->
-    case is_boolean_type(V, Sub) of
-	true -> Res;
-	false-> Call
-    end;
-eval_bool_op(Call, 'and', [#c_literal{val=false}=Res,#c_var{name=V}], Sub) ->
-    case is_boolean_type(V, Sub) of
-	true -> Res;
-	false-> Call
-    end;
-eval_bool_op(Call, 'and', [#c_var{name=V},#c_literal{val=false}=Res], Sub) ->
-    case is_boolean_type(V, Sub) of
-	true -> Res;
-	false-> Call
-    end;
+
+eval_bool_op(Call, 'and', [#c_literal{val=true},Term], Sub) ->
+    eval_bool_op_1(Call, Term, Term, Sub);
+eval_bool_op(Call, 'and', [Term,#c_literal{val=true}], Sub) ->
+    eval_bool_op_1(Call, Term, Term, Sub);
+eval_bool_op(Call, 'and', [#c_literal{val=false}=Res,Term], Sub) ->
+    eval_bool_op_1(Call, Res, Term, Sub);
+eval_bool_op(Call, 'and', [Term,#c_literal{val=false}=Res], Sub) ->
+    eval_bool_op_1(Call, Res, Term, Sub);
 eval_bool_op(Call, _, _, _) -> Call.
 
+eval_bool_op_1(Call, Res, Term, Sub) ->
+    case is_boolean_type(Term, Sub) of
+	yes -> Res;
+	no -> eval_failure(Call, badarg);
+	maybe -> Call
+    end.
+
 %% Evaluate is_boolean/1 using type information.
-eval_is_boolean(Call, #c_var{name=V}, Sub) ->
-    case is_boolean_type(V, Sub) of
-	true -> #c_literal{val=true};
-	false -> Call
-    end;
-eval_is_boolean(_, #c_cons{}, _) ->
-    #c_literal{val=false};
-eval_is_boolean(_, #c_tuple{}, _) ->
-    #c_literal{val=false};
-eval_is_boolean(Call, _, _) ->
-    Call.
+eval_is_boolean(Call, Term, Sub) ->
+    case is_boolean_type(Term, Sub) of
+	no -> #c_literal{val=false};
+	yes -> #c_literal{val=true};
+	maybe -> Call
+    end.
 
 %% eval_length(Call, List) -> Val.
 %%  Evaluates the length for the prefix of List which has a known
@@ -1257,33 +969,33 @@ eval_append(Call, X, Y) ->
 %%  Evaluates element/2 if the position Pos is a literal and
 %%  the shape of the tuple Tuple is known.
 %%
-eval_element(Call, #c_literal{val=Pos}, #c_tuple{es=Es}, _Types) when is_integer(Pos) ->
-    if
-	1 =< Pos, Pos =< length(Es) ->
-	    lists:nth(Pos, Es);
-	true ->
-	    eval_failure(Call, badarg)
-    end;
-eval_element(Call, #c_literal{val=Pos}, #c_var{name=V}, Types)
+eval_element(Call, #c_literal{val=Pos}, Tuple, Types)
   when is_integer(Pos) ->
-    case orddict:find(V, Types#sub.t) of
-	{ok,#c_tuple{es=Elements}} ->
+    case get_type(Tuple, Types) of
+	none ->
+	    Call;
+	Type ->
+	    Es = case cerl:is_c_tuple(Type) of
+		     false -> [];
+		     true -> cerl:tuple_es(Type)
+		 end,
 	    if
-		1 =< Pos, Pos =< length(Elements) ->
-		    case lists:nth(Pos, Elements) of
-			#c_alias{var=Alias} -> Alias;
-			Res -> Res
+		1 =< Pos, Pos =< length(Es) ->
+		    El = lists:nth(Pos, Es),
+		    try
+			cerl:set_ann(pat_to_expr(El), [compiler_generated])
+		    catch
+			throw:impossible ->
+			    Call
 		    end;
 		true ->
+		    %% Index outside tuple or not a tuple.
 		    eval_failure(Call, badarg)
-	    end;
-	{ok,_} ->
-	    eval_failure(Call, badarg);
-	error ->
-	    Call
+	    end
     end;
-eval_element(Call, Pos, Tuple, _Types) ->
-    case is_not_integer(Pos) orelse is_not_tuple(Tuple) of
+eval_element(Call, Pos, Tuple, Sub) ->
+    case is_int_type(Pos, Sub) =:= no orelse
+	is_tuple_type(Tuple, Sub) =:= no of
 	true ->
 	    eval_failure(Call, badarg);
 	false ->
@@ -1293,56 +1005,55 @@ eval_element(Call, Pos, Tuple, _Types) ->
 %% eval_is_record(Call, Var, Tag, Size, Types) -> Val.
 %%  Evaluates is_record/3 using type information.
 %%
-eval_is_record(Call, #c_var{name=V}, #c_literal{val=NeededTag}=Lit,
+eval_is_record(Call, Term, #c_literal{val=NeededTag},
 	       #c_literal{val=Size}, Types) ->
-    case orddict:find(V, Types#sub.t) of
-	{ok,#c_tuple{es=[#c_literal{val=Tag}|_]=Es}} ->
-	    Lit#c_literal{val=Tag =:= NeededTag andalso
-			  length(Es) =:= Size};
-	_ ->
-	    Call
+    case get_type(Term, Types) of
+	none ->
+	    Call;
+	Type ->
+	    Es = case cerl:is_c_tuple(Type) of
+		     false -> [];
+		     true -> cerl:tuple_es(Type)
+		 end,
+	    case Es of
+		[#c_literal{val=Tag}|_] ->
+		    Bool = Tag =:= NeededTag andalso
+			length(Es) =:= Size,
+		    #c_literal{val=Bool};
+		_ ->
+		    #c_literal{val=false}
+	    end
     end;
 eval_is_record(Call, _, _, _, _) -> Call.
 
-%% is_not_integer(Core) -> true | false.
-%%  Returns true if Core is definitely not an integer.
-
-is_not_integer(#c_literal{val=Val}) when not is_integer(Val) -> true;
-is_not_integer(#c_tuple{}) -> true;
-is_not_integer(#c_cons{}) -> true;
-is_not_integer(_) -> false.
-
-%% is_not_tuple(Core) -> true | false.
-%%  Returns true if Core is definitely not a tuple.
-
-is_not_tuple(#c_literal{val=Val}) when not is_tuple(Val) -> true;
-is_not_tuple(#c_cons{}) -> true;
-is_not_tuple(_) -> false.
-
 %% eval_setelement(Call, Pos, Tuple, NewVal) -> Core.
 %%  Evaluates setelement/3 if position Pos is an integer
-%%  the shape of the tuple Tuple is known.
+%%  and the shape of the tuple Tuple is known.
 %%
-eval_setelement(Call, Pos, Tuple, NewVal) ->
-    try
-	eval_setelement_1(Pos, Tuple, NewVal)
-    catch
-	error:_ ->
-	    Call
-    end.
-
-eval_setelement_1(#c_literal{val=Pos}, #c_tuple{anno=A,es=Es}, NewVal)
-  when is_integer(Pos) ->
-    ann_c_tuple(A, eval_setelement_2(Pos, Es, NewVal));
-eval_setelement_1(#c_literal{val=Pos}, #c_literal{anno=A,val=Es0}, NewVal)
+eval_setelement(Call, #c_literal{val=Pos}, Tuple, NewVal)
   when is_integer(Pos) ->
-    Es = [#c_literal{anno=A,val=E} || E <- tuple_to_list(Es0)],
-    ann_c_tuple(A, eval_setelement_2(Pos, Es, NewVal)).
+    case cerl:is_data(Tuple) of
+	false ->
+	    Call;
+	true ->
+	    Es0 = case cerl:is_c_tuple(Tuple) of
+		      false -> [];
+		      true -> cerl:tuple_es(Tuple)
+		  end,
+	    if
+		1 =< Pos, Pos =< length(Es0) ->
+		    Es = eval_setelement_1(Pos, Es0, NewVal),
+		    cerl:update_c_tuple(Tuple, Es);
+		true ->
+		    eval_failure(Call, badarg)
+	    end
+    end;
+eval_setelement(Call, _, _, _) -> Call.
 
-eval_setelement_2(1, [_|T], NewVal) ->
+eval_setelement_1(1, [_|T], NewVal) ->
     [NewVal|T];
-eval_setelement_2(Pos, [H|T], NewVal) when Pos > 1 ->
-    [H|eval_setelement_2(Pos-1, T, NewVal)].
+eval_setelement_1(Pos, [H|T], NewVal) when Pos > 1 ->
+    [H|eval_setelement_1(Pos-1, T, NewVal)].
 
 %% eval_failure(Call, Reason) -> Core.
 %%  Warn for a call that will fail and replace the call with
@@ -1378,15 +1089,28 @@ is_atom_or_var(_) -> false.
 
 %% clause(Clause, Cepxr, Context, Sub) -> Clause.
 
-clause(#c_clause{pats=Ps0,guard=G0,body=B0}=Cl, Cexpr, Ctxt, Sub0) ->
-    {Ps1,Sub1} = pattern_list(Ps0, Sub0),
+clause(#c_clause{pats=Ps0}=Cl, Cexpr, Ctxt, Sub0) ->
+    try pattern_list(Ps0, Sub0) of
+	{Ps1,Sub1} ->
+	    clause_1(Cl, Ps1, Cexpr, Ctxt, Sub1)
+    catch
+	nomatch ->
+	    Cl#c_clause{anno=[compiler_generated],
+			guard=#c_literal{val=false}}
+    end.
+
+clause_1(#c_clause{guard=G0,body=B0}=Cl, Ps1, Cexpr, Ctxt, Sub1) ->
     Sub2 = update_types(Cexpr, Ps1, Sub1),
-    GSub = case {Cexpr,Ps1} of
-	       {#c_var{name='_'},_} ->
+    GSub = case {Cexpr,Ps1,G0} of
+	       {_,_,#c_literal{}} ->
+		   %% No need for substitution tricks when the guard
+		   %% does not contain any variables.
+		   Sub2;
+	       {#c_var{name='_'},_,_} ->
 		   %% In a 'receive', Cexpr is the variable '_', which represents the
 		   %% message being matched. We must NOT do any extra substiutions.
 		   Sub2;
-	       {#c_var{},[#c_var{}=Var]} ->
+	       {#c_var{},[#c_var{}=Var],_} ->
 		   %% The idea here is to optimize expressions such as
 		   %%
 		   %%   case A of A -> ...
@@ -1420,22 +1144,34 @@ clause(#c_clause{pats=Ps0,guard=G0,body=B0}=Cl, Cexpr, Ctxt, Sub0) ->
 %%  the unsubstituted variables and values.
 
 let_substs(Vs0, As0, Sub0) ->
-    {Vs1,Sub1} = pattern_list(Vs0, Sub0),
+    {Vs1,Sub1} = var_list(Vs0, Sub0),
     {Vs2,As1,Ss} = let_substs_1(Vs1, As0, Sub1),
-    Sub2 = scope_add([V || #c_var{name=V} <- Vs2], Sub1),
+    Sub2 = sub_add_scope([V || #c_var{name=V} <- Vs2], Sub1),
     {Vs2,As1,
-     foldl(fun ({V,S}, Sub) -> sub_set_name(V, S, Sub) end, Sub2, Ss)}.
+    foldl(fun ({V,S}, Sub) -> sub_set_name(V, S, Sub) end, Sub2, Ss)}.
 
 let_substs_1(Vs, #c_values{es=As}, Sub) ->
     let_subst_list(Vs, As, Sub);
 let_substs_1([V], A, Sub) -> let_subst_list([V], [A], Sub);
 let_substs_1(Vs, A, _) -> {Vs,A,[]}.
 
-let_subst_list([V|Vs0], [A|As0], Sub) ->
+let_subst_list([V|Vs0], [A0|As0], Sub) ->
     {Vs1,As1,Ss} = let_subst_list(Vs0, As0, Sub),
-    case is_subst(A) of
-	true -> {Vs1,As1,sub_subst_var(V, A, Sub) ++ Ss};
-	false -> {[V|Vs1],[A|As1],Ss}
+    case is_subst(A0) of
+	true ->
+	    A = case is_compiler_generated(V) andalso
+		    not is_compiler_generated(A0) of
+		    true ->
+			%% Propagate the 'compiler_generated' annotation
+			%% along with the value.
+			Ann = [compiler_generated|cerl:get_ann(A0)],
+			cerl:set_ann(A0, Ann);
+		    false ->
+			A0
+		end,
+	    {Vs1,As1,sub_subst_var(V, A, Sub) ++ Ss};
+	false ->
+	    {[V|Vs1],[A0|As1],Ss}
     end;
 let_subst_list([], [], _) -> {[],[],[]}.
 
@@ -1452,14 +1188,14 @@ let_subst_list([], [], _) -> {[],[],[]}.
 
 %%pattern(Pat, Sub) -> pattern(Pat, Sub, Sub).
 
-pattern(#c_var{name=V0}=Pat, Isub, Osub) ->
+pattern(#c_var{}=Pat, Isub, Osub) ->
     case sub_is_val(Pat, Isub) of
 	true ->
 	    V1 = make_var_name(),
 	    Pat1 = #c_var{name=V1},
-	    {Pat1,sub_set_var(Pat, Pat1, scope_add([V1], Osub))};
+	    {Pat1,sub_set_var(Pat, Pat1, sub_add_scope([V1], Osub))};
 	false ->
-	    {Pat,sub_del_var(Pat, scope_add([V0], Osub))}
+	    {Pat,sub_del_var(Pat, Osub)}
     end;
 pattern(#c_literal{}=Pat, _, Osub) -> {Pat,Osub};
 pattern(#c_cons{anno=Anno,hd=H0,tl=T0}, Isub, Osub0) ->
@@ -1469,6 +1205,9 @@ pattern(#c_cons{anno=Anno,hd=H0,tl=T0}, Isub, Osub0) ->
 pattern(#c_tuple{anno=Anno,es=Es0}, Isub, Osub0) ->
     {Es1,Osub1} = pattern_list(Es0, Isub, Osub0),
     {ann_c_tuple(Anno, Es1),Osub1};
+pattern(#c_map{anno=Anno,es=Es0}=Map, Isub, Osub0) ->
+    {Es1,Osub1} = map_pair_pattern_list(Es0, Isub, Osub0),
+    {Map#c_map{anno=Anno,es=Es1},Osub1};
 pattern(#c_binary{segments=V0}=Pat, Isub, Osub0) ->
     {V1,Osub1} = bin_pattern_list(V0, Isub, Osub0),
     {Pat#c_binary{segments=V1},Osub1};
@@ -1478,24 +1217,145 @@ pattern(#c_alias{var=V0,pat=P0}=Pat, Isub, Osub0) ->
     Osub = update_types(V1, [P1], Osub2),
     {Pat#c_alias{var=V1,pat=P1},Osub}.
 
+map_pair_pattern_list(Ps0, Isub, Osub0) ->
+    {Ps,{_,Osub}} = mapfoldl(fun map_pair_pattern/2, {Isub,Osub0}, Ps0),
+    {Ps,Osub}.
+
+map_pair_pattern(#c_map_pair{op=#c_literal{val=exact},key=K0,val=V0}=Pair,{Isub,Osub0}) ->
+    K = expr(K0, Isub),
+    {V,Osub} = pattern(V0,Isub,Osub0),
+    {Pair#c_map_pair{key=K,val=V},{Isub,Osub}}.
+
 bin_pattern_list(Ps0, Isub, Osub0) ->
     {Ps,{_,Osub}} = mapfoldl(fun bin_pattern/2, {Isub,Osub0}, Ps0),
     {Ps,Osub}.
 
-bin_pattern(#c_bitstr{val=E0,size=Size0}=Pat, {Isub0,Osub0}) ->
+bin_pattern(#c_bitstr{val=E0,size=Size0}=Pat0, {Isub0,Osub0}) ->
     Size1 = expr(Size0, Isub0),
     {E1,Osub} = pattern(E0, Isub0, Osub0),
     Isub = case E0 of
 	       #c_var{} -> sub_set_var(E0, E1, Isub0);
 	       _ -> Isub0
 	   end,
-    {Pat#c_bitstr{val=E1,size=Size1},{Isub,Osub}}.
+    Pat = Pat0#c_bitstr{val=E1,size=Size1},
+    bin_pat_warn(Pat),
+    {Pat,{Isub,Osub}}.
 
 pattern_list(Ps, Sub) -> pattern_list(Ps, Sub, Sub).
 
 pattern_list(Ps0, Isub, Osub0) ->
     mapfoldl(fun (P, Osub) -> pattern(P, Isub, Osub) end, Osub0, Ps0).
 
+%% var_list([Var], InSub) -> {Pattern,OutSub}.
+%%  Works like pattern_list/2 but only accept variables and is
+%%  guaranteed not to throw an exception.
+
+var_list(Vs, Sub0) ->
+    mapfoldl(fun (#c_var{}=V, Sub) ->
+		     pattern(V, Sub, Sub)
+	     end, Sub0, Vs).
+
+
+%%%
+%%% Generate warnings for binary patterns that will not match.
+%%%
+
+bin_pat_warn(#c_bitstr{type=#c_literal{val=Type},
+		       val=Val0,
+		       size=#c_literal{val=Sz},
+		       unit=#c_literal{val=Unit},
+		       flags=Fl}=Pat) ->
+    case {Type,Sz} of
+	{_,_} when is_integer(Sz), Sz >= 0 -> ok;
+	{binary,all} -> ok;
+	{utf8,undefined} -> ok;
+	{utf16,undefined} -> ok;
+	{utf32,undefined} -> ok;
+	{_,_} ->
+	    add_warning(Pat, {nomatch_bit_syntax_size,Sz}),
+	    throw(nomatch)
+    end,
+    case {Type,Val0} of
+	{integer,#c_literal{val=Val}} when is_integer(Val) ->
+	    Signedness = signedness(Fl),
+	    TotalSz = Sz * Unit,
+	    bit_pat_warn_int(Val, TotalSz, Signedness, Pat);
+	{float,#c_literal{val=Val}} when is_float(Val) ->
+	    ok;
+	{utf8,#c_literal{val=Val}} when is_integer(Val) ->
+	    bit_pat_warn_unicode(Val, Pat);
+	{utf16,#c_literal{val=Val}} when is_integer(Val) ->
+	    bit_pat_warn_unicode(Val, Pat);
+	{utf32,#c_literal{val=Val}} when is_integer(Val) ->
+	    bit_pat_warn_unicode(Val, Pat);
+	{_,#c_literal{val=Val}} ->
+	    add_warning(Pat, {nomatch_bit_syntax_type,Val,Type}),
+	    throw(nomatch);
+	{_,_} ->
+	    ok
+    end;
+bin_pat_warn(#c_bitstr{type=#c_literal{val=Type},val=Val0,flags=Fl}=Pat) ->
+    %% Size is variable. Not much that we can check.
+    case {Type,Val0} of
+	{integer,#c_literal{val=Val}} when is_integer(Val) ->
+	    case signedness(Fl) of
+		unsigned when Val < 0 ->
+		    add_warning(Pat, {nomatch_bit_syntax_unsigned,Val}),
+		    throw(nomatch);
+		_ ->
+		    ok
+	    end;
+	{float,#c_literal{val=Val}} when is_float(Val) ->
+	    ok;
+	{_,#c_literal{val=Val}} ->
+	    add_warning(Pat, {nomatch_bit_syntax_type,Val,Type}),
+	    throw(nomatch);
+	{_,_} ->
+	    ok
+    end.
+
+bit_pat_warn_int(Val, 0, signed, Pat) ->
+    if
+	Val =:= 0 ->
+	    ok;
+	true ->
+	    add_warning(Pat, {nomatch_bit_syntax_truncated,signed,Val,0}),
+	    throw(nomatch)
+    end;
+bit_pat_warn_int(Val, Sz, signed, Pat) ->
+    if
+	Val < 0, Val bsr (Sz - 1) =/= -1 ->
+	    add_warning(Pat, {nomatch_bit_syntax_truncated,signed,Val,Sz}),
+	    throw(nomatch);
+	Val > 0, Val bsr (Sz - 1) =/= 0 ->
+	    add_warning(Pat, {nomatch_bit_syntax_truncated,signed,Val,Sz}),
+	    throw(nomatch);
+	true ->
+	    ok
+    end;
+bit_pat_warn_int(Val, _Sz, unsigned, Pat) when Val < 0 ->
+    add_warning(Pat, {nomatch_bit_syntax_unsigned,Val}),
+    throw(nomatch);
+bit_pat_warn_int(Val, Sz, unsigned, Pat) ->
+    if
+	Val bsr Sz =:= 0 ->
+	    ok;
+	true ->
+	    add_warning(Pat, {nomatch_bit_syntax_truncated,unsigned,Val,Sz}),
+	    throw(nomatch)
+    end.
+
+bit_pat_warn_unicode(U, _Pat) when 0 =< U, U =< 16#10FFFF ->
+    ok;
+bit_pat_warn_unicode(U, Pat) ->
+    add_warning(Pat, {nomatch_bit_syntax_unicode,U}),
+    throw(nomatch).
+
+signedness(#c_literal{val=Flags}) ->
+    [S] = [F || F <- Flags, F =:= signed orelse F =:= unsigned],
+    S.
+
+
 %% is_subst(Expr) -> true | false.
 %%  Test whether an expression is a suitable substitution.
 
@@ -1515,6 +1375,7 @@ is_subst(_) -> false.
 %% sub_del_var(Var, #sub{}) -> #sub{}.
 %% sub_subst_var(Var, Value, #sub{}) -> [{Name,Value}].
 %% sub_is_val(Var, #sub{}) -> boolean().
+%% sub_add_scope(#sub{}) -> #sub{}
 %% sub_subst_scope(#sub{}) -> #sub{}
 %%
 %%  We use the variable name as key so as not have problems with
@@ -1522,14 +1383,18 @@ is_subst(_) -> false.
 %%  chains so we never have to search more than once.  Use orddict so
 %%  we know the format.
 %%
-%%  sub_subst_scope/1 adds dummy substitutions for all variables
-%%  in the scope in order to force renaming if variables in the
-%%  scope occurs as pattern variables.
+%%  In addition to the list of substitutions, we also keep track of
+%%  all variable currently live (the scope).
+%%
+%%  sub_add_scope/2 adds variables to the scope.  sub_subst_scope/1
+%%  adds dummy substitutions for all variables in the scope in order
+%%  to force renaming if variables in the scope occurs as pattern
+%%  variables.
 
-sub_new() -> #sub{v=orddict:new(),s=gb_trees:empty(),t=[]}.
+sub_new() -> #sub{v=orddict:new(),s=cerl_sets:new(),t=#{}}.
 
 sub_new(#sub{}=Sub) ->
-    Sub#sub{v=orddict:new(),t=[]}.
+    Sub#sub{v=orddict:new(),t=#{}}.
 
 sub_new_preserve_types(#sub{}=Sub) ->
     Sub#sub{v=orddict:new()}.
@@ -1546,60 +1411,78 @@ sub_set_var(#c_var{name=V}, Val, Sub) ->
 sub_set_name(V, Val, #sub{v=S,s=Scope,t=Tdb0}=Sub) ->
     Tdb1 = kill_types(V, Tdb0),
     Tdb = copy_type(V, Val, Tdb1),
-    Sub#sub{v=orddict:store(V, Val, S),s=gb_sets:add(V, Scope),t=Tdb}.
-
-sub_del_var(#c_var{name=V}, #sub{v=S,t=Tdb}=Sub) ->
-    Sub#sub{v=orddict:erase(V, S),t=kill_types(V, Tdb)}.
+    Sub#sub{v=orddict:store(V, Val, S),s=cerl_sets:add_element(V, Scope),t=Tdb}.
+
+sub_del_var(#c_var{name=V}, #sub{v=S,s=Scope,t=Tdb}=Sub) ->
+    %% Profiling shows that for programs with many record operations,
+    %% sub_del_var/2 is a bottleneck. Since the scope contains all
+    %% variables that are live, we know that V cannot be present in S
+    %% if it is not in the scope.
+    case cerl_sets:is_element(V, Scope) of
+	false ->
+	    Sub#sub{s=cerl_sets:add_element(V, Scope)};
+	true ->
+	    Sub#sub{v=orddict:erase(V, S),t=kill_types(V, Tdb)}
+    end.
 
 sub_subst_var(#c_var{name=V}, Val, #sub{v=S0}) ->
     %% Fold chained substitutions.
     [{V,Val}] ++ [ {K,Val} || {K,#c_var{name=V1}} <- S0, V1 =:= V].
 
+sub_add_scope(Vs, #sub{s=Scope0}=Sub) ->
+    Scope = foldl(fun(V, S) when is_integer(V); is_atom(V) ->
+			  cerl_sets:add_element(V, S)
+		  end, Scope0, Vs),
+    Sub#sub{s=Scope}.
+
 sub_subst_scope(#sub{v=S0,s=Scope}=Sub) ->
-    S = [{-1,#c_var{name=Sv}} || Sv <- gb_sets:to_list(Scope)]++S0,
+    S = [{-1,#c_var{name=Sv}} || Sv <- cerl_sets:to_list(Scope)]++S0,
     Sub#sub{v=S}.
 
-sub_is_val(#c_var{name=V}, #sub{v=S}) ->
-    v_is_value(V, S).
-
-v_is_value(Var, Sub) ->
-    any(fun ({_,#c_var{name=Val}}) when Val =:= Var -> true;
-	    (_) -> false
-	end, Sub).
-
-%% clauses(E, [Clause], TopLevel, Context, Sub) -> [Clause].
-%%  Trim the clauses by removing all clauses AFTER the first one which
-%%  is guaranteed to match.  Also remove all trivially false clauses.
-
-clauses(E, Cs0, TopLevel, Ctxt, Sub) ->
-    Cs = clauses_1(E, Cs0, Ctxt, Sub),
-
-    %% Here we want to warn if no clauses whatsoever will ever
-    %% match, because that is probably a mistake.
-    case all(fun is_compiler_generated/1, Cs) andalso
-	any(fun(C) -> not is_compiler_generated(C) end, Cs0) of
+sub_is_val(#c_var{name=V}, #sub{v=S,s=Scope}) ->
+    %% When the bottleneck in sub_del_var/2 was eliminated, this
+    %% became the new bottleneck. Since the scope contains all
+    %% live variables, a variable V can only be the target for
+    %% a substitution if it is in the scope.
+    cerl_sets:is_element(V, Scope) andalso v_is_value(V, S).
+
+v_is_value(Var, [{_,#c_var{name=Var}}|_]) -> true;
+v_is_value(Var, [_|T]) -> v_is_value(Var, T);
+v_is_value(_, []) -> false.
+
+%% warn_no_clause_match(CaseOrig, CaseOpt) -> ok
+%%  Generate a warning if none of the user-specified clauses
+%%  will match.
+
+warn_no_clause_match(CaseOrig, CaseOpt) ->
+    OrigCs = cerl:case_clauses(CaseOrig),
+    OptCs = cerl:case_clauses(CaseOpt),
+    case any(fun(C) -> not is_compiler_generated(C) end, OrigCs) andalso
+	all(fun is_compiler_generated/1, OptCs) of
 	true ->
 	    %% The original list of clauses did contain at least one
 	    %% user-specified clause, but none of them will match.
 	    %% That is probably a mistake.
-	    add_warning(TopLevel, no_clause_match);
+	    add_warning(CaseOrig, no_clause_match);
 	false ->
 	    %% Either there were user-specified clauses left in
 	    %% the transformed clauses, or else none of the original
 	    %% clauses were user-specified to begin with (as in 'andalso').
 	    ok
-    end,
+    end.
 
-    Cs.
+%% clauses(E, [Clause], TopLevel, Context, Sub) -> [Clause].
+%%  Trim the clauses by removing all clauses AFTER the first one which
+%%  is guaranteed to match.  Also remove all trivially false clauses.
 
-clauses_1(E, [C0|Cs], Ctxt, Sub) ->
+clauses(E, [C0|Cs], Ctxt, Sub, LitExpr) ->
     #c_clause{pats=Ps,guard=G} = C1 = clause(C0, E, Ctxt, Sub),
     %%ok = io:fwrite("~w: ~p~n", [?LINE,{E,Ps}]),
     case {will_match(E, Ps),will_succeed(G)} of
 	{yes,yes} ->
-	    Line = get_line(core_lib:get_anno(C1)),
-	    case core_lib:is_literal(E) of
+	    case LitExpr of
 		false ->
+		    Line = get_line(cerl:get_ann(C1)),
 		    shadow_warning(Cs, Line);
 		true ->
 		    %% If the case expression is a literal,
@@ -1608,15 +1491,13 @@ clauses_1(E, [C0|Cs], Ctxt, Sub) ->
 		    ok
 	    end,
 	    [C1];				%Skip the rest
-	{no,_Suc} ->
-	    clauses_1(E, Cs, Ctxt, Sub);	%Skip this clause
-	{_Mat,no} ->
+	{_Mat,no} ->				%Guard fails.
 	    add_warning(C1, nomatch_guard),
-	    clauses_1(E, Cs, Ctxt, Sub);	%Skip this clause
+	    clauses(E, Cs, Ctxt, Sub, LitExpr);	%Skip this clause
 	{_Mat,_Suc} ->
-	    [C1|clauses_1(E, Cs, Ctxt, Sub)]
+	    [C1|clauses(E, Cs, Ctxt, Sub, LitExpr)]
     end;
-clauses_1(_, [], _, _) -> [].
+clauses(_, [], _, _, _) -> [].
 
 shadow_warning([C|Cs], none) ->
     add_warning(C, nomatch_shadow),
@@ -1634,69 +1515,18 @@ will_succeed(#c_literal{val=true}) -> yes;
 will_succeed(#c_literal{val=false}) -> no;
 will_succeed(_Guard) -> maybe.
 
-%% will_match(Expr, [Pattern]) -> yes | maybe | no.
-%%  Test if we know whether a match will succeed/fail or just don't
-%%  know.  Be conservative.
+%% will_match(Expr, [Pattern]) -> yes | maybe.
+%%  We KNOW that this function is only used after optimizations
+%%  in case_opt/4. Therefore clauses that can definitely not match
+%%  have already been pruned.
 
 will_match(#c_values{es=Es}, Ps) ->
-    will_match_list(Es, Ps, yes);
+    will_match_1(cerl_clauses:match_list(Ps, Es));
 will_match(E, [P]) ->
-    will_match_1(E, P).
-
-will_match_1(_E, #c_var{}) -> yes;		%Will always match
-will_match_1(E, #c_alias{pat=P}) ->		%Pattern decides
-    will_match_1(E, P);
-will_match_1(#c_var{}, _P) -> maybe;
-will_match_1(#c_tuple{es=Es}, #c_tuple{es=Ps}) ->
-    will_match_list(Es, Ps, yes);
-will_match_1(#c_literal{val=Lit}, P) ->
-    will_match_lit(Lit, P);
-will_match_1(_, _) -> maybe.
-
-will_match_list([E|Es], [P|Ps], M) ->
-    case will_match_1(E, P) of
-	yes -> will_match_list(Es, Ps, M);
-	maybe -> will_match_list(Es, Ps, maybe);
-	no -> no
-    end;
-will_match_list([], [], M) -> M.
-
-will_match_lit(Cons, #c_cons{hd=Hp,tl=Tp}) ->
-    case Cons of
-	[H|T] ->
-	    case will_match_lit(H, Hp) of
-		yes -> will_match_lit(T, Tp);
-		Other -> Other
-	    end;
-	_ ->
-	    no
-    end;
-will_match_lit(Tuple, #c_tuple{es=Es}) ->
-    case is_tuple(Tuple) andalso tuple_size(Tuple) =:= length(Es) of
-	true -> will_match_lit_list(tuple_to_list(Tuple), Es);
-	false -> no
-    end;
-will_match_lit(Bin, #c_binary{}) ->
-    case is_bitstring(Bin) of
-	true -> maybe;
-	false -> no
-    end;
-will_match_lit(_, #c_var{}) ->
-    yes;
-will_match_lit(Lit, #c_alias{pat=P}) ->
-    will_match_lit(Lit, P);
-will_match_lit(Lit1, #c_literal{val=Lit2}) ->
-    case Lit1 =:= Lit2 of
-	true -> yes;
-	false -> no
-    end.
+    will_match_1(cerl_clauses:match(P, E)).
 
-will_match_lit_list([H|T], [P|Ps]) ->
-    case will_match_lit(H, P) of
-	yes -> will_match_lit_list(T, Ps);
-	Other -> Other
-    end;
-will_match_lit_list([], []) -> yes.
+will_match_1({false,_}) -> maybe;
+will_match_1({true,_}) -> yes.
 
 %% opt_bool_case(CoreExpr) - CoreExpr'.
 %%  Do various optimizations to case statement that has a
@@ -1760,9 +1590,14 @@ opt_bool_clauses([#c_clause{pats=[#c_literal{val=Lit}],
 	true ->
 	    %% This clause will match.
 	    C = C0#c_clause{body=opt_bool_case(B)},
-	    case Lit of
-		false -> [C|opt_bool_clauses(Cs, SeenT, true)];
-		true -> [C|opt_bool_clauses(Cs, true, SeenF)]
+	    case {Lit,SeenT,SeenF} of
+                {false,_,false} ->
+                    [C|opt_bool_clauses(Cs, SeenT, true)];
+                {true,false,_} ->
+                    [C|opt_bool_clauses(Cs, true, SeenF)];
+                _ ->
+                    add_warning(C, nomatch_shadow),
+                    opt_bool_clauses(Cs, SeenT, SeenF)
 	    end
     end;
 opt_bool_clauses([#c_clause{pats=Ps,guard=#c_literal{val=true}}=C|Cs], SeenT, SeenF) ->
@@ -1881,7 +1716,7 @@ opt_bool_case_guard(#c_case{arg=Arg,clauses=Cs0}=Case) ->
 	    Case;
 	true ->
 	    Cs = opt_bool_case_guard(Arg, Cs0),
-	    Case#c_case{arg=#c_values{anno=core_lib:get_anno(Arg),es=[]},
+	    Case#c_case{arg=#c_values{anno=cerl:get_ann(Arg),es=[]},
 			clauses=Cs}
     end.
 
@@ -1895,165 +1730,373 @@ opt_bool_case_guard(Arg, [#c_clause{pats=[#c_literal{val=false}]}=Fc,Tc]) ->
 %%  last clause is guaranteed to match so if there is only one clause
 %%  with a pattern containing only variables then rewrite to a let.
 
-eval_case(#c_case{arg=#c_var{name=V},
-		  clauses=[#c_clause{pats=[P],guard=G,body=B}|_]}=Case,
-	  #sub{t=Tdb}=Sub) ->
-    case orddict:find(V, Tdb) of
-	{ok,Type} ->
-	    case {will_match_type(P, Type),will_succeed(G)} of
-		{yes,yes} ->
-		    {Ps,Es} = remove_non_vars(P, Type),
-		    expr(#c_let{vars=Ps,arg=#c_values{es=Es},body=B},
-			 sub_new(Sub));
-		{_,_} ->
-		    eval_case_1(Case, Sub)
-	    end;
-	error -> eval_case_1(Case, Sub)
-    end;
-eval_case(Case, Sub) -> eval_case_1(Case, Sub).
-
-eval_case_1(#c_case{arg=E,clauses=[#c_clause{pats=Ps,body=B}]}=Case, Sub) ->
-    case is_var_pat(Ps) of
-	true -> expr(#c_let{vars=Ps,arg=E,body=B}, sub_new(Sub));
-	false -> eval_case_2(E, Ps, B, Case)
-    end;
-eval_case_1(Case, _) -> Case.
-
-eval_case_2(E, [P], B, Case) ->
-    %% Recall that there is only one clause and that it is guaranteed to match.
-    %%   If E and P are literals, they must be the same literal and the body
-    %% can be used directly as there are no variables that need to be bound.
-    %%   Otherwise, P could be an alias meaning that two or more variables
-    %% would be bound to E. We don't bother to optimize that case as it
-    %% is rather uncommon.
-    case core_lib:is_literal(E) andalso core_lib:is_literal(P) of
-	false -> Case;
-	true -> B
-    end;
-eval_case_2(_, _, _, Case) -> Case.
-
-is_var_pat(Ps) ->
-    all(fun (#c_var{}) -> true;
-	    (_Pat) -> false
-	end, Ps).
-
-will_match_type(#c_tuple{es=Es}, #c_tuple{es=Ps}) ->
-    will_match_list_type(Es, Ps);
-will_match_type(#c_literal{val=Atom}, #c_literal{val=Atom}) -> yes;
-will_match_type(#c_var{}, #c_var{}) -> yes;
-will_match_type(#c_var{}, #c_alias{}) -> yes;
-will_match_type(_, _) -> no.
-
-will_match_list_type([E|Es], [P|Ps]) ->
-    case will_match_type(E, P) of
-	yes -> will_match_list_type(Es, Ps);
-	no -> no
-    end;
-will_match_list_type([], []) -> yes;
-will_match_list_type(_, _) -> no.		%Different length
-
-remove_non_vars(Ps0, Es0) ->
-    {Ps,Es} = remove_non_vars(Ps0, Es0, [], []),
-    {reverse(Ps),reverse(Es)}.
-
-remove_non_vars(#c_tuple{es=Ps}, #c_tuple{es=Es}, Pacc, Eacc) ->
-    remove_non_vars_list(Ps, Es, Pacc, Eacc);
-remove_non_vars(#c_var{}=Var, #c_alias{var=Evar}, Pacc, Eacc) ->
-    {[Var|Pacc],[Evar|Eacc]};
-remove_non_vars(#c_var{}=Var, #c_var{}=Evar, Pacc, Eacc) ->
-    {[Var|Pacc],[Evar|Eacc]};
-remove_non_vars(P, E, Pacc, Eacc) ->
-    true = core_lib:is_literal(P) andalso core_lib:is_literal(E), %Assertion.
-    {Pacc,Eacc}.
-
-remove_non_vars_list([P|Ps], [E|Es], Pacc0, Eacc0) ->
-    {Pacc,Eacc} = remove_non_vars(P, E, Pacc0, Eacc0),
-    remove_non_vars_list(Ps, Es, Pacc, Eacc);
-remove_non_vars_list([], [], Pacc, Eacc) ->
-    {Pacc,Eacc}.
+eval_case(#c_case{arg=E,clauses=[#c_clause{pats=Ps0,
+					   guard=#c_literal{val=true},
+					   body=B}]}=Case, Sub) ->
+    Es = case cerl:is_c_values(E) of
+	     true -> cerl:values_es(E);
+	     false -> [E]
+	 end,
+    %% Consider:
+    %%
+    %%   case SomeSideEffect() of
+    %%      X=Y -> ...
+    %%   end
+    %%
+    %% We must not rewrite it to:
+    %%
+    %%   let <X,Y> = <SomeSideEffect(),SomeSideEffect()> in ...
+    %%
+    %% because SomeSideEffect() would be evaluated twice.
+    %%
+    %% Instead we must evaluate the case expression in an outer let
+    %% like this:
+    %%
+    %%   let NewVar = SomeSideEffect() in
+    %%       let <X,Y> = <NewVar,NewVar> in ...
+    %%
+    Vs = make_vars([], length(Es)),
+    case cerl_clauses:match_list(Ps0, Vs) of
+	{false,_} ->
+	    %% This can only happen if the Core Erlang code is
+	    %% handwritten or generated by another code generator
+	    %% than v3_core. Assuming that the Core Erlang program
+	    %% is correct, the clause will always match at run-time.
+	    Case;
+	{true,Bs} ->
+	    eval_case_warn(B),
+	    {Ps,As} = unzip(Bs),
+	    InnerLet = cerl:c_let(Ps, core_lib:make_values(As), B),
+	    Let = cerl:c_let(Vs, E, InnerLet),
+	    expr(Let, sub_new(Sub))
+    end;
+eval_case(Case, _) -> Case.
+
+eval_case_warn(#c_primop{anno=Anno,
+			 name=#c_literal{val=match_fail},
+			 args=[_]}=Core) ->
+    case keyfind(eval_failure, 1, Anno) of
+	false ->
+	    ok;
+	{eval_failure,Reason} ->
+	    %% Example: M = not_map, M#{k:=v}
+	    add_warning(Core, {eval_failure,Reason})
+    end;
+eval_case_warn(_) -> ok.
 
 %% case_opt(CaseArg, [Clause]) -> {CaseArg,[Clause]}.
-%%  Try and optimise case by avoid building a tuple in
-%%  the case expression. Instead of building a tuple
-%%  in the case expression, combine the elements into
-%%  multiple "values". If a clause refers to the tuple
-%%  in the case expression (that was not built), introduce
-%%  a let into the guard and/or body to build the tuple.
-%%
-%%     case {Expr1,Expr2} of		 case <Expr1,Expr2> of
-%%         {P1,P2} -> ...		     <P1,P2> -> ...
+%%  Try and optimise a case by avoid building tuples or lists
+%%  in the case expression. Instead combine the variable parts
+%%  of the case expression to multiple "values". If a clause
+%%  refers to the constructed term in the case expression (which
+%%  was not built), introduce a let into the guard and/or body to
+%%  build the term.
+%%
+%%     case {ok,[Expr1,Expr2]} of	case <Expr1,Expr2> of
+%%         {ok,[P1,P2]} -> ...		    <P1,P2> -> ...
 %%          .  	       	       	  ==>        .
 %%          .				     .
 %%          .				     .
-%%         Var ->                            <Var1,Var2> ->
-%%             ... Var ...                      let <Var> = {Var1,Var2}
-%%                                                  in ... Var ...
+%%         Var ->                           <Var1,Var2> ->
+%%             ... Var ...                     let <Var> = {ok,[Var1,Var2]}
+%%                                                 in ... Var ...
 %%          .                                 .
 %%          .                                 .
 %%          .				      .
-%%     end.				 end.
-%%
-case_opt(#c_tuple{anno=A,es=Es}, Cs0) ->
-    Cs1 = case_opt_cs(Cs0, length(Es)),
-    {core_lib:set_anno(core_lib:make_values(Es), A),Cs1};
-case_opt(Arg, Cs) -> {Arg,Cs}.
-
-case_opt_cs([#c_clause{pats=Ps0,guard=G,body=B}=C|Cs], Arity) ->
-    case case_tuple_pat(Ps0, Arity) of
-	{ok,Ps1,Avs} ->
-	    Flet = fun ({V,Pat}, Body) -> letify(V, Pat, Body) end,
-	    [C#c_clause{pats=Ps1,
-			guard=foldl(Flet, G, Avs),
-			body=foldl(Flet, B, Avs)}|case_opt_cs(Cs, Arity)];
-	error ->				%Can't match
-	    add_warning(C, nomatch_clause_type),
-	    case_opt_cs(Cs, Arity)
-    end;
-case_opt_cs([], _) -> [].
-
-%% case_tuple_pat([Pattern], Arity) -> {ok,[Pattern],[{AliasVar,Pat}]} | error.
-
-case_tuple_pat([#c_tuple{es=Ps}], Arity) when length(Ps) =:= Arity ->
-    {ok,Ps,[]};
-case_tuple_pat([#c_literal{val=T}], Arity) when tuple_size(T) =:= Arity ->
-    Ps = [#c_literal{val=E} || E <- tuple_to_list(T)],
-    {ok,Ps,[]};
-case_tuple_pat([#c_var{anno=Anno0}=V], Arity) ->
-    Vars = make_vars(Anno0, 1, Arity),
-
-    %% If the entire case statement is evaluated in an effect
-    %% context (e.g. "case {A,B} of ... end, ok"), there will
-    %% be a warning that a term is constructed but never used.
-    %% To avoid that warning, we must annotate the tuple as
-    %% compiler generated.
-
-    Anno = [compiler_generated|Anno0],
-    {ok,Vars,[{V,#c_tuple{anno=Anno,es=Vars}}]};
-case_tuple_pat([#c_alias{var=V,pat=P}], Arity) ->
-    case case_tuple_pat([P], Arity) of
-	{ok,Ps,Avs} ->
-	    Anno0 = core_lib:get_anno(P),
-	    Anno = [compiler_generated|Anno0],
-	    {ok,Ps,[{V,#c_tuple{anno=Anno,es=unalias_pat_list(Ps)}}|Avs]};
-	error ->
-	    error
-    end;
-case_tuple_pat(_, _) -> error.
-
-%% unalias_pat(Pattern) -> Pattern.
-%%  Remove all the aliases in a pattern but using the alias variables
-%%  instead of the values.  We KNOW they will be bound.
-
-unalias_pat(#c_alias{var=V}) -> V;
-unalias_pat(#c_cons{anno=Anno,hd=H0,tl=T0}) ->
-    H1 = unalias_pat(H0),
-    T1 = unalias_pat(T0),
-    ann_c_cons(Anno, H1, T1);
-unalias_pat(#c_tuple{anno=Anno,es=Ps}) ->
-    ann_c_tuple(Anno, unalias_pat_list(Ps));
-unalias_pat(Atomic) -> Atomic.
-
-unalias_pat_list(Ps) -> [unalias_pat(P) || P <- Ps].
+%%     end.				end.
+%%
+case_opt(Arg, Cs0, Sub) ->
+    Cs1 = [{cerl:clause_pats(C),C,[],[]} || C <- Cs0],
+    Args0 = case cerl:is_c_values(Arg) of
+		false -> [Arg];
+		true -> cerl:values_es(Arg)
+	    end,
+    LitExpr = cerl:is_literal(Arg),
+    {Args,Cs2} = case_opt_args(Args0, Cs1, Sub, LitExpr, []),
+    Cs = [cerl:update_c_clause(C,
+			       reverse(Ps),
+			       letify(Bs, cerl:clause_guard(C)),
+			       letify(Bs, cerl:clause_body(C))) ||
+	     {[],C,Ps,Bs} <- Cs2],
+    {core_lib:make_values(Args),Cs}.
+
+case_opt_args([A0|As0], Cs0, Sub, LitExpr, Acc) ->
+    case case_opt_arg(A0, Sub, Cs0, LitExpr) of
+        {error,Cs1} ->
+	    %% Nothing to be done. Move on to the next argument.
+            Cs = [{Ps,C,[P|PsAcc],Bs} || {[P|Ps],C,PsAcc,Bs} <- Cs1],
+	    case_opt_args(As0, Cs, Sub, LitExpr, [A0|Acc]);
+	{ok,As1,Cs} ->
+	    %% The argument was either expanded (from tuple/list) or
+	    %% removed (literal).
+	    case_opt_args(As1++As0, Cs, Sub, LitExpr, Acc)
+    end;
+case_opt_args([], Cs, _Sub, _LitExpr, Acc) ->
+    {reverse(Acc),Cs}.
+
+%% case_opt_arg(Expr, Sub, Clauses0, LitExpr) ->
+%%         {ok,Args,Clauses} | error
+%%  Try to expand one argument to several arguments (if tuple/list)
+%%  or to remove a literal argument.
+%%
+case_opt_arg(E0, Sub, Cs, LitExpr) ->
+    case cerl:is_c_var(E0) of
+	false ->
+	    case_opt_arg_1(E0, Cs, LitExpr);
+	true ->
+	    case case_will_var_match(Cs) of
+		true ->
+		    %% All clauses will match a variable in the
+		    %% current position. Don't expand this variable
+		    %% (that can only make the code worse).
+		    {error,Cs};
+		false ->
+		    %% If possible, expand this variable to a previously
+		    %% matched term.
+		    E = case_expand_var(E0, Sub),
+		    case_opt_arg_1(E, Cs, LitExpr)
+	    end
+    end.
+
+case_opt_arg_1(E0, Cs0, LitExpr) ->
+    case cerl:is_data(E0) of
+	false ->
+            {error,Cs0};
+	true ->
+	    E = case_opt_compiler_generated(E0),
+	    Cs = case_opt_nomatch(E, Cs0, LitExpr),
+	    case cerl:data_type(E) of
+		{atomic,_} ->
+		    case_opt_lit(E, Cs);
+		_ ->
+		    case_opt_data(E, Cs)
+	    end
+    end.
+
+%% case_will_var_match([Clause]) -> true | false.
+%%  Return if all clauses will match a variable in the
+%%  current position.
+%%
+case_will_var_match(Cs) ->
+    all(fun({[P|_],_,_,_}) ->
+		case cerl_clauses:match(P, any) of
+		    {true,_} -> true;
+		    _ -> false
+		end
+	end, Cs).
+
+
+%% case_opt_compiler_generated(Core) -> Core'
+%%  Mark Core expressions as compiler generated to ensure that
+%%  no warnings are generated if they turn out to be unused.
+%%  To pretty-printed Core Erlang easier to read, don't mark
+%%  constructs that can't cause warnings to be emitted.
+%%
+case_opt_compiler_generated(Core) ->
+    F = fun(C) ->
+		case cerl:type(C) of
+		    alias -> C;
+		    var -> C;
+		    _ -> cerl:set_ann(C, [compiler_generated])
+		end
+	end,
+    cerl_trees:map(F, Core).
+
+
+%% case_expand_var(Expr0, Sub) -> Expr
+%%  If Expr0 is a variable that has been previously matched and
+%%  is known to be a tuple, return the tuple instead. Otherwise
+%%  return Expr0 unchanged.
+%%
+case_expand_var(E, #sub{t=Tdb}) ->
+    Key = cerl:var_name(E),
+    case Tdb of
+        #{Key:=T0} ->
+	    case cerl:is_c_tuple(T0) of
+		false ->
+		    E;
+		true ->
+		    %% The pattern was a tuple. Now we must make sure
+		    %% that the elements of the tuple are suitable. In
+		    %% particular, we don't want binary or map
+		    %% construction here, since that means that the
+		    %% binary or map will be constructed in the 'case'
+		    %% argument. That is wasteful for binaries. Even
+		    %% worse is that any map pattern that use the ':='
+		    %% operator will fail when used in map
+		    %% construction (only the '=>' operator is allowed
+		    %% when constructing a map from scratch).
+		    try
+			cerl_trees:map(fun coerce_to_data/1, T0)
+		    catch
+			throw:impossible ->
+			    %% Something unsuitable was found (map or
+			    %% or binary). Keep the variable.
+			    E
+		    end
+	    end;
+        _ ->
+	    E
+    end.
+
+%% coerce_to_data(Core) -> Core'
+%%  Coerce an element originally from a pattern to an data item or or
+%%  variable. Throw an 'impossible' exception if non-data Core Erlang
+%%  terms such as binary construction or map construction are
+%%  encountered.
+
+coerce_to_data(C) ->
+    case cerl:is_c_alias(C) of
+	false ->
+	    case cerl:is_data(C) orelse cerl:is_c_var(C) of
+		true -> C;
+		false -> throw(impossible)
+	    end;
+	true ->
+	    coerce_to_data(cerl:alias_pat(C))
+    end.
+
+%% case_opt_nomatch(E, Clauses, LitExpr) -> Clauses'
+%%  Remove all clauses that cannot possibly match.
+
+case_opt_nomatch(E, [{[P|_],C,_,_}=Current|Cs], LitExpr) ->
+    case cerl_clauses:match(P, E) of
+        none ->
+            %% The pattern will not match the case expression. Remove
+            %% the clause.  Unless the entire case expression is a
+            %% literal, also emit a warning.
+            case LitExpr of
+                false -> add_warning(C, nomatch_clause_type);
+                true -> ok
+            end,
+            case_opt_nomatch(E, Cs, LitExpr);
+        _ ->
+            [Current|case_opt_nomatch(E, Cs, LitExpr)]
+    end;
+case_opt_nomatch(_, [], _) -> [].
+
+%% case_opt_lit(Literal, Clauses0) -> {ok,[],Clauses} | error
+%%  The current part of the case expression is a literal. That
+%%  means that we will know at compile-time whether a clause
+%%  will match, and we can remove the corresponding pattern from
+%%  each clause.
+%%
+%%  The only complication is if the literal is a binary or map.
+%%  In general, it is difficult to know whether a binary or
+%%  map pattern will match, so we give up in that case.
+
+case_opt_lit(Lit, Cs0) ->
+    try case_opt_lit_1(Lit, Cs0) of
+	Cs ->
+	    {ok,[],Cs}
+    catch
+	throw:impossible ->
+            {error,Cs0}
+    end.
+
+case_opt_lit_1(E, [{[P|Ps],C,PsAcc,Bs0}|Cs]) ->
+    %% Non-matching clauses have already been removed
+    %% in case_opt_nomatch/3.
+    case cerl_clauses:match(P, E) of
+	{true,Bs} ->
+	    %% The pattern matches the literal. Remove the pattern
+	    %% and update the bindings.
+            [{Ps,C,PsAcc,Bs++Bs0}|case_opt_lit_1(E, Cs)];
+	{false,_} ->
+	    %% Binary literal and pattern. We are not sure whether
+	    %% the pattern will match.
+	    throw(impossible)
+    end;
+case_opt_lit_1(_, []) -> [].
+
+%% case_opt_data(Expr, Clauses0, LitExpr) -> {ok,Exprs,Clauses}
+%%  The case expression is a non-atomic data constructor (cons
+%%  or tuple). We can know at compile time whether each clause
+%%  will match, and we can delay the building of the data to
+%%  the clauses where it is actually needed.
+
+case_opt_data(E, Cs0) ->
+    Es = cerl:data_es(E),
+    TypeSig = {cerl:data_type(E),cerl:data_arity(E)},
+    try case_opt_data_1(Cs0, Es, TypeSig) of
+	Cs ->
+	    {ok,Es,Cs}
+    catch
+	throw:impossible ->
+	    %% The pattern contained a binary or map.
+	    {error,Cs0}
+    end.
+
+case_opt_data_1([{[P0|Ps0],C,PsAcc,Bs0}|Cs], Es, TypeSig) ->
+    P = case_opt_compiler_generated(P0),
+    BindTo = #c_var{name=dummy},
+    {Ps1,[{BindTo,_}|Bs1]} = case_data_pat_alias(P, BindTo, TypeSig, []),
+    [{Ps1++Ps0,C,PsAcc,Bs1++Bs0}|case_opt_data_1(Cs, Es, TypeSig)];
+case_opt_data_1([], _, _) -> [].
+
+case_data_pat_alias(P, BindTo0, TypeSig, Bs0) ->
+    case cerl:type(P) of
+	alias ->
+	    %% Recursively handle the pattern and bind to
+	    %% the alias variable.
+	    BindTo = cerl:alias_var(P),
+	    Apat0 = cerl:alias_pat(P),
+	    Ann = [compiler_generated],
+	    Apat = cerl:set_ann(Apat0, Ann),
+	    {Ps,Bs} = case_data_pat_alias(Apat, BindTo, TypeSig, Bs0),
+	    {Ps,[{BindTo0,BindTo}|Bs]};
+	var ->
+	    %% Here we will need to actually build the data and bind
+	    %% it to the variable.
+	    {Type,Arity} = TypeSig,
+	    Ann = [compiler_generated],
+	    Vars = make_vars(Ann, Arity),
+	    Data = cerl:ann_make_data(Ann, Type, Vars),
+	    Bs = [{BindTo0,P},{P,Data}|Bs0],
+	    {Vars,Bs};
+	_ ->
+	    %% Since case_opt_nomatch/3 has removed all clauses that
+	    %% cannot match, we KNOW that this clause must match and
+	    %% that the pattern must be a data constructor.
+	    %% Here we must build the data and bind it to the variable.
+	    {Type,_} = TypeSig,
+	    DataEs = cerl:data_es(P),
+	    Vars = pat_to_expr_list(DataEs),
+	    Ann = [compiler_generated],
+	    Data = cerl:ann_make_data(Ann, Type, Vars),
+	    {DataEs,[{BindTo0,Data}]}
+    end.
+
+%% pat_to_expr(Pattern) -> Expression.
+%%  Convert a pattern to an expression if possible. We KNOW that
+%%  all variables in the pattern will be bound.
+%%
+%%  Throw an 'impossible' exception if a map or (non-literal)
+%%  binary is encountered. Trying to use a map pattern as an
+%%  expression is incorrect, while rebuilding a potentially
+%%  huge binary in an expression would be wasteful.
+
+pat_to_expr(P) ->
+    case cerl:type(P) of
+	alias ->
+	    cerl:alias_var(P);
+	var ->
+	    P;
+	_ ->
+	    case cerl:is_data(P) of
+		false ->
+		    %% Map or binary.
+		    throw(impossible);
+		true ->
+		    Es = pat_to_expr_list(cerl:data_es(P)),
+		    cerl:update_data(P, cerl:data_type(P), Es)
+	    end
+    end.
+
+pat_to_expr_list(Ps) -> [pat_to_expr(P) || P <- Ps].
+
+make_vars(A, Max) ->
+    make_vars(A, 1, Max).
 
 make_vars(A, I, Max) when I =< Max ->
     [make_var(A)|make_vars(A, I+1, Max)];
@@ -2067,54 +2110,129 @@ make_var_name() ->
     put(new_var_num, N+1),
     list_to_atom("fol"++integer_to_list(N)).
 
-letify(#c_var{name=Vname}=Var, Val, Body) ->
-    case core_lib:is_var_used(Vname, Body) of
-	true ->
-	    A = element(2, Body),
-	    #c_let{anno=A,vars=[Var],arg=Val,body=Body};
-	false -> Body
-    end.
+letify(Bs, Body) ->
+    Ann = cerl:get_ann(Body),
+    foldr(fun({V,Val}, B) ->
+		  cerl:ann_c_let(Ann, [V], Val, B)
+	  end, Body, Bs).
 
-%% opt_case_in_let(LetExpr) -> LetExpr'
+%% opt_not_in_let(Let) -> Cerl
+%%  Try to optimize away a 'not' operator in a 'let'.
 
-opt_case_in_let(#c_let{vars=Vs,arg=Arg,body=B}=Let) ->
-    opt_case_in_let_0(Vs, Arg, B, Let).
+-spec opt_not_in_let(cerl:c_let()) -> cerl:cerl().
 
-opt_case_in_let_0([#c_var{name=V}], Arg,
-		  #c_case{arg=#c_var{name=V},clauses=Cs}=Case, Let) ->
-    case opt_case_in_let_1(V, Arg, Cs) of
-	impossible ->
-	    case is_simple_case_arg(Arg) andalso
-		not core_lib:is_var_used(V, Case#c_case{arg=#c_literal{val=nil}}) of
-		true ->
-		    opt_bool_case(Case#c_case{arg=Arg});
-		false ->
-		    Let
+opt_not_in_let(#c_let{vars=[_]=Vs0,arg=Arg0,body=Body0}=Let) ->
+    case opt_not_in_let(Vs0, Arg0, Body0) of
+	{[],#c_values{es=[]},Body} ->
+	    Body;
+	{Vs,Arg,Body} ->
+	    Let#c_let{vars=Vs,arg=Arg,body=Body}
+    end;
+opt_not_in_let(Let) -> Let.
+
+%% opt_not_in_let(Vs, Arg, Body) -> {Vs',Arg',Body'}
+%%  Try to optimize away a 'not' operator in a 'let'.
+
+-spec opt_not_in_let([cerl:c_var()], cerl:cerl(), cerl:cerl()) ->
+			    {[cerl:c_var()],cerl:cerl(),cerl:cerl()}.
+
+opt_not_in_let([#c_var{name=V}]=Vs0, Arg0, Body0) ->
+    case cerl:type(Body0) of
+	call ->
+	    %% let <V> = Expr in not V  ==>
+	    %%    let <> = <> in notExpr
+	    case opt_not_in_let_1(V, Body0, Arg0) of
+		no ->
+		    {Vs0,Arg0,Body0};
+		{yes,Body} ->
+		    {[],#c_values{es=[]},Body}
+	    end;
+	'let' ->
+	    %% let <V> = Expr in let <Var> = not V in Body  ==>
+	    %%    let <Var> = notExpr in Body
+	    %% V must not be used in Body.
+	    LetArg = cerl:let_arg(Body0),
+	    case opt_not_in_let_1(V, LetArg, Arg0) of
+		no ->
+		    {Vs0,Arg0,Body0};
+		{yes,Arg} ->
+		    LetBody = cerl:let_body(Body0),
+		    case core_lib:is_var_used(V, LetBody) of
+			true ->
+			    {Vs0,Arg0,Body0};
+			false ->
+			    LetVars = cerl:let_vars(Body0),
+			    {LetVars,Arg,LetBody}
+		    end
 	    end;
-	Expr -> Expr
+	_ ->
+	    {Vs0,Arg0,Body0}
     end;
-opt_case_in_let_0(_, _, _, Let) -> Let.
+opt_not_in_let(Vs, Arg, Body) ->
+    {Vs,Arg,Body}.
 
-opt_case_in_let_1(V, Arg, Cs) ->
-    try
-	opt_case_in_let_2(V, Arg, Cs)
-    catch
-	_:_ -> impossible
+opt_not_in_let_1(V, Call, Body) ->
+    case Call of
+	#c_call{module=#c_literal{val=erlang},
+		name=#c_literal{val='not'},
+		args=[#c_var{name=V}]} ->
+	    opt_not_in_let_2(Body, Call);
+	_ ->
+	    no
     end.
 
-opt_case_in_let_2(V, Arg0,
-		  [#c_clause{pats=[#c_tuple{es=Es}],
-			     guard=#c_literal{val=true},body=B}|_]) ->
-
-    %%  In {V1,V2,...} = case E of P -> ... {Val1,Val2,...}; ... end.
-    %%  avoid building tuples, by converting tuples to multiple values.
-    %%  (The optimisation is not done if the built tuple is used or returned.)
-
-    true = all(fun (#c_var{}) -> true;
-		   (_) -> false end, Es),	%Only variables in tuple
-    false = core_lib:is_var_used(V, B),		%Built tuple must not be used.
-    Arg1 = tuple_to_values(Arg0, length(Es)),	%Might fail.
-    #c_let{vars=Es,arg=Arg1,body=B}.
+opt_not_in_let_2(#c_case{clauses=Cs0}=Case, NotCall) ->
+    Vars = make_vars([], 1),
+    Body = NotCall#c_call{args=Vars},
+    Cs = [begin
+	      Let = #c_let{vars=Vars,arg=B,body=Body},
+	      C#c_clause{body=opt_not_in_let(Let)}
+	  end || #c_clause{body=B}=C <- Cs0],
+    {yes,Case#c_case{clauses=Cs}};
+opt_not_in_let_2(#c_call{}=Call0, _NotCall) ->
+    invert_call(Call0);
+opt_not_in_let_2(_, _) -> no.
+
+invert_call(#c_call{module=#c_literal{val=erlang},
+		    name=#c_literal{val=Name0},
+		    args=[_,_]}=Call) ->
+    case inverse_rel_op(Name0) of
+	no -> no;
+	Name -> {yes,Call#c_call{name=#c_literal{val=Name}}}
+    end;
+invert_call(#c_call{}) -> no.
+
+%% inverse_rel_op(Op) -> no | RevOp
+
+inverse_rel_op('=:=') -> '=/=';
+inverse_rel_op('=/=') -> '=:=';
+inverse_rel_op('==') -> '/=';
+inverse_rel_op('/=') -> '==';
+inverse_rel_op('>') -> '=<';
+inverse_rel_op('<') -> '>=';
+inverse_rel_op('>=') -> '<';
+inverse_rel_op('=<') -> '>';
+inverse_rel_op(_) -> no.
+
+
+%% opt_bool_case_in_let(LetExpr, Sub) -> Core
+
+opt_bool_case_in_let(#c_let{vars=Vs,arg=Arg,body=B}=Let, Sub) ->
+    opt_case_in_let_1(Vs, Arg, B, Let, Sub).
+
+opt_case_in_let_1([#c_var{name=V}], Arg,
+		  #c_case{arg=#c_var{name=V}}=Case0, Let, Sub) ->
+    case is_simple_case_arg(Arg) of
+	true ->
+	    Case = opt_bool_case(Case0#c_case{arg=Arg}),
+	    case core_lib:is_var_used(V, Case) of
+		false -> expr(Case, sub_new(Sub));
+		true -> Let
+	    end;
+	false ->
+	    Let
+    end;
+opt_case_in_let_1(_, _, _, Let, _) -> Let.
 
 %% is_simple_case_arg(Expr) -> true|false
 %%  Determine whether the Expr is simple enough to be worth
@@ -2156,18 +2274,15 @@ is_bool_expr(#c_clause{body=B}, Sub) ->
     is_bool_expr(B, Sub);
 is_bool_expr(#c_let{vars=[V],arg=Arg,body=B}, Sub0) ->
     Sub = case is_bool_expr(Arg, Sub0) of
-	      true -> update_types(V, [#c_literal{val=true}], Sub0);
+	      true -> update_types(V, [bool], Sub0);
 	      false -> Sub0
 	  end,
     is_bool_expr(B, Sub);
 is_bool_expr(#c_let{body=B}, Sub) ->
     %% Binding of multiple variables.
     is_bool_expr(B, Sub);
-is_bool_expr(#c_literal{val=Bool}, _) when is_boolean(Bool) ->
-    true;
-is_bool_expr(#c_var{name=V}, Sub) ->
-    is_boolean_type(V, Sub);
-is_bool_expr(_, _) -> false.
+is_bool_expr(C, Sub) ->
+    is_boolean_type(C, Sub) =:= yes.
 
 is_bool_expr_list([C|Cs], Sub) ->
     is_bool_expr(C, Sub) andalso is_bool_expr_list(Cs, Sub);
@@ -2180,19 +2295,34 @@ is_bool_expr_list([], _) -> true.
 %%  functions, or is_record/2).
 %%
 is_safe_bool_expr(Core, Sub) ->
-    is_safe_bool_expr_1(Core, Sub, gb_sets:empty()).
+    is_safe_bool_expr_1(Core, Sub, cerl_sets:new()).
 
 is_safe_bool_expr_1(#c_call{module=#c_literal{val=erlang},
-			    name=#c_literal{val=is_record},
-			    args=[_,_]},
-		    _Sub, _BoolVars) ->
+                            name=#c_literal{val=is_record},
+                            args=[A,#c_literal{val=Tag},#c_literal{val=Size}]},
+                    Sub, _BoolVars) when is_atom(Tag), is_integer(Size) ->
+    is_safe_simple(A, Sub);
+is_safe_bool_expr_1(#c_call{module=#c_literal{val=erlang},
+                            name=#c_literal{val=is_record}},
+                    _Sub, _BoolVars) ->
     %% The is_record/2 BIF is NOT allowed in guards.
+    %% The is_record/3 BIF where its second argument is not an atom or its third
+    %% is not an integer is NOT allowed in guards.
     %%
     %% NOTE: Calls like is_record(Expr, LiteralTag), where LiteralTag
     %% is a literal atom referring to a defined record, have already
     %% been rewritten to is_record(Expr, LiteralTag, TupleSize).
     false;
 is_safe_bool_expr_1(#c_call{module=#c_literal{val=erlang},
+                            name=#c_literal{val=is_function},
+                            args=[A,#c_literal{val=Arity}]},
+                    Sub, _BoolVars) when is_integer(Arity), Arity >= 0 ->
+    is_safe_simple(A, Sub);
+is_safe_bool_expr_1(#c_call{module=#c_literal{val=erlang},
+                            name=#c_literal{val=is_function}},
+                    _Sub, _BoolVars) ->
+    false;
+is_safe_bool_expr_1(#c_call{module=#c_literal{val=erlang},
 			    name=#c_literal{val=Name},args=Args},
 		    Sub, BoolVars) ->
     NumArgs = length(Args),
@@ -2211,7 +2341,7 @@ is_safe_bool_expr_1(#c_let{vars=Vars,arg=Arg,body=B}, Sub, BoolVars) ->
 	true ->
 	    case {is_safe_bool_expr_1(Arg, Sub, BoolVars),Vars} of
 		{true,[#c_var{name=V}]} ->
-		    is_safe_bool_expr_1(B, Sub, gb_sets:add(V, BoolVars));
+		    is_safe_bool_expr_1(B, Sub, cerl_sets:add_element(V, BoolVars));
 		{false,_} ->
 		    is_safe_bool_expr_1(B, Sub, BoolVars)
 	    end;
@@ -2220,7 +2350,7 @@ is_safe_bool_expr_1(#c_let{vars=Vars,arg=Arg,body=B}, Sub, BoolVars) ->
 is_safe_bool_expr_1(#c_literal{val=Val}, _Sub, _) ->
     is_boolean(Val);
 is_safe_bool_expr_1(#c_var{name=V}, _Sub, BoolVars) ->
-    gb_sets:is_element(V, BoolVars);
+    cerl_sets:is_element(V, BoolVars);
 is_safe_bool_expr_1(_, _, _) -> false.
 
 is_safe_bool_expr_list([C|Cs], Sub, BoolVars) ->
@@ -2230,38 +2360,6 @@ is_safe_bool_expr_list([C|Cs], Sub, BoolVars) ->
     end;
 is_safe_bool_expr_list([], _, _) -> true.
 
-%% tuple_to_values(Expr, TupleArity) -> Expr'
-%%  Convert tuples in return position of arity TupleArity to values.
-%%  Throws an exception for constructs that are not handled.
-
-tuple_to_values(#c_tuple{es=Es}, Arity) when length(Es) =:= Arity ->
-    core_lib:make_values(Es);
-tuple_to_values(#c_literal{val=Tuple}=Lit, Arity) when tuple_size(Tuple) =:= Arity ->
-    Es = [Lit#c_literal{val=E} || E <- tuple_to_list(Tuple)],
-    core_lib:make_values(Es);
-tuple_to_values(#c_case{clauses=Cs0}=Case, Arity) ->
-    Cs1 = [tuple_to_values(E, Arity) || E <- Cs0],
-    Case#c_case{clauses=Cs1};
-tuple_to_values(#c_seq{body=B0}=Seq, Arity) ->
-    Seq#c_seq{body=tuple_to_values(B0, Arity)};
-tuple_to_values(#c_let{body=B0}=Let, Arity) ->
-    Let#c_let{body=tuple_to_values(B0, Arity)};
-tuple_to_values(#c_receive{clauses=Cs0,timeout=Timeout,action=A0}=Rec, Arity) ->
-    Cs = [tuple_to_values(E, Arity) || E <- Cs0],
-    A = case Timeout of
-	    #c_literal{val=infinity} -> A0;
-	    _ -> tuple_to_values(A0, Arity)
-	end,
-    Rec#c_receive{clauses=Cs,action=A};
-tuple_to_values(#c_clause{body=B0}=Clause, Arity) ->
-    B = tuple_to_values(B0, Arity),
-    Clause#c_clause{body=B};
-tuple_to_values(Expr, _) ->
-    case will_fail(Expr) of
-	true -> Expr;
-	false -> erlang:error({not_handled,Expr})
-    end.
-
 %% simplify_let(Let, Sub) -> Expr | impossible
 %%  If the argument part of an let contains a complex expression, such
 %%  as a let or a sequence, move the original let body into the complex
@@ -2286,12 +2384,12 @@ move_let_into_expr(#c_let{vars=InnerVs0,body=InnerBody0}=Inner,
     %%    in <InnerBody>
     %%
     Arg = body(Arg0, Sub0),
-    ScopeSub0 = sub_subst_scope(Sub0#sub{t=[]}),
-    {OuterVs,ScopeSub} = pattern_list(OuterVs0, ScopeSub0),
-    
+    ScopeSub0 = sub_subst_scope(Sub0#sub{t=#{}}),
+    {OuterVs,ScopeSub} = var_list(OuterVs0, ScopeSub0),
+
     OuterBody = body(OuterBody0, ScopeSub),
 
-    {InnerVs,Sub} = pattern_list(InnerVs0, Sub0),
+    {InnerVs,Sub} = var_list(InnerVs0, Sub0),
     InnerBody = body(InnerBody0, Sub),
     Outer#c_let{vars=OuterVs,arg=Arg,
 		body=Inner#c_let{vars=InnerVs,arg=OuterBody,body=InnerBody}};
@@ -2307,128 +2405,401 @@ move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let,
     case {TwoClauses,is_failing_clause(Ca0),is_failing_clause(Cb0)} of
 	{true,false,true} ->
 	    %% let <Lvars> = case <Case-expr> of
-	    %%                  <Cvars> -> <Clause-body>;
-	    %%                  <OtherCvars> -> erlang:error(...)
+	    %%                  <Cpats> -> <Clause-body>;
+	    %%                  <OtherCpats> -> erlang:error(...)
 	    %%               end
 	    %% in <Let-body>
 	    %%
 	    %%     ==>
 	    %%
 	    %% case <Case-expr> of
-	    %%   <Cvars> ->
+	    %%   <Cpats> ->
 	    %%       let <Lvars> = <Clause-body>
 	    %%       in <Let-body>;
-	    %%   <OtherCvars> -> erlang:error(...)
+	    %%   <OtherCpats> -> erlang:error(...)
 	    %% end
 
 	    Cexpr = body(Cexpr0, Sub0),
-	    CaVars0 = Ca0#c_clause.pats,
+	    CaPats0 = Ca0#c_clause.pats,
 	    G0 = Ca0#c_clause.guard,
 	    B0 = Ca0#c_clause.body,
-	    ScopeSub0 = sub_subst_scope(Sub0#sub{t=[]}),
-	    {CaVars,ScopeSub} = pattern_list(CaVars0, ScopeSub0),
-	    G = guard(G0, ScopeSub),
-
-	    B1 = body(B0, ScopeSub),
-
-	    {Lvs,B2,Sub1} = let_substs(Lvs0, B1, Sub0),
-	    Sub2 = Sub1#sub{s=gb_sets:union(ScopeSub#sub.s,
-					    Sub1#sub.s)},
-	    Lbody = body(Lbody0, Sub2),
-	    B = Let#c_let{vars=Lvs,arg=core_lib:make_values(B2),body=Lbody},
-
-	    Ca = Ca0#c_clause{pats=CaVars,guard=G,body=B},
-	    Cb = clause(Cb0, Cexpr, value, Sub0),
-	    Case#c_case{arg=Cexpr,clauses=[Ca,Cb]};
+	    ScopeSub0 = sub_subst_scope(Sub0#sub{t=#{}}),
+	    try pattern_list(CaPats0, ScopeSub0) of
+		{CaPats,ScopeSub} ->
+		    G = guard(G0, ScopeSub),
+
+		    B1 = body(B0, ScopeSub),
+
+		    {Lvs,B2,Sub1} = let_substs(Lvs0, B1, Sub0),
+		    Sub2 = Sub1#sub{s=cerl_sets:union(ScopeSub#sub.s,
+						      Sub1#sub.s)},
+		    Lbody = body(Lbody0, Sub2),
+		    B = Let#c_let{vars=Lvs,
+				  arg=core_lib:make_values(B2),
+				  body=Lbody},
+
+		    Ca = Ca0#c_clause{pats=CaPats,guard=G,body=B},
+		    Cb = clause(Cb0, Cexpr, value, Sub0),
+		    Case#c_case{arg=Cexpr,clauses=[Ca,Cb]}
+	    catch
+		nomatch ->
+		    %% This is not a defeat. The code will eventually
+		    %% be optimized to erlang:error(...) by the other
+		    %% optimizations done in this module.
+		    impossible
+	    end;
 	{_,_,_} -> impossible
     end;
+move_let_into_expr(#c_let{vars=Lvs0,body=Lbody0}=Let,
+		   #c_seq{arg=Sarg0,body=Sbody0}=Seq, Sub0) ->
+    %%
+    %% let <Lvars> = do <Seq-arg>
+    %%                  <Seq-body>
+    %% in <Let-body>
+    %%
+    %%       ==>
+    %%
+    %% do <Seq-arg>
+    %%    let <Lvars> = <Seq-body>
+    %%    in <Let-body>
+    %%
+    Sarg = body(Sarg0, Sub0),
+    Sbody1 = body(Sbody0, Sub0),
+    {Lvs,Sbody,Sub} = let_substs(Lvs0, Sbody1, Sub0),
+    Lbody = body(Lbody0, Sub),
+    Seq#c_seq{arg=Sarg,body=Let#c_let{vars=Lvs,arg=core_lib:make_values(Sbody),
+				      body=Lbody}};
 move_let_into_expr(_Let, _Expr, _Sub) -> impossible.
 
 is_failing_clause(#c_clause{body=B}) ->
     will_fail(B).
 
-scope_add(Vs, #sub{s=Scope0}=Sub) ->
-    Scope = foldl(fun(V, S) when is_integer(V); is_atom(V) ->
-			  gb_sets:add(V, S)
-		  end, Scope0, Vs),
-    Sub#sub{s=Scope}.
+%% opt_case_in_let(Let) -> Let'
+%%  Try to avoid building tuples that are immediately matched.
+%%  A common pattern is:
+%%
+%%      {V1,V2,...} = case E of P -> ... {Val1,Val2,...}; ... end
+%%
+%%  In Core Erlang the pattern would look like this:
+%%
+%%   let <V> = case E of
+%%             	 ... -> ... {Val1,Val2}
+%%   	         ...
+%%   	       end,
+%%   in case V of
+%%   	{A,B} -> ... <use A and B> ...
+%%   end
+%%
+%%  Rewrite this to:
+%%
+%%   let <V1,V2> = case E of
+%%             	 ... -> ... <Val1,Val2>
+%%   	         ...
+%%   	       end,
+%%   in
+%%      let <V> = {V1,V2}
+%%      in case V of
+%%   	    {A,B} -> ... <use A and B> ...
+%%        end
+%%
+%%  Note that the second 'case' is unchanged. The other optimizations
+%%  in this module will eliminate the building of the tuple and
+%%  rewrite the second case to:
+%%
+%%   case <V1,V2> of
+%%    <A,B> -> ... <use A and B> ...
+%%   end
+%%
+
+opt_case_in_let(#c_let{vars=Vs,arg=Arg0,body=B}=Let0) ->
+    case matches_data(Vs, B) of
+	{yes,TypeSig} ->
+	    case delay_build(Arg0, TypeSig) of
+		no ->
+		    Let0;
+		{yes,Vars,Arg,Data} ->
+		    InnerLet = Let0#c_let{arg=Data},
+		    Let0#c_let{vars=Vars,arg=Arg,body=InnerLet}
+	    end;
+	no ->
+	    Let0
+    end.
+
+matches_data([#c_var{name=V}], #c_case{arg=#c_var{name=V},
+				       clauses=[#c_clause{pats=[P]}|_]}) ->
+    case cerl:is_data(P) of
+	false ->
+	    no;
+	true ->
+	    case cerl:data_type(P) of
+		{atomic,_} ->
+		    no;
+		Type ->
+		    {yes,{Type,cerl:data_arity(P)}}
+	    end
+    end;
+matches_data(_, _) -> no.
+
+delay_build(Core, TypeSig) ->
+    case cerl:is_data(Core) of
+	true -> no;
+	false -> delay_build_1(Core, TypeSig)
+    end.
+
+delay_build_1(Core0, TypeSig) ->
+    try delay_build_expr(Core0, TypeSig) of
+	Core ->
+	    {Type,Arity} = TypeSig,
+	    Ann = [compiler_generated],
+	    Vars = make_vars(Ann, Arity),
+	    Data = cerl:ann_make_data(Ann, Type, Vars),
+	    {yes,Vars,Core,Data}
+    catch
+	throw:impossible ->
+	    no
+    end.
+
+delay_build_cs([#c_clause{body=B0}=C0|Cs], TypeSig) ->
+    B = delay_build_expr(B0, TypeSig),
+    C = C0#c_clause{body=B},
+    [C|delay_build_cs(Cs, TypeSig)];
+delay_build_cs([], _) -> [].
+
+delay_build_expr(Core, {Type,Arity}=TypeSig) ->
+    case cerl:is_data(Core) of
+	false ->
+	    delay_build_expr_1(Core, TypeSig);
+	true ->
+	    case {cerl:data_type(Core),cerl:data_arity(Core)} of
+		{Type,Arity} ->
+		    core_lib:make_values(cerl:data_es(Core));
+		{_,_} ->
+		    throw(impossible)
+	    end
+    end.
+
+delay_build_expr_1(#c_case{clauses=Cs0}=Case, TypeSig) ->
+    Cs = delay_build_cs(Cs0, TypeSig),
+    Case#c_case{clauses=Cs};
+delay_build_expr_1(#c_let{body=B0}=Let, TypeSig) ->
+    B = delay_build_expr(B0, TypeSig),
+    Let#c_let{body=B};
+delay_build_expr_1(#c_receive{clauses=Cs0,
+			      timeout=Timeout,
+			      action=A0}=Rec, TypeSig) ->
+    Cs = delay_build_cs(Cs0, TypeSig),
+    A = case Timeout of
+	    #c_literal{val=infinity} -> A0;
+	    _ -> delay_build_expr(A0, TypeSig)
+	end,
+    Rec#c_receive{clauses=Cs,action=A};
+delay_build_expr_1(#c_seq{body=B0}=Seq, TypeSig) ->
+    B = delay_build_expr(B0, TypeSig),
+    Seq#c_seq{body=B};
+delay_build_expr_1(Core, _TypeSig) ->
+    case will_fail(Core) of
+	true -> Core;
+	false -> throw(impossible)
+    end.
 
 %% opt_simple_let(#c_let{}, Context, Sub) -> CoreTerm
 %%  Optimize a let construct that does not contain any lets in
 %%  in its argument.
 
-opt_simple_let(#c_let{arg=Arg0}=Let, Ctxt, Sub0) ->
-    Arg = body(Arg0, value, Sub0),		%This is a body
+opt_simple_let(Let0, Ctxt, Sub) ->
+    case opt_not_in_let(Let0) of
+	#c_let{}=Let ->
+	    opt_simple_let_0(Let, Ctxt, Sub);
+	Expr ->
+	    expr(Expr, Ctxt, Sub)
+    end.
+
+opt_simple_let_0(#c_let{arg=Arg0}=Let, Ctxt, Sub) ->
+    Arg = body(Arg0, value, Sub),		%This is a body
     case will_fail(Arg) of
 	true -> Arg;
-	false -> opt_simple_let_1(Let, Arg, Ctxt, Sub0)
+	false -> opt_simple_let_1(Let, Arg, Ctxt, Sub)
     end.
 
 opt_simple_let_1(#c_let{vars=Vs0,body=B0}=Let, Arg0, Ctxt, Sub0) ->
     %% Optimise let and add new substitutions.
-    {Vs,Args,Sub1} = let_substs(Vs0, Arg0, Sub0),
-    BodySub = case {Vs,Args} of
-		  {[V],[A]} ->
-		      case is_bool_expr(A, Sub0) of
-			  true ->
-			      update_types(V, [#c_literal{val=true}], Sub1);
-			  false ->
-			      Sub1
-		      end;
-		  {_,_} -> Sub1
-	      end,
-    B = body(B0, Ctxt, BodySub),
-    Arg = core_lib:make_values(Args),
-    opt_simple_let_2(Let, Vs, Arg, B, Ctxt, Sub1).
-
-opt_simple_let_2(Let0, Vs0, Arg0, Body0, effect, Sub) ->
-    case {Vs0,Arg0,Body0} of
-	{[],#c_values{es=[]},Body} ->
-	    %% No variables left (because of substitutions).
-	    Body;
-	{[_|_],Arg,#c_literal{}} ->
-	    %% The body is a literal. That means that we can ignore
-	    %% it and that the return value is Arg revisited in
-	    %% effect context.
-	    body(Arg, effect, sub_new_preserve_types(Sub));
-	{Vs,Arg,Body} ->
-	    %% Since we are in effect context, there is a chance
-	    %% that the body no longer references the variables.
-	    %% In that case we can construct a sequence and visit
-	    %% that in effect context:
-	    %%   let <Var> = Arg in BodyWithoutVar  ==> seq Arg BodyWithoutVar
-	    case is_any_var_used(Vs, Body) of
-		false ->
-		    expr(#c_seq{arg=Arg,body=Body}, effect, sub_new_preserve_types(Sub));
-		true ->
-		    Let = Let0#c_let{vars=Vs,arg=Arg,body=Body},
-		    opt_case_in_let_arg(opt_case_in_let(Let), effect, Sub)
-	    end
-    end;
-opt_simple_let_2(Let, Vs0, Arg0, Body, value, Sub) ->
+    {Vs1,Args,Sub1} = let_substs(Vs0, Arg0, Sub0),
+    BodySub = update_let_types(Vs1, Args, Sub1),
+    B1 = body(B0, Ctxt, BodySub),
+    Arg1 = core_lib:make_values(Args),
+    {Vs,Arg,B} = opt_not_in_let(Vs1, Arg1, B1),
+    opt_simple_let_2(Let, Vs, Arg, B, B0, Ctxt, Sub1).
+
+opt_simple_let_2(Let0, Vs0, Arg0, Body, PrevBody, Ctxt, Sub) ->
     case {Vs0,Arg0,Body} of
-	{[#c_var{name=N1}],Arg,#c_var{name=N2}} ->
+	{[#c_var{name=N1}],Arg1,#c_var{name=N2}} ->
 	    case N1 =:= N2 of
 		true ->
 		    %% let <Var> = Arg in <Var>  ==>  Arg
-		    Arg;
+		    Arg1;
 		false ->
 		    %% let <Var> = Arg in <OtherVar>  ==>  seq Arg OtherVar
-		    expr(#c_seq{arg=Arg,body=Body}, value, sub_new_preserve_types(Sub))
+		    Arg = maybe_suppress_warnings(Arg1, Vs0, PrevBody),
+		    expr(#c_seq{arg=Arg,body=Body}, Ctxt,
+			 sub_new_preserve_types(Sub))
 	    end;
 	{[],#c_values{es=[]},_} ->
 	    %% No variables left.
 	    Body;
-	{_,Arg,#c_literal{}} ->
-	    %% The variable is not used in the body. The argument
-	    %% can be evaluated in effect context to simplify it.
-	    expr(#c_seq{arg=Arg,body=Body}, value, sub_new_preserve_types(Sub));
-	{Vs,Arg,Body} ->
-	    opt_case_in_let_arg(
-	      opt_case_in_let(Let#c_let{vars=Vs,arg=Arg,body=Body}),
-	      value, Sub)
+	{Vs,Arg1,#c_literal{}} ->
+	    Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody),
+	    E = case Ctxt of
+		    effect ->
+			%% Throw away the literal body.
+			Arg;
+		    value ->
+			%% Since the variable is not used in the body, we
+			%% can rewrite the let to a sequence.
+			%%  let <Var> = Arg in Literal ==> seq Arg Literal
+			#c_seq{arg=Arg,body=Body}
+		end,
+	    expr(E, Ctxt, sub_new_preserve_types(Sub));
+	{Vs,Arg1,Body} ->
+	    %% If none of the variables are used in the body, we can
+	    %% rewrite the let to a sequence:
+	    %%    let <Var> = Arg in BodyWithoutVar ==>
+	    %%        seq Arg BodyWithoutVar
+	    case is_any_var_used(Vs, Body) of
+		false ->
+		    Arg = maybe_suppress_warnings(Arg1, Vs, PrevBody),
+		    expr(#c_seq{arg=Arg,body=Body}, Ctxt,
+			 sub_new_preserve_types(Sub));
+		true ->
+		    Let1 = Let0#c_let{vars=Vs,arg=Arg1,body=Body},
+		    Let2 = opt_bool_case_in_let(Let1, Sub),
+		    opt_case_in_let_arg(Let2, Ctxt, Sub)
+	    end
+    end.
+
+%% maybe_suppress_warnings(Arg, [#c_var{}], PreviousBody) -> Arg'
+%%  Try to suppress false warnings when a variable is not used.
+%%  For instance, we don't expect a warning for useless building in:
+%%
+%%    R = #r{},  %No warning expected.
+%%    R#r.f      %Optimization would remove the reference to R.
+%%
+%%  To avoid false warnings, we will check whether the variables were
+%%  referenced in the original unoptimized code. If they were, we will
+%%  consider the warning false and suppress it.
+
+maybe_suppress_warnings(Arg, Vs, PrevBody) ->
+    case should_suppress_warning(Arg) of
+	true ->
+	    Arg;				%Already suppressed.
+	false ->
+	    case is_any_var_used(Vs, PrevBody) of
+		true ->
+		    suppress_warning([Arg]);
+		false ->
+		    Arg
+	    end
     end.
 
+%% Suppress warnings for a Core Erlang expression whose value will
+%% be ignored.
+suppress_warning([H|T]) ->
+    case cerl:is_literal(H) of
+	true ->
+	    suppress_warning(T);
+	false ->
+	    case cerl:is_data(H) of
+		true ->
+		    suppress_warning(cerl:data_es(H) ++ T);
+		false ->
+		    %% Some other thing, such as a function call.
+		    %% This cannot be the compiler's fault, so the
+		    %% warning should not be suppressed. We must
+		    %% be careful not to destroy tail-recursion.
+		    case T of
+			[] ->
+			    H;
+			[_|_] ->
+			    cerl:c_seq(H, suppress_warning(T))
+		    end
+	    end
+    end;
+suppress_warning([]) -> void().
+
+move_case_into_arg(#c_case{arg=#c_let{vars=OuterVars0,arg=OuterArg,
+                                      body=InnerArg0}=Outer,
+                           clauses=InnerClauses}=Inner, Sub) ->
+    %%
+    %% case let <OuterVars> = <OuterArg> in <InnerArg> of
+    %%     <InnerClauses>
+    %% end
+    %%
+    %%       ==>
+    %%
+    %% let <OuterVars> = <OuterArg>
+    %% in case <InnerArg> of <InnerClauses> end
+    %%
+    ScopeSub0 = sub_subst_scope(Sub#sub{t=#{}}),
+    {OuterVars,ScopeSub} = var_list(OuterVars0, ScopeSub0),
+    InnerArg = body(InnerArg0, ScopeSub),
+    Outer#c_let{vars=OuterVars,arg=OuterArg,
+                body=Inner#c_case{arg=InnerArg,clauses=InnerClauses}};
+move_case_into_arg(#c_case{arg=#c_case{arg=OuterArg,
+                                       clauses=[OuterCa0,OuterCb]}=Outer,
+                           clauses=InnerClauses}=Inner0, Sub) ->
+    case is_failing_clause(OuterCb) of
+        true ->
+            #c_clause{pats=OuterPats0,guard=OuterGuard0,
+                      body=InnerArg0} = OuterCa0,
+            %%
+            %% case case <OuterArg> of
+            %%          <OuterPats> when <OuterGuard> -> <InnerArg>
+            %%          <OuterCb>
+            %%          ...
+            %%      end of
+            %%     <InnerClauses>
+            %% end
+            %%
+            %%       ==>
+            %%
+            %% case <OuterArg> of
+            %%     <OuterPats> when <OuterGuard> ->
+            %%         case <InnerArg> of <InnerClauses> end
+            %%     <OuterCb>
+            %% end
+            %%
+            ScopeSub0 = sub_subst_scope(Sub#sub{t=#{}}),
+
+	    %% We KNOW that pattern_list/2 has already been called for OuterPats0;
+	    %% therefore, it cannot throw an exception.
+	    {OuterPats,ScopeSub} = pattern_list(OuterPats0, ScopeSub0),
+	    OuterGuard = guard(OuterGuard0, ScopeSub),
+	    InnerArg = body(InnerArg0, ScopeSub),
+	    Inner = Inner0#c_case{arg=InnerArg,clauses=InnerClauses},
+	    OuterCa = OuterCa0#c_clause{pats=OuterPats,
+					guard=OuterGuard,
+					body=Inner},
+	    Outer#c_case{arg=OuterArg,
+			 clauses=[OuterCa,OuterCb]};
+        false ->
+            impossible
+    end;
+move_case_into_arg(#c_case{arg=#c_seq{arg=OuterArg,body=InnerArg}=Outer,
+                           clauses=InnerClauses}=Inner, _Sub) ->
+    %%
+    %% case do <OuterArg> <InnerArg> of
+    %%     <InnerClauses>
+    %% end
+    %%
+    %%       ==>
+    %%
+    %% do <OuterArg>
+    %%    case <InnerArg> of <InerClauses> end
+    %%
+    Outer#c_seq{arg=OuterArg,
+                body=Inner#c_case{arg=InnerArg,clauses=InnerClauses}};
+move_case_into_arg(_, _) ->
+    impossible.
+
 %% In guards only, rewrite a case in a let argument like
 %%
 %%    let <Var> = case <> of
@@ -2445,7 +2816,7 @@ opt_simple_let_2(Let, Vs0, Arg0, Body, value, Sub) ->
 %%         <> when 'true' ->
 %%              let <Var> = Literal2 in LetBody
 %%    end
-%%    
+%%
 %% In the worst case, the size of the code could increase.
 %% In practice, though, substituting the literals into
 %% LetBody and doing constant folding will decrease the code
@@ -2478,14 +2849,120 @@ is_any_var_used([#c_var{name=V}|Vs], Expr) ->
     end;
 is_any_var_used([], _) -> false.
 
-is_boolean_type(V, #sub{t=Tdb}) ->
-    case orddict:find(V, Tdb) of
-	{ok,bool} -> true;
-	_ -> false
+%%%
+%%% Retrieving information about types.
+%%%
+
+-spec get_type(cerl:cerl(), #sub{}) -> type_info() | 'none'.
+
+get_type(#c_var{name=V}, #sub{t=Tdb}) ->
+    case Tdb of
+        #{V:=Type} -> Type;
+        _ -> none
+    end;
+get_type(C, _) ->
+    case cerl:type(C) of
+	binary -> C;
+	map -> C;
+	_ ->
+	    case cerl:is_data(C) of
+		true -> C;
+		false -> none
+	    end
+    end.
+
+-spec is_boolean_type(cerl:cerl(), sub()) -> yes_no_maybe().
+
+is_boolean_type(Var, Sub) ->
+    case get_type(Var, Sub) of
+	none ->
+	    maybe;
+	bool ->
+	    yes;
+	C ->
+	    B = cerl:is_c_atom(C) andalso
+		is_boolean(cerl:atom_val(C)),
+	    yes_no(B)
     end.
 
+-spec is_int_type(cerl:cerl(), sub()) -> yes_no_maybe().
+
+is_int_type(Var, Sub) ->
+    case get_type(Var, Sub) of
+	none -> maybe;
+	integer -> yes;
+	C -> yes_no(cerl:is_c_int(C))
+    end.
+
+-spec is_tuple_type(cerl:cerl(), sub()) -> yes_no_maybe().
+
+is_tuple_type(Var, Sub) ->
+    case get_type(Var, Sub) of
+	none -> maybe;
+	C -> yes_no(cerl:is_c_tuple(C))
+    end.
+
+yes_no(true) -> yes;
+yes_no(false) -> no.
+
+%%%
+%%% Update type information.
+%%%
+
+update_let_types(Vs, Args, Sub) when is_list(Args) ->
+    update_let_types_1(Vs, Args, Sub);
+update_let_types(_Vs, _Arg, Sub) ->
+    %% The argument is a complex expression (such as a 'case')
+    %% that returns multiple values.
+    Sub.
+
+update_let_types_1([#c_var{}=V|Vs], [A|As], Sub0) ->
+    Sub = update_types_from_expr(V, A, Sub0),
+    update_let_types_1(Vs, As, Sub);
+update_let_types_1([], [], Sub) -> Sub.
+
+update_types_from_expr(V, Expr, Sub) ->
+    Type = extract_type(Expr, Sub),
+    update_types(V, [Type], Sub).
+
+extract_type(#c_call{module=#c_literal{val=erlang},
+		     name=#c_literal{val=Name},
+		     args=Args}=Call, Sub) ->
+    case returns_integer(Name, Args) of
+	true -> integer;
+	false -> extract_type_1(Call, Sub)
+    end;
+extract_type(Expr, Sub) ->
+    extract_type_1(Expr, Sub).
+
+extract_type_1(Expr, Sub) ->
+    case is_bool_expr(Expr, Sub) of
+	false -> Expr;
+	true -> bool
+    end.
+
+returns_integer('band', [_,_]) -> true;
+returns_integer('bnot', [_]) -> true;
+returns_integer('bor', [_,_]) -> true;
+returns_integer('bxor', [_,_]) -> true;
+returns_integer(bit_size, [_]) -> true;
+returns_integer('bsl', [_,_]) -> true;
+returns_integer('bsr', [_,_]) -> true;
+returns_integer(byte_size, [_]) -> true;
+returns_integer('div', [_,_]) -> true;
+returns_integer(length, [_]) -> true;
+returns_integer('rem', [_,_]) -> true;
+returns_integer('round', [_]) -> true;
+returns_integer(size, [_]) -> true;
+returns_integer(tuple_size, [_]) -> true;
+returns_integer(trunc, [_]) -> true;
+returns_integer(_, _) -> false.
+
 %% update_types(Expr, Pattern, Sub) -> Sub'
 %%  Update the type database.
+
+-spec update_types(cerl:cerl(), [type_info()], sub()) -> sub().
+
 update_types(Expr, Pat, #sub{t=Tdb0}=Sub) ->
     Tdb = update_types_1(Expr, Pat, Tdb0),
     Sub#sub{t=Tdb}.
@@ -2502,33 +2979,38 @@ update_types_1(#c_var{name=V,anno=Anno}, Pat, Types) ->
 update_types_1(_, _, Types) -> Types.
 
 update_types_2(V, [#c_tuple{}=P], Types) ->
-    orddict:store(V, P, Types);
+    Types#{V=>P};
 update_types_2(V, [#c_literal{val=Bool}], Types) when is_boolean(Bool) ->
-    orddict:store(V, bool, Types);
+    Types#{V=>bool};
+update_types_2(V, [Type], Types) when is_atom(Type) ->
+    Types#{V=>Type};
 update_types_2(_, _, Types) -> Types.
 
 %% kill_types(V, Tdb) -> Tdb'
 %%  Kill any entries that references the variable,
 %%  either in the key or in the value.
 
-kill_types(V, [{V,_}|Tdb]) ->
-    kill_types(V, Tdb);
-kill_types(V, [{_,#c_tuple{}=Tuple}=Entry|Tdb]) ->
+kill_types(V, Tdb) ->
+    maps:from_list(kill_types2(V,maps:to_list(Tdb))).
+
+kill_types2(V, [{V,_}|Tdb]) ->
+    kill_types2(V, Tdb);
+kill_types2(V, [{_,#c_tuple{}=Tuple}=Entry|Tdb]) ->
     case core_lib:is_var_used(V, Tuple) of
-	false -> [Entry|kill_types(V, Tdb)];
-	true -> kill_types(V, Tdb)
+	false -> [Entry|kill_types2(V, Tdb)];
+	true -> kill_types2(V, Tdb)
     end;
-kill_types(V, [{_,Atom}=Entry|Tdb]) when is_atom(Atom) ->
-    [Entry|kill_types(V, Tdb)];
-kill_types(_, []) -> [].
+kill_types2(V, [{_,Atom}=Entry|Tdb]) when is_atom(Atom) ->
+    [Entry|kill_types2(V, Tdb)];
+kill_types2(_, []) -> [].
 
 %% copy_type(DestVar, SrcVar, Tdb) -> Tdb'
 %%  If the SrcVar has a type, assign it to DestVar.
 %%
 copy_type(V, #c_var{name=Src}, Tdb) ->
-    case orddict:find(Src, Tdb) of
-	{ok,Type} -> orddict:store(V, Type, Tdb);
-	error -> Tdb
+    case Tdb of
+        #{Src:=Type} -> Tdb#{V=>Type};
+        _ -> Tdb
     end;
 copy_type(_, _, Tdb) -> Tdb.
 
@@ -2763,15 +3245,15 @@ bsm_ensure_no_partition_2([#c_var{name=V}|Ps], N, G, Vstate, S) ->
 bsm_ensure_no_partition_2([_|Ps], N, G, _, S) ->
     bsm_ensure_no_partition_2(Ps, N-1, G, bin_argument_order, S).
 
-bsm_ensure_no_partition_after([#c_clause{pats=Ps}|Cs], Pos) ->
+bsm_ensure_no_partition_after([#c_clause{pats=Ps}=C|Cs], Pos) ->
     case nth(Pos, Ps) of
 	#c_var{} ->
 	    bsm_ensure_no_partition_after(Cs, Pos);
-	P ->
-	    bsm_problem(P, bin_partition)
+	_ ->
+	    bsm_problem(C, bin_partition)
     end;
 bsm_ensure_no_partition_after([], _) -> ok.
-    
+
 bsm_could_match_binary(#c_alias{pat=P}) -> bsm_could_match_binary(P);
 bsm_could_match_binary(#c_cons{}) -> false;
 bsm_could_match_binary(#c_tuple{}) -> false;
@@ -2805,11 +3287,11 @@ add_bin_opt_info(Core, Term) ->
     end.
 
 add_warning(Core, Term) ->
-    case is_compiler_generated(Core) of
+    case should_suppress_warning(Core) of
 	true ->
 	    ok;
 	false ->
-	    Anno = core_lib:get_anno(Core),
+	    Anno = cerl:get_ann(Core),
 	    Line = get_line(Anno),
 	    File = get_file(Anno),
 	    Key = {?MODULE,warnings},
@@ -2830,9 +3312,17 @@ get_file([{file,File}|_]) -> File;
 get_file([_|T]) -> get_file(T);
 get_file([]) -> "no_file". % should not happen
 
+should_suppress_warning(Core) ->
+    is_compiler_generated(Core) orelse
+	is_result_unwanted(Core).
+
 is_compiler_generated(Core) ->
-    Anno = core_lib:get_anno(Core),
-    member(compiler_generated, Anno).
+    Ann = cerl:get_ann(Core),
+    member(compiler_generated, Ann).
+
+is_result_unwanted(Core) ->
+    Ann = cerl:get_ann(Core),
+    member(result_not_wanted, Ann).
 
 get_warnings() ->
     ordsets:from_list((erase({?MODULE,warnings}))).
@@ -2871,6 +3361,29 @@ format_error(nomatch_shadow) ->
     "this clause cannot match because a previous clause always matches";
 format_error(nomatch_guard) ->
     "the guard for this clause evaluates to 'false'";
+format_error({nomatch_bit_syntax_truncated,Signess,Val,Sz}) ->
+    S = case Signess of
+	    signed -> "a 'signed'";
+	    unsigned -> "an 'unsigned'"
+	end,
+    F = "this clause cannot match because the value ~P"
+	" will not fit in ~s binary segment of size ~p",
+    flatten(io_lib:format(F, [Val,10,S,Sz]));
+format_error({nomatch_bit_syntax_unsigned,Val}) ->
+    F = "this clause cannot match because the negative value ~P"
+	" will never match the value of an 'unsigned' binary segment",
+    flatten(io_lib:format(F, [Val,10]));
+format_error({nomatch_bit_syntax_size,Sz}) ->
+    F = "this clause cannot match because '~P' is not a valid size for a binary segment",
+    flatten(io_lib:format(F, [Sz,10]));
+format_error({nomatch_bit_syntax_type,Val,Type}) ->
+    F = "this clause cannot match because '~P' is not of the"
+	" expected type '~p'",
+    flatten(io_lib:format(F, [Val,10,Type]));
+format_error({nomatch_bit_syntax_unicode,Val}) ->
+    F = "this clause cannot match because the value ~p"
+	" is not a valid Unicode code point",
+    flatten(io_lib:format(F, [Val]));
 format_error(no_clause_match) ->
     "no clause will ever match";
 format_error(nomatch_clause_type) ->
@@ -2891,6 +3404,8 @@ format_error({no_effect,{erlang,F,A}}) ->
 format_error(result_ignored) ->
     "the result of the expression is ignored "
 	"(suppress the warning by assigning the expression to the _ variable)";
+format_error(invalid_call) ->
+    "invalid function call";
 format_error(useless_building) ->
     "a term is constructed, but never used";
 format_error(bin_opt_alias) ->
@@ -2924,12 +3439,12 @@ format_error(bin_var_used_in_guard) ->
 verify_scope(E, #sub{s=Scope}) ->
     Free0 = cerl_trees:free_variables(E),
     Free = [V || V <- Free0, not is_tuple(V)],	%Ignore function names.
-    case ordsets:is_subset(Free, gb_sets:to_list(Scope)) of
+    case ordsets:is_subset(Free, cerl_sets:to_list(Scope)) of
 	true -> true;
 	false ->
 	    io:format("~p\n", [E]),
 	    io:format("~p\n", [Free]),
-	    io:format("~p\n", [gb_sets:to_list(Scope)]),
+	    io:format("~p\n", [cerl_sets:to_list(Scope)]),
 	    false
     end.
 -endif.
diff --git a/lib/compiler/src/sys_core_fold_lists.erl b/lib/compiler/src/sys_core_fold_lists.erl
new file mode 100644
index 0000000000..9867fab46a
--- /dev/null
+++ b/lib/compiler/src/sys_core_fold_lists.erl
@@ -0,0 +1,387 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2015. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+%% Purpose : Inline high order lists functions from the lists module.
+
+-module(sys_core_fold_lists).
+
+-export([call/4]).
+
+-include("core_parse.hrl").
+
+%% We inline some very common higher order list operations.
+%% We use the same evaluation order as the library function.
+
+-spec call(cerl:c_call(), atom(), atom(), [cerl:cerl()]) ->
+		  'none' | cerl:cerl().
+
+call(#c_call{anno=Anno}, lists, all, [Arg1,Arg2]) ->
+    Loop = #c_var{name={'lists^all',1}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    Err1 = #c_tuple{es=[#c_literal{val='case_clause'}, X]},
+    CC1 = #c_clause{pats=[#c_literal{val=true}], guard=#c_literal{val=true},
+		    body=#c_apply{anno=Anno, op=Loop, args=[Xs]}},
+    CC2 = #c_clause{pats=[#c_literal{val=false}], guard=#c_literal{val=true},
+		    body=#c_literal{val=false}},
+    CC3 = #c_clause{pats=[X], guard=#c_literal{val=true},
+		    body=match_fail(Anno, Err1)},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_case{arg=#c_apply{anno=Anno, op=F, args=[X]},
+				clauses = [CC1, CC2, CC3]}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=1}]},
+		   body=#c_literal{val=true}},
+    Err2 = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^all',1}}|Anno], Err2)},
+    Fun = #c_fun{vars=[Xs],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L]}}};
+call(#c_call{anno=Anno}, lists, any, [Arg1,Arg2]) ->
+    Loop = #c_var{name={'lists^any',1}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    Err1 = #c_tuple{es=[#c_literal{val='case_clause'}, X]},
+    CC1 = #c_clause{pats=[#c_literal{val=true}], guard=#c_literal{val=true},
+		    body=#c_literal{val=true}},
+    CC2 = #c_clause{pats=[#c_literal{val=false}], guard=#c_literal{val=true},
+		    body=#c_apply{anno=Anno, op=Loop, args=[Xs]}},
+    CC3 = #c_clause{pats=[X], guard=#c_literal{val=true},
+		    body=match_fail(Anno, Err1)},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_case{arg=#c_apply{anno=Anno, op=F, args=[X]},
+				clauses = [CC1, CC2, CC3]}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=1}]},
+		   body=#c_literal{val=false}},
+    Err2 = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^any',1}}|Anno], Err2)},
+    Fun = #c_fun{vars=[Xs],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L]}}};
+call(#c_call{anno=Anno}, lists, foreach, [Arg1,Arg2]) ->
+    Loop = #c_var{name={'lists^foreach',1}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_seq{arg=#c_apply{anno=Anno, op=F, args=[X]},
+			       body=#c_apply{anno=Anno, op=Loop, args=[Xs]}}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=1}]},
+		   body=#c_literal{val=ok}},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^foreach',1}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L]}}};
+call(#c_call{anno=Anno}, lists, map, [Arg1,Arg2]) ->
+    Loop = #c_var{name={'lists^map',1}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    H = #c_var{name='H'},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_let{vars=[H], arg=#c_apply{anno=Anno,
+						      op=F,
+						      args=[X]},
+			       body=#c_cons{hd=H,
+					    anno=[compiler_generated],
+					    tl=#c_apply{anno=Anno,
+							op=Loop,
+							args=[Xs]}}}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=1}]},
+		   body=#c_literal{val=[]}},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^map',1}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L]}}};
+call(#c_call{anno=Anno}, lists, flatmap, [Arg1,Arg2]) ->
+    Loop = #c_var{name={'lists^flatmap',1}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    H = #c_var{name='H'},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_let{vars=[H],
+			       arg=#c_apply{anno=Anno, op=F, args=[X]},
+			       body=#c_call{anno=[compiler_generated|Anno],
+					    module=#c_literal{val=erlang},
+					    name=#c_literal{val='++'},
+					    args=[H,
+						  #c_apply{anno=Anno,
+							   op=Loop,
+							   args=[Xs]}]}}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=1}]},
+		   body=#c_literal{val=[]}},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^flatmap',1}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L]}}};
+call(#c_call{anno=Anno}, lists, filter, [Arg1,Arg2]) ->
+    Loop = #c_var{name={'lists^filter',1}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    B = #c_var{name='B'},
+    Err1 = #c_tuple{es=[#c_literal{val='case_clause'}, X]},
+    CC1 = #c_clause{pats=[#c_literal{val=true}], guard=#c_literal{val=true},
+		    body=#c_cons{anno=[compiler_generated], hd=X, tl=Xs}},
+    CC2 = #c_clause{pats=[#c_literal{val=false}], guard=#c_literal{val=true},
+		    body=Xs},
+    CC3 = #c_clause{pats=[X], guard=#c_literal{val=true},
+		    body=match_fail(Anno, Err1)},
+    Case = #c_case{arg=B, clauses = [CC1, CC2, CC3]},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_let{vars=[B],
+			       arg=#c_apply{anno=Anno, op=F, args=[X]},
+			       body=#c_let{vars=[Xs],
+					   arg=#c_apply{anno=Anno,
+							op=Loop,
+							args=[Xs]},
+					   body=Case}}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=1}]},
+		   body=#c_literal{val=[]}},
+    Err2 = #c_tuple{es=[#c_literal{val='function_clause'}, F, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^filter',1}}|Anno], Err2)},
+    Fun = #c_fun{vars=[Xs],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, L], arg=#c_values{es=[Arg1, Arg2]},
+		body=#c_letrec{defs=[{Loop,Fun}],
+			       body=#c_apply{anno=Anno, op=Loop, args=[L]}}};
+call(#c_call{anno=Anno}, lists, foldl, [Arg1,Arg2,Arg3]) ->
+    Loop = #c_var{name={'lists^foldl',2}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    A = #c_var{name='A'},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_apply{anno=Anno,
+				 op=Loop,
+				 args=[Xs, #c_apply{anno=Anno,
+						    op=F,
+						    args=[X, A]}]}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=2}]},
+		   body=A},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, A, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^foldl',2}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs, A],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, A, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L, A]}}};
+call(#c_call{anno=Anno}, lists, foldr, [Arg1,Arg2,Arg3]) ->
+    Loop = #c_var{name={'lists^foldr',2}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    A = #c_var{name='A'},
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=#c_apply{anno=Anno,
+				 op=F,
+				 args=[X, #c_apply{anno=Anno,
+						   op=Loop,
+						   args=[Xs, A]}]}},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=2}]},
+		   body=A},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, A, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^foldr',2}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs, A],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, A, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+			  body=#c_apply{anno=Anno, op=Loop, args=[L, A]}}};
+call(#c_call{anno=Anno}, lists, mapfoldl, [Arg1,Arg2,Arg3]) ->
+    Loop = #c_var{name={'lists^mapfoldl',2}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    Avar = #c_var{name='A'},
+    Match =
+	fun (A, P, E) ->
+		C1 = #c_clause{pats=[P], guard=#c_literal{val=true}, body=E},
+		Err = #c_tuple{es=[#c_literal{val='badmatch'}, X]},
+		C2 = #c_clause{pats=[X], guard=#c_literal{val=true},
+			       body=match_fail(Anno, Err)},
+		#c_case{arg=A, clauses=[C1, C2]}
+	end,
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+		   body=Match(#c_apply{anno=Anno, op=F, args=[X, Avar]},
+			      #c_tuple{es=[X, Avar]},
+%%% Tuple passing version
+			      Match(#c_apply{anno=Anno,
+					     op=Loop,
+					     args=[Xs, Avar]},
+				    #c_tuple{es=[Xs, Avar]},
+				    #c_tuple{anno=[compiler_generated],
+					     es=[#c_cons{anno=[compiler_generated],
+							 hd=X, tl=Xs},
+						 Avar]})
+%%% Multiple-value version
+%%% 			      #c_let{vars=[Xs,A],
+%%% 				     %% The tuple here will be optimised
+%%% 				     %% away later; no worries.
+%%% 				     arg=#c_apply{op=Loop, args=[Xs, A]},
+%%% 				     body=#c_values{es=[#c_cons{hd=X, tl=Xs},
+%%% 							A]}}
+			     )},
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=2}]},
+%%% Tuple passing version
+		   body=#c_tuple{anno=[compiler_generated],
+				 es=[#c_literal{val=[]}, Avar]}},
+%%% Multiple-value version
+%%% 		   body=#c_values{es=[#c_literal{val=[]}, A]}},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Avar, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^mapfoldl',2}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs, Avar],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, Avar, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+%%% Tuple passing version
+			  body=#c_apply{anno=Anno,
+					op=Loop,
+					args=[L, Avar]}}};
+%%% Multiple-value version
+%%% 			       body=#c_let{vars=[Xs, A],
+%%% 					   arg=#c_apply{op=Loop,
+%%% 							args=[L, A]},
+%%% 					   body=#c_tuple{es=[Xs, A]}}}};
+call(#c_call{anno=Anno}, lists, mapfoldr, [Arg1,Arg2,Arg3]) ->
+    Loop = #c_var{name={'lists^mapfoldr',2}},
+    F = #c_var{name='F'},
+    Xs = #c_var{name='Xs'},
+    X = #c_var{name='X'},
+    Avar = #c_var{name='A'},
+    Match =
+	fun (A, P, E) ->
+		C1 = #c_clause{pats=[P], guard=#c_literal{val=true}, body=E},
+		Err = #c_tuple{es=[#c_literal{val='badmatch'}, X]},
+		C2 = #c_clause{pats=[X], guard=#c_literal{val=true},
+			       body=match_fail(Anno, Err)},
+		#c_case{arg=A, clauses=[C1, C2]}
+	end,
+    C1 = #c_clause{pats=[#c_cons{hd=X, tl=Xs}], guard=#c_literal{val=true},
+%%% Tuple passing version
+		   body=Match(#c_apply{anno=Anno,
+				       op=Loop,
+				       args=[Xs, Avar]},
+			      #c_tuple{es=[Xs, Avar]},
+			      Match(#c_apply{anno=Anno, op=F, args=[X, Avar]},
+				    #c_tuple{es=[X, Avar]},
+				    #c_tuple{anno=[compiler_generated],
+					     es=[#c_cons{anno=[compiler_generated],
+							 hd=X, tl=Xs}, Avar]}))
+%%% Multiple-value version
+%%% 		   body=#c_let{vars=[Xs,A],
+%%% 			       %% The tuple will be optimised away
+%%% 			       arg=#c_apply{op=Loop, args=[Xs, A]},
+%%% 			       body=Match(#c_apply{op=F, args=[X, A]},
+%%% 					  #c_tuple{es=[X, A]},
+%%% 					  #c_values{es=[#c_cons{hd=X, tl=Xs},
+%%% 						        A]})}
+		  },
+    C2 = #c_clause{pats=[#c_literal{val=[]}],
+		   guard=#c_call{module=#c_literal{val=erlang},
+				 name=#c_literal{val=is_function},
+				 args=[F, #c_literal{val=2}]},
+%%% Tuple passing version
+		   body=#c_tuple{anno=[compiler_generated],
+				 es=[#c_literal{val=[]}, Avar]}},
+%%% Multiple-value version
+%%% 		   body=#c_values{es=[#c_literal{val=[]}, A]}},
+    Err = #c_tuple{es=[#c_literal{val='function_clause'}, F, Avar, Xs]},
+    C3 = #c_clause{pats=[Xs], guard=#c_literal{val=true},
+		   body=match_fail([{function_name,{'lists^mapfoldr',2}}|Anno], Err)},
+    Fun = #c_fun{vars=[Xs, Avar],
+		 body=#c_case{arg=Xs, clauses=[C1, C2, C3]}},
+    L = #c_var{name='L'},
+    #c_let{vars=[F, Avar, L], arg=#c_values{es=[Arg1, Arg2, Arg3]},
+	   body=#c_letrec{defs=[{Loop,Fun}],
+%%% Tuple passing version
+			  body=#c_apply{anno=Anno,
+					op=Loop,
+					args=[L, Avar]}}};
+%%% Multiple-value version
+%%% 			       body=#c_let{vars=[Xs, A],
+%%% 					   arg=#c_apply{op=Loop,
+%%% 							args=[L, A]},
+%%% 					   body=#c_tuple{es=[Xs, A]}}}};
+call(_, _, _, _) ->
+    none.
+
+match_fail(Ann, Arg) ->
+    Name = cerl:abstract(match_fail),
+    Args = [Arg],
+    cerl:ann_c_primop(Ann, Name, Args).
diff --git a/lib/compiler/src/sys_core_inline.erl b/lib/compiler/src/sys_core_inline.erl
index 9f93acb666..8c1f69d5de 100644
--- a/lib/compiler/src/sys_core_inline.erl
+++ b/lib/compiler/src/sys_core_inline.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2000-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -195,10 +196,10 @@ kill_id_anns(Body) ->
 			   A = kill_id_anns_1(A0),
 			   CFun#c_fun{anno=A};
 		      (Expr) ->
-			   %% Mark everything as compiler generated to suppress
-			   %% bogus warnings.
-			   A = compiler_generated(core_lib:get_anno(Expr)),
-			   core_lib:set_anno(Expr, A)
+			   %% Mark everything as compiler generated to
+			   %% suppress bogus warnings.
+			   A = compiler_generated(cerl:get_ann(Expr)),
+			   cerl:set_ann(Expr, A)
 		   end, Body).
 
 kill_id_anns_1([{'id',_}|As]) ->
diff --git a/lib/compiler/src/sys_pre_attributes.erl b/lib/compiler/src/sys_pre_attributes.erl
index a6b7274b07..bc93c85989 100644
--- a/lib/compiler/src/sys_pre_attributes.erl
+++ b/lib/compiler/src/sys_pre_attributes.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/compiler/src/sys_pre_expand.erl b/lib/compiler/src/sys_pre_expand.erl
index 7d918a55ed..7ab4e1845c 100644
--- a/lib/compiler/src/sys_pre_expand.erl
+++ b/lib/compiler/src/sys_pre_expand.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2015. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -28,30 +29,26 @@
 %% Main entry point.
 -export([module/2]).
 
--import(ordsets, [from_list/1,union/2]).
 -import(lists,   [member/2,foldl/3,foldr/3]).
 
--include("../include/erl_bits.hrl").
+-type fa() :: {atom(), arity()}.
 
 -record(expand, {module=[],                     %Module name
                  exports=[],                    %Exports
-                 imports=[],                    %Imports
-                 compile=[],                    %Compile flags
                  attributes=[],                 %Attributes
                  callbacks=[],                  %Callbacks
-                 defined,			%Defined functions (gb_set)
+                 optional_callbacks=[] :: [fa()],  %Optional callbacks
                  vcount=0,                      %Variable counter
                  func=[],                       %Current function
                  arity=[],                      %Arity for current function
-                 fcount=0,                      %Local fun count
-                 bitdefault,
-                 bittypes
+                 fcount=0,			%Local fun count
+		 ctype				%Call type map
                 }).
 
 %% module(Forms, CompileOptions)
 %%      {ModuleName,Exports,TransformedForms,CompileOptions'}
-%%  Expand the forms in one module. N.B.: the lists of predefined
-%%  exports and imports are really ordsets!
+%%  Expand the forms in one module.
+%%
 %%  CompileOptions is augmented with options from -compile attributes.
 
 module(Fs0, Opts0) ->
@@ -64,63 +61,87 @@ module(Fs0, Opts0) ->
     %% Set pre-defined exported functions.
     PreExp = [{module_info,0},{module_info,1}],
 
+    %% Build the set of defined functions and the initial call
+    %% type map.
+    Defined = defined_functions(Fs, PreExp),
+    Ctype = maps:from_list([{K,local} || K <- Defined]),
+
     %% Build initial expand record.
     St0 = #expand{exports=PreExp,
-                  compile=Opts,
-                  defined=PreExp,
-                  bitdefault = erl_bits:system_bitdefault(),
-                  bittypes = erl_bits:system_bittypes()
+		  ctype=Ctype
                  },
+
     %% Expand the functions.
-    {Tfs,St1} = forms(Fs, define_functions(Fs, St0)),
+    {Tfs,St1} = forms(Fs, St0),
+
     %% Get the correct list of exported functions.
-    Exports = case member(export_all, St1#expand.compile) of
-                  true -> gb_sets:to_list(St1#expand.defined);
+    Exports = case member(export_all, Opts) of
+                  true -> Defined;
                   false -> St1#expand.exports
               end,
+    St2 = St1#expand{exports=Exports,ctype=undefined},
+
     %% Generate all functions from stored info.
-    {Ats,St3} = module_attrs(St1#expand{exports = Exports}),
+    {Ats,St3} = module_attrs(St2),
     {Mfs,St4} = module_predef_funcs(St3),
     {St4#expand.module, St4#expand.exports, Ats ++ Tfs ++ Mfs,
-     St4#expand.compile}.
+     Opts}.
 
 compiler_options(Forms) ->
     lists:flatten([C || {attribute,_,compile,C} <- Forms]).
     
-%% define_function(Form, State) -> State.
+%% defined_function(Forms, Predef) -> Functions.
 %%  Add function to defined if form is a function.
 
-define_functions(Forms, #expand{defined=Predef}=St) ->
+defined_functions(Forms, Predef) ->
     Fs = foldl(fun({function,_,N,A,_Cs}, Acc) -> [{N,A}|Acc];
                   (_, Acc) -> Acc
                end, Predef, Forms),
-    St#expand{defined=gb_sets:from_list(Fs)}.
+    ordsets:from_list(Fs).
 
 module_attrs(#expand{attributes=Attributes}=St) ->
     Attrs = [{attribute,Line,Name,Val} || {Name,Line,Val} <- Attributes],
     Callbacks = [Callback || {_,_,callback,_}=Callback <- Attrs],
-    {Attrs,St#expand{callbacks=Callbacks}}.
-
-module_predef_funcs(St) ->
-    {Mpf1,St1}=module_predef_func_beh_info(St),
-    {Mpf2,St2}=module_predef_funcs_mod_info(St1),
-    {Mpf1++Mpf2,St2}.
+    OptionalCallbacks = get_optional_callbacks(Attrs),
+    {Attrs,St#expand{callbacks=Callbacks,
+                     optional_callbacks=OptionalCallbacks}}.
+
+get_optional_callbacks(Attrs) ->
+    L = [O ||
+            {attribute, _, optional_callbacks, O} <- Attrs,
+            is_fa_list(O)],
+    lists:append(L).
+
+is_fa_list([{FuncName, Arity}|L])
+  when is_atom(FuncName), is_integer(Arity), Arity >= 0 ->
+    is_fa_list(L);
+is_fa_list([]) -> true;
+is_fa_list(_) -> false.
+
+module_predef_funcs(St0) ->
+    {Mpf1,St1} = module_predef_func_beh_info(St0),
+    Mpf2 = module_predef_funcs_mod_info(St1),
+    Mpf = [erl_parse:new_anno(F) || F <- Mpf1++Mpf2],
+    {Mpf,St1}.
 
 module_predef_func_beh_info(#expand{callbacks=[]}=St) ->
     {[], St};
-module_predef_func_beh_info(#expand{callbacks=Callbacks,defined=Defined,
+module_predef_func_beh_info(#expand{callbacks=Callbacks,
+                                    optional_callbacks=OptionalCallbacks,
 				    exports=Exports}=St) ->
-    PreDef=[{behaviour_info,1}],
-    PreExp=PreDef,
-    {[gen_beh_info(Callbacks)],
-     St#expand{defined=gb_sets:union(gb_sets:from_list(PreDef), Defined),
-	       exports=union(from_list(PreExp), Exports)}}.
+    PreDef0 = [{behaviour_info,1}],
+    PreDef = ordsets:from_list(PreDef0),
+    {[gen_beh_info(Callbacks, OptionalCallbacks)],
+     St#expand{exports=ordsets:union(PreDef, Exports)}}.
 
-gen_beh_info(Callbacks) ->
+gen_beh_info(Callbacks, OptionalCallbacks) ->
     List = make_list(Callbacks),
+    OptionalList = make_optional_list(OptionalCallbacks),
     {function,0,behaviour_info,1,
      [{clause,0,[{atom,0,callbacks}],[],
-       [List]}]}.
+       [List]},
+      {clause,0,[{atom,0,optional_callbacks}],[],
+       [OptionalList]}]}.
 
 make_list([]) -> {nil,0};
 make_list([{_,_,_,[{{Name,Arity},_}]}|Rest]) ->
@@ -130,20 +151,24 @@ make_list([{_,_,_,[{{Name,Arity},_}]}|Rest]) ->
        {integer,0,Arity}]},
      make_list(Rest)}.
 
-module_predef_funcs_mod_info(St) ->
-    PreDef = [{module_info,0},{module_info,1}],
-    PreExp = PreDef,
-    {[{function,0,module_info,0,
-       [{clause,0,[],[],
+make_optional_list([]) -> {nil,0};
+make_optional_list([{Name,Arity}|Rest]) ->
+    {cons,0,
+     {tuple,0,
+      [{atom,0,Name},
+       {integer,0,Arity}]},
+     make_optional_list(Rest)}.
+
+module_predef_funcs_mod_info(#expand{module=Mod}) ->
+    ModAtom = {atom,0,Mod},
+    [{function,0,module_info,0,
+      [{clause,0,[],[],
         [{call,0,{remote,0,{atom,0,erlang},{atom,0,get_module_info}},
-          [{atom,0,St#expand.module}]}]}]},
-      {function,0,module_info,1,
-       [{clause,0,[{var,0,'X'}],[],
+          [ModAtom]}]}]},
+     {function,0,module_info,1,
+      [{clause,0,[{var,0,'X'}],[],
         [{call,0,{remote,0,{atom,0,erlang},{atom,0,get_module_info}},
-          [{atom,0,St#expand.module},{var,0,'X'}]}]}]}],
-     St#expand{defined=gb_sets:union(gb_sets:from_list(PreDef),
-				     St#expand.defined),
-               exports=union(from_list(PreExp), St#expand.exports)}}.
+          [ModAtom,{var,0,'X'}]}]}]}].
 
 %% forms(Forms, State) ->
 %%      {TransformedForms,State'}
@@ -170,7 +195,8 @@ attribute(module, Module, _L, St) ->
     true = is_atom(Module),
     St#expand{module=Module};
 attribute(export, Es, _L, St) ->
-    St#expand{exports=union(from_list(Es), St#expand.exports)};
+    St#expand{exports=ordsets:union(ordsets:from_list(Es),
+				    St#expand.exports)};
 attribute(import, Is, _L, St) ->
     import(Is, St);
 attribute(compile, _C, _L, St) ->
@@ -205,8 +231,6 @@ head(As, St) -> pattern_list(As, St).
 %%      {TransformedPattern,State'}
 %%
 
-pattern({var,_,'_'}=Var, St) ->                 %Ignore anonymous variable.
-    {Var,St};
 pattern({var,_,_}=Var, St) ->
     {Var,St};
 pattern({char,_,_}=Char, St) ->
@@ -228,6 +252,22 @@ pattern({cons,Line,H,T}, St0) ->
 pattern({tuple,Line,Ps}, St0) ->
     {TPs,St1} = pattern_list(Ps, St0),
     {{tuple,Line,TPs},St1};
+pattern({map,Line,Ps}, St0) ->
+    {TPs,St1} = pattern_list(Ps, St0),
+    {{map,Line,TPs},St1};
+pattern({map_field_exact,Line,K0,V0}, St0) ->
+    %% Key should be treated as an expression
+    %% but since expressions are not allowed yet,
+    %% process it through pattern .. and handle assoc
+    %% (normalise unary op integer -> integer)
+    {K,St1} = pattern(K0, St0),
+    {V,St2} = pattern(V0, St1),
+    {{map_field_exact,Line,K,V},St2};
+pattern({map_field_assoc,Line,K0,V0}, St0) ->
+    %% when keys are Maps
+    {K,St1} = pattern(K0, St0),
+    {V,St2} = pattern(V0, St1),
+    {{map_field_assoc,Line,K,V},St2};
 %%pattern({struct,Line,Tag,Ps}, St0) ->
 %%    {TPs,TPsvs,St1} = pattern_list(Ps, St0),
 %%    {{tuple,Line,[{atom,Line,Tag}|TPs]},TPsvs,St1};
@@ -321,6 +361,21 @@ expr({tuple,Line,Es0}, St0) ->
 %%expr({struct,Line,Tag,Es0}, Vs, St0) ->
 %%    {Es1,Esvs,Esus,St1} = expr_list(Es0, Vs, St0),
 %%    {{tuple,Line,[{atom,Line,Tag}|Es1]},Esvs,Esus,St1};
+expr({map,Line,Es0}, St0) ->
+    {Es1,St1} = expr_list(Es0, St0),
+    {{map,Line,Es1},St1};
+expr({map,Line,E0,Es0}, St0) ->
+    {E1,St1} = expr(E0, St0),
+    {Es1,St2} = expr_list(Es0, St1),
+    {{map,Line,E1,Es1},St2};
+expr({map_field_assoc,Line,K0,V0}, St0) ->
+    {K,St1} = expr(K0, St0),
+    {V,St2} = expr(V0, St1),
+    {{map_field_assoc,Line,K,V},St2};
+expr({map_field_exact,Line,K0,V0}, St0) ->
+    {K,St1} = expr(K0, St0),
+    {V,St2} = expr(V0, St1),
+    {{map_field_exact,Line,K,V},St2};
 expr({bin,Line,Es0}, St0) ->
     {Es1,St1} = expr_bin(Es0, St0),
     {{bin,Line,Es1},St1};
@@ -328,40 +383,36 @@ expr({block,Line,Es0}, St0) ->
     {Es,St1} = exprs(Es0, St0),
     {{block,Line,Es},St1};
 expr({'if',Line,Cs0}, St0) ->
-    {Cs,St1} = icr_clauses(Cs0, St0),
+    {Cs,St1} = clauses(Cs0, St0),
     {{'if',Line,Cs},St1};
 expr({'case',Line,E0,Cs0}, St0) ->
     {E,St1} = expr(E0, St0),
-    {Cs,St2} = icr_clauses(Cs0, St1),
+    {Cs,St2} = clauses(Cs0, St1),
     {{'case',Line,E,Cs},St2};
 expr({'receive',Line,Cs0}, St0) ->
-    {Cs,St1} = icr_clauses(Cs0, St0),
+    {Cs,St1} = clauses(Cs0, St0),
     {{'receive',Line,Cs},St1};
 expr({'receive',Line,Cs0,To0,ToEs0}, St0) ->
     {To,St1} = expr(To0, St0),
     {ToEs,St2} = exprs(ToEs0, St1),
-    {Cs,St3} = icr_clauses(Cs0, St2),
+    {Cs,St3} = clauses(Cs0, St2),
     {{'receive',Line,Cs,To,ToEs},St3};
 expr({'fun',Line,Body}, St) ->
     fun_tq(Line, Body, St);
+expr({named_fun,Line,Name,Cs}, St) ->
+    fun_tq(Line, Cs, St, Name);
 expr({call,Line,{atom,La,N}=Atom,As0}, St0) ->
     {As,St1} = expr_list(As0, St0),
     Ar = length(As),
-    case defined(N,Ar,St1) of
-	true ->
+    Key = {N,Ar},
+    case St1#expand.ctype of
+	#{Key:=local} ->
 	    {{call,Line,Atom,As},St1};
+	#{Key:={imported,Mod}} ->
+	    {{call,Line,{remote,La,{atom,La,Mod},Atom},As},St1};
 	_ ->
-	    case imported(N, Ar, St1) of
-		{yes,Mod} ->
-		    {{call,Line,{remote,La,{atom,La,Mod},Atom},As},St1};
-		no ->
-		    case erl_internal:bif(N, Ar) of
-			true ->
-			    {{call,Line,{remote,La,{atom,La,erlang},Atom},As},St1};
-			false -> %% This should have been handled by erl_lint
-			    {{call,Line,Atom,As},St1}
-		    end
-	    end
+	    true = erl_internal:bif(N, Ar),
+	    {{call,Line,{remote,La,{atom,La,erlang},Atom},As},St1}
     end;
 expr({call,Line,{remote,Lr,M0,F},As0}, St0) ->
     {[M1,F1|As1],St1} = expr_list([M0,F|As0], St0),
@@ -371,12 +422,11 @@ expr({call,Line,F,As0}, St0) ->
     {{call,Line,Fun1,As1},St1};
 expr({'try',Line,Es0,Scs0,Ccs0,As0}, St0) ->
     {Es1,St1} = exprs(Es0, St0),
-    {Scs1,St2} = icr_clauses(Scs0, St1),
-    {Ccs1,St3} = icr_clauses(Ccs0, St2),
+    {Scs1,St2} = clauses(Scs0, St1),
+    {Ccs1,St3} = clauses(Ccs0, St2),
     {As1,St4} = exprs(As0, St3),
     {{'try',Line,Es1,Scs1,Ccs1,As1},St4};
 expr({'catch',Line,E0}, St0) ->
-    %% Catch exports no new variables.
     {E,St1} = expr(E0, St0),
     {{'catch',Line,E},St1};
 expr({match,Line,P0,E0}, St0) ->
@@ -397,21 +447,6 @@ expr_list([E0|Es0], St0) ->
     {[E|Es],St2};
 expr_list([], St) -> {[],St}.
 
-%% icr_clauses([Clause], State) -> {[TransformedClause],State'}
-%%  Be very careful here to return the variables that are really used
-%%  and really new.
-
-icr_clauses([], St) -> {[],St};
-icr_clauses(Clauses, St) -> icr_clauses2(Clauses, St).
-
-icr_clauses2([{clause,Line,H0,G0,B0}|Cs0], St0) ->
-    {H,St1} = head(H0, St0),
-    {G,St2} = guard(G0, St1),
-    {B,St3} = exprs(B0, St2),
-    {Cs,St4} = icr_clauses2(Cs0, St3),
-    {[{clause,Line,H,G,B}|Cs],St4};
-icr_clauses2([], St) -> {[],St}.
-
 %% lc_tq(Line, Qualifiers, State) ->
 %%      {[TransQual],State'}
 
@@ -427,16 +462,9 @@ lc_tq(Line, [{b_generate,Lg,P0,G0}|Qs0], St0) ->
     {Qs1,St3} = lc_tq(Line, Qs0, St2),
     {[{b_generate,Lg,P1,G1}|Qs1],St3};
 lc_tq(Line, [F0 | Qs0], St0) ->
-    case erl_lint:is_guard_test(F0) of
-        true ->
-            {F1,St1} = guard_test(F0, St0),
-            {Qs1,St2} = lc_tq(Line, Qs0, St1),
-            {[F1|Qs1],St2};
-        false ->
-            {F1,St1} = expr(F0, St0),
-            {Qs1,St2} = lc_tq(Line, Qs0, St1),
-            {[F1 | Qs1],St2}
-    end;
+    {F1,St1} = expr(F0, St0),
+    {Qs1,St2} = lc_tq(Line, Qs0, St1),
+    {[F1|Qs1],St2};
 lc_tq(_Line, [], St0) ->
     {[],St0}.
 
@@ -468,26 +496,26 @@ fun_tq(L, {function,M,F,A}, St) when is_atom(M), is_atom(F), is_integer(A) ->
 fun_tq(Lf, {function,_,_,_}=ExtFun, St) ->
     {{'fun',Lf,ExtFun},St};
 fun_tq(Lf, {clauses,Cs0}, St0) ->
-    {Cs1,St1} = fun_clauses(Cs0, St0),
+    {Cs1,St1} = clauses(Cs0, St0),
     {Fname,St2} = new_fun_name(St1),
     %% Set dummy values for Index and Uniq -- the real values will
     %% be assigned by beam_asm.
     Index = Uniq = 0,
     {{'fun',Lf,{clauses,Cs1},{Index,Uniq,Fname}},St2}.
 
-fun_clauses([{clause,L,H0,G0,B0}|Cs0], St0) ->
-    {H,St1} = head(H0, St0),
-    {G,St2} = guard(G0, St1),
-    {B,St3} = exprs(B0, St2),
-    {Cs,St4} = fun_clauses(Cs0, St3),
-    {[{clause,L,H,G,B}|Cs],St4};
-fun_clauses([], St) -> {[],St}.
+fun_tq(Line, Cs0, St0, Name) ->
+    {Cs1,St1} = clauses(Cs0, St0),
+    {Fname,St2} = new_fun_name(St1, Name),
+    {{named_fun,Line,Name,Cs1,{0,0,Fname}},St2}.
 
 %% new_fun_name(State) -> {FunName,State}.
 
-new_fun_name(#expand{func=F,arity=A,fcount=I}=St) ->
+new_fun_name(St) ->
+    new_fun_name(St, 'fun').
+
+new_fun_name(#expand{func=F,arity=A,fcount=I}=St, FName) ->
     Name = "-" ++ atom_to_list(F) ++ "/" ++ integer_to_list(A)
-        ++ "-fun-" ++ integer_to_list(I) ++ "-",
+        ++ "-" ++ atom_to_list(FName) ++ "-" ++ integer_to_list(I) ++ "-",
     {list_to_atom(Name),St#expand{fcount=I+1}}.
 
 %% pattern_bin([Element], State) -> {[Element],[Variable],[UsedVar],State}.
@@ -504,7 +532,6 @@ pattern_element({bin_element,Line,Expr0,Size0,Type0}, {Es,St0}) ->
     {[{bin_element,Line,Expr,Size,Type}|Es],St2}.
 
 pat_bit_size(default, St) -> {default,St};
-pat_bit_size({atom,_La,all}=All, St) -> {All,St};
 pat_bit_size({var,_Lv,_V}=Var, St) -> {Var,St};
 pat_bit_size(Size, St) ->
     Line = element(2, Size),
@@ -525,8 +552,7 @@ coerce_to_float({integer,L,I}=E, [float|_]) ->
     try
         {float,L,float(I)}
     catch
-        error:badarg -> E;
-        error:badarith -> E
+        error:badarg -> E
     end;
 coerce_to_float(E, _) -> E.
     
@@ -580,25 +606,11 @@ string_to_conses(Line, Cs, Tail) ->
 
 %% import(Line, Imports, State) ->
 %%      State'
-%% imported(Name, Arity, State) ->
-%%      {yes,Module} | no
-%%  Handle import declarations and test for imported functions. No need to
-%%  check when building imports as code is correct.
+%%  Handle import declarations.
 
-import({Mod,Fs}, St) ->
+import({Mod,Fs}, #expand{ctype=Ctype0}=St) ->
     true = is_atom(Mod),
-    Mfs = from_list(Fs),
-    St#expand{imports=add_imports(Mod, Mfs, St#expand.imports)}.
-
-add_imports(Mod, [F|Fs], Is) ->
-    add_imports(Mod, Fs, orddict:store(F, Mod, Is));
-add_imports(_, [], Is) -> Is.
-
-imported(F, A, St) ->
-    case orddict:find({F,A}, St#expand.imports) of
-        {ok,Mod} -> {yes,Mod};
-        error -> no
-    end.
-
-defined(F, A, St) ->
-    gb_sets:is_element({F,A}, St#expand.defined).
+    Ctype = foldl(fun(F, A) ->
+			  A#{F=>{imported,Mod}}
+		  end, Ctype0, Fs),
+    St#expand{ctype=Ctype}.
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index 6a13495523..4df1aadd0a 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -43,7 +44,7 @@
 -export([module/2]).
 
 -import(lists, [member/2,keymember/3,keysort/2,keydelete/3,
-		append/1,map/2,flatmap/2,filter/2,foldl/3,foldr/3,mapfoldl/3,
+		append/1,flatmap/2,filter/2,foldl/3,foldr/3,mapfoldl/3,
 		sort/1,reverse/1,reverse/2]).
 -import(v3_life, [vdb_find/2]).
 
@@ -57,8 +58,7 @@
 	     break,				%Break label
 	     recv,				%Receive label
 	     is_top_block,			%Boolean: top block or not
-	     functable=gb_trees:empty(),	%Gb tree of local functions:
-						% {{Name,Arity},Label}
+	     functable=#{},	                %Map of local functions: {Name,Arity}=>Label
 	     in_catch=false,			%Inside a catch or not.
 	     need_frame,			%Need a stack frame.
 	     ultimate_failure			%Label for ultimate match failure.
@@ -69,10 +69,8 @@
 	     stk=[],				%Stack table
 	     res=[]}).				%Reserved regs: [{reserved,I,V}]
 
-module({Mod,Exp,Attr,Forms}, Options) ->
-    put(?MODULE, Options),
+module({Mod,Exp,Attr,Forms}, _Options) ->
     {Fs,St} = functions(Forms, {atom,Mod}),
-    erase(?MODULE),
     {ok,{Mod,Exp,Attr,Fs,St#cg.lcount}}.
 
 functions(Forms, AtomMod) ->
@@ -123,24 +121,15 @@ cg_fun(Les, Hvs, Vdb, AtomMod, NameArity, Anno, St0) ->
 					   put_reg(V, Reg)
 				   end, [], Hvs),
 			 stk=[]}, 0, Vdb),
-    {B0,_Aft,St} = cg_list(Les, 0, Vdb, Bef,
+    {B,_Aft,St} = cg_list(Les, 0, Vdb, Bef,
 			  St3#cg{bfail=0,
 				 ultimate_failure=UltimateMatchFail,
 				 is_top_block=true}),
-    B = fix_bs_match_strings(B0),
     {Name,Arity} = NameArity,
     Asm = [{label,Fi},line(Anno),{func_info,AtomMod,{atom,Name},Arity},
 	   {label,Fl}|B++[{label,UltimateMatchFail},if_end]],
     {Asm,Fl,St}.
 
-fix_bs_match_strings([{test,bs_match_string,F,[Ctx,BinList]}|Is])
-  when is_list(BinList) ->
-    I = {test,bs_match_string,F,[Ctx,list_to_bitstring(BinList)]},
-    [I|fix_bs_match_strings(Is)];
-fix_bs_match_strings([I|Is]) ->
-    [I|fix_bs_match_strings(Is)];
-fix_bs_match_strings([]) -> [].
-
 %% cg(Lkexpr, Vdb, StackReg, State) -> {[Ainstr],StackReg,State}.
 %%  Generate code for a kexpr.
 %%  Split function into two steps for clarity, not efficiency.
@@ -210,6 +199,8 @@ need_heap_0([], H, Acc) ->
 
 need_heap_1(#l{ke={set,_,{binary,_}},i=I}, H) ->
     {need_heap_need(I, H),0};
+need_heap_1(#l{ke={set,_,{map,_,_,_}},i=I}, H) ->
+    {need_heap_need(I, H),0};
 need_heap_1(#l{ke={set,_,Val}}, H) ->
     %% Just pass through adding to needed heap.
     {[],H + case Val of
@@ -453,8 +444,11 @@ basic_block([Le|Les], Acc) ->
 	    end;
 	no_block -> {reverse(Acc, [Le]),Les}
     end.
+
+%% sets that may garbage collect are not allowed in basic blocks.
 	
 collect_block({set,_,{binary,_}})    -> no_block;
+collect_block({set,_,{map,_,_,_}})   -> no_block;
 collect_block({set,_,_})             -> include;
 collect_block({call,{var,_}=Var,As,_Rs}) -> {block_end,As++[Var]};
 collect_block({call,Func,As,_Rs})   -> {block_end,As++func_vars(Func)};
@@ -581,7 +575,7 @@ top_level_block(Keis, Bef, MaxRegs, _St) ->
 			(return) ->
 			    [{deallocate,FrameSz},return];
 			(Tuple) when is_tuple(Tuple) ->
-			    [turn_yregs(tuple_size(Tuple), Tuple, MaxY)];
+			    [turn_yregs(Tuple, MaxY)];
 			(Other) ->
 			    [Other]
 		    end, Keis),
@@ -593,15 +587,49 @@ top_level_block(Keis, Bef, MaxRegs, _St) ->
 %%   catches work.  The code generation algorithm gives a lower register
 %%   number to the outer catch, which is wrong.
 
-turn_yregs(0, Tp, _) -> Tp;
-turn_yregs(El, Tp, MaxY) when element(1, element(El, Tp)) =:= yy ->
-    turn_yregs(El-1, setelement(El, Tp, {y,MaxY-element(2, element(El, Tp))}), MaxY);
-turn_yregs(El, Tp, MaxY) when is_list(element(El, Tp)) ->
-    New = map(fun ({yy,YY}) -> {y,MaxY-YY};
-		  (Other) -> Other end, element(El, Tp)),
-    turn_yregs(El-1, setelement(El, Tp, New), MaxY);
-turn_yregs(El, Tp, MaxY) ->
-    turn_yregs(El-1, Tp, MaxY).
+turn_yregs({call,_,_}=I, _MaxY) -> I;
+turn_yregs({call_ext,_,_}=I, _MaxY) -> I;
+turn_yregs({jump,_}=I, _MaxY) -> I;
+turn_yregs({label,_}=I, _MaxY) -> I;
+turn_yregs({line,_}=I, _MaxY) -> I;
+turn_yregs({test_heap,_,_}=I, _MaxY) -> I;
+turn_yregs({bif,Op,F,A,B}, MaxY) ->
+    {bif,Op,F,turn_yreg(A, MaxY),turn_yreg(B, MaxY)};
+turn_yregs({gc_bif,Op,F,Live,A,B}, MaxY) when is_integer(Live) ->
+    {gc_bif,Op,F,Live,turn_yreg(A, MaxY),turn_yreg(B, MaxY)};
+turn_yregs({get_tuple_element,S,N,D}, MaxY) ->
+    {get_tuple_element,turn_yreg(S, MaxY),N,turn_yreg(D, MaxY)};
+turn_yregs({put_tuple,Arity,D}, MaxY) ->
+    {put_tuple,Arity,turn_yreg(D, MaxY)};
+turn_yregs({select_val,R,F,L}, MaxY) ->
+    {select_val,turn_yreg(R, MaxY),F,L};
+turn_yregs({test,Op,F,L}, MaxY) ->
+    {test,Op,F,turn_yreg(L, MaxY)};
+turn_yregs({test,Op,F,Live,A,B}, MaxY) when is_integer(Live) ->
+    {test,Op,F,Live,turn_yreg(A, MaxY),turn_yreg(B, MaxY)};
+turn_yregs({Op,A}, MaxY) ->
+    {Op,turn_yreg(A, MaxY)};
+turn_yregs({Op,A,B}, MaxY) ->
+    {Op,turn_yreg(A, MaxY),turn_yreg(B, MaxY)};
+turn_yregs({Op,A,B,C}, MaxY) ->
+    {Op,turn_yreg(A, MaxY),turn_yreg(B, MaxY),turn_yreg(C, MaxY)};
+turn_yregs(Tuple, MaxY) ->
+    turn_yregs(tuple_size(Tuple), Tuple, MaxY).
+
+turn_yregs(1, Tp, _) ->
+    Tp;
+turn_yregs(N, Tp, MaxY) ->
+    E = turn_yreg(element(N, Tp), MaxY),
+    turn_yregs(N-1, setelement(N, Tp, E), MaxY).
+
+turn_yreg({yy,YY}, MaxY) ->
+    {y,MaxY-YY};
+turn_yreg({list,Ls},MaxY) ->
+    {list,turn_yreg(Ls, MaxY)};
+turn_yreg([_|_]=Ts, MaxY) ->
+    [turn_yreg(T, MaxY) || T <- Ts];
+turn_yreg(Other, _MaxY) ->
+    Other.
 
 %% select_cg(Sclause, V, TypeFail, ValueFail, StackReg, State) ->
 %%      {Is,StackReg,State}.
@@ -623,6 +651,8 @@ select_cg(#l{ke={type_clause,bin_int,S}}, {var,V}, Tf, _Vf, Bef, St) ->
     select_bin_segs(S, V, Tf, Bef, St);
 select_cg(#l{ke={type_clause,bin_end,[S]}}, {var,V}, Tf, _Vf, Bef, St) ->
     select_bin_end(S, V, Tf, Bef, St);
+select_cg(#l{ke={type_clause,map,S}}, {var,V}, Tf, Vf, Bef, St) ->
+    select_map(S, V, Tf, Vf, Bef, St);
 select_cg(#l{ke={type_clause,Type,Scs}}, {var,V}, Tf, Vf, Bef, St0) ->
     {Vis,{Aft,St1}} =
 	mapfoldl(fun (S, {Int,Sta}) ->
@@ -643,9 +673,7 @@ select_val_cg(Type, R, [Val, {f,Lbl}], Tf, Vf, [{label,Lbl}|Sis]) ->
     [{test,select_type_test(Type),{f,Tf},[R]},
      {test,is_eq_exact,{f,Vf},[R,{Type,Val}]}|Sis];
 select_val_cg(Type, R, Vls0, Tf, Vf, Sis) ->
-    Vls1 = map(fun ({f,_Lbl} = F) -> F;
-		   (Value) -> {Type,Value}
-	       end, Vls0),
+    Vls1 = [case Value of {f,_Lbl} -> Value; _ -> {Type,Value} end || Value <- Vls0],
     [{test,select_type_test(Type),{f,Tf},[R]}, {select_val,R,{f,Vf},{list,Vls1}}|Sis].
     
 select_type_test(integer) -> is_integer;
@@ -678,22 +706,37 @@ select_nil(#l{ke={val_clause,nil,B}}, V, Tf, Vf, Bef, St0) ->
 select_binary(#l{ke={val_clause,{binary,{var,V}},B},i=I,vdb=Vdb},
 	      V, Tf, Vf, Bef, St0) ->
     Int0 = clear_dead(Bef#sr{reg=Bef#sr.reg}, I, Vdb),
-    {Bis,Aft,St1} = match_cg(B, Vf, Int0, St0),
+    {Bis0,Aft,St1} = match_cg(B, Vf, Int0, St0),
     CtxReg = fetch_var(V, Int0),
     Live = max_reg(Bef#sr.reg),
-    {[{test,bs_start_match2,{f,Tf},Live,[CtxReg,V],CtxReg},
-      {bs_save2,CtxReg,{V,V}}|Bis],
-     Aft,St1};
+    Bis1 = [{test,bs_start_match2,{f,Tf},Live,[CtxReg,V],CtxReg},
+	    {bs_save2,CtxReg,{V,V}}|Bis0],
+    Bis = finish_select_binary(Bis1),
+    {Bis,Aft,St1};
 select_binary(#l{ke={val_clause,{binary,{var,Ivar}},B},i=I,vdb=Vdb},
 	      V, Tf, Vf, Bef, St0) ->
     Regs = put_reg(Ivar, Bef#sr.reg),
     Int0 = clear_dead(Bef#sr{reg=Regs}, I, Vdb),
-    {Bis,Aft,St1} = match_cg(B, Vf, Int0, St0),
+    {Bis0,Aft,St1} = match_cg(B, Vf, Int0, St0),
     CtxReg = fetch_var(Ivar, Int0),
     Live = max_reg(Bef#sr.reg),
-    {[{test,bs_start_match2,{f,Tf},Live,[fetch_var(V, Bef),Ivar],CtxReg},
-      {bs_save2,CtxReg,{Ivar,Ivar}}|Bis],
-     Aft,St1}.
+    Bis1 = [{test,bs_start_match2,{f,Tf},Live,[fetch_var(V, Bef),Ivar],CtxReg},
+	    {bs_save2,CtxReg,{Ivar,Ivar}}|Bis0],
+    Bis = finish_select_binary(Bis1),
+    {Bis,Aft,St1}.
+
+finish_select_binary([{bs_save2,R,Point}=I,{bs_restore2,R,Point}|Is]) ->
+    [I|finish_select_binary(Is)];
+finish_select_binary([{bs_save2,R,Point}=I,{test,is_eq_exact,_,_}=Test,
+		      {bs_restore2,R,Point}|Is]) ->
+    [I,Test|finish_select_binary(Is)];
+finish_select_binary([{test,bs_match_string,F,[Ctx,BinList]}|Is])
+  when is_list(BinList) ->
+    I = {test,bs_match_string,F,[Ctx,list_to_bitstring(BinList)]},
+    [I|finish_select_binary(Is)];
+finish_select_binary([I|Is]) ->
+    [I|finish_select_binary(Is)];
+finish_select_binary([]) -> [].
 
 %% New instructions for selection of binary segments.
 
@@ -784,21 +827,24 @@ select_extract_bin([{var,Hd},{var,Tl}], Size0, Unit, Type, Flags, Vf,
 		  {bs_save2,CtxReg,{Ctx,Tl}}],Int1}
 	end,
     {Es,clear_dead(Aft, I, Vdb),St};
-select_extract_bin([{var,Hd}], Size0, Unit, binary, Flags, Vf,
+select_extract_bin([{var,Hd}], Size, Unit, binary, Flags, Vf,
 		   I, Vdb, Bef, Ctx, Body, St) ->
-    SizeReg = get_bin_size_reg(Size0, Bef),
+    %% Match the last segment of a binary. We KNOW that the size
+    %% must be 'all'.
+    Size = {atom,all},				%Assertion.
     {Es,Aft} =
 	case vdb_find(Hd, Vdb) of
 	    {_,_,Lhd} when Lhd =< I ->
+		%% The result will not be used. Furthermore, since we
+		%% we are at the end of the binary, the position will
+		%% not be used again; thus, it is safe to do a cheaper
+		%% test of the unit.
 		CtxReg = fetch_var(Ctx, Bef),
-		{case SizeReg =:= {atom,all} andalso is_context_unused(Body) of
-		     true when Unit =:= 1 ->
+		{case Unit of
+		     1 ->
 			 [];
-		     true ->
-			 [{test,bs_test_unit,{f,Vf},[CtxReg,Unit]}];
-		     false ->
-			 [{test,bs_skip_bits2,{f,Vf},
-			   [CtxReg,SizeReg,Unit,{field_flags,Flags}]}]
+		     _ ->
+			 [{test,bs_test_unit,{f,Vf},[CtxReg,Unit]}]
 		 end,Bef};
 	    {_,_,_} ->
 		case is_context_unused(Body) of
@@ -810,7 +856,7 @@ select_extract_bin([{var,Hd}], Size0, Unit, binary, Flags, Vf,
 			Name = bs_get_binary2,
 			Live = max_reg(Bef#sr.reg),
 			{[{test,Name,{f,Vf},Live,
-			   [CtxReg,SizeReg,Unit,{field_flags,Flags}],Rhd}],
+			   [CtxReg,Size,Unit,{field_flags,Flags}],Rhd}],
 			 Int1};
 		    true ->
 			%% Since the matching context will not be used again,
@@ -825,7 +871,7 @@ select_extract_bin([{var,Hd}], Size0, Unit, binary, Flags, Vf,
 			Name = bs_get_binary2,
 			Live = max_reg(Int1#sr.reg),
 			{[{test,Name,{f,Vf},Live,
-			   [CtxReg,SizeReg,Unit,{field_flags,Flags}],CtxReg}],
+			   [CtxReg,Size,Unit,{field_flags,Flags}],CtxReg}],
 			 Int1}
 		end
 	end,
@@ -915,6 +961,59 @@ select_extract_tuple(Src, Vs, I, Vdb, Bef, St) ->
     {Es,{Aft,_}} = flatmapfoldl(F, {Bef,0}, Vs),
     {Es,Aft,St}.
 
+select_map(Scs, V, Tf, Vf, Bef, St0) ->
+    Reg = fetch_var(V, Bef),
+    {Is,Aft,St1} =
+	match_fmf(fun(#l{ke={val_clause,{map,exact,_,Es},B},i=I,vdb=Vdb}, Fail, St1) ->
+			  select_map_val(V, Es, B, Fail, I, Vdb, Bef, St1)
+		  end, Vf, St0, Scs),
+    {[{test,is_map,{f,Tf},[Reg]}|Is],Aft,St1}.
+
+select_map_val(V, Es, B, Fail, I, Vdb, Bef, St0) ->
+    {Eis,Int,St1} = select_extract_map(V, Es, Fail, I, Vdb, Bef, St0),
+    {Bis,Aft,St2} = match_cg(B, Fail, Int, St1),
+    {Eis++Bis,Aft,St2}.
+
+select_extract_map(_, [], _, _, _, Bef, St) -> {[],Bef,St};
+select_extract_map(Src, Vs, Fail, I, Vdb, Bef, St) ->
+    %% First split the instruction flow
+    %% We want one set of each
+    %% 1) has_map_fields (no target registers)
+    %% 2) get_map_elements (with target registers)
+    %% Assume keys are term-sorted
+    Rsrc = fetch_var(Src, Bef),
+
+    {{HasKs,GetVs,HasVarKs,GetVarVs},Aft} = lists:foldr(fun
+	    ({map_pair,{var,K},{var,V}},{{HasKsi,GetVsi,HasVarVsi,GetVarVsi},Int0}) ->
+		case vdb_find(V, Vdb) of
+		    {V,_,L} when L =< I ->
+			RK = fetch_var(K,Int0),
+			{{HasKsi,GetVsi,[RK|HasVarVsi],GetVarVsi},Int0};
+		    _Other ->
+			Reg1 = put_reg(V, Int0#sr.reg),
+			Int1 = Int0#sr{reg=Reg1},
+			RK = fetch_var(K,Int0),
+			RV = fetch_reg(V,Reg1),
+			{{HasKsi,GetVsi,HasVarVsi,[[RK,RV]|GetVarVsi]},Int1}
+		end;
+	    ({map_pair,Key,{var,V}},{{HasKsi,GetVsi,HasVarVsi,GetVarVsi},Int0}) ->
+		case vdb_find(V, Vdb) of
+		    {V,_,L} when L =< I ->
+			{{[Key|HasKsi],GetVsi,HasVarVsi,GetVarVsi},Int0};
+		    _Other ->
+			Reg1 = put_reg(V, Int0#sr.reg),
+			Int1 = Int0#sr{reg=Reg1},
+			{{HasKsi,[Key,fetch_reg(V, Reg1)|GetVsi],HasVarVsi,GetVarVsi},Int1}
+		end
+	end, {{[],[],[],[]},Bef}, Vs),
+
+    Code = [{test,has_map_fields,{f,Fail},Rsrc,{list,HasKs}} || HasKs =/= []] ++
+	   [{test,has_map_fields,{f,Fail},Rsrc,{list,[K]}}   || K <- HasVarKs] ++
+	   [{get_map_elements,   {f,Fail},Rsrc,{list,GetVs}} || GetVs =/= []] ++
+	   [{get_map_elements,   {f,Fail},Rsrc,{list,[K,V]}} || [K,V] <- GetVarVs],
+    {Code, Aft, St}.
+
+
 select_extract_cons(Src, [{var,Hd}, {var,Tl}], I, Vdb, Bef, St) ->
     {Es,Aft} = case {vdb_find(Hd, Vdb), vdb_find(Tl, Vdb)} of
 		   {{_,_,Lhd}, {_,_,Ltl}} when Lhd =< I, Ltl =< I ->
@@ -982,7 +1081,7 @@ protected_cg(Ts, Rs, _Fail, I, Vdb, Bef, St0) ->
 				  St2#cg{bfail=Pfail}),
     %%ok = io:fwrite("cg ~w: ~p~n", [?LINE,{Rs,I,Vdb,Aft}]),
     %% Set return values to false.
-    Mis = map(fun ({var,V}) -> {move,{atom,false},fetch_var(V, Aft)} end, Rs),
+    Mis = [{move,{atom,false},fetch_var(V,Aft)}||{var,V} <- Rs],
     {Tis ++ [{jump,{f,Psucc}},
 	     {label,Pfail}] ++ Mis ++ [{label,Psucc}],
      Aft,St3#cg{bfail=St0#cg.bfail}}.    
@@ -990,6 +1089,23 @@ protected_cg(Ts, Rs, _Fail, I, Vdb, Bef, St0) ->
 %% test_cg(TestName, Args, Fail, I, Vdb, Bef, St) -> {[Ainstr],Aft,St}.
 %%  Generate test instruction.  Use explicit fail label here.
 
+test_cg(is_map, [A], Fail, I, Vdb, Bef, St) ->
+    %% We must avoid creating code like this:
+    %%
+    %%   move x(0) y(0)
+    %%   is_map Fail [x(0)]
+    %%   make_fun => x(0)  %% Overwrite x(0)
+    %%   put_map_assoc y(0) ...
+    %%
+    %% The code is safe, but beam_validator does not understand that.
+    %% Extending beam_validator to handle such (rare) code as the
+    %% above would make it slower for all programs. Instead, change
+    %% the code generator to always prefer the Y register for is_map()
+    %% and put_map_assoc() instructions, ensuring that they use the
+    %% same register.
+    Arg = cg_reg_arg_prefer_y(A, Bef),
+    Aft = clear_dead(Bef, I, Vdb),
+    {[{test,is_map,{f,Fail},[Arg]}],Aft,St};
 test_cg(Test, As, Fail, I, Vdb, Bef, St) ->
     Args = cg_reg_args(As, Bef),
     Aft = clear_dead(Bef, I, Vdb),
@@ -1056,19 +1172,15 @@ call_cg(Func, As, Rs, Le, Vdb, Bef, St0) ->
 	    %% Inside a guard. The only allowed function call is to
 	    %% erlang:error/1,2. We will generate the following code:
 	    %%
-	    %%     jump FailureLabel
 	    %%     move {atom,ok} DestReg
-	    %%
-	    %% The 'move' instruction will never be executed, but we
-	    %% generate it anyway in case the beam_validator is run
-	    %% on unoptimized code.
+	    %%     jump FailureLabel
 	    {remote,{atom,erlang},{atom,error}} = Func,	%Assertion.
 	    [{var,DestVar}] = Rs,
 	    Int0 = clear_dead(Bef, Le#l.i, Vdb),
 	    Reg = put_reg(DestVar, Int0#sr.reg),
 	    Int = Int0#sr{reg=Reg},
 	    Dst = fetch_reg(DestVar, Reg),
-	    {[{jump,{f,Fail}},{move,{atom,ok},Dst}],
+	    {[{move,{atom,ok},Dst},{jump,{f,Fail}}],
 	     clear_dead(Int, Le#l.i, Vdb),St0};
 	#cg{} ->
 	    %% Ordinary function call in a function body.
@@ -1165,13 +1277,12 @@ enter_line(_, _, _) ->
 local_func_label(Name, Arity, St) ->
     local_func_label({Name,Arity}, St).
 
-local_func_label(Key, #cg{functable=Tab}=St0) ->
-    case gb_trees:lookup(Key, Tab) of
-	{value,Label} ->
-	    {Label,St0};
-	none ->
+local_func_label(Key, #cg{functable=Map}=St0) ->
+    case Map of
+        #{Key := Label} -> {Label,St0};
+        _ ->
   	    {Label,St} = new_label(St0),
-	    {Label,St#cg{functable=gb_trees:insert(Key, Label, Tab)}}
+	    {Label,St#cg{functable=Map#{Key => Label}}}
     end.
 
 %% need_stack_frame(State) -> State'
@@ -1232,12 +1343,13 @@ bif_cg(Bif, As, [{var,V}], Le, Vdb, Bef, St0) ->
     %% that we save any variable that will be live after this BIF call.
 
     MayFail = not erl_bifs:is_safe(erlang, Bif, length(As)),
-    {Sis,Int0} = case St0#cg.in_catch andalso
-		     St0#cg.bfail =:= 0 andalso
-		     MayFail of
-		     true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb);
-		     false -> {[],Bef}
-		 end,
+    {Sis,Int0} =
+	case MayFail of
+	    true ->
+		maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0);
+	    false ->
+		{[],Bef}
+	end,
     Int1 = clear_dead(Int0, Le#l.i, Vdb),
     Reg = put_reg(V, Int1#sr.reg),
     Int = Int1#sr{reg=Reg},
@@ -1268,11 +1380,7 @@ gc_bif_cg(Bif, As, [{var,V}], Le, Vdb, Bef, St0) ->
     %%   Currently, we are somewhat pessimistic in
     %% that we save any variable that will be live after this BIF call.
 
-    {Sis,Int0} =
-	case St0#cg.in_catch andalso St0#cg.bfail =:= 0 of
-	    true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb);
-	    false -> {[],Bef}
-	end,
+    {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0),
 
     Int1 = clear_dead(Int0, Le#l.i, Vdb),
     Reg = put_reg(V, Int1#sr.reg),
@@ -1408,7 +1516,7 @@ catch_cg(C, {var,R}, Le, Vdb, Bef, St0) ->
 %%  annotation must reflect this and make sure that the return
 %%  variable is allocated first.
 %%
-%%  put_list for constructing a cons is an atomic instruction
+%%  put_list and put_map are atomic instructions, both of
 %%  which can safely resuse one of the source registers as target.
 
 set_cg([{var,R}], {cons,Es}, Le, Vdb, Bef, St) ->
@@ -1417,8 +1525,7 @@ set_cg([{var,R}], {cons,Es}, Le, Vdb, Bef, St) ->
     Int1 = Int0#sr{reg=put_reg(R, Int0#sr.reg)},
     Ret = fetch_reg(R, Int1#sr.reg),
     {[{put_list,S1,S2,Ret}], Int1, St};
-set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef,
-       #cg{in_catch=InCatch, bfail=Bfail}=St) ->
+set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef, #cg{bfail=Bfail}=St) ->
     %% At run-time, binaries are constructed in three stages:
     %% 1) First the size of the binary is calculated.
     %% 2) Then the binary is allocated.
@@ -1437,17 +1544,58 @@ set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef,
     %% First generate the code that constructs each field.
     Fail = {f,Bfail},
     PutCode = cg_bin_put(Segs, Fail, Bef),
-    {Sis,Int1} =
-	case InCatch of
-	    true -> adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb);
-	    false -> {[],Int0}
-	end,
+    {Sis,Int1} = maybe_adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb, St),
     MaxRegs = max_reg(Bef#sr.reg),
     Aft = clear_dead(Int1, Le#l.i, Vdb),
 
     %% Now generate the complete code for constructing the binary.
     Code = cg_binary(PutCode, Target, Temp, Fail, MaxRegs, Le#l.a),
     {Sis++Code,Aft,St};
+
+%% Map: single variable key.
+set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, Le, Vdb, Bef, St0) ->
+    {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0),
+
+    SrcReg = cg_reg_arg_prefer_y(Map, Int0),
+    Line = line(Le#l.a),
+
+    List = [cg_reg_arg(K,Int0),cg_reg_arg(V,Int0)],
+
+    Live = max_reg(Bef#sr.reg),
+
+    %% The target register can reuse one of the source registers.
+    Aft0 = clear_dead(Int0, Le#l.i, Vdb),
+    Aft = Aft0#sr{reg=put_reg(R, Aft0#sr.reg)},
+    Target = fetch_reg(R, Aft#sr.reg),
+
+    {Is,St1} = set_cg_map(Line, Op, SrcReg, Target, Live, List, St0),
+    {Sis++Is,Aft,St1};
+
+%% Map: (possibly) multiple literal keys.
+set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef, St0) ->
+
+    %% assert key literals
+    [] = [Var||{map_pair,{var,_}=Var,_} <- Es],
+
+    {Sis,Int0} = maybe_adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb, St0),
+    SrcReg = cg_reg_arg_prefer_y(Map, Int0),
+    Line = line(Le#l.a),
+
+    %% fetch registers for values to be put into the map
+    Pairs = [{K,V} || {_,K,V} <- Es],
+    List = flatmap(fun({K,V}) -> [K,cg_reg_arg(V,Int0)] end, Pairs),
+
+    Live = max_reg(Bef#sr.reg),
+
+    %% The target register can reuse one of the source registers.
+    Aft0 = clear_dead(Int0, Le#l.i, Vdb),
+    Aft = Aft0#sr{reg=put_reg(R, Aft0#sr.reg)},
+    Target = fetch_reg(R, Aft#sr.reg),
+
+    {Is,St1} = set_cg_map(Line, Op, SrcReg, Target, Live, List, St0),
+    {Sis++Is,Aft,St1};
+
+%% Everything else.
 set_cg([{var,R}], Con, Le, Vdb, Bef, St) ->
     %% Find a place for the return register first.
     Int = Bef#sr{reg=put_reg(R, Bef#sr.reg)},
@@ -1460,16 +1608,45 @@ set_cg([{var,R}], Con, Le, Vdb, Bef, St) ->
 	  end,
     {Ais,clear_dead(Int, Le#l.i, Vdb),St}.
 
+
+set_cg_map(Line, Op0, SrcReg, Target, Live, List, St0) ->
+    Bfail = St0#cg.bfail,
+    Fail = {f,St0#cg.bfail},
+    Op = case Op0 of
+	     assoc -> put_map_assoc;
+	     exact -> put_map_exact
+	 end,
+    {OkLbl,St1} = new_label(St0),
+    {BadLbl,St2} = new_label(St1),
+    Is = if
+	     Bfail =:= 0 orelse Op =:= put_map_assoc ->
+		 [Line,{Op,{f,0},SrcReg,Target,Live,{list,List}}];
+	     true ->
+		 %% Ensure that Target is always set, even if
+		 %% the map update operation fails. That is necessary
+		 %% because Target may be included in a test_heap
+		 %% instruction.
+		 [Line,
+		  {Op,{f,BadLbl},SrcReg,Target,Live,{list,List}},
+		  {jump,{f,OkLbl}},
+		  {label,BadLbl},
+		  {move,{atom,ok},Target},
+		  {jump,Fail},
+		  {label,OkLbl}]
+	 end,
+    {Is,St2}.
+
 %%%
 %%% Code generation for constructing binaries.
 %%%
 
 cg_binary([{bs_put_binary,Fail,{atom,all},U,_Flags,Src}|PutCode],
 	  Target, Temp, Fail, MaxRegs, Anno) ->
+    Line = line(Anno),
     Live = cg_live(Target, MaxRegs),
     SzCode = cg_bitstr_size(PutCode, Target, Temp, Fail, Live),
     BinFlags = {field_flags,[]},
-    Code = SzCode ++
+    Code = [Line|SzCode] ++
 	[case member(single_use, Anno) of
 	     true ->
 		 {bs_private_append,Fail,Target,U,Src,BinFlags,Target};
@@ -1701,6 +1878,9 @@ cg_reg_args(As, Bef) -> [cg_reg_arg(A, Bef) || A <- As].
 cg_reg_arg({var,V}, Bef) -> fetch_var(V, Bef);
 cg_reg_arg(Literal, _) -> Literal.
 
+cg_reg_arg_prefer_y({var,V}, Bef) -> fetch_var_prefer_y(V, Bef);
+cg_reg_arg_prefer_y(Literal, _) -> Literal.
+
 %% cg_setup_call([Arg], Bef, Cur, Vdb) -> {[Instr],Aft}.
 %%  Do the complete setup for a call/enter.
 
@@ -1833,25 +2013,28 @@ clear_dead(Sr, Until, Vdb) ->
 	  stk=clear_dead_stk(Sr#sr.stk, Until, Vdb)}.
 
 clear_dead_reg(Sr, Until, Vdb) ->
-    Reg = map(fun ({_I,V} = IV) ->
-		      case vdb_find(V, Vdb) of
-			  {V,_,L} when L > Until -> IV;
-			  _ -> free		%Remove anything else
-		      end;
-		  ({reserved,_I,_V} = Reserved) -> Reserved;
-		  (free) -> free
-	      end, Sr#sr.reg),
+    Reg = [case R of
+            {_I,V} = IV ->
+                case vdb_find(V, Vdb) of
+                    {V,_,L} when L > Until -> IV;
+                    _ -> free		%Remove anything else
+                end;
+            {reserved,_I,_V} = Reserved -> Reserved;
+            free -> free
+        end || R <- Sr#sr.reg],
     reserve(Sr#sr.res, Reg, Sr#sr.stk).
 
 clear_dead_stk(Stk, Until, Vdb) ->
-    map(fun ({V} = T) ->
-		case vdb_find(V, Vdb) of
-		    {V,_,L} when L > Until -> T;
-		    _ -> dead			%Remove anything else
-		end;
-	    (free) -> free;
-	    (dead) -> dead
-	end, Stk).
+    [case S of
+	    {V} = T ->
+            case vdb_find(V, Vdb) of
+                {V,_,L} when L > Until -> T;
+                _ -> dead   %Remove anything else
+            end;
+        free -> free;
+        dead -> dead
+     end || S <- Stk].
+
 
 %% sr_merge(Sr1, Sr2) -> Sr.
 %%  Merge two stack/register states keeping the longest of both stack
@@ -1879,6 +2062,19 @@ trim_free([R|Rs0]) ->
     end;
 trim_free([]) -> [].
 
+%% maybe_adjust_stack(Bef, FirstBefore, LastFrom, Vdb, St) -> {[Ainstr],Aft}.
+%%  Adjust the stack, but only if the code is inside a catch and not
+%%  inside a guard.  Use this funtion before instructions that may
+%%  cause an exception.
+
+maybe_adjust_stack(Bef, Fb, Lf, Vdb, St) ->
+    case St of
+	#cg{in_catch=true,bfail=0} ->
+	    adjust_stack(Bef, Fb, Lf, Vdb);
+	#cg{} ->
+	    {[],Bef}
+    end.
+
 %% adjust_stack(Bef, FirstBefore, LastFrom, Vdb) -> {[Ainstr],Aft}.
 %%  Do complete stack adjustment by compressing stack and adding
 %%  variables to be saved.  Try to optimise ordering on stack by
@@ -1926,11 +2122,17 @@ fetch_var(V, Sr) ->
 	error -> fetch_stack(V, Sr#sr.stk)
     end.
 
+fetch_var_prefer_y(V, #sr{reg=Reg,stk=Stk}) ->
+    case find_stack(V, Stk) of
+	{ok,R} -> R;
+	error -> fetch_reg(V, Reg)
+    end.
+
 load_vars(Vs, Regs) ->
     foldl(fun ({var,V}, Rs) -> put_reg(V, Rs) end, Regs, Vs).
 
 %% put_reg(Val, Regs) -> Regs.
-%% find_reg(Val, Regs) -> ok{r{R}} | error.
+%% find_reg(Val, Regs) -> {ok,r{R}} | error.
 %% fetch_reg(Val, Regs) -> r{R}.
 %%  Functions to interface the registers.
 
@@ -1981,9 +2183,11 @@ put_stack(Val, [free|Stk]) -> [{Val}|Stk];
 put_stack(Val, [NotFree|Stk]) -> [NotFree|put_stack(Val, Stk)].
 
 put_stack_carefully(Val, Stk0) ->
-    case catch put_stack_carefully1(Val, Stk0) of
-	error -> error;
-	Stk1 when is_list(Stk1) -> Stk1
+    try
+	put_stack_carefully1(Val, Stk0)
+    catch
+	throw:error ->
+	    error
     end.
 
 put_stack_carefully1(_, []) -> throw(error);
@@ -1997,11 +2201,11 @@ fetch_stack(Var, Stk) -> fetch_stack(Var, Stk, 0).
 fetch_stack(V, [{V}|_], I) -> {yy,I};
 fetch_stack(V, [_|Stk], I) -> fetch_stack(V, Stk, I+1).
 
-% find_stack(Var, Stk) -> find_stack(Var, Stk, 0).
+find_stack(Var, Stk) -> find_stack(Var, Stk, 0).
 
-% find_stack(V, [{V}|Stk], I) -> {ok,{yy,I}};
-% find_stack(V, [O|Stk], I) -> find_stack(V, Stk, I+1);
-% find_stack(V, [], I) -> error.
+find_stack(V, [{V}|_], I) -> {ok,{yy,I}};
+find_stack(V, [_|Stk], I) -> find_stack(V, Stk, I+1);
+find_stack(_, [], _) -> error.
 
 on_stack(V, Stk) -> keymember(V, 1, Stk).
 
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index d6fdcb2b21..d71411de80 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -66,6 +67,7 @@
 %% match arguments are novars
 %% case arguments are novars
 %% receive timeouts are novars
+%% binaries and maps are novars
 %% let/set arguments are expressions
 %% fun is not a safe
 
@@ -74,10 +76,11 @@
 -export([module/2,format_error/1]).
 
 -import(lists, [reverse/1,reverse/2,map/2,member/2,foldl/3,foldr/3,mapfoldl/3,
-		splitwith/2,keyfind/3,sort/1,foreach/2]).
+		splitwith/2,keyfind/3,sort/1,foreach/2,droplast/1,last/1]).
 -import(ordsets, [add_element/2,del_element/2,is_element/2,
 		  union/1,union/2,intersection/2,subtract/2]).
--import(cerl, [ann_c_cons/3,ann_c_cons_skel/3,ann_c_tuple/2,c_tuple/1]).
+-import(cerl, [ann_c_cons/3,ann_c_tuple/2,c_tuple/1,
+	       ann_c_map/3]).
 
 -include("core_parse.hrl").
 
@@ -92,7 +95,7 @@
 -record(icase,     {anno=#a{},args,clauses,fc}).
 -record(icatch,    {anno=#a{},body}).
 -record(iclause,   {anno=#a{},pats,pguard=[],guard,body}).
--record(ifun,      {anno=#a{},id,vars,clauses,fc}).
+-record(ifun,      {anno=#a{},id,vars,clauses,fc,name=unnamed}).
 -record(iletrec,   {anno=#a{},defs,body}).
 -record(imatch,    {anno=#a{},pat,guard=[],arg,fc}).
 -record(iprimop,   {anno=#a{},name,args}).
@@ -101,6 +104,10 @@
 -record(ireceive2, {anno=#a{},clauses,timeout,action}).
 -record(iset,      {anno=#a{},var,arg}).
 -record(itry,      {anno=#a{},args,vars,body,evars,handler}).
+-record(ifilter,   {anno=#a{},arg}).
+-record(igen,      {anno=#a{},ceps=[],acc_pat,acc_guard,
+		    skip_pat,tail,tail_pat,arg}).
+-record(isimple,   {anno=#a{},term :: cerl:cerl()}).
 
 -type iapply()    :: #iapply{}.
 -type ibinary()   :: #ibinary{}.
@@ -117,10 +124,14 @@
 -type ireceive2() :: #ireceive2{}.
 -type iset()      :: #iset{}.
 -type itry()      :: #itry{}.
+-type ifilter()   :: #ifilter{}.
+-type igen()      :: #igen{}.
+-type isimple()   :: #isimple{}.
 
 -type i() :: iapply()   | ibinary()   | icall()     | icase()  | icatch()
            | iclause()  | ifun()      | iletrec()   | imatch() | iprimop()
-           | iprotect() | ireceive1() | ireceive2() | iset()   | itry().
+           | iprotect() | ireceive1() | ireceive2() | iset()   | itry()
+           | ifilter()  | igen()      | isimple().
 
 -type warning() :: {file:filename(), [{integer(), module(), term()}]}.
 
@@ -158,63 +169,86 @@ form({attribute,_,file,{File,_Line}}, {Fs,As,Ws,_}, _Opts) ->
 form({attribute,_,_,_}=F, {Fs,As,Ws,File}, _Opts) ->
     {Fs,[attribute(F)|As],Ws,File}.
 
-attribute({attribute,Line,Name,Val}) ->
-    {#c_literal{val=Name, anno=[Line]}, #c_literal{val=Val, anno=[Line]}}.
+attribute(Attribute) ->
+    Fun = fun(A) ->  [erl_anno:location(A)] end,
+    {attribute,Line,Name,Val} = erl_parse:map_anno(Fun, Attribute),
+    {#c_literal{val=Name, anno=Line}, #c_literal{val=Val, anno=Line}}.
+
+%% function_dump(module_info,_,_,_) -> ok;
+%% function_dump(Name,Arity,Format,Terms) ->
+%%     io:format("~w/~w " ++ Format,[Name,Arity]++Terms),
+%%     ok.
 
 function({function,_,Name,Arity,Cs0}, Ws0, File, Opts) ->
-    %%ok = io:fwrite("~p - ", [{Name,Arity}]),
     St0 = #core{vcount=0,opts=Opts,ws=Ws0,file=[{file,File}]},
     {B0,St1} = body(Cs0, Name, Arity, St0),
-    %%ok = io:fwrite("1", []),
-    %%ok = io:fwrite("~w:~p~n", [?LINE,B0]),
+    %% ok = function_dump(Name,Arity,"body:~n~p~n",[B0]),
     {B1,St2} = ubody(B0, St1),
-    %%ok = io:fwrite("2", []),
-    %%ok = io:fwrite("~w:~p~n", [?LINE,B1]),
+    %% ok = function_dump(Name,Arity,"ubody:~n~p~n",[B1]),
     {B2,#core{ws=Ws}} = cbody(B1, St2),
-    %%ok = io:fwrite("3~n", []),
-    %%ok = io:fwrite("~w:~p~n", [?LINE,B2]),
+    %% ok = function_dump(Name,Arity,"cbody:~n~p~n",[B2]),
     {{#c_var{name={Name,Arity}},B2},Ws}.
 
 body(Cs0, Name, Arity, St0) ->
     Anno = lineno_anno(element(2, hd(Cs0)), St0),
     {Args,St1} = new_vars(Anno, Arity, St0),
-    {Cs1,St2} = clauses(Cs0, St1),
-    {Ps,St3} = new_vars(Arity, St2),    %Need new variables here
-    Fc = function_clause(Ps, Anno, {Name,Arity}),
-    {#ifun{anno=#a{anno=Anno},id=[],vars=Args,clauses=Cs1,fc=Fc},St3}.
+    case clauses(Cs0, St1) of
+	{Cs1,[],St2} ->
+	    {Ps,St3} = new_vars(Arity, St2),    %Need new variables here
+	    Fc = function_clause(Ps, Anno, {Name,Arity}),
+	    {#ifun{anno=#a{anno=Anno},id=[],vars=Args,clauses=Cs1,fc=Fc},St3};
+	{Cs1,Eps,St2} ->
+	    %% We have pre-expressions from patterns and
+	    %% these needs to be letified before matching
+	    %% since only bound variables are allowed
+	    AnnoGen = #a{anno=[compiler_generated]},
+	    {Ps1,St3} = new_vars(Arity, St2),    %Need new variables here
+	    Fc1 = function_clause(Ps1, Anno, {Name,Arity}),
+	    {Ps2,St4} = new_vars(Arity, St3),    %Need new variables here
+	    Fc2 = function_clause(Ps2, Anno, {Name,Arity}),
+	    Case = #icase{anno=AnnoGen,args=Args,
+			  clauses=Cs1,
+			  fc=Fc2},
+	    {#ifun{anno=#a{anno=Anno},id=[],vars=Args,
+		   clauses=[#iclause{anno=AnnoGen,pats=Ps1,
+				     guard=[#c_literal{val=true}],
+				     body=Eps ++ [Case]}],
+		   fc=Fc1},St4}
+    end.
 
 %% clause(Clause, State) -> {Cclause,State} | noclause.
 %% clauses([Clause], State) -> {[Cclause],State}.
 %%  Convert clauses.  Trap bad pattern aliases and remove clause from
 %%  clause list.
 
-clauses([C0|Cs0], St0) ->
+clauses([C0|Cs0],St0) ->
     case clause(C0, St0) of
-	{noclause,St} -> clauses(Cs0, St);
-	{C,St1} ->
-	    {Cs,St2} = clauses(Cs0, St1),
-	    {[C|Cs],St2}
+	{noclause,_,St} -> clauses(Cs0,St);
+	{C,Eps1,St1} ->
+	    {Cs,Eps2,St2} = clauses(Cs0, St1),
+	    {[C|Cs],Eps1++Eps2,St2}
     end;
-clauses([], St) -> {[],St}.
+clauses([],St) -> {[],[],St}.
 
 clause({clause,Lc,H0,G0,B0}, St0) ->
     try head(H0, St0) of
-	H1 ->
-	    {G1,St1} = guard(G0, St0),
-	    {B1,St2} = exprs(B0, St1),
-            Anno = lineno_anno(Lc, St2),
-	    {#iclause{anno=#a{anno=Anno},pats=H1,guard=G1,body=B1},St2}
+	{H1,Eps,St1} ->
+	    {G1,St2} = guard(G0, St1),
+	    {B1,St3} = exprs(B0, St2),
+            Anno = lineno_anno(Lc, St3),
+	    {#iclause{anno=#a{anno=Anno},pats=H1,guard=G1,body=B1},Eps,St3}
     catch
 	throw:nomatch ->
 	    St = add_warning(Lc, nomatch, St0),
-	    {noclause,St}			%Bad pattern
+	    {noclause,[],St}			%Bad pattern
     end.
 
 clause_arity({clause,_,H0,_,_}) -> length(H0).
 
-%% head([P], State) -> [P].
+%% head([P], State) -> {[P],[Cexpr],State}.
 
-head(Ps, St) -> pattern_list(Ps, St).
+head(Ps, St) ->
+    pattern_list(Ps, St).
 
 %% guard([Expr], State) -> {[Cexpr],State}.
 %%  Build an explict and/or tree of guard alternatives, then traverse
@@ -226,13 +260,13 @@ guard(Gs0, St0) ->
 			Gt1 = guard_tests(Gt0),
 			L = element(2, Gt1),
 			{op,L,'or',Gt1,Rhs}
-		end, guard_tests(last(Gs0)), first(Gs0)),
+		end, guard_tests(last(Gs0)), droplast(Gs0)),
     {Gs,St} = gexpr_top(Gs1, St0#core{in_guard=true}),
     {Gs,St#core{in_guard=false}}.
     
 guard_tests(Gs) ->
     L = element(2, hd(Gs)),
-    {protect,L,foldr(fun (G, Rhs) -> {op,L,'and',G,Rhs} end, last(Gs), first(Gs))}.
+    {protect,L,foldr(fun (G, Rhs) -> {op,L,'and',G,Rhs} end, last(Gs), droplast(Gs))}.
 
 %% gexpr_top(Expr, State) -> {Cexpr,State}.
 %%  Generate an internal core expression of a guard test.  Explicitly
@@ -258,62 +292,80 @@ gexpr({protect,Line,Arg}, Bools0, St0) ->
 	    {#iprotect{anno=#a{anno=Anno},body=Eps++[E]},[],Bools0,St}
     end;
 gexpr({op,L,'andalso',E1,E2}, Bools, St0) ->
-    {#c_var{name=V0},St} = new_var(L, St0),
+    Anno = lineno_anno(L, St0),
+    {#c_var{name=V0},St} = new_var(Anno, St0),
     V = {var,L,V0},
     False = {atom,L,false},
     E = make_bool_switch_guard(L, E1, V, E2, False),
     gexpr(E, Bools, St);
 gexpr({op,L,'orelse',E1,E2}, Bools, St0) ->
-    {#c_var{name=V0},St} = new_var(L, St0),
+    Anno = lineno_anno(L, St0),
+    {#c_var{name=V0},St} = new_var(Anno, St0),
     V = {var,L,V0},
     True = {atom,L,true},
     E = make_bool_switch_guard(L, E1, V, True, E2),
     gexpr(E, Bools, St);
-gexpr({op,Line,Op,L,R}=Call, Bools0, St0) ->
+gexpr({op,Line,Op,L,R}=E, Bools, St) ->
     case erl_internal:bool_op(Op, 2) of
-	true ->
-	    {Le,Lps,Bools1,St1} = gexpr(L, Bools0, St0),
-	    {Ll,Llps,St2} = force_safe(Le, St1),
-	    {Re,Rps,Bools,St3} = gexpr(R, Bools1, St2),
-	    {Rl,Rlps,St4} = force_safe(Re, St3),
-	    Anno = lineno_anno(Line, St4),
-	    {#icall{anno=#a{anno=Anno},	%Must have an #a{}
-		    module=#c_literal{anno=Anno,val=erlang},
-		    name=#c_literal{anno=Anno,val=Op},
-		    args=[Ll,Rl]},Lps ++ Llps ++ Rps ++ Rlps,Bools,St4};
-	false ->
-	    gexpr_test(Call, Bools0, St0)
+        true ->
+            gexpr_bool(Op, L, R, Bools, St, Line);
+        false ->
+            gexpr_test(E, Bools, St)
     end;
-gexpr({op,Line,Op,A}=Call, Bools0, St0) ->
-    case Op of
-	'not' ->
-	    {Ae0,Aps,Bools,St1} = gexpr(A, Bools0, St0),
-	    case Ae0 of
-		#icall{module=#c_literal{val=erlang},
-		       name=#c_literal{val='=:='},
-		       args=[E,#c_literal{val=true}]}=EqCall ->
-		    %%
-		    %% Doing the following transformation
-		    %%    not(Expr =:= true)  ==>  Expr =:= false
-		    %% will help eliminating redundant is_boolean/1 tests.
-		    %%
-		    Ae = EqCall#icall{args=[E,#c_literal{val=false}]},
-		    {Al,Alps,St2} = force_safe(Ae, St1),
-		    {Al,Aps ++ Alps,Bools,St2};
-		Ae ->
-		    {Al,Alps,St2} = force_safe(Ae, St1),
-		    Anno = lineno_anno(Line, St2),
-		    {#icall{anno=#a{anno=Anno},	%Must have an #a{}
-			    module=#c_literal{anno=Anno,val=erlang},
-			    name=#c_literal{anno=Anno,val=Op},
-			    args=[Al]},Aps ++ Alps,Bools,St2}
-	    end;
-	_ ->
-	    gexpr_test(Call, Bools0, St0)
+gexpr({call,Line,{remote,_,{atom,_,erlang},{atom,_,Op}},[L,R]}=E, Bools, St) ->
+    case erl_internal:bool_op(Op, 2) of
+        true ->
+            gexpr_bool(Op, L, R, Bools, St, Line);
+        false ->
+            gexpr_test(E, Bools, St)
     end;
+gexpr({op,Line,'not',A}, Bools, St) ->
+    gexpr_not(A, Bools, St, Line);
+gexpr({call,Line,{remote,_,{atom,_,erlang},{atom,_,'not'}},[A]}, Bools, St) ->
+    gexpr_not(A, Bools, St, Line);
 gexpr(E0, Bools, St0) ->
     gexpr_test(E0, Bools, St0).
 
+%% gexpr_not(L, R, Bools, State) -> {Cexpr,[PreExp],Bools,State}.
+%%  Generate a guard for boolean operators
+
+gexpr_bool(Op, L, R, Bools0, St0, Line) ->
+    {Le,Lps,Bools1,St1} = gexpr(L, Bools0, St0),
+    {Ll,Llps,St2} = force_safe(Le, St1),
+    {Re,Rps,Bools,St3} = gexpr(R, Bools1, St2),
+    {Rl,Rlps,St4} = force_safe(Re, St3),
+    Anno = lineno_anno(Line, St4),
+    {#icall{anno=#a{anno=Anno}, %Must have an #a{}
+            module=#c_literal{anno=Anno,val=erlang},
+            name=#c_literal{anno=Anno,val=Op},
+            args=[Ll,Rl]},Lps ++ Llps ++ Rps ++ Rlps,Bools,St4}.
+
+%% gexpr_not(Expr, Bools, State) -> {Cexpr,[PreExp],Bools,State}.
+%%  Generate an erlang:'not'/1 guard test.
+
+gexpr_not(A, Bools0, St0, Line) ->
+    {Ae0,Aps,Bools,St1} = gexpr(A, Bools0, St0),
+    case Ae0 of
+        #icall{module=#c_literal{val=erlang},
+               name=#c_literal{val='=:='},
+               args=[E,#c_literal{val=true}]}=EqCall ->
+            %%
+            %% Doing the following transformation
+            %%    not(Expr =:= true)  ==>  Expr =:= false
+            %% will help eliminating redundant is_boolean/1 tests.
+            %%
+            Ae = EqCall#icall{args=[E,#c_literal{val=false}]},
+            {Al,Alps,St2} = force_safe(Ae, St1),
+            {Al,Aps ++ Alps,Bools,St2};
+        Ae ->
+            {Al,Alps,St2} = force_safe(Ae, St1),
+            Anno = lineno_anno(Line, St2),
+            {#icall{anno=#a{anno=Anno}, %Must have an #a{}
+                    module=#c_literal{anno=Anno,val=erlang},
+                    name=#c_literal{anno=Anno,val='not'},
+                    args=[Al]},Aps ++ Alps,Bools,St2}
+    end.
+
 %% gexpr_test(Expr, Bools, State) -> {Cexpr,[PreExp],Bools,State}.
 %%  Generate a guard test.  At this stage we must be sure that we have
 %%  a proper boolean value here so wrap things with an true test if we
@@ -330,39 +382,37 @@ gexpr_test(E0, Bools0, St0) ->
 	#icall{anno=Anno,module=#c_literal{val=erlang},name=#c_literal{val=N},args=As} ->
 	    Ar = length(As),
 	    case erl_internal:type_test(N, Ar) orelse
-		erl_internal:comp_op(N, Ar) of
+                erl_internal:comp_op(N, Ar) orelse
+                erl_internal:bool_op(N, Ar) of
 		true -> {E1,Eps0,Bools0,St1};
 		false ->
 		    Lanno = Anno#a.anno,
 		    {New,St2} = new_var(Lanno, St1),
 		    Bools = [New|Bools0],
-		    {#icall{anno=Anno,	%Must have an #a{}
-			    module=#c_literal{anno=Lanno,val=erlang},
-			    name=#c_literal{anno=Lanno,val='=:='},
-			    args=[New,#c_literal{anno=Lanno,val=true}]},
+		    {icall_eq_true(New),
 		     Eps0 ++ [#iset{anno=Anno,var=New,arg=E1}],Bools,St2}
 	    end;
 	_ ->
-	    Anno = get_ianno(E1),
 	    Lanno = get_lineno_anno(E1),
+	    ACompGen = #a{anno=[compiler_generated]},
 	    case is_simple(E1) of
 		true ->
 		    Bools = [E1|Bools0],
-		    {#icall{anno=Anno,	%Must have an #a{}
-			    module=#c_literal{anno=Lanno,val=erlang},
-			    name=#c_literal{anno=Lanno,val='=:='},
-			    args=[E1,#c_literal{anno=Lanno,val=true}]},Eps0,Bools,St1};
+		    {icall_eq_true(E1),Eps0,Bools,St1};
 		false ->
 		    {New,St2} = new_var(Lanno, St1),
 		    Bools = [New|Bools0],
-		    {#icall{anno=Anno,	%Must have an #a{}
-			    module=#c_literal{anno=Lanno,val=erlang},
-			    name=#c_literal{anno=Lanno,val='=:='},
-			    args=[New,#c_literal{anno=Lanno,val=true}]},
-		     Eps0 ++ [#iset{anno=Anno,var=New,arg=E1}],Bools,St2}
+		    {icall_eq_true(New),
+		     Eps0 ++ [#iset{anno=ACompGen,var=New,arg=E1}],Bools,St2}
 	    end
     end.
 
+icall_eq_true(Arg) ->
+    #icall{anno=#a{anno=[compiler_generated]},
+	   module=#c_literal{val=erlang},
+	   name=#c_literal{val='=:='},
+	   args=[Arg,#c_literal{val=true}]}.
+
 force_booleans(Vs0, E, Eps, St) ->
     Vs1 = [set_anno(V, []) || V <- Vs0],
     Vs = unforce(E, Eps, Vs1),
@@ -372,16 +422,15 @@ force_booleans_1([], E, Eps, St) ->
     {E,Eps,St};
 force_booleans_1([V|Vs], E0, Eps0, St0) ->
     {E1,Eps1,St1} = force_safe(E0, St0),
-    Lanno = element(2, V),
-    Anno = #a{anno=Lanno},
-    Call = #icall{anno=Anno,module=#c_literal{anno=Lanno,val=erlang},
-		  name=#c_literal{anno=Lanno,val=is_boolean},
+    ACompGen = #a{anno=[compiler_generated]},
+    Call = #icall{anno=ACompGen,module=#c_literal{val=erlang},
+		  name=#c_literal{val=is_boolean},
 		  args=[V]},
-    {New,St} = new_var(Lanno, St1),
-    Iset = #iset{anno=Anno,var=New,arg=Call},
+    {New,St} = new_var([], St1),
+    Iset = #iset{var=New,arg=Call},
     Eps = Eps0 ++ Eps1 ++ [Iset],
-    E = #icall{anno=Anno,
-	       module=#c_literal{anno=Lanno,val=erlang},name=#c_literal{anno=Lanno,val='and'},
+    E = #icall{anno=ACompGen,
+	       module=#c_literal{val=erlang},name=#c_literal{val='and'},
 	       args=[E1,New]},
     force_booleans_1(Vs, E, Eps, St).
 
@@ -420,7 +469,8 @@ unforce_tree([#iset{var=#c_var{name=V},arg=Arg0}|Es], D0) ->
     unforce_tree(Es, D);
 unforce_tree([#icall{}=Call], D) ->
     unforce_tree_subst(Call, D);
-unforce_tree([Top], _) -> Top.
+unforce_tree([#c_var{name=V}], D) ->
+    gb_trees:get(V, D).
 
 unforce_tree_subst(#icall{module=#c_literal{val=erlang},
 			  name=#c_literal{val='=:='},
@@ -468,27 +518,32 @@ exprs([], St) -> {[],St}.
 %%  Generate an internal core expression.
 
 expr({var,L,V}, St) -> {#c_var{anno=lineno_anno(L, St),name=V},[],St};
-expr({char,L,C}, St) -> {#c_literal{anno=lineno_anno(L, St),val=C},[],St};
-expr({integer,L,I}, St) -> {#c_literal{anno=lineno_anno(L, St),val=I},[],St};
-expr({float,L,F}, St) -> {#c_literal{anno=lineno_anno(L, St),val=F},[],St};
-expr({atom,L,A}, St) -> {#c_literal{anno=lineno_anno(L, St),val=A},[],St};
-expr({nil,L}, St) -> {#c_literal{anno=lineno_anno(L, St),val=[]},[],St};
-expr({string,L,S}, St) -> {#c_literal{anno=lineno_anno(L, St),val=S},[],St};
+expr({char,L,C}, St) -> {#c_literal{anno=full_anno(L, St),val=C},[],St};
+expr({integer,L,I}, St) -> {#c_literal{anno=full_anno(L, St),val=I},[],St};
+expr({float,L,F}, St) -> {#c_literal{anno=full_anno(L, St),val=F},[],St};
+expr({atom,L,A}, St) -> {#c_literal{anno=full_anno(L, St),val=A},[],St};
+expr({nil,L}, St) -> {#c_literal{anno=full_anno(L, St),val=[]},[],St};
+expr({string,L,S}, St) -> {#c_literal{anno=full_anno(L, St),val=S},[],St};
 expr({cons,L,H0,T0}, St0) ->
     {H1,Hps,St1} = safe(H0, St0),
     {T1,Tps,St2} = safe(T0, St1),
-    A = lineno_anno(L, St2),
-    {ann_c_cons(A, H1, T1),Hps ++ Tps,St2};
-expr({lc,L,E,Qs}, St) ->
-    lc_tq(L, E, Qs, #c_literal{anno=lineno_anno(L, St),val=[]}, St);
+    A = full_anno(L, St2),
+    {annotate_cons(A, H1, T1, St2),Hps ++ Tps,St2};
+expr({lc,L,E,Qs0}, St0) ->
+    {Qs1,St1} = preprocess_quals(L, Qs0, St0),
+    lc_tq(L, E, Qs1, #c_literal{anno=lineno_anno(L, St1),val=[]}, St1);
 expr({bc,L,E,Qs}, St) ->
-    bc_tq(L, E, Qs, {nil,L}, St);
+    bc_tq(L, E, Qs, St);
 expr({tuple,L,Es0}, St0) ->
     {Es1,Eps,St1} = safe_list(Es0, St0),
-    A = lineno_anno(L, St1),
-    {ann_c_tuple(A, Es1),Eps,St1};
+    A = record_anno(L, St1),
+    {annotate_tuple(A, Es1, St1),Eps,St1};
+expr({map,L,Es0}, St0) ->
+    map_build_pairs(#c_literal{val=#{}}, Es0, full_anno(L, St0), St0);
+expr({map,L,M,Es}, St) ->
+    expr_map(M, Es, L, St);
 expr({bin,L,Es0}, St0) ->
-    try expr_bin(Es0, lineno_anno(L, St0), St0) of
+    try expr_bin(Es0, full_anno(L, St0), St0) of
 	{_,_,_}=Res -> Res
     catch
 	throw:bad_binary ->
@@ -502,30 +557,30 @@ expr({bin,L,Es0}, St0) ->
     end;
 expr({block,_,Es0}, St0) ->
     %% Inline the block directly.
-    {Es1,St1} = exprs(first(Es0), St0),
+    {Es1,St1} = exprs(droplast(Es0), St0),
     {E1,Eps,St2} = expr(last(Es0), St1),
     {E1,Es1 ++ Eps,St2};
 expr({'if',L,Cs0}, St0) ->
-    {Cs1,St1} = clauses(Cs0, St0),
+    {Cs1,Ceps,St1} = clauses(Cs0, St0),
     Lanno = lineno_anno(L, St1),
     Fc = fail_clause([], Lanno, #c_literal{val=if_clause}),
-    {#icase{anno=#a{anno=Lanno},args=[],clauses=Cs1,fc=Fc},[],St1};
+    {#icase{anno=#a{anno=Lanno},args=[],clauses=Cs1,fc=Fc},Ceps,St1};
 expr({'case',L,E0,Cs0}, St0) ->
     {E1,Eps,St1} = novars(E0, St0),
-    {Cs1,St2} = clauses(Cs0, St1),
+    {Cs1,Ceps,St2} = clauses(Cs0, St1),
     {Fpat,St3} = new_var(St2),
     Lanno = lineno_anno(L, St2),
     Fc = fail_clause([Fpat], Lanno, c_tuple([#c_literal{val=case_clause},Fpat])),
-    {#icase{anno=#a{anno=Lanno},args=[E1],clauses=Cs1,fc=Fc},Eps,St3};
+    {#icase{anno=#a{anno=Lanno},args=[E1],clauses=Cs1,fc=Fc},Eps++Ceps,St3};
 expr({'receive',L,Cs0}, St0) ->
-    {Cs1,St1} = clauses(Cs0, St0),
-    {#ireceive1{anno=#a{anno=lineno_anno(L, St1)},clauses=Cs1}, [], St1};
+    {Cs1,Ceps,St1} = clauses(Cs0, St0),
+    {#ireceive1{anno=#a{anno=lineno_anno(L, St1)},clauses=Cs1},Ceps, St1};
 expr({'receive',L,Cs0,Te0,Tes0}, St0) ->
     {Te1,Teps,St1} = novars(Te0, St0),
     {Tes1,St2} = exprs(Tes0, St1),
-    {Cs1,St3} = clauses(Cs0, St2),
+    {Cs1,Ceps,St3} = clauses(Cs0, St2),
     {#ireceive2{anno=#a{anno=lineno_anno(L, St3)},
-		clauses=Cs1,timeout=Te1,action=Tes1},Teps,St3};
+		clauses=Cs1,timeout=Te1,action=Tes1},Teps++Ceps,St3};
 expr({'try',L,Es0,[],Ecs,[]}, St0) ->
     %% 'try ... catch ... end'
     {Es1,St1} = exprs(Es0, St0),
@@ -539,7 +594,7 @@ expr({'try',L,Es0,Cs0,Ecs,[]}, St0) ->
     %% 'try ... of ... catch ... end'
     {Es1,St1} = exprs(Es0, St0),
     {V,St2} = new_var(St1),		%This name should be arbitrary
-    {Cs1,St3} = clauses(Cs0, St2),
+    {Cs1,Ceps,St3} = clauses(Cs0, St2),
     {Fpat,St4} = new_var(St3),
     Lanno = lineno_anno(L, St4),
     Fc = fail_clause([Fpat], Lanno,
@@ -548,21 +603,28 @@ expr({'try',L,Es0,Cs0,Ecs,[]}, St0) ->
     {#itry{anno=#a{anno=lineno_anno(L, St5)},args=Es1,
 	   vars=[V],body=[#icase{anno=#a{anno=Lanno},args=[V],clauses=Cs1,fc=Fc}],
 	   evars=Evs,handler=Hs},
-     [],St5};
+     Ceps,St5};
 expr({'try',L,Es0,[],[],As0}, St0) ->
     %% 'try ... after ... end'
     {Es1,St1} = exprs(Es0, St0),
     {As1,St2} = exprs(As0, St1),
-    {Evs,Hs0,St3} = try_after(As1, St2),
-    %% We must kill the id for any funs in the duplicated after body,
-    %% to avoid getting two local functions having the same name.
-    Hs = kill_id_anns(Hs0),
+    {Name,St3} = new_fun_name("after", St2),
     {V,St4} = new_var(St3),		% (must not exist in As1)
-    %% TODO: this duplicates the 'after'-code; should lift to function.
-    Lanno = lineno_anno(L, St4),
-    {#itry{anno=#a{anno=Lanno},args=Es1,vars=[V],body=As1++[V],
-	   evars=Evs,handler=Hs},
-     [],St4};
+    LA = lineno_anno(L, St4),
+    Lanno = #a{anno=LA},
+    Fc = function_clause([], LA, {Name,0}),
+    Fun = #ifun{anno=Lanno,id=[],vars=[],
+		clauses=[#iclause{anno=Lanno,pats=[],
+				  guard=[#c_literal{val=true}],
+				  body=As1}],
+		fc=Fc},
+    App = #iapply{anno=#a{anno=[compiler_generated|LA]},
+		  op=#c_var{anno=LA,name={Name,0}},args=[]},
+    {Evs,Hs,St5} = try_after([App], St4),
+    Try = #itry{anno=Lanno,args=Es1,vars=[V],body=[App,V],evars=Evs,handler=Hs},
+    Letrec = #iletrec{anno=Lanno,defs=[{{Name,0},Fun}],
+		      body=[Try]},
+    {Letrec,[],St5};
 expr({'try',L,Es,Cs,Ecs,As}, St0) ->
     %% 'try ... [of ...] [catch ...] after ... end'
     expr({'try',L,[{'try',L,Es,Cs,Ecs,[]}],[],[],As}, St0);
@@ -571,31 +633,31 @@ expr({'catch',L,E0}, St0) ->
     Lanno = lineno_anno(L, St1),
     {#icatch{anno=#a{anno=Lanno},body=Eps ++ [E1]},[],St1};
 expr({'fun',L,{function,F,A},{_,_,_}=Id}, St) ->
-    Lanno = lineno_anno(L, St),
+    Lanno = full_anno(L, St),
     {#c_var{anno=Lanno++[{id,Id}],name={F,A}},[],St};
 expr({'fun',L,{function,M,F,A}}, St0) ->
     {As,Aps,St1} = safe_list([M,F,A], St0),
-    Lanno = lineno_anno(L, St1),
+    Lanno = full_anno(L, St1),
     {#icall{anno=#a{anno=Lanno},
 	    module=#c_literal{val=erlang},
 	    name=#c_literal{val=make_fun},
 	    args=As},Aps,St1};
 expr({'fun',L,{clauses,Cs},Id}, St) ->
-    fun_tq(Id, Cs, L, St);
-expr({call,L,{remote,_,M,F},As0}, #core{wanted=Wanted}=St0) ->
+    fun_tq(Id, Cs, L, St, unnamed);
+expr({named_fun,L,'_',Cs,Id}, St) ->
+    fun_tq(Id, Cs, L, St, unnamed);
+expr({named_fun,L,Name,Cs,Id}, St) ->
+    fun_tq(Id, Cs, L, St, {named,Name});
+expr({call,L,{remote,_,M,F},As0}, St0) ->
     {[M1,F1|As1],Aps,St1} = safe_list([M,F|As0], St0),
-    Lanno = lineno_anno(L, St1),
-    Anno = case Wanted of
-	       false -> [result_not_wanted|Lanno];
-	       true -> Lanno
-	   end,
+    Anno = full_anno(L, St1),
     {#icall{anno=#a{anno=Anno},module=M1,name=F1,args=As1},Aps,St1};
 expr({call,Lc,{atom,Lf,F},As0}, St0) ->
     {As1,Aps,St1} = safe_list(As0, St0),
     Op = #c_var{anno=lineno_anno(Lf, St1),name={F,length(As1)}},
     {#iapply{anno=#a{anno=lineno_anno(Lc, St1)},op=Op,args=As1},Aps,St1};
 expr({call,L,FunExp,As0}, St0) ->
-    {Fun,Fps,St1} = safe(FunExp, St0),
+    {Fun,Fps,St1} = safe_fun(length(As0), FunExp, St0),
     {As1,Aps,St2} = safe_list(As0, St1),
     Lanno = lineno_anno(L, St2),
     {#iapply{anno=#a{anno=Lanno},op=Fun,args=As1},Fps ++ Aps,St2};
@@ -606,26 +668,53 @@ expr({match,L,P0,E0}, St0) ->
 	      {var,_,'_'} -> St0#core{wanted=false};
 	      _ -> St0
 	  end,
-    {E2,Eps,St2} = novars(E1, St1),
+    {E2,Eps1,St2} = novars(E1, St1),
     St3 = St2#core{wanted=St0#core.wanted},
-    P2 = try
-	     pattern(P1, St3)
+    {P2,Eps2,St4} = try
+	    pattern(P1, St3)
 	 catch
 	     throw:Thrown ->
-		 Thrown
+		{Thrown,[],St3}
 	 end,
-    {Fpat,St4} = new_var(St3),
-    Lanno = lineno_anno(L, St4),
+    {Fpat,St5} = new_var(St4),
+    Lanno = lineno_anno(L, St5),
     Fc = fail_clause([Fpat], Lanno, c_tuple([#c_literal{val=badmatch},Fpat])),
     case P2 of
 	nomatch ->
-	    St = add_warning(L, nomatch, St4),
-	    {#icase{anno=#a{anno=Lanno},
-		    args=[E2],clauses=[],fc=Fc},Eps,St};
+	    %% The pattern will not match. We must take care here to
+	    %% bind all variables that the pattern would have bound
+	    %% so that subsequent expressions do not refer to unbound
+	    %% variables.
+	    %%
+	    %% As an example, this code:
+	    %%
+	    %%   [X] = {Y} = E,
+	    %%   X + Y.
+	    %%
+	    %% will be rewritten to:
+	    %%
+	    %%   error({badmatch,E}),
+	    %%   case E of
+	    %%      {[X],{Y}} ->
+	    %%        X + Y;
+	    %%      Other ->
+	    %%        error({badmatch,Other})
+	    %%   end.
+	    %%
+	    St6 = add_warning(L, nomatch, St5),
+	    {Expr,Eps3,St7} = safe(E1, St6),
+	    SanPat0 = sanitize(P1),
+	    {SanPat,Eps4,St} = pattern(SanPat0, St7),
+	    Badmatch = c_tuple([#c_literal{val=badmatch},Expr]),
+	    Fail = #iprimop{anno=#a{anno=Lanno},
+			    name=#c_literal{val=match_fail},
+			    args=[Badmatch]},
+	    Eps = Eps3 ++ Eps4 ++ [Fail],
+	    {#imatch{anno=#a{anno=Lanno},pat=SanPat,arg=Expr,fc=Fc},Eps,St};
 	Other when not is_atom(Other) ->
-	    {#imatch{anno=#a{anno=Lanno},pat=P2,arg=E2,fc=Fc},Eps,St4}
+	    {#imatch{anno=#a{anno=Lanno},pat=P2,arg=E2,fc=Fc},Eps1++Eps2,St5}
     end;
-expr({op,_,'++',{lc,Llc,E,Qs},More}, St0) ->
+expr({op,_,'++',{lc,Llc,E,Qs0},More}, St0) ->
     %% Optimise '++' here because of the list comprehension algorithm.
     %%
     %% To avoid achieving quadratic complexity if there is a chain of
@@ -633,40 +722,69 @@ expr({op,_,'++',{lc,Llc,E,Qs},More}, St0) ->
     %% evaluation of More now. Evaluating More here could also reduce the
     %% number variables in the environment for letrec.
     {Mc,Mps,St1} = safe(More, St0),
-    {Y,Yps,St} = lc_tq(Llc, E, Qs, Mc, St1),
+    {Qs,St2} = preprocess_quals(Llc, Qs0, St1),
+    {Y,Yps,St} = lc_tq(Llc, E, Qs, Mc, St2),
     {Y,Mps++Yps,St};
 expr({op,L,'andalso',E1,E2}, St0) ->
-    {#c_var{name=V0},St} = new_var(L, St0),
+    Anno = lineno_anno(L, St0),
+    {#c_var{name=V0},St} = new_var(Anno, St0),
     V = {var,L,V0},
     False = {atom,L,false},
     E = make_bool_switch(L, E1, V, E2, False, St0),
     expr(E, St);
 expr({op,L,'orelse',E1,E2}, St0) ->
-    {#c_var{name=V0},St} = new_var(L, St0),
+    Anno = lineno_anno(L, St0),
+    {#c_var{name=V0},St} = new_var(Anno, St0),
     V = {var,L,V0},
     True = {atom,L,true},
     E = make_bool_switch(L, E1, V, True, E2, St0),
     expr(E, St);
 expr({op,L,Op,A0}, St0) ->
     {A1,Aps,St1} = safe(A0, St0),
-    LineAnno = lineno_anno(L, St1),
+    LineAnno = full_anno(L, St1),
     {#icall{anno=#a{anno=LineAnno},		%Must have an #a{}
 	    module=#c_literal{anno=LineAnno,val=erlang},
 	    name=#c_literal{anno=LineAnno,val=Op},args=[A1]},Aps,St1};
 expr({op,L,Op,L0,R0}, St0) ->
     {As,Aps,St1} = safe_list([L0,R0], St0),
-    LineAnno = lineno_anno(L, St1),
+    LineAnno = full_anno(L, St1),
     {#icall{anno=#a{anno=LineAnno},		%Must have an #a{}
 	    module=#c_literal{anno=LineAnno,val=erlang},
 	    name=#c_literal{anno=LineAnno,val=Op},args=As},Aps,St1}.
 
+
+%% sanitize(Pat) -> SanitizedPattern
+%%  Rewrite Pat so that it will be accepted by pattern/2 and will
+%%  bind the same variables as the original pattern.
+%%
+%%  Here is an example of a pattern that would cause a pattern/2
+%%  to generate a 'nomatch' exception:
+%%
+%%      #{k:=X,k:=Y} = [Z]
+%%
+%%  The sanitized pattern will look like:
+%%
+%%      {{X,Y},[Z]}
+
+sanitize({match,L,P1,P2}) ->
+    {tuple,L,[sanitize(P1),sanitize(P2)]};
+sanitize({cons,L,H,T}) ->
+    {cons,L,sanitize(H),sanitize(T)};
+sanitize({tuple,L,Ps0}) ->
+    Ps = [sanitize(P) || P <- Ps0],
+    {tuple,L,Ps};
+sanitize({map,L,Ps0}) ->
+    Ps = [sanitize(V) || {map_field_exact,_,_,V} <- Ps0],
+    {tuple,L,Ps};
+sanitize(P) -> P.
+
 make_bool_switch(L, E, V, T, F, #core{in_guard=true}) ->
     make_bool_switch_guard(L, E, V, T, F);
 make_bool_switch(L, E, V, T, F, #core{}) ->
     make_bool_switch_body(L, E, V, T, F).
 
 make_bool_switch_body(L, E, V, T, F) ->
-    NegL = neg_line(abs_line(L)),
+    NegL = no_compiler_warning(L),
     Error = {tuple,NegL,[{atom,NegL,badarg},V]},
     {'case',NegL,E,
      [{clause,NegL,[{atom,NegL,true}],[],[T]},
@@ -677,36 +795,98 @@ make_bool_switch_body(L, E, V, T, F) ->
 
 make_bool_switch_guard(_, E, _, {atom,_,true}, {atom,_,false}) -> E;
 make_bool_switch_guard(L, E, V, T, F) ->
-    NegL = neg_line(abs_line(L)),
+    NegL = no_compiler_warning(L),
     {'case',NegL,E,
      [{clause,NegL,[{atom,NegL,true}],[],[T]},
       {clause,NegL,[{atom,NegL,false}],[],[F]},
       {clause,NegL,[V],[],[V]}
      ]}.
 
+expr_map(M0, Es0, L, St0) ->
+    {M1,Eps0,St1} = safe(M0, St0),
+    Badmap = badmap_term(M1, St1),
+    A = lineno_anno(L, St1),
+    Fc = fail_clause([], [{eval_failure,badmap}|A], Badmap),
+    case is_valid_map_src(M1) of
+	true ->
+	    {M2,Eps1,St2} = map_build_pairs(M1, Es0, full_anno(L, St1), St1),
+	    M3 = case Es0 of
+		     [] -> M1;
+		     [_|_] -> M2
+		 end,
+	    Cs = [#iclause{
+		     anno=#a{anno=[compiler_generated|A]},
+		     pats=[],
+		     guard=[#icall{anno=#a{anno=A},
+				   module=#c_literal{anno=A,val=erlang},
+			           name=#c_literal{anno=A,val=is_map},
+				   args=[M1]}],
+		     body=[M3]}],
+	    Eps = Eps0 ++ Eps1,
+	    {#icase{anno=#a{anno=A},args=[],clauses=Cs,fc=Fc},Eps,St2};
+	false ->
+	    %% Not a map source. The update will always fail.
+	    St2 = add_warning(L, badmap, St1),
+	    #iclause{body=[Fail]} = Fc,
+	    {Fail,Eps0,St2}
+    end.
+
+badmap_term(_Map, #core{in_guard=true}) ->
+    %% The code generator cannot handle complex error reasons
+    %% in guards. But the exact error reason does not matter anyway
+    %% since it is not user-visible.
+    #c_literal{val=badmap};
+badmap_term(Map, #core{in_guard=false}) ->
+    c_tuple([#c_literal{val=badmap},Map]).
+
+map_build_pairs(Map, Es0, Ann, St0) ->
+    {Es,Pre,St1} = map_build_pairs_1(Es0, St0),
+    {ann_c_map(Ann, Map, Es),Pre,St1}.
+
+map_build_pairs_1([{Op0,L,K0,V0}|Es], St0) ->
+    {K,Pre0,St1} = safe(K0, St0),
+    {V,Pre1,St2} = safe(V0, St1),
+    {Pairs,Pre2,St3} = map_build_pairs_1(Es, St2),
+    As = lineno_anno(L, St3),
+    Op = map_op(Op0),
+    Pair = cerl:ann_c_map_pair(As, Op, K, V),
+    {[Pair|Pairs],Pre0++Pre1++Pre2,St3};
+map_build_pairs_1([], St) ->
+    {[],[],St}.
+
+map_op(map_field_assoc) -> #c_literal{val=assoc};
+map_op(map_field_exact) -> #c_literal{val=exact}.
+
+is_valid_map_src(#c_literal{val = M}) when is_map(M) -> true;
+is_valid_map_src(#c_var{}=Var)  -> not cerl:is_c_fname(Var);
+is_valid_map_src(_)         -> false.
 
 %% try_exception([ExcpClause], St) -> {[ExcpVar],Handler,St}.
 
 try_exception(Ecs0, St0) ->
     %% Note that Tag is not needed for rethrow - it is already in Info.
     {Evs,St1} = new_vars(3, St0), % Tag, Value, Info
-    {Ecs1,St2} = clauses(Ecs0, St1),
+    {Ecs1,Ceps,St2} = clauses(Ecs0, St1),
     [_,Value,Info] = Evs,
-    Ec = #iclause{anno=#a{anno=[compiler_generated]},
+    LA = case Ecs1 of
+	     [] -> [];
+	     [C|_] -> get_lineno_anno(C)
+	 end,
+    Ec = #iclause{anno=#a{anno=[compiler_generated|LA]},
 		  pats=[c_tuple(Evs)],guard=[#c_literal{val=true}],
 		  body=[#iprimop{anno=#a{},       %Must have an #a{}
 				 name=#c_literal{val=raise},
 				 args=[Info,Value]}]},
-    Hs = [#icase{anno=#a{},args=[c_tuple(Evs)],clauses=Ecs1,fc=Ec}],
-    {Evs,Hs,St2}.
+    Hs = [#icase{anno=#a{anno=LA},args=[c_tuple(Evs)],clauses=Ecs1,fc=Ec}],
+    {Evs,Ceps++Hs,St2}.
 
 try_after(As, St0) ->
     %% See above.
-    {Evs,St1} = new_vars(3, St0),		% Tag, Value, Info
+    {Evs,St1} = new_vars(3, St0),	 % Tag, Value, Info
     [_,Value,Info] = Evs,
-    B = As ++ [#iprimop{anno=#a{},       %Must have an #a{}
-			 name=#c_literal{val=raise},
-			 args=[Info,Value]}],
+    B = As ++ [#iprimop{anno=#a{},       % Must have an #a{}
+			name=#c_literal{val=raise},
+			args=[Info,Value]}],
     Ec = #iclause{anno=#a{anno=[compiler_generated]},
 		  pats=[c_tuple(Evs)],guard=[#c_literal{val=true}],
 		  body=B},
@@ -748,10 +928,10 @@ constant_bin_1(Es) ->
 		 ({float,_,F}, B) -> {value,F,B};
 		 ({atom,_,undefined}, B) -> {value,undefined,B}
 	      end,
-    case catch eval_bits:expr_grp(Es, EmptyBindings, EvalFun) of
+    try eval_bits:expr_grp(Es, EmptyBindings, EvalFun) of
 	{value,Bin,EmptyBindings} ->
-	    Bin;
-	_ ->
+	    Bin
+    catch error:_ ->
 	    error
     end.
 
@@ -798,7 +978,7 @@ verify_suitable_fields([]) -> ok.
 %% (We don't need an exact result for this purpose.)
 
 count_bits(Int) -> 
-    count_bits_1(abs_line(Int), 64).
+    count_bits_1(abs(Int), 64).
 
 count_bits_1(0, Bits) -> Bits;
 count_bits_1(Int, Bits) -> count_bits_1(Int bsr 64, Bits+64).
@@ -836,148 +1016,62 @@ bitstr({bin_element,_,E0,Size0,[Type,{unit,Unit}|Flags]}, St0) ->
 	       flags=#c_literal{val=Flags}},
      Eps ++ Eps2,St2}.
 
-%% fun_tq(Id, [Clauses], Line, State) -> {Fun,[PreExp],State}.
+%% fun_tq(Id, [Clauses], Line, State, NameInfo) -> {Fun,[PreExp],State}.
 
-fun_tq({_,_,Name}=Id, Cs0, L, St0) ->
+fun_tq({_,_,Name}=Id, Cs0, L, St0, NameInfo) ->
     Arity = clause_arity(hd(Cs0)),
-    {Cs1,St1} = clauses(Cs0, St0),
+    {Cs1,Ceps,St1} = clauses(Cs0, St0),
     {Args,St2} = new_vars(Arity, St1),
     {Ps,St3} = new_vars(Arity, St2),		%Need new variables here
-    Anno = lineno_anno(L, St3),
+    Anno = full_anno(L, St3),
     Fc = function_clause(Ps, Anno, {Name,Arity}),
     Fun = #ifun{anno=#a{anno=Anno},
 		id=[{id,Id}],				%We KNOW!
-		vars=Args,clauses=Cs1,fc=Fc},
-    {Fun,[],St3}.
+		vars=Args,clauses=Cs1,fc=Fc,name=NameInfo},
+    {Fun,Ceps,St3}.
 
 %% lc_tq(Line, Exp, [Qualifier], Mc, State) -> {LetRec,[PreExp],State}.
 %%  This TQ from Simon PJ pp 127-138.  
-%%  This gets a bit messy as we must transform all directly here.  We
-%%  recognise guard tests and try to fold them together and join to a
-%%  preceding generators, this should give us better and more compact
-%%  code.
 
-lc_tq(Line, E, [{generate,Lg,P,G}|Qs0], Mc, St0) ->
-    {Gs,Qs1} =  splitwith(fun is_guard_test/1, Qs0),
+lc_tq(Line, E, [#igen{anno=GAnno,ceps=Ceps,
+		      acc_pat=AccPat,acc_guard=AccGuard,
+                      skip_pat=SkipPat,tail=Tail,tail_pat=TailPat,
+                      arg={Pre,Arg}}|Qs], Mc, St0) ->
     {Name,St1} = new_fun_name("lc", St0),
-    {Head,St2} = new_var(St1),
-    {Tname,St3} = new_var_name(St2),
-    LA = lineno_anno(Line, St3),
-    LAnno = #a{anno=LA},
-    Tail = #c_var{anno=LA,name=Tname},
-    {Arg,St4} = new_var(St3),
-    {Nc,[],St5} = expr({call,Lg,{atom,Lg,Name},[{var,Lg,Tname}]}, St4),
-    {Guardc,St6} = lc_guard_tests(Gs, St5),	%These are always flat!
-    {Lc,Lps,St7} = lc_tq(Line, E, Qs1, Nc, St6),
-    {Pc,St8} = list_gen_pattern(P, Line, St7),
-    {Gc,Gps,St9} = safe(G, St8),		%Will be a function argument!
-    Fc = function_clause([Arg], LA, {Name,1}),
-
-    %% Avoid constructing a default clause if the list comprehension
-    %% only has a variable as generator and there are no guard
-    %% tests. In other words, if the comprehension is equivalent to
-    %% lists:map/2.
-    Cs0 = case {Guardc, Pc} of
-	      {[], #c_var{}} ->
-		  [#iclause{anno=LAnno,
-			    pats=[#c_literal{anno=LA,val=[]}],guard=[],
-			    body=[Mc]}];
-	      _ ->
-		  [#iclause{anno=#a{anno=[compiler_generated|LA]},
-			    pats=[ann_c_cons(LA, Head, Tail)],
-			    guard=[],
-			    body=[Nc]},
-		   #iclause{anno=LAnno,
-			    pats=[#c_literal{anno=LA,val=[]}],guard=[],
-			    body=[Mc]}]
-	  end,
-    Cs = case Pc of
-	     nomatch -> Cs0;
-	     _ ->
-		 [#iclause{anno=LAnno,
-			   pats=[ann_c_cons(LA, Pc, Tail)],
-			   guard=Guardc,
-			   body=Lps ++ [Lc]}|Cs0]
-	 end,
-    Fun = #ifun{anno=LAnno,id=[],vars=[Arg],clauses=Cs,fc=Fc},
-    {#iletrec{anno=LAnno,defs=[{{Name,1},Fun}],
-	      body=Gps ++ [#iapply{anno=LAnno,
-				   op=#c_var{anno=LA,name={Name,1}},
-				   args=[Gc]}]},
-     [],St9};
-lc_tq(Line, E, [{b_generate,Lg,P,G}|Qs0], Mc, St0) ->
-    {Gs,Qs1} =  splitwith(fun is_guard_test/1, Qs0),
-    {Name,St1} = new_fun_name("blc", St0),
     LA = lineno_anno(Line, St1),
     LAnno = #a{anno=LA},
-    HeadBinPattern = pattern(P, St1),
-    #c_binary{segments=Ps0} = HeadBinPattern,
-    {Ps,Tail,St2} = append_tail_segment(Ps0, St1),
-    {EPs,St3} = emasculate_segments(Ps, St2),
-    Pattern = HeadBinPattern#c_binary{segments=Ps},
-    EPattern = HeadBinPattern#c_binary{segments=EPs},
-    {Arg,St4} = new_var(St3),
-    {Guardc,St5} = lc_guard_tests(Gs, St4),	%These are always flat!
-    Tname = Tail#c_var.name,
-    {Nc,[],St6} = expr({call,Lg,{atom,Lg,Name},[{var,Lg,Tname}]}, St5),
-    {Bc,Bps,St7} = lc_tq(Line, E, Qs1, Nc, St6),
-    {Gc,Gps,St10} = safe(G, St7),		%Will be a function argument!
-    Fc = function_clause([Arg], LA, {Name,1}),
-    {TailSegList,_,St} = append_tail_segment([], St10),
-    Cs = [#iclause{anno=#a{anno=[compiler_generated|LA]},
-		   pats=[Pattern],
-		   guard=Guardc,
-		   body=Bps ++ [Bc]},
-	  #iclause{anno=#a{anno=[compiler_generated|LA]},
-		   pats=[EPattern],
-		   guard=[],
-		   body=[#iapply{anno=LAnno,
-				 op=#c_var{anno=LA,name={Name,1}},
-				 args=[Tail]}]},
-	  #iclause{anno=LAnno,
-		   pats=[#c_binary{anno=LA,segments=TailSegList}],guard=[],
-		   body=[Mc]}],
-    Fun = #ifun{anno=LAnno,id=[],vars=[Arg],clauses=Cs,fc=Fc},
-    {#iletrec{anno=LAnno,defs=[{{Name,1},Fun}],
-	      body=Gps ++ [#iapply{anno=LAnno,
-				   op=#c_var{anno=LA,name={Name,1}},
-				   args=[Gc]}]},
-     [],St};
-lc_tq(Line, E, [Fil0|Qs0], Mc, St0) ->
-    %% Special case sequences guard tests.
-    LA = lineno_anno(element(2, Fil0), St0),
-    LAnno = #a{anno=LA},
-    case is_guard_test(Fil0) of
-	true ->
-	    {Gs0,Qs1} = splitwith(fun is_guard_test/1, Qs0),
-	    {Lc,Lps,St1} = lc_tq(Line, E, Qs1, Mc, St0),
-	    {Gs,St2} = lc_guard_tests([Fil0|Gs0], St1), %These are always flat!
-	    {#icase{anno=LAnno,
-		    args=[],
-		    clauses=[#iclause{anno=LAnno,pats=[],
-				      guard=Gs,body=Lps ++ [Lc]}],
-		    fc=#iclause{anno=LAnno,pats=[],guard=[],body=[Mc]}},
-	     [],St2};
-	false ->
-	    {Lc,Lps,St1} = lc_tq(Line, E, Qs0, Mc, St0),
-	    {Fpat,St2} = new_var(St1),
-	    Fc = fail_clause([Fpat], LA,
-			     c_tuple([#c_literal{val=case_clause},Fpat])),
-	    %% Do a novars little optimisation here.
-	    {Filc,Fps,St3} = novars(Fil0, St2),
-	    {#icase{anno=LAnno,
-		    args=[Filc],
-		    clauses=[#iclause{anno=LAnno,
-				      pats=[#c_literal{anno=LA,val=true}],
-				      guard=[],
-				      body=Lps ++ [Lc]},
-			     #iclause{anno=LAnno#a{anno=[compiler_generated|LA]},
-				      pats=[#c_literal{anno=LA,val=false}],
-				      guard=[],
-				      body=[Mc]}],
-		    fc=Fc},
-	     Fps,St3}
-    end;
+    F = #c_var{anno=LA,name={Name,1}},
+    Nc = #iapply{anno=GAnno,op=F,args=[Tail]},
+    {Var,St2} = new_var(St1),
+    Fc = function_clause([Var], LA, {Name,1}),
+    TailClause = #iclause{anno=LAnno,pats=[TailPat],guard=[],body=[Mc]},
+    Cs0 = case {AccPat,AccGuard} of
+              {SkipPat,[]} ->
+                  %% Skip and accumulator patterns are the same and there is
+                  %% no guard, no need to generate a skip clause.
+                  [TailClause];
+              _ ->
+                  [#iclause{anno=#a{anno=[compiler_generated|LA]},
+                            pats=[SkipPat],guard=[],body=[Nc]},
+                   TailClause]
+          end,
+    {Cs,St4} = case AccPat of
+                   nomatch ->
+                       %% The accumulator pattern never matches, no need
+                       %% for an accumulator clause.
+                       {Cs0,St2};
+                   _ ->
+                       {Lc,Lps,St3} = lc_tq(Line, E, Qs, Nc, St2),
+                       {[#iclause{anno=LAnno,pats=[AccPat],guard=AccGuard,
+                                  body=Lps ++ [Lc]}|Cs0],
+                        St3}
+               end,
+    Fun = #ifun{anno=LAnno,id=[],vars=[Var],clauses=Cs,fc=Fc},
+    {#iletrec{anno=LAnno#a{anno=[list_comprehension|LA]},defs=[{{Name,1},Fun}],
+              body=Pre ++ [#iapply{anno=LAnno,op=F,args=[Arg]}]},
+     Ceps,St4};
+lc_tq(Line, E, [#ifilter{}=Filter|Qs], Mc, St) ->
+    filter_tq(Line, E, Filter, Mc, St, Qs, fun lc_tq/5);
 lc_tq(Line, E0, [], Mc0, St0) ->
     {H1,Hps,St1} = safe(E0, St0),
     {T1,Tps,St} = force_safe(Mc0, St1),
@@ -987,174 +1081,249 @@ lc_tq(Line, E0, [], Mc0, St0) ->
 
 %% bc_tq(Line, Exp, [Qualifier], More, State) -> {LetRec,[PreExp],State}.
 %%  This TQ from Gustafsson ERLANG'05.  
-%%  This gets a bit messy as we must transform all directly here.  We
-%%  recognise guard tests and try to fold them together and join to a
-%%  preceding generators, this should give us better and more compact
-%%  code.
 %%  More could be transformed before calling bc_tq.
 
-bc_tq(Line, Exp, Qualifiers, _, St0) ->
+bc_tq(Line, Exp, Qs0, St0) ->
     {BinVar,St1} = new_var(St0),
-    {Sz,SzPre,St2} = bc_initial_size(Exp, Qualifiers, St1),
-    {E,BcPre,St} = bc_tq1(Line, Exp, Qualifiers, BinVar, St2),
+    {Sz,SzPre,St2} = bc_initial_size(Exp, Qs0, St1),
+    {Qs,St3} = preprocess_quals(Line, Qs0, St2),
+    {E,BcPre,St} = bc_tq1(Line, Exp, Qs, BinVar, St3),
     Pre = SzPre ++
 	[#iset{var=BinVar,
 	       arg=#iprimop{name=#c_literal{val=bs_init_writable},
 			    args=[Sz]}}] ++ BcPre,
     {E,Pre,St}.
 
-bc_tq1(Line, E, [{generate,Lg,P,G}|Qs0], AccExpr, St0) ->
-    {Gs,Qs1} =  splitwith(fun is_guard_test/1, Qs0),
+bc_tq1(Line, E, [#igen{anno=GAnno,ceps=Ceps,
+		       acc_pat=AccPat,acc_guard=AccGuard,
+                       skip_pat=SkipPat,tail=Tail,tail_pat=TailPat,
+                       arg={Pre,Arg}}|Qs], Mc, St0) ->
     {Name,St1} = new_fun_name("lbc", St0),
     LA = lineno_anno(Line, St1),
-    {[Head,Tail,AccVar],St2} = new_vars(LA, 3, St1),
     LAnno = #a{anno=LA},
-    {Arg,St3} = new_var(St2),
-    NewMore = {call,Lg,{atom,Lg,Name},[{var,Lg,Tail#c_var.name},
-				       {var,Lg,AccVar#c_var.name}]},
-    {Guardc,St4} = lc_guard_tests(Gs, St3),	%These are always flat!
-    {Lc,Lps,St5} = bc_tq1(Line, E, Qs1, AccVar, St4),
-    {Nc,Nps,St6} = expr(NewMore, St5),
-    {Pc,St7} = list_gen_pattern(P, Line, St6),
-    {Gc,Gps,St8} = safe(G, St7),		%Will be a function argument!
-    Fc = function_clause([Arg,AccVar], LA, {Name,2}),
-    Cs0 = case {Guardc, Pc} of
-	      {[], #c_var{}} ->
-		  [#iclause{anno=LAnno,
-			    pats=[#c_literal{anno=LA,val=[]},AccVar],guard=[],
-			    body=[AccVar]}];
-	      _ ->
-		  [#iclause{anno=#a{anno=[compiler_generated|LA]},
-			    pats=[ann_c_cons(LA, Head, Tail),AccVar],
-			    guard=[],
-			    body=Nps ++ [Nc]},
-		   #iclause{anno=LAnno,
-			    pats=[#c_literal{anno=LA,val=[]},AccVar],guard=[],
-			    body=[AccVar]}]
-	  end,
-    Cs = case Pc of
-	     nomatch -> Cs0;
-	     _ ->
-		 Body = Lps ++ Nps ++ [#iset{var=AccVar,arg=Lc},Nc],
-		 [#iclause{anno=LAnno,
-			   pats=[ann_c_cons(LA,Pc,Tail),AccVar],
-			   guard=Guardc,
-			   body=Body}|Cs0]
-	 end,
-    Fun = #ifun{anno=LAnno,id=[],vars=[Arg,AccVar],clauses=Cs,fc=Fc},
-    {#iletrec{anno=LAnno,defs=[{{Name,2},Fun}],
-	      body=Gps ++ [#iapply{anno=LAnno,
-				   op=#c_var{anno=LA,name={Name,2}},
-				   args=[Gc,AccExpr]}]},
-     [],St8};
-bc_tq1(Line, E, [{b_generate,Lg,P,G}|Qs0], AccExpr, St0) ->
-    {Gs,Qs1} =  splitwith(fun is_guard_test/1, Qs0),
-    {Name,St1} = new_fun_name("lbc", St0),
-    LA = lineno_anno(Line, St1),
-    {AccVar,St2} = new_var(LA, St1),
-    LAnno = #a{anno=LA},
-    HeadBinPattern = pattern(P, St2),
-    #c_binary{segments=Ps0} = HeadBinPattern,
-    {Ps,Tail,St3} = append_tail_segment(Ps0, St2),
-    {EPs,St4} = emasculate_segments(Ps, St3),
-    Pattern = HeadBinPattern#c_binary{segments=Ps},
-    EPattern = HeadBinPattern#c_binary{segments=EPs},
-    {Arg,St5} = new_var(St4),
-    NewMore = {call,Lg,{atom,Lg,Name},[{var,Lg,Tail#c_var.name},
-				       {var,Lg,AccVar#c_var.name}]},
-    {Guardc,St6} = lc_guard_tests(Gs, St5),	%These are always flat!
-    {Bc,Bps,St7} = bc_tq1(Line, E, Qs1, AccVar, St6),
-    {Nc,Nps,St8} = expr(NewMore, St7),
-    {Gc,Gps,St9} = safe(G, St8),	 %Will be a function argument!
-    Fc = function_clause([Arg,AccVar], LA, {Name,2}),
-    Body = Bps ++ Nps ++ [#iset{var=AccVar,arg=Bc},Nc],
-    {TailSegList,_,St} = append_tail_segment([], St9),
-    Cs = [#iclause{anno=LAnno,
-		   pats=[Pattern,AccVar],
-		   guard=Guardc,
-		   body=Body},
-	  #iclause{anno=#a{anno=[compiler_generated|LA]},
-		   pats=[EPattern,AccVar],
-		   guard=[],
-		   body=Nps ++ [Nc]},
-	  #iclause{anno=LAnno,
-		   pats=[#c_binary{anno=LA,segments=TailSegList},AccVar],
-		   guard=[],
-		   body=[AccVar]}],
-    Fun = #ifun{anno=LAnno,id=[],vars=[Arg,AccVar],clauses=Cs,fc=Fc},
-    {#iletrec{anno=LAnno,defs=[{{Name,2},Fun}],
-	      body=Gps ++ [#iapply{anno=LAnno,
-				   op=#c_var{anno=LA,name={Name,2}},
-				   args=[Gc,AccExpr]}]},
-     [],St};
-bc_tq1(Line, E, [Fil0|Qs0], AccVar, St0) ->
-    %% Special case sequences guard tests.
-    LA = lineno_anno(element(2, Fil0), St0),
-    LAnno = #a{anno=LA},
-    case is_guard_test(Fil0) of
-	true ->
-	    {Gs0,Qs1} = splitwith(fun is_guard_test/1, Qs0),
-	    {Bc,Bps,St1} = bc_tq1(Line, E, Qs1, AccVar, St0),
-	    {Gs,St} = lc_guard_tests([Fil0|Gs0], St1), %These are always flat!
-	    {#icase{anno=LAnno,
-		    args=[],
-		    clauses=[#iclause{anno=LAnno,
-				      pats=[],
-				      guard=Gs,body=Bps ++ [Bc]}],
-		    fc=#iclause{anno=LAnno,pats=[],guard=[],body=[AccVar]}},
-	     [],St};
-	false ->
-	    {Bc,Bps,St1} = bc_tq1(Line, E, Qs0, AccVar, St0),
-	    {Fpat,St2} = new_var(St1),
-	    Fc = fail_clause([Fpat], LA,
-			     c_tuple([#c_literal{val=case_clause},Fpat])),
-	    %% Do a novars little optimisation here.
-	    {Filc,Fps,St} = novars(Fil0, St2),
-	    {#icase{anno=LAnno,
-		    args=[Filc],
-		    clauses=[#iclause{anno=LAnno,
-				      pats=[#c_literal{anno=LA,val=true}],
-				      guard=[],
-				      body=Bps ++ [Bc]},
-			     #iclause{anno=LAnno#a{anno=[compiler_generated|LA]},
-				      pats=[#c_literal{anno=LA,val=false}],
-				      guard=[],
-				      body=[AccVar]}],
-		    fc=Fc},
-	     Fps,St}
-    end;
+    {Vars=[_,AccVar],St2} = new_vars(LA, 2, St1),
+    F = #c_var{anno=LA,name={Name,2}},
+    Nc = #iapply{anno=GAnno,op=F,args=[Tail,AccVar]},
+    Fc = function_clause(Vars, LA, {Name,2}),
+    TailClause = #iclause{anno=LAnno,pats=[TailPat,AccVar],guard=[],
+                          body=[AccVar]},
+    Cs0 = case {AccPat,AccGuard} of
+              {SkipPat,[]} ->
+                  %% Skip and accumulator patterns are the same and there is
+                  %% no guard, no need to generate a skip clause.
+                  [TailClause];
+              _ ->
+                  [#iclause{anno=#a{anno=[compiler_generated|LA]},
+                            pats=[SkipPat,AccVar],guard=[],body=[Nc]},
+                   TailClause]
+          end,
+    {Cs,St4} = case AccPat of
+                   nomatch ->
+                       %% The accumulator pattern never matches, no need
+                       %% for an accumulator clause.
+                       {Cs0,St2};
+                   _ ->
+                       {Bc,Bps,St3} = bc_tq1(Line, E, Qs, AccVar, St2),
+                       Body = Bps ++ [#iset{var=AccVar,arg=Bc},Nc],
+                       {[#iclause{anno=LAnno,
+                                  pats=[AccPat,AccVar],guard=AccGuard,
+                                  body=Body}|Cs0],
+                        St3}
+               end,
+    Fun = #ifun{anno=LAnno,id=[],vars=Vars,clauses=Cs,fc=Fc},
+    {#iletrec{anno=LAnno#a{anno=[list_comprehension|LA]},defs=[{{Name,2},Fun}],
+              body=Pre ++ [#iapply{anno=LAnno,op=F,args=[Arg,Mc]}]},
+     Ceps,St4};
+bc_tq1(Line, E, [#ifilter{}=Filter|Qs], Mc, St) ->
+    filter_tq(Line, E, Filter, Mc, St, Qs, fun bc_tq1/5);
 bc_tq1(_, {bin,Bl,Elements}, [], AccVar, St0) ->
-    {E,Pre,St} = expr({bin,Bl,[{bin_element,Bl,
-				{var,Bl,AccVar#c_var.name},
-				{atom,Bl,all},
-				[binary,{unit,1}]}|Elements]}, St0),
+    bc_tq_build(Bl, [], AccVar, Elements, St0);
+bc_tq1(Line, E0, [], AccVar, St0) ->
+    BsFlags = [binary,{unit,1}],
+    BsSize = {atom,Line,all},
+    {E1,Pre0,St1} = safe(E0, St0),
+    case E1 of
+	#c_var{name=VarName} ->
+	    Var = {var,Line,VarName},
+	    Els = [{bin_element,Line,Var,BsSize,BsFlags}],
+	    bc_tq_build(Line, Pre0, AccVar, Els, St1);
+	#c_literal{val=Val} when is_bitstring(Val) ->
+	    Bits = bit_size(Val),
+	    <<Int0:Bits>> = Val,
+	    Int = {integer,Line,Int0},
+	    Sz = {integer,Line,Bits},
+	    Els = [{bin_element,Line,Int,Sz,[integer,{unit,1},big]}],
+	    bc_tq_build(Line, Pre0, AccVar, Els, St1);
+	_ ->
+	    %% Any other safe (cons, tuple, literal) is not a
+	    %% bitstring. Force the evaluation to fail (and
+	    %% generate a warning).
+	    Els = [{bin_element,Line,{atom,Line,bad_value},BsSize,BsFlags}],
+	    bc_tq_build(Line, Pre0, AccVar, Els, St1)
+    end.
+
+bc_tq_build(Line, Pre0, #c_var{name=AccVar}, Elements0, St0) ->
+    Elements = [{bin_element,Line,{var,Line,AccVar},{atom,Line,all},
+		 [binary,{unit,1}]}|Elements0],
+    {E,Pre,St} = expr({bin,Line,Elements}, St0),
     #a{anno=A} = Anno0 = get_anno(E),
     Anno = Anno0#a{anno=[compiler_generated,single_use|A]},
-    %%Anno = Anno0#a{anno=[compiler_generated|A]},
-    {set_anno(E, Anno),Pre,St}.
-
-append_tail_segment(Segs, St) ->
-    app_tail_seg(Segs, St, []).
-
-app_tail_seg([#c_bitstr{val=Var0,size=#c_literal{val=all}}=Seg0]=L,
-	     St0, Acc) ->
-    case Var0 of
-	#c_var{name='_'} ->
-	    {Var,St} = new_var(St0),
-	    Seg = Seg0#c_bitstr{val=Var},
-	    {reverse(Acc, [Seg]),Var,St};
-	#c_var{} ->
-	    {reverse(Acc, L),Var0,St0}
+    {set_anno(E, Anno),Pre0++Pre,St}.
+
+
+%% filter_tq(Line, Expr, Filter, Mc, State, [Qualifier], TqFun) ->
+%%     {Case,[PreExpr],State}.
+%%  Transform an intermediate comprehension filter to its intermediate case
+%%  representation.
+
+filter_tq(Line, E, #ifilter{anno=#a{anno=LA}=LAnno,arg={Pre,Arg}},
+          Mc, St0, Qs, TqFun) ->
+    %% The filter is an expression, it is compiled to a case of degree 1 with
+    %% 3 clauses, one accumulating, one skipping and the final one throwing
+    %% {case_clause,Value} where Value is the result of the filter and is not a
+    %% boolean.
+    {Lc,Lps,St1} = TqFun(Line, E, Qs, Mc, St0),
+    {FailPat,St2} = new_var(St1),
+    Fc = fail_clause([FailPat], LA,
+                     c_tuple([#c_literal{val=case_clause},FailPat])),
+    {#icase{anno=LAnno#a{anno=[list_comprehension|LA]},args=[Arg],
+            clauses=[#iclause{anno=LAnno,
+                              pats=[#c_literal{val=true}],guard=[],
+                              body=Lps ++ [Lc]},
+                     #iclause{anno=LAnno#a{anno=[compiler_generated|LA]},
+                              pats=[#c_literal{val=false}],guard=[],
+                              body=[Mc]}],
+            fc=Fc},
+     Pre,St2};
+filter_tq(Line, E, #ifilter{anno=#a{anno=LA}=LAnno,arg=Guard},
+          Mc, St0, Qs, TqFun) when is_list(Guard) ->
+    %% Otherwise it is a guard, compiled to a case of degree 0 with 2 clauses,
+    %% the first matches if the guard succeeds and the comprehension continues
+    %% or the second one is selected and the current element is skipped.
+    {Lc,Lps,St1} = TqFun(Line, E, Qs, Mc, St0),
+    {#icase{anno=LAnno#a{anno=[list_comprehension|LA]},args=[],
+            clauses=[#iclause{anno=LAnno,pats=[],guard=Guard,body=Lps ++ [Lc]}],
+            fc=#iclause{anno=LAnno#a{anno=[compiler_generated|LA]},
+                        pats=[],guard=[],body=[Mc]}},
+     [],St1}.
+
+%% preprocess_quals(Line, [Qualifier], State) -> {[Qualifier'],State}.
+%%  Preprocess a list of Erlang qualifiers into its intermediate representation,
+%%  represented as a list of #igen{} and #ifilter{} records. We recognise guard
+%%  tests and try to fold them together and join to a preceding generators, this
+%%  should give us better and more compact code.
+
+preprocess_quals(Line, Qs, St) ->
+    preprocess_quals(Line, Qs, St, []).
+
+preprocess_quals(Line, [Q|Qs0], St0, Acc) ->
+    case is_generator(Q) of
+        true ->
+            {Gs,Qs} = splitwith(fun is_guard_test/1, Qs0),
+            {Gen,St} = generator(Line, Q, Gs, St0),
+            preprocess_quals(Line, Qs, St, [Gen|Acc]);
+        false ->
+            LAnno = #a{anno=lineno_anno(get_qual_anno(Q), St0)},
+            case is_guard_test(Q) of
+                true ->
+                    %% When a filter is a guard test, its argument in the
+                    %% #ifilter{} record is a list as returned by
+                    %% lc_guard_tests/2.
+                    {Gs,Qs} = splitwith(fun is_guard_test/1, Qs0),
+                    {Cg,St} = lc_guard_tests([Q|Gs], St0),
+                    Filter = #ifilter{anno=LAnno,arg=Cg},
+                    preprocess_quals(Line, Qs, St, [Filter|Acc]);
+                false ->
+                    %% Otherwise, it is a pair {Pre,Arg} as in a generator
+                    %% input.
+                    {Ce,Pre,St} = novars(Q, St0),
+                    Filter = #ifilter{anno=LAnno,arg={Pre,Ce}},
+                    preprocess_quals(Line, Qs0, St, [Filter|Acc])
+            end
     end;
-app_tail_seg([H|T], St, Acc) ->
-    app_tail_seg(T, St, [H|Acc]);
-app_tail_seg([], St0, Acc) ->
+preprocess_quals(_, [], St, Acc) ->
+    {reverse(Acc),St}.
+
+is_generator({generate,_,_,_}) -> true;
+is_generator({b_generate,_,_,_}) -> true;
+is_generator(_) -> false.
+
+%% Retrieve the annotation from an Erlang AST form.
+%% (Use get_anno/1 to retrieve the annotation from Core Erlang forms).
+
+get_qual_anno(Abstract) -> element(2, Abstract).
+
+%%
+%% Generators are abstracted as sextuplets:
+%%  - acc_pat is the accumulator pattern, e.g. [Pat|Tail] for Pat <- Expr.
+%%  - acc_guard is the list of guards immediately following the current
+%%    generator in the qualifier list input.
+%%  - skip_pat is the skip pattern, e.g. <<X,_:X,Tail/bitstring>> for
+%%    <<X,1:X>> <= Expr.
+%%  - tail is the variable used in AccPat and SkipPat bound to the rest of the
+%%    generator input.
+%%  - tail_pat is the tail pattern, respectively [] and <<_/bitstring>> for list
+%%    and bit string generators.
+%%  - arg is a pair {Pre,Arg} where Pre is the list of expressions to be
+%%    inserted before the comprehension function and Arg is the expression
+%%    that it should be passed.
+%%
+
+%% generator(Line, Generator, Guard, State) -> {Generator',State}.
+%%  Transform a given generator into its #igen{} representation.
+
+generator(Line, {generate,Lg,P0,E}, Gs, St0) ->
+    LA = lineno_anno(Line, St0),
+    GA = lineno_anno(Lg, St0),
+    {Head,Ceps,St1} = list_gen_pattern(P0, Line, St0),
+    {[Tail,Skip],St2} = new_vars(2, St1),
+    {Cg,St3} = lc_guard_tests(Gs, St2),
+    {AccPat,SkipPat} = case Head of
+                           #c_var{} ->
+                               %% If the generator pattern is a variable, the
+                               %% pattern from the accumulator clause can be
+                               %% reused in the skip one. lc_tq and bc_tq1 takes
+                               %% care of dismissing the latter in that case.
+                               Cons = ann_c_cons(LA, Head, Tail),
+                               {Cons,Cons};
+                           nomatch ->
+                               %% If it never matches, there is no need for
+                               %% an accumulator clause.
+                               {nomatch,ann_c_cons(LA, Skip, Tail)};
+                           _ ->
+                               {ann_c_cons(LA, Head, Tail),
+                                ann_c_cons(LA, Skip, Tail)}
+                       end,
+    {Ce,Pre,St4} = safe(E, St3),
+    Gen = #igen{anno=#a{anno=GA},ceps=Ceps,
+		acc_pat=AccPat,acc_guard=Cg,skip_pat=SkipPat,
+                tail=Tail,tail_pat=#c_literal{anno=LA,val=[]},arg={Pre,Ce}},
+    {Gen,St4};
+generator(Line, {b_generate,Lg,P,E}, Gs, St0) ->
+    LA = lineno_anno(Line, St0),
+    GA = lineno_anno(Lg, St0),
+    {Cp = #c_binary{segments=Segs},[],St1} = pattern(P, St0),
+    
+    %% The function append_tail_segment/2 keeps variable patterns as-is, making
+    %% it possible to have the same skip clause removal as with list generators.
+    {AccSegs,Tail,TailSeg,St2} = append_tail_segment(Segs, St1),
+    AccPat = Cp#c_binary{segments=AccSegs},
+    {Cg,St3} = lc_guard_tests(Gs, St2),
+    {SkipSegs,St4} = emasculate_segments(AccSegs, St3),
+    SkipPat = Cp#c_binary{segments=SkipSegs},
+    {Ce,Pre,St5} = safe(E, St4),
+    Gen = #igen{anno=#a{anno=GA},acc_pat=AccPat,acc_guard=Cg,skip_pat=SkipPat,
+                tail=Tail,tail_pat=#c_binary{anno=LA,segments=[TailSeg]},
+                arg={Pre,Ce}},
+    {Gen,St5}.
+
+append_tail_segment(Segs, St0) ->
     {Var,St} = new_var(St0),
     Tail = #c_bitstr{val=Var,size=#c_literal{val=all},
 		     unit=#c_literal{val=1},
 		     type=#c_literal{val=binary},
 		     flags=#c_literal{val=[unsigned,big]}},
-    {reverse(Acc, [Tail]),Var,St}.
+    {Segs++[Tail],Var,Tail,St}.
 
 emasculate_segments(Segs, St) ->
     emasculate_segments(Segs, St, []).
@@ -1165,7 +1334,7 @@ emasculate_segments([B|Rest], St0, Acc) ->
     {Var,St1} = new_var(St0),
     emasculate_segments(Rest, St1, [B#c_bitstr{val=Var}|Acc]);
 emasculate_segments([], St, Acc) ->
-    {lists:reverse(Acc),St}.
+    {reverse(Acc),St}.
 
 lc_guard_tests([], St) -> {[],St};
 lc_guard_tests(Gs0, St0) ->
@@ -1175,9 +1344,9 @@ lc_guard_tests(Gs0, St0) ->
 
 list_gen_pattern(P0, Line, St) ->
     try
-	{pattern(P0, St),St}
+	pattern(P0,St)
     catch 
-	nomatch -> {nomatch,add_warning(Line, nomatch, St)}
+	nomatch -> {nomatch,[],add_warning(Line, nomatch, St)}
     end.
 
 %%%
@@ -1221,7 +1390,9 @@ bc_elem_size({bin,_,El}, St0) ->
 	    Vs = [V || {_,#c_var{name=V}} <- Vars0],
 	    {E,Pre,St} = bc_mul_pairs(F, #c_literal{val=Bits}, [], St0),
 	    {E,Pre,Vs,St}
-    end.
+    end;
+bc_elem_size(_, _) ->
+    throw(impossible).
 
 bc_elem_size_1([{bin_element,_,_,{integer,_,N},Flags}|Es], Bits, Vars) ->
     {unit,U} = keyfind(unit, 1, Flags),
@@ -1397,9 +1568,22 @@ force_novars(#iapply{}=App, St) -> {App,[],St};
 force_novars(#icall{}=Call, St) -> {Call,[],St};
 force_novars(#ifun{}=Fun, St) -> {Fun,[],St};	%These are novars too
 force_novars(#ibinary{}=Bin, St) -> {Bin,[],St};
+force_novars(#c_map{}=Bin, St) -> {Bin,[],St};
 force_novars(Ce, St) ->
     force_safe(Ce, St).
 
+
+%% safe_pattern_expr(Expr, State) -> {Cexpr,[PreExpr],State}.
+%%   only literals and variables are safe expressions in patterns
+safe_pattern_expr(E,St0) ->
+    case safe(E,St0) of
+	{#c_var{},_,_}=Safe -> Safe;
+	{#c_literal{},_,_}=Safe -> Safe;
+	{Ce,Eps,St1} ->
+	    {V,St2} = new_var(St1),
+	    {V,Eps++[#iset{var=V,arg=Ce}],St2}
+    end.
+
 %% safe(Expr, State) -> {Safe,[PreExpr],State}.
 %%  Generate an internal safe expression.  These are simples without
 %%  binaries which can fail.  At this level we do not need to do a
@@ -1410,6 +1594,15 @@ safe(E0, St0) ->
     {Se,Sps,St2} = force_safe(E1, St1),
     {Se,Eps ++ Sps,St2}.
 
+safe_fun(A0, E0, St0) ->
+    case safe(E0, St0) of
+        {#c_var{name={_,A1}}=E1,Eps,St1} when A1 =/= A0 ->
+            {V,St2} = new_var(St1),
+            {V,Eps ++ [#iset{var=V,arg=E1}],St2};
+        Result ->
+            Result
+    end.
+
 safe_list(Es, St) ->
     foldr(fun (E, {Ces,Esp,St0}) ->
 		  {Ce,Ep,St1} = safe(E, St0),
@@ -1465,34 +1658,92 @@ fold_match({match,L,P0,E0}, P) ->
     {{match,L,P0,P1},E1};
 fold_match(E, P) -> {P,E}.
 
-%% pattern(Pattern, State) -> CorePat.
+%% pattern(Pattern, State) -> {CorePat,[PreExp],State}.
 %% Transform a pattern by removing line numbers.  We also normalise
 %% aliases in patterns to standard form, {alias,Pat,[Var]}.
-
-pattern({var,L,V}, St) -> #c_var{anno=lineno_anno(L, St),name=V};
-pattern({char,L,C}, St) -> #c_literal{anno=lineno_anno(L, St),val=C};
-pattern({integer,L,I}, St) -> #c_literal{anno=lineno_anno(L, St),val=I};
-pattern({float,L,F}, St) -> #c_literal{anno=lineno_anno(L, St),val=F};
-pattern({atom,L,A}, St) -> #c_literal{anno=lineno_anno(L, St),val=A};
-pattern({string,L,S}, St) -> #c_literal{anno=lineno_anno(L, St),val=S};
-pattern({nil,L}, St) -> #c_literal{anno=lineno_anno(L, St),val=[]};
+%%
+%% In patterns we may have expressions
+%% 1) Binaries -> #c_bitstr{size=Expr}
+%% 2) Maps -> #c_map_pair{key=Expr}
+%%
+%% Both of these may generate pre-expressions since only bound variables
+%% or literals are allowed for these in core patterns.
+%%
+%% Therefor, we need to drag both the state and the collection of pre-expression
+%% around in the whole pattern transformation tree.
+
+pattern({var,L,V}, St) -> {#c_var{anno=lineno_anno(L, St),name=V},[],St};
+pattern({char,L,C}, St) -> {#c_literal{anno=lineno_anno(L, St),val=C},[],St};
+pattern({integer,L,I}, St) -> {#c_literal{anno=lineno_anno(L, St),val=I},[],St};
+pattern({float,L,F}, St) -> {#c_literal{anno=lineno_anno(L, St),val=F},[],St};
+pattern({atom,L,A}, St) -> {#c_literal{anno=lineno_anno(L, St),val=A},[],St};
+pattern({string,L,S}, St) -> {#c_literal{anno=lineno_anno(L, St),val=S},[],St};
+pattern({nil,L}, St) -> {#c_literal{anno=lineno_anno(L, St),val=[]},[],St};
 pattern({cons,L,H,T}, St) ->
-    ann_c_cons(lineno_anno(L, St), pattern(H, St), pattern(T, St));
+    {Ph,Eps1,St1} = pattern(H, St),
+    {Pt,Eps2,St2} = pattern(T, St1),
+    {annotate_cons(lineno_anno(L, St), Ph, Pt, St2),Eps1++Eps2,St2};
 pattern({tuple,L,Ps}, St) ->
-    ann_c_tuple(lineno_anno(L, St), pattern_list(Ps, St));
+    {Ps1,Eps,St1} = pattern_list(Ps,St),
+    {annotate_tuple(record_anno(L, St), Ps1, St),Eps,St1};
+pattern({map,L,Pairs}, St0) ->
+    {Ps,Eps,St1} = pattern_map_pairs(Pairs, St0),
+    {#c_map{anno=lineno_anno(L, St1),es=Ps,is_pat=true},Eps,St1};
 pattern({bin,L,Ps}, St) ->
     %% We don't create a #ibinary record here, since there is
     %% no need to hold any used/new annotations in a pattern.
-    #c_binary{anno=lineno_anno(L, St),segments=pat_bin(Ps, St)};
+    {#c_binary{anno=lineno_anno(L, St),segments=pat_bin(Ps, St)},[],St};
 pattern({match,_,P1,P2}, St) ->
-    pat_alias(pattern(P1, St), pattern(P2, St)).
+    {Cp1,Eps1,St1} = pattern(P1,St),
+    {Cp2,Eps2,St2} = pattern(P2,St1),
+    {pat_alias(Cp1,Cp2),Eps1++Eps2,St2}.
+
+%% pattern_map_pairs([MapFieldExact],State) -> [#c_map_pairs{}]
+pattern_map_pairs(Ps, St) ->
+    %% check literal key uniqueness
+    %%   - guaranteed via aliasing map pairs
+    %% pattern all pairs in two steps
+    %% 1) Construct Core Pattern
+    %% 2) Alias Keys in Core Pattern
+    {CMapPairs, {Eps,St1}} = lists:mapfoldl(fun
+	    (P,{EpsM,Sti0}) ->
+		{CMapPair,EpsP,Sti1} = pattern_map_pair(P,Sti0),
+		{CMapPair, {EpsM++EpsP,Sti1}}
+	end, {[],St}, Ps),
+    {pat_alias_map_pairs(CMapPairs),Eps,St1}.
+
+pattern_map_pair({map_field_exact,L,K,V}, St0) ->
+    {Ck,EpsK,St1} = safe_pattern_expr(K, St0),
+    {Cv,EpsV,St2} = pattern(V, St1),
+    {#c_map_pair{anno=lineno_anno(L, St2),
+		 op=#c_literal{val=exact},
+		 key=Ck,
+		 val=Cv},EpsK++EpsV,St2}.
+
+pat_alias_map_pairs(Ps) ->
+    D = foldl(fun(#c_map_pair{key=K0}=Pair, D0) ->
+		      K = cerl:set_ann(K0, []),
+		      dict:append(K, Pair, D0)
+	      end, dict:new(), Ps),
+    pat_alias_map_pairs_1(dict:to_list(D)).
+
+pat_alias_map_pairs_1([{_,[#c_map_pair{val=V0}=Pair|Vs]}|T]) ->
+    V = foldl(fun(#c_map_pair{val=V}, Pat) ->
+		      pat_alias(V, Pat)
+	      end, V0, Vs),
+    [Pair#c_map_pair{val=V}|pat_alias_map_pairs_1(T)];
+pat_alias_map_pairs_1([]) -> [].
 
 %% pat_bin([BinElement], State) -> [BinSeg].
 
 pat_bin(Ps, St) -> [pat_segment(P, St) || P <- Ps].
 
-pat_segment({bin_element,_,Term,Size,[Type,{unit,Unit}|Flags]}, St) ->
-    #c_bitstr{val=pattern(Term, St),size=pattern(Size, St),
+pat_segment({bin_element,L,Val,Size,[Type,{unit,Unit}|Flags]}, St) ->
+    Anno = lineno_anno(L, St),
+    {Pval,[],St1} = pattern(Val,St),
+    {Psize,[],_St2} = pattern(Size,St1),
+    #c_bitstr{anno=Anno,
+	      val=Pval,size=Psize,
 	      unit=#c_literal{val=Unit},
 	      type=#c_literal{val=Type},
 	      flags=#c_literal{val=Flags}}.
@@ -1500,38 +1751,55 @@ pat_segment({bin_element,_,Term,Size,[Type,{unit,Unit}|Flags]}, St) ->
 %% pat_alias(CorePat, CorePat) -> AliasPat.
 %%  Normalise aliases.  Trap bad aliases by throwing 'nomatch'.
 
-pat_alias(#c_var{name=V1}, P2) -> #c_alias{var=#c_var{name=V1},pat=P2};
-pat_alias(P1, #c_var{name=V2}) -> #c_alias{var=#c_var{name=V2},pat=P1};
-pat_alias(#c_cons{}=Cons, #c_literal{anno=A,val=[H|T]}=S) ->
-    pat_alias(Cons, ann_c_cons_skel(A, #c_literal{anno=A,val=H},
-				    S#c_literal{val=T}));
-pat_alias(#c_literal{anno=A,val=[H|T]}=S, #c_cons{}=Cons) ->
-    pat_alias(ann_c_cons_skel(A, #c_literal{anno=A,val=H},
-			      S#c_literal{val=T}), Cons);
-pat_alias(#c_cons{anno=Anno,hd=H1,tl=T1}, #c_cons{hd=H2,tl=T2}) ->
-    ann_c_cons(Anno, pat_alias(H1, H2), pat_alias(T1, T2));
-pat_alias(#c_tuple{anno=Anno,es=Es1}, #c_literal{val=T}) when is_tuple(T) ->
-    Es2 = [#c_literal{val=E} || E <- tuple_to_list(T)],
-    ann_c_tuple(Anno, pat_alias_list(Es1, Es2));
-pat_alias(#c_literal{anno=Anno,val=T}, #c_tuple{es=Es2}) when is_tuple(T) ->
-    Es1 = [#c_literal{val=E} || E <- tuple_to_list(T)],
-    ann_c_tuple(Anno, pat_alias_list(Es1, Es2));
-pat_alias(#c_tuple{anno=Anno,es=Es1}, #c_tuple{es=Es2}) ->
-    ann_c_tuple(Anno, pat_alias_list(Es1, Es2));
-pat_alias(#c_alias{var=V1,pat=P1},
-	  #c_alias{var=V2,pat=P2}) ->
-    if V1 =:= V2 -> #c_alias{var=V1,pat=pat_alias(P1, P2)};
-       true -> #c_alias{var=V1,pat=#c_alias{var=V2,pat=pat_alias(P1, P2)}}
+pat_alias(#c_var{name=V1}=P, #c_var{name=V1}) -> P;
+pat_alias(#c_var{name=V1}=Var,
+	  #c_alias{var=#c_var{name=V2},pat=Pat}=Alias) ->
+    if
+	V1 =:= V2 ->
+	    Alias;
+	true ->
+	    Alias#c_alias{pat=pat_alias(Var, Pat)}
+    end;
+pat_alias(#c_var{}=P1, P2) -> #c_alias{var=P1,pat=P2};
+
+pat_alias(#c_alias{var=#c_var{name=V1}}=Alias, #c_var{name=V1}) ->
+    Alias;
+pat_alias(#c_alias{var=#c_var{name=V1}=Var1,pat=P1},
+	  #c_alias{var=#c_var{name=V2}=Var2,pat=P2}) ->
+    Pat = pat_alias(P1, P2),
+    if
+	V1 =:= V2 ->
+	    #c_alias{var=Var1,pat=Pat};
+	true ->
+	    pat_alias(Var1, pat_alias(Var2, Pat))
     end;
-pat_alias(#c_alias{var=V1,pat=P1}, P2) ->
-    #c_alias{var=V1,pat=pat_alias(P1, P2)};
-pat_alias(P1, #c_alias{var=V2,pat=P2}) ->
-    #c_alias{var=V2,pat=pat_alias(P1, P2)};
+pat_alias(#c_alias{var=#c_var{}=Var,pat=P1}, P2) ->
+    #c_alias{var=Var,pat=pat_alias(P1, P2)};
+
+pat_alias(#c_map{es=Es1}=M, #c_map{es=Es2}) ->
+    M#c_map{es=pat_alias_map_pairs(Es1 ++ Es2)};
+
+pat_alias(P1, #c_var{}=Var) ->
+    #c_alias{var=Var,pat=P1};
+pat_alias(P1, #c_alias{pat=P2}=Alias) ->
+    Alias#c_alias{pat=pat_alias(P1, P2)};
+
 pat_alias(P1, P2) ->
-    case {set_anno(P1, []),set_anno(P2, [])} of
-	{P,P} -> P;
+    %% Aliases between binaries are not allowed, so the only
+    %% legal patterns that remain are data patterns.
+    case cerl:is_data(P1) andalso cerl:is_data(P2) of
+	false -> throw(nomatch);
+	true -> ok
+    end,
+    Type = cerl:data_type(P1),
+    case cerl:data_type(P2) of
+	Type -> ok;
 	_ -> throw(nomatch)
-    end.
+    end,
+    Es1 = cerl:data_es(P1),
+    Es2 = cerl:data_es(P2),
+    Es = pat_alias_list(Es1, Es2),
+    cerl:make_data(Type, Es).
 
 %% pat_alias_list([A1], [A2]) -> [A].
 
@@ -1540,18 +1808,15 @@ pat_alias_list([A1|A1s], [A2|A2s]) ->
 pat_alias_list([], []) -> [];
 pat_alias_list(_, _) -> throw(nomatch).
 
-%% pattern_list([P], State) -> [P].
-
-pattern_list(Ps, St) -> [pattern(P, St) || P <- Ps].
+%% pattern_list([P], State) -> {[P],Exprs,St}
 
-%% first([A]) -> [A].
-%% last([A]) -> A.
+pattern_list([P0|Ps0], St0) ->
+    {P1,Eps,St1} = pattern(P0, St0),
+    {Ps1,Epsl,St2} = pattern_list(Ps0, St1),
+    {[P1|Ps1], Eps ++ Epsl, St2};
+pattern_list([], St) ->
+    {[],[],St}.
 
-first([_]) -> [];
-first([H|T]) -> [H|first(T)].
-
-last([L]) -> L;
-last([_|T]) -> last(T).
 
 %% make_vars([Name]) -> [{Var,Name}].
 
@@ -1573,7 +1838,7 @@ new_var_name(#core{vcount=C}=St) ->
 new_var(St) ->
     new_var([], St).
 
-new_var(Anno, St0) ->
+new_var(Anno, St0) when is_list(Anno) ->
     {New,St} = new_var_name(St0),
     {#c_var{anno=Anno,name=New},St}.
 
@@ -1600,6 +1865,26 @@ fail_clause(Pats, Anno, Arg) ->
 	     body=[#iprimop{anno=#a{anno=Anno},name=#c_literal{val=match_fail},
 			    args=[Arg]}]}.
 
+annotate_tuple(A, Es, St) ->
+    case member(dialyzer, St#core.opts) of
+        true ->
+            %% Do not coalesce constant tuple elements. A Hack.
+            Node = cerl:ann_c_tuple(A, [cerl:c_var(any)]),
+            cerl:update_c_tuple_skel(Node, Es);
+        false ->
+            ann_c_tuple(A, Es)
+    end.
+
+annotate_cons(A, H, T, St) ->
+    case member(dialyzer, St#core.opts) of
+        true ->
+            %% Do not coalesce constant conses. A Hack.
+            Node= cerl:ann_c_cons(A, cerl:c_var(any), cerl:c_var(any)),
+            cerl:update_c_cons_skel(Node, H, T);
+        false ->
+            ann_c_cons(A, H, T)
+    end.
+
 ubody(B, St) -> uexpr(B, [], St).
 
 %% uclauses([Lclause], [KnownVar], State) -> {[Lclause],State}.
@@ -1611,7 +1896,7 @@ uclauses(Lcs, Ks, St0) ->
 
 uclause(Cl0, Ks, St0) ->
     {Cl1,_Pvs,Used,New,St1} = uclause(Cl0, Ks, Ks, St0),
-    A0 = get_ianno(Cl1),
+    A0 = get_anno(Cl1),
     A = A0#a{us=Used,ns=New},
     {Cl1#iclause{anno=A},St1}.
 
@@ -1635,13 +1920,13 @@ uclause(#iclause{anno=Anno,pats=Ps0,guard=G0,body=B0}, Pks, Ks0, St0) ->
 uguard([], [], _, St) -> {[],St};
 uguard(Pg, [], Ks, St) ->
     %% No guard, so fold together equality tests.
-    uguard(first(Pg), [last(Pg)], Ks, St);
+    uguard(droplast(Pg), [last(Pg)], Ks, St);
 uguard(Pg, Gs0, Ks, St0) ->
     %% Gs0 must contain at least one element here.
     {Gs3,St5} = foldr(fun (T, {Gs1,St1}) ->
 			      {L,St2} = new_var(St1),
 			      {R,St3} = new_var(St2),
-			      {[#iset{var=L,arg=T}] ++ first(Gs1) ++
+			      {[#iset{var=L,arg=T}] ++ droplast(Gs1) ++
 			       [#iset{var=R,arg=last(Gs1)},
 				#icall{anno=#a{}, %Must have an #a{}
 				       module=#c_literal{val=erlang},
@@ -1655,27 +1940,22 @@ uguard(Pg, Gs0, Ks, St0) ->
 %% uexprs([Kexpr], [KnownVar], State) -> {[Kexpr],State}.
 
 uexprs([#imatch{anno=A,pat=P0,arg=Arg,fc=Fc}|Les], Ks, St0) ->
-    %% Optimise for simple set of unbound variable.
-    case upattern(P0, Ks, St0) of
-	{#c_var{},[],_Pvs,_Pus,_} ->
-	    %% Throw our work away and just set to iset.
+    case upat_is_new_var(P0, Ks) of
+	true ->
+	    %% Assignment to a new variable.
 	    uexprs([#iset{var=P0,arg=Arg}|Les], Ks, St0);
-	_Other ->
-	    %% Throw our work away and set to icase.
-	    if
-		Les =:= [] ->
-		    %% Need to explicitly return match "value", make
-		    %% safe for efficiency.
-		    {La0,Lps,St1} = force_safe(Arg, St0),
-		    La = mark_compiler_generated(La0),
-		    Mc = #iclause{anno=A,pats=[P0],guard=[],body=[La]},
-		    uexprs(Lps ++ [#icase{anno=A,
-					  args=[La0],clauses=[Mc],fc=Fc}], Ks, St1);
-		true ->
-		    Mc = #iclause{anno=A,pats=[P0],guard=[],body=Les},
-		    uexprs([#icase{anno=A,args=[Arg],
-				   clauses=[Mc],fc=Fc}], Ks, St0)
-	    end
+	false when Les =:= [] ->
+	    %% Need to explicitly return match "value", make
+	    %% safe for efficiency.
+	    {La0,Lps,St1} = force_safe(Arg, St0),
+	    La = mark_compiler_generated(La0),
+	    Mc = #iclause{anno=A,pats=[P0],guard=[],body=[La]},
+	    uexprs(Lps ++ [#icase{anno=A,
+				  args=[La0],clauses=[Mc],fc=Fc}], Ks, St1);
+	false ->
+	    Mc = #iclause{anno=A,pats=[P0],guard=[],body=Les},
+	    uexprs([#icase{anno=A,args=[Arg],
+			   clauses=[Mc],fc=Fc}], Ks, St0)
     end;
 uexprs([Le0|Les0], Ks, St0) ->
     {Le1,St1} = uexpr(Le0, Ks, St0),
@@ -1683,6 +1963,15 @@ uexprs([Le0|Les0], Ks, St0) ->
     {[Le1|Les1],St2};
 uexprs([], _, St) -> {[],St}.
 
+%% upat_is_new_var(Pattern, [KnownVar]) -> true|false.
+%%  Test whether the pattern is a single, previously unknown
+%%  variable.
+
+upat_is_new_var(#c_var{name=V}, Ks) ->
+    not is_element(V, Ks);
+upat_is_new_var(_, _) ->
+    false.
+
 %% Mark a "safe" as compiler-generated.
 mark_compiler_generated(#c_cons{anno=A,hd=H,tl=T}) ->
     ann_c_cons([compiler_generated|A], mark_compiler_generated(H),
@@ -1710,21 +1999,29 @@ uexpr(#iletrec{anno=A,defs=Fs0,body=B0}, Ks, St0) ->
     {B1,St2} = uexprs(B0, Ks, St1),
     Used = used_in_any(map(fun ({_,F}) -> F end, Fs1) ++ B1),
     {#iletrec{anno=A#a{us=Used,ns=[]},defs=Fs1,body=B1},St2};
-uexpr(#icase{anno=A,args=As0,clauses=Cs0,fc=Fc0}, Ks, St0) ->
+uexpr(#icase{anno=#a{anno=Anno}=A,args=As0,clauses=Cs0,fc=Fc0}, Ks, St0) ->
     %% As0 will never generate new variables.
     {As1,St1} = uexpr_list(As0, Ks, St0),
     {Cs1,St2} = uclauses(Cs0, Ks, St1),
     {Fc1,St3} = uclause(Fc0, Ks, St2),
     Used = union(used_in_any(As1), used_in_any(Cs1)),
-    New = new_in_all(Cs1),
+    New = case member(list_comprehension, Anno) of
+              true -> [];
+              false -> new_in_all(Cs1)
+          end,
     {#icase{anno=A#a{us=Used,ns=New},args=As1,clauses=Cs1,fc=Fc1},St3};
-uexpr(#ifun{anno=A,id=Id,vars=As,clauses=Cs0,fc=Fc0}, Ks0, St0) ->
+uexpr(#ifun{anno=A0,id=Id,vars=As,clauses=Cs0,fc=Fc0,name=Name}, Ks0, St0) ->
     Avs = lit_list_vars(As),
-    Ks1 = union(Avs, Ks0),
-    {Cs1,St1} = ufun_clauses(Cs0, Ks1, St0),
-    {Fc1,St2} = ufun_clause(Fc0, Ks1, St1),
-    Used = subtract(intersection(used_in_any(Cs1), Ks0), Avs),
-    {#ifun{anno=A#a{us=Used,ns=[]},id=Id,vars=As,clauses=Cs1,fc=Fc1},St2};
+    Ks1 = case Name of
+              unnamed -> Ks0;
+              {named,FName} -> union(subtract([FName], Avs), Ks0)
+          end,
+    Ks2 = union(Avs, Ks1),
+    {Cs1,St1} = ufun_clauses(Cs0, Ks2, St0),
+    {Fc1,St2} = ufun_clause(Fc0, Ks2, St1),
+    Used = subtract(intersection(used_in_any(Cs1), Ks1), Avs),
+    A1 = A0#a{us=Used,ns=[]},
+    {#ifun{anno=A1,id=Id,vars=As,clauses=Cs1,fc=Fc1,name=Name},St2};
 uexpr(#iapply{anno=A,op=Op,args=As}, _, St) ->
     Used = union(lit_vars(Op), lit_list_vars(As)),
     {#iapply{anno=A#a{us=Used},op=Op,args=As},St};
@@ -1772,11 +2069,11 @@ uexpr(#ibinary{anno=A,segments=Ss}, _, St) ->
 uexpr(#c_literal{}=Lit, _, St) ->
     Anno = get_anno(Lit),
     {set_anno(Lit, #a{us=[],anno=Anno}),St};
-uexpr(Lit, _, St) ->
-    true = is_simple(Lit),			%Sanity check!
-    Vs = lit_vars(Lit),
-    Anno = get_anno(Lit),
-    {set_anno(Lit, #a{us=Vs,anno=Anno}),St}.
+uexpr(Simple, _, St) ->
+    true = is_simple(Simple),			%Sanity check!
+    Vs = lit_vars(Simple),
+    Anno = get_anno(Simple),
+    {#isimple{anno=#a{us=Vs,anno=Anno},term=Simple},St}.
 
 uexpr_list(Les0, Ks, St0) ->
     mapfoldl(fun (Le, St) -> uexpr(Le, Ks, St) end, St0, Les0).
@@ -1790,7 +2087,7 @@ ufun_clauses(Lcs, Ks, St0) ->
 
 ufun_clause(Cl0, Ks, St0) ->
     {Cl1,Pvs,Used,_,St1} = uclause(Cl0, [], Ks, St0),
-    A0 = get_ianno(Cl1),
+    A0 = get_anno(Cl1),
     A = A0#a{us=subtract(intersection(Used, Ks), Pvs),ns=[]},
     {Cl1#iclause{anno=A},St1}.
 
@@ -1805,7 +2102,8 @@ upattern(#c_var{name=V}=Var, Ks, St0) ->
 	true ->
 	    {N,St1} = new_var_name(St0),
 	    New = #c_var{name=N},
-	    Test = #icall{anno=#a{us=add_element(N, [V])},
+	    LA = get_lineno_anno(Var),
+	    Test = #icall{anno=#a{anno=LA,us=add_element(N, [V])},
 			  module=#c_literal{val=erlang},
 			  name=#c_literal{val='=:='},
 			  args=[New,Var]},
@@ -1820,6 +2118,17 @@ upattern(#c_cons{hd=H0,tl=T0}=Cons, Ks, St0) ->
 upattern(#c_tuple{es=Es0}=Tuple, Ks, St0) ->
     {Es1,Esg,Esv,Eus,St1} = upattern_list(Es0, Ks, St0),
     {Tuple#c_tuple{es=Es1},Esg,Esv,Eus,St1};
+upattern(#c_map{es=Es0}=Map, Ks, St0) ->
+    {Es1,Esg,Esv,Eus,St1} = upattern_list(Es0, Ks, St0),
+    {Map#c_map{es=Es1},Esg,Esv,Eus,St1};
+upattern(#c_map_pair{op=#c_literal{val=exact},key=K0,val=V0}=Pair,Ks,St0) ->
+    {V,Vg,Vn,Vu,St1} = upattern(V0, Ks, St0),
+    % A variable key must be considered used here
+    Ku = case K0 of
+	#c_var{name=Name} -> [Name];
+	_ -> []
+    end,
+    {Pair#c_map_pair{val=V},Vg,Vn,union(Ku,Vu),St1};
 upattern(#c_binary{segments=Es0}=Bin, Ks, St0) ->
     {Es1,Esg,Esv,Eus,St1} = upat_bin(Es0, Ks, St0),
     {Bin#c_binary{segments=Es1},Esg,Esv,Eus,St1};
@@ -1910,7 +2219,7 @@ new_in_all([Le|Les]) ->
     foldl(fun (L, Ns) -> intersection((get_anno(L))#a.ns, Ns) end,
 	  (get_anno(Le))#a.ns, Les);
 new_in_all([]) -> [].
-
+
 %% The AfterVars are the variables which are used afterwards.  We need
 %% this to work out which variables are actually exported and used
 %% from case/receive.  In subblocks/clauses the AfterVars of the block
@@ -1942,7 +2251,8 @@ cguard(Gs, St0) ->
 
 cexprs([#iset{var=#c_var{name=Name}=Var}=Iset], As, St) ->
     %% Make return value explicit, and make Var true top level.
-    cexprs([Iset,Var#c_var{anno=#a{us=[Name]}}], As, St);
+    Isimple = #isimple{anno=#a{us=[Name]},term=Var},
+    cexprs([Iset,Isimple], As, St);
 cexprs([Le], As, St0) ->
     {Ce,Es,Us,St1} = cexpr(Le, As, St0),
     Exp = make_vars(As),			%The export variables
@@ -2019,15 +2329,25 @@ cexpr(#itry{anno=A,args=La,vars=Vs,body=Lb,evars=Evs,handler=Lh}, As, St0) ->
 cexpr(#icatch{anno=A,body=Les}, _As, St0) ->
     {Ces,_Us1,St1} = cexprs(Les, [], St0),	%Never export!
     {#c_catch{body=Ces},[],A#a.us,St1};
-cexpr(#ifun{anno=A,id=Id,vars=Args,clauses=Lcs,fc=Lfc}, _As, St0) ->
-    {Ccs,St1} = cclauses(Lcs, [], St0),		%NEVER export!
-    {Cfc,St2} = cclause(Lfc, [], St1),
-    Anno = A#a.anno,
-    {#c_fun{anno=Id++Anno,vars=Args,
-	    body=#c_case{anno=Anno,
-			 arg=set_anno(core_lib:make_values(Args), Anno),
-			 clauses=Ccs ++ [Cfc]}},
-     [],A#a.us,St2};
+cexpr(#ifun{name=unnamed}=Fun, As, St0) ->
+    cfun(Fun, As, St0);
+cexpr(#ifun{anno=#a{us=Us0}=A0,name={named,Name},fc=#iclause{pats=Ps}}=Fun0,
+      As, St0) ->
+    case is_element(Name, Us0) of
+        false ->
+            cfun(Fun0, As, St0);
+        true ->
+            A1 = A0#a{us=del_element(Name, Us0)},
+            Fun1 = Fun0#ifun{anno=A1},
+            {#c_fun{body=Body}=CFun0,[],Us1,St1} = cfun(Fun1, As, St0),
+            RecVar = #c_var{name={Name,length(Ps)}},
+            Let = #c_let{vars=[#c_var{name=Name}],arg=RecVar,body=Body},
+            CFun1 = CFun0#c_fun{body=Let},
+            Letrec = #c_letrec{anno=A0#a.anno,
+			       defs=[{RecVar,CFun1}],
+                               body=RecVar},
+            {Letrec,[],Us1,St1}
+    end;
 cexpr(#iapply{anno=A,op=Op,args=Args}, _As, St) ->
     {#c_apply{anno=A#a.anno,op=Op,args=Args},[],A#a.us,St};
 cexpr(#icall{anno=A,module=Mod,name=Name,args=Args}, _As, St) ->
@@ -2047,30 +2367,19 @@ cexpr(#c_literal{}=Lit, _As, St) ->
     Anno = get_anno(Lit),
     Vs = Anno#a.us,
     {set_anno(Lit, Anno#a.anno),[],Vs,St};
-cexpr(Lit, _As, St) ->
-    true = is_simple(Lit),		%Sanity check!
-    Anno = get_anno(Lit),
-    Vs = Anno#a.us,
-    %%Vs = lit_vars(Lit),
-    {set_anno(Lit, Anno#a.anno),[],Vs,St}.
-
-%% Kill the id annotations for any fun inside the expression.
-%% Necessary when duplicating code in try ... after.
-
-kill_id_anns(#ifun{clauses=Cs0}=Fun) ->
-    Cs = kill_id_anns(Cs0),
-    Fun#ifun{clauses=Cs,id=[]};
-kill_id_anns(#a{}=A) ->
-    %% Optimization: Don't waste time searching for funs inside annotations.
-    A;
-kill_id_anns([H|T]) ->
-    [kill_id_anns(H)|kill_id_anns(T)];
-kill_id_anns([]) -> [];
-kill_id_anns(Tuple) when is_tuple(Tuple) ->
-    L0 = tuple_to_list(Tuple),
-    L = kill_id_anns(L0),
-    list_to_tuple(L);
-kill_id_anns(Other) -> Other.
+cexpr(#isimple{anno=#a{us=Vs},term=Simple}, _As, St) ->
+    true = is_simple(Simple),		%Sanity check!
+    {Simple,[],Vs,St}.
+
+cfun(#ifun{anno=A,id=Id,vars=Args,clauses=Lcs,fc=Lfc}, _As, St0) ->
+    {Ccs,St1} = cclauses(Lcs, [], St0),     %NEVER export!
+    {Cfc,St2} = cclause(Lfc, [], St1),
+    Anno = A#a.anno,
+    {#c_fun{anno=Id++Anno,vars=Args,
+            body=#c_case{anno=Anno,
+                         arg=set_anno(core_lib:make_values(Args), Anno),
+                         clauses=Ccs ++ [Cfc]}},
+     [],A#a.us,St2}.
 
 %% lit_vars(Literal) -> [Var].
 
@@ -2078,14 +2387,11 @@ lit_vars(Lit) -> lit_vars(Lit, []).
 
 lit_vars(#c_cons{hd=H,tl=T}, Vs) -> lit_vars(H, lit_vars(T, Vs));
 lit_vars(#c_tuple{es=Es}, Vs) -> lit_list_vars(Es, Vs);
+lit_vars(#c_map{arg=V,es=Es}, Vs) -> lit_vars(V, lit_list_vars(Es, Vs));
+lit_vars(#c_map_pair{key=K,val=V}, Vs) -> lit_vars(K, lit_vars(V, Vs));
 lit_vars(#c_var{name=V}, Vs) -> add_element(V, Vs); 
 lit_vars(_, Vs) -> Vs.				%These are atomic
 
-% lit_bin_vars(Segs, Vs) ->
-%     foldl(fun (#c_bitstr{val=V,size=S}, Vs0) ->
-% 		  lit_vars(V, lit_vars(S, Vs0))
-% 	  end, Vs, Segs).
-
 lit_list_vars(Ls) -> lit_list_vars(Ls, []).
 
 lit_list_vars(Ls, Vs) ->
@@ -2099,20 +2405,26 @@ bitstr_vars(Segs, Vs) ->
  		  lit_vars(V, lit_vars(S, Vs0))
 	  end, Vs, Segs).
 
-lineno_anno(L, St) ->
-    {line, Line} = erl_parse:get_attribute(L, line),
-    if
-	Line < 0 ->
-	    [-Line] ++ St#core.file ++ [compiler_generated];
-	true ->
-	    [Line] ++ St#core.file
+record_anno(L, St) ->
+    case
+        erl_anno:record(L) andalso member(dialyzer, St#core.opts)
+    of
+        true ->
+            [record | lineno_anno(L, St)];
+        false ->
+            full_anno(L, St)
     end.
 
-get_ianno(Ce) ->
-    case get_anno(Ce) of
-	#a{}=A -> A;
-	A when is_list(A) -> #a{anno=A}
-    end.
+full_anno(L, #core{wanted=false}=St) ->
+    [result_not_wanted|lineno_anno(L, St)];
+full_anno(L, #core{wanted=true}=St) ->
+    lineno_anno(L, St).
+
+lineno_anno(L, St) ->
+    Line = erl_anno:line(L),
+    Generated = erl_anno:generated(L),
+    CompilerGenerated = [compiler_generated || Generated],
+    [Line] ++ St#core.file ++ CompilerGenerated.
 
 get_lineno_anno(Ce) ->
     case get_anno(Ce) of
@@ -2120,15 +2432,8 @@ get_lineno_anno(Ce) ->
 	A when is_list(A) -> A
     end.
 
-location(L) ->
-    {location,Location} = erl_parse:get_attribute(L, location),
-    Location.
-
-abs_line(L) ->
-    erl_parse:set_line(L, fun(Line) -> abs(Line) end).
-
-neg_line(L) ->
-    erl_parse:set_line(L, fun(Line) -> -abs(Line) end).
+no_compiler_warning(Anno) ->
+    erl_anno:set_generated(true, Anno).
 
 %%
 %% The following three functions are used both with cerl:cerl() and with i()'s
@@ -2148,6 +2453,9 @@ is_simple(#c_literal{}) -> true;
 is_simple(#c_cons{hd=H,tl=T}) ->
     is_simple(H) andalso is_simple(T);
 is_simple(#c_tuple{es=Es}) -> is_simple_list(Es);
+is_simple(#c_map{es=Es}) -> is_simple_list(Es);
+is_simple(#c_map_pair{key=K,val=V}) ->
+    is_simple(K) andalso is_simple(V);
 is_simple(_) -> false.
 
 -spec is_simple_list([cerl:cerl()]) -> boolean().
@@ -2165,8 +2473,14 @@ is_simple_list(Es) -> lists:all(fun is_simple/1, Es).
 format_error(nomatch) ->
     "pattern cannot possibly match";
 format_error(bad_binary) ->
-    "binary construction will fail because of a type mismatch".
-
-add_warning(Line, Term, #core{ws=Ws,file=[{file,File}]}=St) when Line >= 0 ->
-    St#core{ws=[{File,[{location(Line),?MODULE,Term}]}|Ws]};
-add_warning(_, _, St) -> St.
+    "binary construction will fail because of a type mismatch";
+format_error(badmap) ->
+    "map construction will fail because of a type mismatch".
+
+add_warning(Anno, Term, #core{ws=Ws,file=[{file,File}]}=St) ->
+    case erl_anno:generated(Anno) of
+        false ->
+            St#core{ws=[{File,[{erl_anno:location(Anno),?MODULE,Term}]}|Ws]};
+        true ->
+            St
+    end.
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 5f1c108f7c..b4bbc5e739 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -81,7 +82,7 @@
 -export([module/2,format_error/1]).
 
 -import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,splitwith/2,member/2,
-		keymember/3,keyfind/3,partition/2]).
+		keymember/3,keyfind/3,partition/2,droplast/1,last/1]).
 -import(ordsets, [add_element/2,del_element/2,union/2,union/1,subtract/2]).
 -import(cerl, [c_tuple/1]).
 
@@ -114,9 +115,9 @@ copy_anno(Kdst, Ksrc) ->
 	       ff,				%Current function
 	       vcount=0,			%Variable counter
 	       fcount=0,			%Fun counter
-	       ds=[],				%Defined variables
+               ds=cerl_sets:new() :: cerl_sets:set(), %Defined variables
 	       funs=[],				%Fun functions
-	       free=[],				%Free variables
+	       free=#{},			%Free variables
 	       ws=[]   :: [warning()],		%Warnings.
 	       guard_refc=0}).			%> 0 means in guard
 
@@ -131,24 +132,27 @@ module(#c_module{anno=A,name=M,exports=Es,attrs=As,defs=Fs}, _Options) ->
     {ok,#k_mdef{anno=A,name=M#c_literal.val,exports=Kes,attributes=Kas,
 		body=Kfs ++ St#kern.funs},lists:sort(St#kern.ws)}.
 
-attributes([{#c_literal{val=Name},Val}|As]) ->
+attributes([{#c_literal{val=Name},#c_literal{val=Val}}|As]) ->
     case include_attribute(Name) of
 	false ->
 	    attributes(As);
 	true ->
-	    [{Name,core_lib:literal_value(Val)}|attributes(As)]
+	    [{Name,Val}|attributes(As)]
     end;
 attributes([]) -> [].
 
 include_attribute(type) -> false;
 include_attribute(spec) -> false;
+include_attribute(callback) -> false;
 include_attribute(opaque) -> false;
 include_attribute(export_type) -> false;
+include_attribute(record) -> false;
+include_attribute(optional_callbacks) -> false;
 include_attribute(_) -> true.
 
 function({#c_var{name={F,Arity}=FA},Body}, St0) ->
     try
-	St1 = St0#kern{func=FA,ff=undefined,vcount=0,fcount=0,ds=sets:new()},
+	St1 = St0#kern{func=FA,ff=undefined,vcount=0,fcount=0,ds=cerl_sets:new()},
 	{#ifun{anno=Ab,vars=Kvs,body=B0},[],St2} = expr(Body, new_sub(), St1),
 	{B1,_,St3} = ubody(B0, return, St2),
 	%%B1 = B0, St3 = St2,				%Null second pass
@@ -160,8 +164,8 @@ function({#c_var{name={F,Arity}=FA},Body}, St0) ->
 	    io:fwrite("Function: ~w/~w\n", [F,Arity]),
 	    erlang:raise(Class, Error, Stack)
     end.
-	
-
+
+
 %% body(Cexpr, Sub, State) -> {Kexpr,[PreKepxr],State}.
 %%  Do the main sequence of a body.  A body ends in an atomic value or
 %%  values.  Must check if vector first so do expr.
@@ -238,7 +242,7 @@ gexpr_test_add(Ke, St0) ->
 expr(#c_var{anno=A,name={_Name,Arity}}=Fname, Sub, St) ->
     %% A local in an expression.
     %% For now, these are wrapped into a fun by reverse
-    %% etha-conversion, but really, there should be exactly one
+    %% eta-conversion, but really, there should be exactly one
     %% such "lambda function" for each escaping local name,
     %% instead of one for each occurrence as done now.
     Vs = [#c_var{name=list_to_atom("V" ++ integer_to_list(V))} ||
@@ -272,6 +276,8 @@ expr(#c_cons{anno=A,hd=Ch,tl=Ct}, Sub, St0) ->
 expr(#c_tuple{anno=A,es=Ces}, Sub, St0) ->
     {Kes,Ep,St1} = atomic_list(Ces, Sub, St0),
     {#k_tuple{anno=A,es=Kes},Ep,St1};
+expr(#c_map{anno=A,arg=Var,es=Ces}, Sub, St0) ->
+    expr_map(A, Var, Ces, Sub, St0);
 expr(#c_binary{anno=A,segments=Cv}, Sub, St0) ->
     try atomic_bin(Cv, Sub, St0) of
 	{Kv,Ep,St1} ->
@@ -347,7 +353,7 @@ expr(#c_case{arg=Ca,clauses=Ccs}, Sub, St0) ->
     {Kvs,Pv,St2} = match_vars(Ka, St1),		%Must have variables here!
     {Km,St3} = kmatch(Kvs, Ccs, Sub, St2),
     Match = flatten_seq(build_match(Kvs, Km)),
-    {last(Match),Pa ++ Pv ++ first(Match),St3};
+    {last(Match),Pa ++ Pv ++ droplast(Match),St3};
 expr(#c_receive{anno=A,clauses=Ccs0,timeout=Ce,action=Ca}, Sub, St0) ->
     {Ke,Pe,St1} = atomic(Ce, Sub, St0),		%Force this to be atomic!
     {Rvar,St2} = new_var(St1),
@@ -396,7 +402,7 @@ expr(#c_call{anno=A,module=M0,name=F0,args=Cargs}, Sub, St0) ->
 	    Call = #c_call{anno=A,
 			   module=#c_literal{val=erlang},
 			   name=#c_literal{val=apply},
-			   args=[M0,F0,make_list(Cargs)]},
+			   args=[M0,F0,cerl:make_list(Cargs)]},
 	    expr(Call, Sub, St1);
 	_ ->
 	    {[M1,F1|Kargs],Ap,St} = atomic_list([M0,F0|Cargs], Sub, St1),
@@ -491,7 +497,91 @@ translate_match_fail_1(Anno, As, Sub, #kern{ff=FF}) ->
     end.
 
 translate_fc(Args) ->
-    [#c_literal{val=function_clause},make_list(Args)].
+    [#c_literal{val=function_clause},cerl:make_list(Args)].
+
+expr_map(A,Var0,Ces,Sub,St0) ->
+    {Var,Mps,St1} = expr(Var0, Sub, St0),
+    {Km,Eps,St2} = map_split_pairs(A, Var, Ces, Sub, St1),
+    {Km,Eps++Mps,St2}.
+
+map_split_pairs(A, Var, Ces, Sub, St0) ->
+    %% 1. Force variables.
+    %% 2. Group adjacent pairs with literal keys.
+    %% 3. Within each such group, remove multiple assignments to the same key.
+    %% 4. Partition each group according to operator ('=>' and ':=').
+    Pairs0 = [{Op,K,V} ||
+		 #c_map_pair{op=#c_literal{val=Op},key=K,val=V} <- Ces],
+    {Pairs,Esp,St1} = foldr(fun
+	    ({Op,K0,V0}, {Ops,Espi,Sti0}) when Op =:= assoc; Op =:= exact ->
+		{K,Eps1,Sti1} = atomic(K0, Sub, Sti0),
+		{V,Eps2,Sti2} = atomic(V0, Sub, Sti1),
+		{[{Op,K,V}|Ops],Eps1 ++ Eps2 ++ Espi,Sti2}
+	end, {[],[],St0}, Pairs0),
+    map_split_pairs_1(A, Var, Pairs, Esp, St1).
+
+map_split_pairs_1(A, Map0, [{Op,Key,Val}|Pairs1]=Pairs0, Esp0, St0) ->
+    {Map1,Em,St1} = force_atomic(Map0, St0),
+    case Key of
+	#k_var{} ->
+	    %% Don't combine variable keys with other keys.
+	    Kes = [#k_map_pair{key=Key,val=Val}],
+	    Map = #k_map{anno=A,op=Op,var=Map1,es=Kes},
+	    map_split_pairs_1(A, Map, Pairs1, Esp0 ++ Em, St1);
+	_ ->
+	    %% Literal key. Split off all literal keys.
+	    {L,Pairs} = splitwith(fun({_,#k_var{},_}) -> false;
+				     ({_,_,_}) -> true
+				  end, Pairs0),
+	    {Map,Esp,St2} = map_group_pairs(A, Map1, L, Esp0 ++ Em, St1),
+	    map_split_pairs_1(A, Map, Pairs, Esp, St2)
+    end;
+map_split_pairs_1(_, Map, [], Esp, St0) ->
+    {Map,Esp,St0}.
+
+map_group_pairs(A, Var, Pairs0, Esp, St0) ->
+    Pairs = map_remove_dup_keys(Pairs0),
+    Assoc = [#k_map_pair{key=K,val=V} || {_,{assoc,K,V}} <- Pairs],
+    Exact = [#k_map_pair{key=K,val=V} || {_,{exact,K,V}} <- Pairs],
+    case {Assoc,Exact} of
+	{[_|_],[]} ->
+	    {#k_map{anno=A,op=assoc,var=Var,es=Assoc},Esp,St0};
+	{[],[_|_]} ->
+	    {#k_map{anno=A,op=exact,var=Var,es=Exact},Esp,St0};
+	{[_|_],[_|_]} ->
+	    Map = #k_map{anno=A,op=assoc,var=Var,es=Assoc},
+	    {Mvar,Em,St1} = force_atomic(Map, St0),
+	    {#k_map{anno=A,op=exact,var=Mvar,es=Exact},Esp ++ Em,St1}
+    end.
+
+map_remove_dup_keys(Es) ->
+    dict:to_list(map_remove_dup_keys(Es, dict:new())).
+
+map_remove_dup_keys([{assoc,K0,V}|Es0],Used0) ->
+    K = map_key_clean(K0),
+    Op = case dict:find(K, Used0) of
+	     {ok,{exact,_,_}} -> exact;
+	     _                -> assoc
+	 end,
+    Used1 = dict:store(K, {Op,K0,V}, Used0),
+    map_remove_dup_keys(Es0, Used1);
+map_remove_dup_keys([{exact,K0,V}|Es0],Used0) ->
+    K = map_key_clean(K0),
+    Op = case dict:find(K, Used0) of
+	     {ok,{assoc,_,_}} -> assoc;
+	     _                -> exact
+	 end,
+    Used1 = dict:store(K, {Op,K0,V}, Used0),
+    map_remove_dup_keys(Es0, Used1);
+map_remove_dup_keys([], Used) -> Used.
+
+%% Be explicit instead of using set_kanno(K, []).
+map_key_clean(#k_var{name=V})    -> {var,V};
+map_key_clean(#k_literal{val=V}) -> {lit,V};
+map_key_clean(#k_int{val=V})     -> {lit,V};
+map_key_clean(#k_float{val=V})   -> {lit,V};
+map_key_clean(#k_atom{val=V})    -> {lit,V};
+map_key_clean(#k_nil{})          -> {lit,[]}.
+
 
 %% call_type(Module, Function, Arity) -> call | bif | apply | error.
 %%  Classify the call.
@@ -569,12 +659,12 @@ atomic_bin([#c_bitstr{anno=A,val=E0,size=S0,unit=U0,type=T,flags=Fs0}|Es0],
     {E,Ap1,St1} = atomic(E0, Sub, St0),
     {S1,Ap2,St2} = atomic(S0, Sub, St1),
     validate_bin_element_size(S1),
-    U1 = core_lib:literal_value(U0),
-    Fs1 = core_lib:literal_value(Fs0),
+    U1 = cerl:concrete(U0),
+    Fs1 = cerl:concrete(Fs0),
     {Es,Ap3,St3} = atomic_bin(Es0, Sub, St2),
     {#k_bin_seg{anno=A,size=S1,
 		unit=U1,
-		type=core_lib:literal_value(T),
+		type=cerl:concrete(T),
 		flags=Fs1,
 		seg=E,next=Es},
      Ap1++Ap2++Ap3,St3};
@@ -629,15 +719,15 @@ force_variable(Ke, St0) ->
 %%  handling.
 
 pattern(#c_var{anno=A,name=V}, _Isub, Osub, St0) ->
-    case sets:is_element(V, St0#kern.ds) of
+    case cerl_sets:is_element(V, St0#kern.ds) of
 	true ->
 	    {New,St1} = new_var_name(St0),
 	    {#k_var{anno=A,name=New},
 	     set_vsub(V, New, Osub),
-	     St1#kern{ds=sets:add_element(New, St1#kern.ds)}};
+	     St1#kern{ds=cerl_sets:add_element(New, St1#kern.ds)}};
 	false ->
 	    {#k_var{anno=A,name=V},Osub,
-	     St0#kern{ds=sets:add_element(V, St0#kern.ds)}}
+	     St0#kern{ds=cerl_sets:add_element(V, St0#kern.ds)}}
     end;
 pattern(#c_literal{anno=A,val=Val}, _Isub, Osub, St) ->
     {#k_literal{anno=A,val=Val},Osub,St};
@@ -648,6 +738,9 @@ pattern(#c_cons{anno=A,hd=Ch,tl=Ct}, Isub, Osub0, St0) ->
 pattern(#c_tuple{anno=A,es=Ces}, Isub, Osub0, St0) ->
     {Kes,Osub1,St1} = pattern_list(Ces, Isub, Osub0, St0),
     {#k_tuple{anno=A,es=Kes},Osub1,St1};
+pattern(#c_map{anno=A,es=Ces}, Isub, Osub0, St0) ->
+    {Kes,Osub1,St1} = pattern_map_pairs(Ces, Isub, Osub0, St0),
+    {#k_map{anno=A,op=exact,es=Kes},Osub1,St1};
 pattern(#c_binary{anno=A,segments=Cv}, Isub, Osub0, St0) ->
     {Kv,Osub1,St1} = pattern_bin(Cv, Isub, Osub0, St0),
     {#k_binary{anno=A,segs=Kv},Osub1,St1};
@@ -662,6 +755,24 @@ flatten_alias(#c_alias{var=V,pat=P}) ->
     {[V|Vs],Pat};
 flatten_alias(Pat) -> {[],Pat}.
 
+pattern_map_pairs(Ces0, Isub, Osub0, St0) ->
+    %% pattern the pair keys and values as normal
+    {Kes,{Osub1,St1}} = lists:mapfoldl(fun
+	    (#c_map_pair{anno=A,key=Ck,val=Cv},{Osubi0,Sti0}) ->
+		{Kk,[],Sti1} = expr(Ck, Isub, Sti0),
+		{Kv,Osubi2,Sti2} = pattern(Cv, Isub, Osubi0, Sti1),
+		{#k_map_pair{anno=A,key=Kk,val=Kv},{Osubi2,Sti2}}
+	end, {Osub0, St0}, Ces0),
+    %% It is later assumed that these keys are term sorted
+    %% so we need to sort them here
+    Kes1 = lists:sort(fun
+	    (#k_map_pair{key=KkA},#k_map_pair{key=KkB}) ->
+		A = map_key_clean(KkA),
+		B = map_key_clean(KkB),
+		erts_internal:cmp_term(A,B) < 0
+	end, Kes),
+    {Kes1,Osub1,St1}.
+
 pattern_bin(Es, Isub, Osub0, St0) ->
     {Kbin,{_,Osub},St} = pattern_bin_1(Es, Isub, Osub0, St0),
     {Kbin,Osub,St}.
@@ -680,8 +791,8 @@ pattern_bin_1([#c_bitstr{anno=A,val=E0,size=S0,unit=U,type=T,flags=Fs}|Es0],
 		%% problems.
 		#k_atom{val=bad_size}
 	end,
-    U0 = core_lib:literal_value(U),
-    Fs0 = core_lib:literal_value(Fs),
+    U0 = cerl:concrete(U),
+    Fs0 = cerl:concrete(Fs),
     %%ok= io:fwrite("~w: ~p~n", [?LINE,{B0,S,U0,Fs0}]),
     {E,Osub1,St2} = pattern(E0, Isub0, Osub0, St1),
     Isub1 = case E0 of
@@ -692,7 +803,7 @@ pattern_bin_1([#c_bitstr{anno=A,val=E0,size=S0,unit=U,type=T,flags=Fs}|Es0],
     {Es,{Isub,Osub},St3} = pattern_bin_1(Es0, Isub1, Osub1, St2),
     {#k_bin_seg{anno=A,size=S,
 		unit=U0,
-		type=core_lib:literal_value(T),
+		type=cerl:concrete(T),
 		flags=Fs0,
 		seg=E,next=Es},
      {Isub,Osub},St3};
@@ -729,12 +840,23 @@ get_vsub(V, Vsub) ->
 set_vsub(V, S, Vsub) ->
     orddict:store(V, S, Vsub).
 
-subst_vsub(V, S, Vsub0) ->
-    %% Fold chained substitutions.
-    Vsub1 = orddict:map(fun (_, V1) when V1 =:= V -> S;
-			    (_, V1) -> V1
-			end, Vsub0),
-    orddict:store(V, S, Vsub1).
+subst_vsub(Key, New, [{K,Key}|Dict]) ->
+    %% Fold chained substitution.
+    [{K,New}|subst_vsub(Key, New, Dict)];
+subst_vsub(Key, New, [{K,_}|_]=Dict) when Key < K ->
+    %% Insert the new substitution here, and continue
+    %% look for chained substitutions.
+    [{Key,New}|subst_vsub_1(Key, New, Dict)];
+subst_vsub(Key, New, [{K,_}=E|Dict]) when Key > K ->
+    [E|subst_vsub(Key, New, Dict)];
+subst_vsub(Key, New, []) -> [{Key,New}].
+
+subst_vsub_1(V, S, [{K,V}|Dict]) ->
+    %% Fold chained substitution.
+    [{K,S}|subst_vsub_1(V, S, Dict)];
+subst_vsub_1(V, S, [E|Dict]) ->
+    [E|subst_vsub_1(V, S, Dict)];
+subst_vsub_1(_, _, []) -> [].
 
 get_fsub(F, A, Fsub) ->
     case orddict:find({F,A}, Fsub) of
@@ -779,7 +901,7 @@ new_vars(0, St, Vs) -> {Vs,St}.
 make_vars(Vs) -> [ #k_var{name=V} || V <- Vs ].
 
 add_var_def(V, St) ->
-    St#kern{ds=sets:add_element(V#k_var.name, St#kern.ds)}.
+    St#kern{ds=cerl_sets:add_element(V#k_var.name, St#kern.ds)}.
 
 %%add_vars_def(Vs, St) ->
 %%    Ds = foldl(fun (#k_var{name=V}, Ds) -> add_element(V, Ds) end,
@@ -826,15 +948,6 @@ foldr2(Fun, Acc0, [E1|L1], [E2|L2]) ->
     foldr2(Fun, Acc1, L1, L2);
 foldr2(_, Acc, [], []) -> Acc.
 
-%% first([A]) -> [A].
-%% last([A]) -> A.
-
-last([L]) -> L;
-last([_|T]) -> last(T).
-
-first([_]) -> [];
-first([H|T]) -> [H|first(T)].
-
 %% This code implements the algorithm for an optimizing compiler for
 %% pattern matching given "The Implementation of Functional
 %% Programming Languages" by Simon Peyton Jones. The code is much
@@ -1015,7 +1128,8 @@ match_con_1([U|_Us] = L, Cs, Def, St0) ->
     %% Extract clauses for different constructors (types).
     %%ok = io:format("match_con ~p~n", [Cs]),
     Ttcs = select_types([k_binary], Cs) ++ select_bin_con(Cs) ++
-	select_types([k_cons,k_tuple,k_atom,k_float,k_int,k_nil,k_literal], Cs),
+	select_types([k_cons,k_tuple,k_map,k_atom,k_float,k_int,
+		      k_nil,k_literal], Cs),
     %%ok = io:format("ttcs = ~p~n", [Ttcs]),
     {Scs,St1} =
 	mapfoldl(fun ({T,Tcs}, St) ->
@@ -1251,10 +1365,9 @@ group_value(k_cons, Cs) -> [Cs];		%These are single valued
 group_value(k_nil, Cs) -> [Cs];
 group_value(k_binary, Cs) -> [Cs];
 group_value(k_bin_end, Cs) -> [Cs];
-group_value(k_bin_seg, Cs) ->
-    group_bin_seg(Cs);
-group_value(k_bin_int, Cs) ->
-    [Cs];
+group_value(k_bin_seg, Cs) -> group_bin_seg(Cs);
+group_value(k_bin_int, Cs) -> [Cs];
+group_value(k_map, Cs) -> group_map(Cs);
 group_value(_, Cs) ->
     %% group_value(Cs).
     Cd = foldl(fun (C, Gcs0) -> dict:append(clause_val(C), C, Gcs0) end,
@@ -1267,6 +1380,12 @@ group_bin_seg([C1|Cs]) ->
     [[C1|More]|group_bin_seg(Rest)];
 group_bin_seg([]) -> [].
 
+group_map([C1|Cs]) ->
+    V1 = clause_val(C1),
+    {More,Rest} = splitwith(fun (C) -> clause_val(C) =:= V1 end, Cs),
+    [[C1|More]|group_map(Rest)];
+group_map([]) -> [].
+
 %% Profiling shows that this quadratic implementation account for a big amount
 %% of the execution time if there are many values.
 % group_value([C|Cs]) ->
@@ -1315,6 +1434,13 @@ get_match(#k_bin_int{}=BinInt, St0) ->
 get_match(#k_tuple{es=Es}, St0) ->
     {Mes,St1} = new_vars(length(Es), St0),
     {#k_tuple{es=Mes},Mes,St1};
+get_match(#k_map{op=exact,es=Es0}, St0) ->
+    {Mes,St1} = new_vars(length(Es0), St0),
+    {Es,_} = mapfoldl(fun
+	    (#k_map_pair{}=Pair, [V|Vs]) ->
+		{Pair#k_map_pair{val=V},Vs}
+	end, Mes, Es0),
+    {#k_map{op=exact,es=Es},Mes,St1};
 get_match(M, St) ->
     {M,[],St}.
 
@@ -1331,7 +1457,11 @@ new_clauses(Cs0, U, St) ->
 				     [S,N|As];
 				 #k_bin_int{next=N} ->
 				     [N|As];
-				 _Other -> As
+				 #k_map{op=exact,es=Es} ->
+				     Vals = [V || #k_map_pair{val=V} <- Es],
+				     Vals ++ As;
+				 _Other ->
+				     As
 			     end,
 		      Vs = arg_alias(Arg),
 		      Osub1 = foldl(fun (#k_var{name=V}, Acc) ->
@@ -1406,6 +1536,7 @@ arg_con(Arg) ->
 	#k_nil{} -> k_nil;
 	#k_cons{} -> k_cons; 
 	#k_tuple{} -> k_tuple;
+	#k_map{} -> k_map;
 	#k_binary{} -> k_binary;
 	#k_bin_end{} -> k_bin_end;
 	#k_bin_seg{} -> k_bin_seg;
@@ -1426,9 +1557,15 @@ arg_val(Arg, C) ->
 		    {#k_var{name=get_vsub(V, Isub)},U,T,Fs};
 		_ ->
 		    {set_kanno(S, []),U,T,Fs}
-	    end
+	    end;
+	#k_map{op=exact,es=Es} ->
+	    lists:sort(fun(A,B) ->
+			%% on the form K :: {'lit' | 'var', term()}
+			%% lit < var as intended
+			erts_internal:cmp_term(A,B) < 0
+		end, [map_key_clean(Key) || #k_map_pair{key=Key} <- Es])
     end.
-
+
 %% ubody_used_vars(Expr, State) -> [UsedVar]
 %%  Return all used variables for the body sequence. Much more
 %%  efficient than using ubody/3 if the body contains nested letrecs.
@@ -1703,14 +1840,17 @@ handle_reuse_anno_1(V, _St) -> V.
 %% get_free(Name, Arity, State) -> [Free].
 %% store_free(Name, Arity, [Free], State) -> State.
 
-get_free(F, A, St) ->
-    case orddict:find({F,A}, St#kern.free) of
-	{ok,Val} -> Val;
-	error -> []
+get_free(F, A, #kern{free=FreeMap}) ->
+    Key = {F,A},
+    case FreeMap of
+	#{Key:=Val} -> Val;
+	_ -> []
     end.
 
-store_free(F, A, Free, St) ->
-    St#kern{free=orddict:store({F,A}, Free, St#kern.free)}.
+store_free(F, A, Free, #kern{free=FreeMap0}=St) ->
+    Key = {F,A},
+    FreeMap = FreeMap0#{Key=>Free},
+    St#kern{free=FreeMap}.
 
 break_rets({break,Rs}) -> Rs;
 break_rets(return) -> [].
@@ -1795,6 +1935,10 @@ lit_vars(#k_atom{}) -> [];
 lit_vars(#k_nil{}) -> [];
 lit_vars(#k_cons{hd=H,tl=T}) ->
     union(lit_vars(H), lit_vars(T));
+lit_vars(#k_map{var=Var,es=Es}) ->
+    lit_list_vars([Var|Es]);
+lit_vars(#k_map_pair{key=K,val=V}) ->
+    union(lit_vars(K), lit_vars(V));
 lit_vars(#k_binary{segs=V}) -> lit_vars(V);
 lit_vars(#k_bin_end{}) -> [];
 lit_vars(#k_bin_seg{size=Size,seg=S,next=N}) ->
@@ -1809,6 +1953,7 @@ lit_list_vars(Ps) ->
 %% pat_vars(Pattern) -> {[UsedVarName],[NewVarName]}.
 %%  Return variables in a pattern.  All variables are new variables
 %%  except those in the size field of binary segments.
+%%  and map_pair keys
 
 pat_vars(#k_var{name=N}) -> {[],[N]};
 %%pat_vars(#k_char{}) -> {[],[]};
@@ -1830,7 +1975,13 @@ pat_vars(#k_bin_int{size=Size}) ->
     {U,[]};
 pat_vars(#k_bin_end{}) -> {[],[]};
 pat_vars(#k_tuple{es=Es}) ->
-    pat_list_vars(Es).
+    pat_list_vars(Es);
+pat_vars(#k_map{es=Es}) ->
+    pat_list_vars(Es);
+pat_vars(#k_map_pair{key=K,val=V}) ->
+    {U1,New} = pat_vars(V),
+    {[], U2} = pat_vars(K),
+    {union(U1,U2),New}.
 
 pat_list_vars(Ps) ->
     foldl(fun (P, {Used0,New0}) ->
@@ -1838,11 +1989,6 @@ pat_list_vars(Ps) ->
 		  {union(Used0, Used),union(New0, New)} end,
 	  {[],[]}, Ps).
 
-make_list(Es) ->
-    foldr(fun(E, Acc) ->
- 		  #c_cons{hd=E,tl=Acc}
- 	  end, #c_literal{val=[]}, Es).
-
 %% List of integers in interval [N,M]. Empty list if N > M.
 
 integers(N, M) when N =< M ->
@@ -1875,7 +2021,7 @@ format_error(bad_segment_size) ->
 
 add_warning(none, Term, Anno, #kern{ws=Ws}=St) ->
     File = get_file(Anno),
-    St#kern{ws=[{File,[{?MODULE,Term}]}|Ws]};
+    St#kern{ws=[{File,[{none,?MODULE,Term}]}|Ws]};
 add_warning(Line, Term, Anno, #kern{ws=Ws}=St) ->
     File = get_file(Anno),
     St#kern{ws=[{File,[{Line,?MODULE,Term}]}|Ws]}.
diff --git a/lib/compiler/src/v3_kernel.hrl b/lib/compiler/src/v3_kernel.hrl
index fb8baf398b..5216a1a620 100644
--- a/lib/compiler/src/v3_kernel.hrl
+++ b/lib/compiler/src/v3_kernel.hrl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -38,6 +39,8 @@
 -record(k_nil, {anno=[]}).
 
 -record(k_tuple, {anno=[],es}).
+-record(k_map, {anno=[],var=#k_literal{val=#{}},op,es}).
+-record(k_map_pair, {anno=[],key,val}).
 -record(k_cons, {anno=[],hd,tl}).
 -record(k_binary, {anno=[],segs}).
 -record(k_bin_seg, {anno=[],size,unit,type,flags,seg,next}).
diff --git a/lib/compiler/src/v3_kernel_pp.erl b/lib/compiler/src/v3_kernel_pp.erl
index e363a5387a..0b90f0a1e0 100644
--- a/lib/compiler/src/v3_kernel_pp.erl
+++ b/lib/compiler/src/v3_kernel_pp.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -104,6 +105,30 @@ format_1(#k_tuple{es=Es}, Ctxt) ->
      format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
      $}
     ];
+format_1(#k_map{var=#k_literal{val=M},op=assoc,es=Es}, Ctxt) when is_map(M), map_size(M) =:= 0 ->
+    ["~{",
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     "}~"
+    ];
+format_1(#k_map{var=#k_literal{val=M},op=exact,es=Es}, Ctxt) when is_map(M), map_size(M) =:= 0 ->
+    ["::{",
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     "}::"
+    ];
+format_1(#k_map{var=Var,op=assoc,es=Es}, Ctxt) ->
+    ["~{",
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     " | ",format_1(Var, Ctxt),
+     "}~"
+    ];
+format_1(#k_map{var=Var,op=exact,es=Es}, Ctxt) ->
+    ["::{",
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     " | ",format_1(Var, Ctxt),
+     "}::"
+    ];
+format_1(#k_map_pair{key=K,val=V}, Ctxt) ->
+    ["<",format(K, Ctxt),",",format(V, Ctxt),">"];
 format_1(#k_binary{segs=S}, Ctxt) ->
     ["#<",format(S, ctxt_bump_indent(Ctxt, 2)),">#"];
 format_1(#k_bin_seg{next=Next}=S, Ctxt) ->
diff --git a/lib/compiler/src/v3_life.erl b/lib/compiler/src/v3_life.erl
index 2cc3493570..1452b78d1d 100644
--- a/lib/compiler/src/v3_life.erl
+++ b/lib/compiler/src/v3_life.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1999-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -45,7 +46,7 @@
 
 -export([vdb_find/2]).
 
--import(lists, [member/2,map/2,foldl/3,reverse/1,sort/1]).
+-import(lists, [member/2,map/2,reverse/1,sort/1]).
 -import(ordsets, [add_element/2,intersection/2,union/2]).
 
 -include("v3_kernel.hrl").
@@ -68,7 +69,7 @@ functions([], Acc) -> reverse(Acc).
 function(#k_fdef{anno=#k{a=Anno},func=F,arity=Ar,vars=Vs,body=Kb}) ->
     try
 	As = var_list(Vs),
-	Vdb0 = foldl(fun ({var,N}, Vdb) -> new_var(N, 0, Vdb) end, [], As),
+	Vdb0 = init_vars(As),
 	%% Force a top-level match!
 	B0 = case Kb of
 		 #k_match{} -> Kb;
@@ -94,14 +95,14 @@ function(#k_fdef{anno=#k{a=Anno},func=F,arity=Ar,vars=Vs,body=Kb}) ->
 body(#k_seq{arg=Ke,body=Kb}, I, Vdb0) ->
     %%ok = io:fwrite("life ~w:~p~n", [?LINE,{Ke,I,Vdb0}]),
     A = get_kanno(Ke),
-    Vdb1 = use_vars(A#k.us, I, new_vars(A#k.ns, I, Vdb0)),
+    Vdb1 = use_vars(union(A#k.us, A#k.ns), I, Vdb0),
     {Es,MaxI,Vdb2} = body(Kb, I+1, Vdb1),
     E = expr(Ke, I, Vdb2),
     {[E|Es],MaxI,Vdb2};
 body(Ke, I, Vdb0) ->
     %%ok = io:fwrite("life ~w:~p~n", [?LINE,{Ke,I,Vdb0}]),
     A = get_kanno(Ke),
-    Vdb1 = use_vars(A#k.us, I, new_vars(A#k.ns, I, Vdb0)),
+    Vdb1 = use_vars(union(A#k.us, A#k.ns), I, Vdb0),
     E = expr(Ke, I, Vdb1),
     {[E],I,Vdb1}.
 
@@ -150,12 +151,12 @@ expr(#k_try_enter{anno=A,arg=Ka,vars=Vs,body=Kb,evars=Evs,handler=Kh}, I, Vdb) -
     %% the body and handler. Add try tag 'variable'.
     Ab = get_kanno(Kb),
     Ah = get_kanno(Kh),
-    Tdb1 = use_vars(Ab#k.us, I+3, use_vars(Ah#k.us, I+3, Tdb0)),
+    Tdb1 = use_vars(union(Ab#k.us, Ah#k.us), I+3, Tdb0),
     Tdb2 = vdb_sub(I, I+2, Tdb1),
     Vnames = fun (Kvar) -> Kvar#k_var.name end,	%Get the variable names
     {Aes,_,Adb} = body(Ka, I+2, add_var({catch_tag,I+1}, I+1, 1000000, Tdb2)),
-    {Bes,_,Bdb} = body(Kb, I+4, new_vars(map(Vnames, Vs), I+3, Tdb2)),
-    {Hes,_,Hdb} = body(Kh, I+4, new_vars(map(Vnames, Evs), I+3, Tdb2)),
+    {Bes,_,Bdb} = body(Kb, I+4, new_vars(sort(map(Vnames, Vs)), I+3, Tdb2)),
+    {Hes,_,Hdb} = body(Kh, I+4, new_vars(sort(map(Vnames, Evs)), I+3, Tdb2)),
     #l{ke={try_enter,#l{ke={block,Aes},i=I+1,vdb=Adb,a=[]},
 	   var_list(Vs),#l{ke={block,Bes},i=I+3,vdb=Bdb,a=[]},
 	   var_list(Evs),#l{ke={block,Hes},i=I+3,vdb=Hdb,a=[]}},
@@ -171,7 +172,7 @@ expr(#k_receive{anno=A,var=V,body=Kb,timeout=T,action=Ka,ret=Rs}, I, Vdb) ->
     %% Work out imported variables which need to be locked.
     Rdb = vdb_sub(I, I+1, Vdb),
     M = match(Kb, add_element(V#k_var.name, A#k.us), I+1, [],
- 	      new_var(V#k_var.name, I, Rdb)),
+	      new_vars([V#k_var.name], I, Rdb)),
     {Tes,_,Adb} = body(Ka, I+1, Rdb),
     #l{ke={receive_loop,atomic(T),variable(V),M,
 	   #l{ke=Tes,i=I+1,vdb=Adb,a=[]},var_list(Rs)},
@@ -199,12 +200,12 @@ body_try(#k_try{anno=A,arg=Ka,vars=Vs,body=Kb,evars=Evs,handler=Kh,ret=Rs},
     %% the body and handler. Add try tag 'variable'.
     Ab = get_kanno(Kb),
     Ah = get_kanno(Kh),
-    Tdb1 = use_vars(Ab#k.us, I+3, use_vars(Ah#k.us, I+3, Tdb0)),
+    Tdb1 = use_vars(union(Ab#k.us, Ah#k.us), I+3, Tdb0),
     Tdb2 = vdb_sub(I, I+2, Tdb1),
     Vnames = fun (Kvar) -> Kvar#k_var.name end,	%Get the variable names
     {Aes,_,Adb} = body(Ka, I+2, add_var({catch_tag,I+1}, I+1, locked, Tdb2)),
-    {Bes,_,Bdb} = body(Kb, I+4, new_vars(map(Vnames, Vs), I+3, Tdb2)),
-    {Hes,_,Hdb} = body(Kh, I+4, new_vars(map(Vnames, Evs), I+3, Tdb2)),
+    {Bes,_,Bdb} = body(Kb, I+4, new_vars(sort(map(Vnames, Vs)), I+3, Tdb2)),
+    {Hes,_,Hdb} = body(Kh, I+4, new_vars(sort(map(Vnames, Evs)), I+3, Tdb2)),
     #l{ke={'try',#l{ke={block,Aes},i=I+1,vdb=Adb,a=[]},
 	   var_list(Vs),#l{ke={block,Bes},i=I+3,vdb=Bdb,a=[]},
 	   var_list(Evs),#l{ke={block,Hes},i=I+3,vdb=Hdb,a=[]},
@@ -270,7 +271,7 @@ match(#k_select{anno=A,var=V,types=Kts}, Ls0, I, Ctxt, Vdb0) ->
 	   end,
     Vdb1 = use_vars(union(A#k.us, Ls1), I, Vdb0),
     Ts = [type_clause(Tc, Ls1, I+1, Ctxt, Vdb1) || Tc <- Kts],
-    #l{ke={select,literal2(V, Ctxt),Ts},i=I,vdb=Vdb1,a=Anno};
+    #l{ke={select,literal(V, Ctxt),Ts},i=I,vdb=Vdb1,a=Anno};
 match(#k_guard{anno=A,clauses=Kcs}, Ls, I, Ctxt, Vdb0) ->
     Vdb1 = use_vars(union(A#k.us, Ls), I, Vdb0),
     Cs = [guard_clause(G, Ls, I+1, Ctxt, Vdb1) || G <- Kcs],
@@ -297,7 +298,7 @@ val_clause(#k_val_clause{anno=A,val=V,body=Kb}, Ls0, I, Ctxt0, Vdb0) ->
 	       _ -> Ctxt0
 	   end,
     B = match(Kb, Ls1, I+1, Ctxt, Vdb1),
-    #l{ke={val_clause,literal2(V, Ctxt),B},i=I,vdb=use_vars(Bus, I+1, Vdb1),a=A#k.a}.
+    #l{ke={val_clause,literal(V, Ctxt),B},i=I,vdb=use_vars(Bus, I+1, Vdb1),a=A#k.a}.
 
 guard_clause(#k_guard_clause{anno=A,guard=Kg,body=Kb}, Ls, I, Ctxt, Vdb0) ->
     Vdb1 = use_vars(union(A#k.us, Ls), I+2, Vdb0),
@@ -323,7 +324,8 @@ type(k_tuple) -> tuple;
 type(k_binary) -> binary;
 type(k_bin_seg) -> bin_seg;
 type(k_bin_int) -> bin_int;
-type(k_bin_end) -> bin_end.
+type(k_bin_end) -> bin_end;
+type(k_map) -> map.
 
 %% variable(Klit) -> Lit.
 %% var_list([Klit]) -> [Lit].
@@ -349,6 +351,7 @@ atomic_list(Ks) -> [atomic(K) || K <- Ks].
 %% literal_list([Klit]) -> [Lit].
 
 literal(#k_var{name=N}, _) -> {var,N};
+literal(#k_literal{val=I}, _) -> {literal,I};
 literal(#k_int{val=I}, _) -> {integer,I};
 literal(#k_float{val=F}, _) -> {float,F};
 literal(#k_atom{val=N}, _) -> {atom,N};
@@ -357,50 +360,29 @@ literal(#k_nil{}, _) -> nil;
 literal(#k_cons{hd=H,tl=T}, Ctxt) ->
     {cons,[literal(H, Ctxt),literal(T, Ctxt)]};
 literal(#k_binary{segs=V}, Ctxt) ->
-	    {binary,literal(V, Ctxt)};
+    {binary,literal(V, Ctxt)};
+literal(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=[]}, Ctxt) ->
+    %% Only occurs in patterns.
+    {bin_seg,Ctxt,literal(S, Ctxt),U,T,Fs,[literal(Seg, Ctxt)]};
 literal(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=N}, Ctxt) ->
     {bin_seg,Ctxt,literal(S, Ctxt),U,T,Fs,
      [literal(Seg, Ctxt),literal(N, Ctxt)]};
+literal(#k_bin_int{size=S,unit=U,flags=Fs,val=Int,next=N}, Ctxt) ->
+    %% Only occurs in patterns.
+    {bin_int,Ctxt,literal(S, Ctxt),U,Fs,Int,
+     [literal(N, Ctxt)]};
 literal(#k_bin_end{}, Ctxt) ->
     {bin_end,Ctxt};
 literal(#k_tuple{es=Es}, Ctxt) ->
     {tuple,literal_list(Es, Ctxt)};
-literal(#k_literal{val=V}, _Ctxt) ->
-    {literal,V}.
+literal(#k_map{op=Op,var=Var,es=Es0}, Ctxt) ->
+    {map,Op,literal(Var, Ctxt),literal_list(Es0, Ctxt)};
+literal(#k_map_pair{key=K,val=V}, Ctxt) ->
+    {map_pair,literal(K, Ctxt),literal(V, Ctxt)}.
 
 literal_list(Ks, Ctxt) ->
     [literal(K, Ctxt) || K <- Ks].
 
-literal2(#k_var{name=N}, _) -> {var,N};
-literal2(#k_literal{val=I}, _) -> {literal,I};
-literal2(#k_int{val=I}, _) -> {integer,I};
-literal2(#k_float{val=F}, _) -> {float,F};
-literal2(#k_atom{val=N}, _) -> {atom,N};
-%%literal2(#k_char{val=C}, _) -> {char,C};
-literal2(#k_nil{}, _) -> nil;
-literal2(#k_cons{hd=H,tl=T}, Ctxt) ->
-    {cons,[literal2(H, Ctxt),literal2(T, Ctxt)]};
-literal2(#k_binary{segs=V}, Ctxt) ->
-    {binary,literal2(V, Ctxt)};
-literal2(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=[]}, Ctxt) ->
-    {bin_seg,Ctxt,literal2(S, Ctxt),U,T,Fs,[literal2(Seg, Ctxt)]};
-literal2(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=N}, Ctxt) ->
-    {bin_seg,Ctxt,literal2(S, Ctxt),U,T,Fs,
-     [literal2(Seg, Ctxt),literal2(N, Ctxt)]};
-literal2(#k_bin_int{size=S,unit=U,flags=Fs,val=Int,next=N}, Ctxt) ->
-    {bin_int,Ctxt,literal2(S, Ctxt),U,Fs,Int,
-     [literal2(N, Ctxt)]};
-literal2(#k_bin_end{}, Ctxt) ->
-    {bin_end,Ctxt};
-literal2(#k_tuple{es=Es}, Ctxt) ->
-    {tuple,literal_list2(Es, Ctxt)}.
-
-literal_list2(Ks, Ctxt) ->
-    [literal2(K, Ctxt) || K <- Ks].
-
-%% literal_bin(#k_bin_seg{size=S,unit=U,type=T,flags=Fs,seg=Seg,next=N}) ->
-%%     {bin_seg,literal(S),U,T,Fs,[literal(Seg),literal(N)]}
-
 
 %% is_gc_bif(Name, Arity) -> true|false
 %%  Determines whether the BIF Name/Arity might do a GC.
@@ -419,79 +401,78 @@ is_gc_bif(Bif, Arity) ->
 	 erl_internal:new_type_test(Bif, Arity) orelse
 	 erl_internal:comp_op(Bif, Arity)).
 
-%% new_var(VarName, I, Vdb) -> Vdb.
+%% Keep track of life time for variables.
+%%
+%% init_vars([{var,VarName}]) -> Vdb.
 %% new_vars([VarName], I, Vdb) -> Vdb.
-%% use_var(VarName, I, Vdb) -> Vdb.
 %% use_vars([VarName], I, Vdb) -> Vdb.
 %% add_var(VarName, F, L, Vdb) -> Vdb.
+%%
+%% The list of variable names for new_vars/3 and use_vars/3
+%% must be sorted.
 
-new_var(V, I, Vdb) ->
-    vdb_store_new(V, I, I, Vdb).
+init_vars(Vs) ->
+    vdb_new(Vs).
 
-new_vars(Vs, I, Vdb0) ->
-    foldl(fun (V, Vdb) -> new_var(V, I, Vdb) end, Vdb0, Vs).
+new_vars([], _, Vdb) -> Vdb;
+new_vars([V], I, Vdb) -> vdb_store_new(V, {V,I,I}, Vdb);
+new_vars(Vs, I, Vdb) -> vdb_update_vars(Vs, Vdb, I).
 
-use_var(V, I, Vdb) ->
+use_vars([], _, Vdb) ->
+    Vdb;
+use_vars([V], I, Vdb) ->
     case vdb_find(V, Vdb) of
-	{V,F,L} when I > L -> vdb_update(V, F, I, Vdb);
+	{V,F,L} when I > L -> vdb_update(V, {V,F,I}, Vdb);
 	{V,_,_} -> Vdb;
-	error -> vdb_store_new(V, I, I, Vdb)
-    end.
+	error -> vdb_store_new(V, {V,I,I}, Vdb)
+    end;
+use_vars(Vs, I, Vdb) -> vdb_update_vars(Vs, Vdb, I).
 
-use_vars([], _, Vdb) -> Vdb;
-use_vars([V], I, Vdb) -> use_var(V, I, Vdb);
-use_vars(Vs, I, Vdb) ->
-    Res = use_vars_1(sort(Vs), Vdb, I),
-    %% The following line can be used as an assertion.
-    %%   Res = foldl(fun (V, Vdb) -> use_var(V, I, Vdb) end, Vdb, Vs),
-    Res.
+add_var(V, F, L, Vdb) ->
+    vdb_store_new(V, {V,F,L}, Vdb).
 
-%% Measurements show that it is worthwhile having this special
-%% function that updates/inserts several variables at once.
+%% is_in_guard() -> true|false.
 
-use_vars_1([V|_]=Vs, [{V1,_,_}=Vd|Vdb], I) when V > V1 ->
-    [Vd|use_vars_1(Vs, Vdb, I)];
-use_vars_1([V|Vs], [{V1,_,_}|_]=Vdb, I) when V < V1 ->
-    %% New variable.
-    [{V,I,I}|use_vars_1(Vs, Vdb, I)];
-use_vars_1([V|Vs], [{_,F,L}=Vd|Vdb], I) ->
-    %% Existing variable.
-    if
-	I > L ->[{V,F,I}|use_vars_1(Vs, Vdb, I)];
-	true -> [Vd|use_vars_1(Vs, Vdb, I)]
-    end;
-use_vars_1([V|Vs], [], I) ->
-    %% New variable.
-    [{V,I,I}|use_vars_1(Vs, [], I)];
-use_vars_1([], Vdb, _) -> Vdb.
+is_in_guard() ->
+    get(guard_refc) > 0.
 
-add_var(V, F, L, Vdb) ->
-    vdb_store_new(V, F, L, Vdb).
+%% vdb
+
+vdb_new(Vs) ->
+    sort([{V,0,0} || {var,V} <- Vs]).
 
 vdb_find(V, Vdb) ->
-    %% Performance note: Profiling shows that this function accounts for
-    %% a lot of the execution time when huge constant terms are built.
-    %% Using the BIF lists:keyfind/3 is a lot faster than the
-    %% original Erlang version.
     case lists:keyfind(V, 1, Vdb) of
 	false -> error;
 	Vd -> Vd
     end.
 
-%vdb_find(V, [{V1,F,L}=Vd|Vdb]) when V < V1 -> error;
-%vdb_find(V, [{V1,F,L}=Vd|Vdb]) when V == V1 -> Vd;
-%vdb_find(V, [{V1,F,L}=Vd|Vdb]) when V > V1 -> vdb_find(V, Vdb);
-%vdb_find(V, []) -> error.
+vdb_update(V, Update, [{V,_,_}|Vdb]) ->
+    [Update|Vdb];
+vdb_update(V, Update, [Vd|Vdb]) ->
+    [Vd|vdb_update(V, Update, Vdb)].
 
-vdb_update(V, F, L, [{V1,_,_}=Vd|Vdb]) when V > V1 ->
-    [Vd|vdb_update(V, F, L, Vdb)];
-vdb_update(V, F, L, [{V1,_,_}|Vdb]) when V == V1 ->
-    [{V,F,L}|Vdb].
+vdb_store_new(V, New, [{V1,_,_}=Vd|Vdb]) when V > V1 ->
+    [Vd|vdb_store_new(V, New, Vdb)];
+vdb_store_new(V, New, [{V1,_,_}|_]=Vdb) when V < V1 ->
+    [New|Vdb];
+vdb_store_new(_, New, []) -> [New].
 
-vdb_store_new(V, F, L, [{V1,_,_}=Vd|Vdb]) when V > V1 ->
-    [Vd|vdb_store_new(V, F, L, Vdb)];
-vdb_store_new(V, F, L, [{V1,_,_}|_]=Vdb) when V < V1 -> [{V,F,L}|Vdb];
-vdb_store_new(V, F, L, []) -> [{V,F,L}].
+vdb_update_vars([V|_]=Vs, [{V1,_,_}=Vd|Vdb], I) when V > V1 ->
+    [Vd|vdb_update_vars(Vs, Vdb, I)];
+vdb_update_vars([V|Vs], [{V1,_,_}|_]=Vdb, I) when V < V1 ->
+    %% New variable.
+    [{V,I,I}|vdb_update_vars(Vs, Vdb, I)];
+vdb_update_vars([V|Vs], [{_,F,L}=Vd|Vdb], I) ->
+    %% Existing variable.
+    if
+	I > L -> [{V,F,I}|vdb_update_vars(Vs, Vdb, I)];
+	true ->  [Vd|vdb_update_vars(Vs, Vdb, I)]
+    end;
+vdb_update_vars([V|Vs], [], I) ->
+    %% New variable.
+    [{V,I,I}|vdb_update_vars(Vs, [], I)];
+vdb_update_vars([], Vdb, _) -> Vdb.
 
 %% vdb_sub(Min, Max, Vdb) -> Vdb.
 %%  Extract variables which are used before and after Min.  Lock
@@ -501,8 +482,3 @@ vdb_sub(Min, Max, Vdb) ->
     [ if L >= Max -> {V,F,locked};
 	 true -> Vd
       end || {V,F,L}=Vd <- Vdb, F < Min, L >= Min ].
-
-%% is_in_guard() -> true|false.
-
-is_in_guard() ->
-    get(guard_refc) > 0.
diff --git a/lib/compiler/src/v3_life.hrl b/lib/compiler/src/v3_life.hrl
index 541e4cf66d..9d03a86ccd 100644
--- a/lib/compiler/src/v3_life.hrl
+++ b/lib/compiler/src/v3_life.hrl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%