Merge branch 'bjorn/compiler/misc'

* bjorn/compiler/misc:
  test_lib: Simplify uniq/0
  beam_dict: Correct comparison in opcode/2
  beam_utils: Re-use the local helper function drop_labels/1
  beam_asm: Speed up encoding of large numbers
  compilation_SUITE: Speed up the self_compile test cases
  beam_listing: Optimize writing of .S files
  v3_core, v3_codegen: Eliminate old-style catches
  cerl_inline: Replace old-style 'catch' with 'try'...'catch'
  sys_core_fold: Suppress warnings better
  beam_utils: Teach check_liveness/3 to understand get_map_elements
  Teach beam_trim to handle map instructions
  beam_utils: Be less conservative about liveness for exit instructions
  beam_validator: Stop validating the 'aligned' flag for binaries
  beam_validator: Clean up updating of types for y register
  beam_validator: Remove support for removed BIF fault/1,2
  beam_validator: Correct merging of states
  beam_validator: Correct merging of y registers
  sys_pre_expand: Remove unused fields in #expand{} record

11 files changed, 177 insertions, 233 deletions

diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index 084686def7..73694b96ce 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -431,45 +431,35 @@ 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_dict.erl b/lib/compiler/src/beam_dict.erl
index ea51673fa3..68dc104dd3 100644
--- a/lib/compiler/src/beam_dict.erl
+++ b/lib/compiler/src/beam_dict.erl
@@ -65,7 +65,7 @@ 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.
diff --git a/lib/compiler/src/beam_listing.erl b/lib/compiler/src/beam_listing.erl
index 50d1f3cdb1..726bb7f5eb 100644
--- a/lib/compiler/src/beam_listing.erl
+++ b/lib/compiler/src/beam_listing.erl
@@ -46,8 +46,8 @@ 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 +56,11 @@ 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_trim.erl b/lib/compiler/src/beam_trim.erl
index fad9c42584..8181e555a1 100644
--- a/lib/compiler/src/beam_trim.erl
+++ b/lib/compiler/src/beam_trim.erl
@@ -172,6 +172,10 @@ 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 +279,8 @@ 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_utils.erl b/lib/compiler/src/beam_utils.erl
index fd666be41e..b82bcd0e95 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -128,8 +128,7 @@ 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).
 
 
@@ -344,14 +343,10 @@ 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) ->
@@ -472,6 +467,22 @@ 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, Is, St) when is_list(Is) ->
 %%     case Is of
 %% 	[I|_] ->
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index c55919dc73..780826b126 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -28,7 +28,7 @@
 
 -include("beam_disasm.hrl").
 
--import(lists, [reverse/1,foldl/3,foreach/2,member/2,dropwhile/2]).
+-import(lists, [reverse/1,foldl/3,foreach/2,dropwhile/2]).
 
 -define(MAXREG, 1024).
 
@@ -153,7 +153,6 @@ validate_0(Module, [{function,Name,Ar,Entry,Code}|Fs], Ft) ->
 	 hf=0,				%Available heap size for floats.
 	 fls=undefined,			%Floating point state.
 	 ct=[],				%List of hot catch/try labels
-	 bits=undefined,	        %Number of bits in bit syntax binary.
 	 setelem=false			%Previous instruction was setelement/3.
 	}).
 
@@ -411,37 +410,33 @@ 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;
@@ -700,8 +695,7 @@ 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),
@@ -713,8 +707,7 @@ 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),
@@ -722,43 +715,35 @@ 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);
 %% Map instructions.
 valfun_4({put_map_assoc,{f,Fail},Src,Dst,Live,{list,List}}, Vst) ->
@@ -1071,55 +1056,7 @@ bsm_restore(Reg, SavePoint, 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.
 %%%
@@ -1135,35 +1072,26 @@ set_type_reg(Type, {x,X}, #vst{current=#st{x=Xs}=St}=Vst)
 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;
+    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}}.
+
 assert_term(Src, Vst) ->
     get_term_type(Src, Vst),
     ok.
@@ -1362,13 +1290,13 @@ 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}=St,
+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),
-    St#st{x=Xs,y=Ys,numy=NumY,h=min(H0, H1),ct=Ct}.
+    #st{x=Xs,y=Ys,numy=NumY,h=min(H0, H1),ct=Ct}.
 
 merge_stk(S, S) -> S;
 merge_stk(_, _) -> undecided.
@@ -1398,20 +1326,24 @@ 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.
@@ -1630,8 +1562,6 @@ 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.
diff --git a/lib/compiler/src/cerl_inline.erl b/lib/compiler/src/cerl_inline.erl
index f8489a800b..02cdb966ce 100644
--- a/lib/compiler/src/cerl_inline.erl
+++ b/lib/compiler/src/cerl_inline.erl
@@ -445,15 +445,14 @@ 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.
@@ -1128,8 +1127,8 @@ 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
@@ -1142,8 +1141,9 @@ 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.
@@ -1736,12 +1736,11 @@ 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.
@@ -1758,19 +1757,16 @@ 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.
 
@@ -1796,11 +1792,12 @@ 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
@@ -1813,11 +1810,7 @@ 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/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index beab2ce897..6f8279f65e 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -2532,18 +2532,35 @@ maybe_suppress_warnings(Arg, _, _, effect) ->
     %% Don't suppress any warnings in effect context.
     Arg;
 maybe_suppress_warnings(Arg, Vs, PrevBody, value) ->
-    case suppress_warning(Arg) of
+    case should_suppress_warning(Arg) of
 	true ->
 	    Arg;				%Already suppressed.
 	false ->
 	    case is_any_var_used(Vs, PrevBody) of
 		true ->
-		    cerl:set_ann(Arg, [compiler_generated]);
+		    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 ->
+		    Arg = cerl:set_ann(H, [compiler_generated]),
+		    cerl:c_seq(Arg, suppress_warning(T))
+	    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) ->
@@ -3093,7 +3110,7 @@ add_bin_opt_info(Core, Term) ->
     end.
 
 add_warning(Core, Term) ->
-    case suppress_warning(Core) of
+    case should_suppress_warning(Core) of
 	true ->
 	    ok;
 	false ->
@@ -3118,7 +3135,7 @@ get_file([{file,File}|_]) -> File;
 get_file([_|T]) -> get_file(T);
 get_file([]) -> "no_file". % should not happen
 
-suppress_warning(Core) ->
+should_suppress_warning(Core) ->
     is_compiler_generated(Core) orelse
 	is_result_unwanted(Core).
 
diff --git a/lib/compiler/src/sys_pre_expand.erl b/lib/compiler/src/sys_pre_expand.erl
index f99307c865..6cc849a9d5 100644
--- a/lib/compiler/src/sys_pre_expand.erl
+++ b/lib/compiler/src/sys_pre_expand.erl
@@ -38,7 +38,6 @@
 -record(expand, {module=[],                     %Module name
                  exports=[],                    %Exports
                  imports=[],                    %Imports
-                 compile=[],                    %Compile flags
                  attributes=[],                 %Attributes
                  callbacks=[],                  %Callbacks
                  optional_callbacks=[] :: [fa()],  %Optional callbacks
@@ -46,9 +45,7 @@
                  vcount=0,                      %Variable counter
                  func=[],                       %Current function
                  arity=[],                      %Arity for current function
-                 fcount=0,                      %Local fun count
-                 bitdefault,
-                 bittypes
+                 fcount=0			%Local fun count
                 }).
 
 %% module(Forms, CompileOptions)
@@ -69,15 +66,12 @@ module(Fs0, Opts0) ->
 
     %% Build initial expand record.
     St0 = #expand{exports=PreExp,
-                  compile=Opts,
-                  defined=PreExp,
-                  bitdefault = erl_bits:system_bitdefault(),
-                  bittypes = erl_bits:system_bittypes()
+                  defined=PreExp
                  },
     %% Expand the functions.
     {Tfs,St1} = forms(Fs, define_functions(Fs, St0)),
     %% Get the correct list of exported functions.
-    Exports = case member(export_all, St1#expand.compile) of
+    Exports = case member(export_all, Opts) of
                   true -> gb_sets:to_list(St1#expand.defined);
                   false -> St1#expand.exports
               end,
@@ -85,7 +79,7 @@ module(Fs0, Opts0) ->
     {Ats,St3} = module_attrs(St1#expand{exports = Exports}),
     {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]).
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index 15a54a5886..aa2ebc0f85 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -2140,9 +2140,11 @@ 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);
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index ed7b55df07..2d12d832a3 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -869,10 +869,10 @@ 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.