Merge branch 'egil/maps/OTP-11616'

* egil/maps/OTP-11616: (112 commits)
  compiler: Add core compile test for maps
  compiler: Fix core parse for Maps
  compiler: Fixup #map_pair{} spec
  erts: Strengthen map_SUITE tests
  erts: Update maps_fold test to respect maps:fold/3
  stdlib: Make maps:fold/3 order-independent
  erts: Fixup enif_make_map_put on windows
  erts: Update preloaded erts_internal.beam
  hipe: Fixup update cerl pretty printer
  erts: Add map construction to driver API
  dialyzer: Add maps tests
  dialyzer: Remove dead code
  dialyzer: Reflect map_pair core changes in dialyzer
  hipe: Update cerl pretty printer
  compiler: Update inliner tests
  compiler: Squash #c_map_pair_*{} to #c_map_pair{}
  compiler: Squash #k_map_pair_*{} to #k_map_pair{}
  preloaded: Fixup export cmp_term in erts_internal
  erts: Change 'size' argument of enif_get_map_size from int* to size_t*
  erts: Fix compile error for halfword emulator
  ...

35 files changed, 936 insertions, 45 deletions

diff --git a/lib/compiler/src/beam_a.erl b/lib/compiler/src/beam_a.erl
index c590c5e35b..3dfa67a771 100644
--- a/lib/compiler/src/beam_a.erl
+++ b/lib/compiler/src/beam_a.erl
@@ -88,6 +88,10 @@ 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({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({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_block.erl b/lib/compiler/src/beam_block.erl
index 402fbe2e2e..3723cc19e1 100644
--- a/lib/compiler/src/beam_block.erl
+++ b/lib/compiler/src/beam_block.erl
@@ -152,6 +152,10 @@ 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({put_map,F,Op,S,D,R,{list,Puts}}) ->
+    {set,[D],[S|Puts],{alloc,R,{put_map,Op,F}}};
+collect({get_map_element,F,S,K,D}) ->
+    {set,[D],[S],{get_map_element,K,F}};
 collect({'catch',R,L})       -> {set,[R],[],{'catch',L}};
 collect(fclearerror)         -> {set,[],[],fclearerror};
 collect({fcheckerror,{f,0}}) -> {set,[],[],fcheckerror};
@@ -236,6 +240,7 @@ 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_element,_,_}}) -> false;
 alloc_may_pass({set,_,_,put_list}) -> false;
 alloc_may_pass({set,_,_,put}) -> false;
 alloc_may_pass({set,_,_,_}) -> true.
@@ -383,6 +388,7 @@ 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.
 
diff --git a/lib/compiler/src/beam_clean.erl b/lib/compiler/src/beam_clean.erl
index 9d89e21a4e..55f985ad0e 100644
--- a/lib/compiler/src/beam_clean.erl
+++ b/lib/compiler/src/beam_clean.erl
@@ -234,6 +234,36 @@ 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([{bs_init2,{f,Lbl},Sz,Words,R,F,Dst}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{bs_init2,{f,label(Lbl, D)},Sz,Words,R,F,Dst}|Acc], D);
+replace([{bs_init_bits,{f,Lbl},Sz,Words,R,F,Dst}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{bs_init_bits,{f,label(Lbl, D)},Sz,Words,R,F,Dst}|Acc], D);
+replace([{bs_put_integer,{f,Lbl},Bits,Unit,Fl,Val}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{bs_put_integer,{f,label(Lbl, D)},Bits,Unit,Fl,Val}|Acc], D);
+replace([{bs_put_utf8=I,{f,Lbl},Fl,Val}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Fl,Val}|Acc], D);
+replace([{bs_put_utf16=I,{f,Lbl},Fl,Val}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Fl,Val}|Acc], D);
+replace([{bs_put_utf32=I,{f,Lbl},Fl,Val}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Fl,Val}|Acc], D);
+replace([{bs_put_binary,{f,Lbl},Bits,Unit,Fl,Val}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{bs_put_binary,{f,label(Lbl, D)},Bits,Unit,Fl,Val}|Acc], D);
+replace([{bs_put_float,{f,Lbl},Bits,Unit,Fl,Val}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{bs_put_float,{f,label(Lbl, D)},Bits,Unit,Fl,Val}|Acc], D);
+replace([{bs_add,{f,Lbl},Src,Dst}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{bs_add,{f,label(Lbl, D)},Src,Dst}|Acc], D);
+replace([{bs_append,{f,Lbl},_,_,_,_,_,_,_}=I0|Is], Acc, D) when Lbl =/= 0 ->
+    I = setelement(2, I0, {f,label(Lbl, D)}),
+    replace(Is, [I|Acc], D);
+replace([{bs_utf8_size=I,{f,Lbl},Src,Dst}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Src,Dst}|Acc], D);
+replace([{bs_utf16_size=I,{f,Lbl},Src,Dst}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Src,Dst}|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_element=I,{f,Lbl},Src,Key,Dst}|Is], Acc, D) when Lbl =/= 0 ->
+    replace(Is, [{I,{f,label(Lbl, D)},Src,Key,Dst}|Acc], D);
 replace([I|Is], Acc, D) ->
     replace(Is, [I|Acc], D);
 replace([], Acc, _) -> Acc.
diff --git a/lib/compiler/src/beam_disasm.erl b/lib/compiler/src/beam_disasm.erl
index 1a8bbcee22..e0d0d0fd1d 100644
--- a/lib/compiler/src/beam_disasm.erl
+++ b/lib/compiler/src/beam_disasm.erl
@@ -365,6 +365,10 @@ 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, Bs, Atoms, Literals);
+	put_map_exact ->
+	    disasm_map_inst(put_map_exact, Bs, Atoms, Literals);
 	_ ->
 	    try decode_n_args(Arity, Bs, Atoms, Literals) of
 		{Args, RestBs} ->
@@ -395,6 +399,17 @@ 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, Bs0, Atoms, Literals) ->
+    {F, Bs1} = decode_arg(Bs0, Atoms, Literals),
+    {S, Bs2} = decode_arg(Bs1, Atoms, Literals),
+    {X, Bs3} = decode_arg(Bs2, Atoms, Literals),
+    {N, Bs4} = decode_arg(Bs3, Atoms, Literals),
+    {Z, Bs5} = decode_arg(Bs4, Atoms, Literals),
+    {U, Bs6} = decode_arg(Bs5, Atoms, Literals),
+    {u, Len} = U,
+    {List, RestBs} = decode_n_args(Len, Bs6, Atoms, Literals),
+    {{Inst, [F,S,X,N,{Z,U,List}]}, RestBs}.
+
 %%-----------------------------------------------------------------------
 %% decode_arg([Byte]) -> {Arg, [Byte]}
 %%
@@ -421,7 +436,7 @@ decode_arg([B|Bs]) ->
 
 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);
@@ -1119,6 +1134,27 @@ resolve_inst({line,[Index]},_,_,_) ->
     {line,resolve_arg(Index)};
 
 %%
+%% R17A.
+%%
+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,Args0},_,_,_) ->
+    [FLbl|Args] = resolve_args(Args0),
+    {test, is_map, FLbl, Args};
+
+resolve_inst({get_map_element,Args},_,_,_) ->
+    [FLbl,Src,Key,Dst] = resolve_args(Args),
+    {get_map_element,FLbl,Src,Key,Dst};
+
+%%
 %% Catches instructions that are not yet handled.
 %%
 resolve_inst(X,_,_,_) -> ?exit({resolve_inst,X}).
diff --git a/lib/compiler/src/beam_flatten.erl b/lib/compiler/src/beam_flatten.erl
index 5603a677e8..534bc6d954 100644
--- a/lib/compiler/src/beam_flatten.erl
+++ b/lib/compiler/src/beam_flatten.erl
@@ -61,6 +61,10 @@ 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}};
+norm({set,[D],[S],{get_map_element,K,F}}) ->
+    {get_map_element,F,S,K,D};
 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 d57fb80ac2..1f720b94c3 100644
--- a/lib/compiler/src/beam_jump.erl
+++ b/lib/compiler/src/beam_jump.erl
@@ -527,6 +527,10 @@ 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_element,Lbl,_Src,_Key,_Dst}, Used) ->
+    mark_used(Lbl, Used);
 ulbl(_, Used) -> Used.
 
 mark_used({f,0}, Used) -> Used;
diff --git a/lib/compiler/src/beam_split.erl b/lib/compiler/src/beam_split.erl
index cacaaebffe..638a4826ea 100644
--- a/lib/compiler/src/beam_split.erl
+++ b/lib/compiler/src/beam_split.erl
@@ -49,6 +49,13 @@ split_block([{set,[R],As,{bif,N,{f,Lbl}=Fail}}|Is], Bl, Acc) when Lbl =/= 0 ->
 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,[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,[D],[S],{get_map_element,K,{f,Lbl}=Fail}}|Is], Bl, Acc)
+  when Lbl =/= 0 ->
+    split_block(Is, [], [{get_map_element,Fail,S,K,D}|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,[],[],{line,_}=Line}|Is], Bl, Acc) ->
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index 36f3200d11..a3f16cfa8f 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -152,6 +152,7 @@ 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};
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index 48f5135aca..97f84da08f 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -865,9 +865,29 @@ valfun_4({bs_final,{f,Fail},Dst}, Vst0) ->
 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_element,{f,Fail},Src,Key,Dst}, Vst0) ->
+    assert_term(Src, Vst0),
+    assert_term(Key, Vst0),
+    Vst = branch_state(Fail, Vst0),
+    set_type_reg(term, Dst, Vst);
 valfun_4(_, _) ->
     error(unknown_instruction).
 
+verify_put_map(Fail, Src, Dst, Live, List, Vst0) ->
+    verify_live(Live, Vst0),
+    verify_y_init(Vst0),
+    [assert_term(Term, Vst0) || Term <- List],
+    assert_term(Src, Vst0),
+    Vst1 = heap_alloc(0, Vst0),
+    Vst2 = branch_state(Fail, Vst1),
+    Vst = prune_x_regs(Live, Vst2),
+    set_type_reg(term, Dst, Vst).
+
 %%
 %% Common code for validating bs_get* instructions.
 %%
diff --git a/lib/compiler/src/beam_z.erl b/lib/compiler/src/beam_z.erl
index 8c6b0c916d..9953a48710 100644
--- a/lib/compiler/src/beam_z.erl
+++ b/lib/compiler/src/beam_z.erl
@@ -74,6 +74,10 @@ 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({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({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..60a8559950 100644
--- a/lib/compiler/src/cerl.erl
+++ b/lib/compiler/src/cerl.erl
@@ -120,7 +120,16 @@
 	 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]).
+	 bitstr_flags/1,
+
+	 %% keep map exports here for now
+	 map_es/1,
+	 update_c_map/2,
+	 ann_c_map/2,
+	 map_pair_op/1,map_pair_key/1,map_pair_val/1,
+	 update_c_map_pair/4,
+	 ann_c_map_pair/4
+     ]).
 
 -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]).
@@ -145,6 +154,8 @@
 -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{}.
@@ -155,9 +166,10 @@
 -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().
 
 %% =====================================================================
@@ -250,8 +262,8 @@
 
 -type ctype() :: 'alias'   | 'apply'  | 'binary' | 'bitrst'  | 'call'  | 'case'
                | 'catch'   | 'clause' | 'cons'   | 'fun'     | 'let'  | 'letrec'
-               | 'literal' | 'module' | 'primop' | 'receive' | 'seq'   | 'try' 
-               | 'tuple'   | 'values' |  'var'.
+               | 'literal' | 'map'    | 'module' | 'primop'  | 'receive' | 'seq'
+	       | 'try'     | 'tuple'  | 'values' |  'var'.
 
 -spec type(cerl()) -> ctype().
 
@@ -268,6 +280,8 @@ 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';
@@ -1558,6 +1572,34 @@ ann_make_list(_, [], Node) ->
 
 
 %% ---------------------------------------------------------------------
+%% maps
+
+-spec map_es(c_map()) -> [cerl()].
+
+map_es(#c_map{es = Es}) ->
+    Es.
+
+ann_c_map(As, Es) ->
+    #c_map{es = Es, anno = As }.
+
+update_c_map(Old, Es) ->
+    #c_map{es = Es, anno = get_ann(Old)}.
+
+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 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()
 %%
@@ -2945,6 +2987,10 @@ 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 ->
+	    pat_list_vars([map_pair_op(Node),map_pair_key(Node),map_pair_val(Node)],Vs);
 	binary ->
 	    pat_list_vars(binary_segments(Node), Vs);
 	bitstr ->
@@ -3803,7 +3849,6 @@ 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 +3880,6 @@ 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 +3936,6 @@ 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 +4065,10 @@ 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 ->
diff --git a/lib/compiler/src/cerl_inline.erl b/lib/compiler/src/cerl_inline.erl
index c6de63c69f..3837b57750 100644
--- a/lib/compiler/src/cerl_inline.erl
+++ b/lib/compiler/src/cerl_inline.erl
@@ -63,7 +63,11 @@
 	       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_es/1, update_c_map/2,
+	       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 +132,8 @@ 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 +339,8 @@ 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
@@ -1324,6 +1332,25 @@ 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, S) ->
+    %% Visit the segments for value.
+    {Es, S1} = mapfoldl(fun (E, S) ->
+				i_map_pair(E, Ctx, Ren, Env, S)
+			end,
+			S, map_es(E)),
+    S2 = count_size(weight(map), S1),
+    {update_c_map(E, Es), S2}.
+
+i_map_pair(E, Ctx, Ren, Env, S) ->
+    %% It is not necessary to visit the Op and Key fields,
+    %% since these are always literals.
+    {Val, S1} = i(map_pair_val(E), Ctx, Ren, Env, S),
+    Op = map_pair_op(E),
+    Key = map_pair_key(E),
+    S2 = count_size(weight(map_pair), S1),
+    {update_c_map_pair(E, Op, Key, Val), S2}.
+
+
 %% This is a simplified version of `i_pattern', for lists of parameter
 %% variables only. It does not modify the state.
 
@@ -1383,6 +1410,14 @@ 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, Es), S2};
 	_ ->
 	    case is_literal(E) of
 		true ->
@@ -1416,6 +1451,15 @@ 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.
+    %% Same goes for Key
+    {Val, S1} = i_pattern(map_pair_val(E), Ren, Env, Ren0, Env0, S),
+    Op = map_pair_op(E), %% should be 'exact' literal
+    Key  = map_pair_key(E),
+    S2 = count_size(weight(map_pair), S1),
+    {update_c_map_pair(E, Op, Key, Val), S2}.
+
 
 %% ---------------------------------------------------------------------
 %% Other central inlining functions
diff --git a/lib/compiler/src/cerl_trees.erl b/lib/compiler/src/cerl_trees.erl
index 1e3755025f..2542841eef 100644
--- a/lib/compiler/src/cerl_trees.erl
+++ b/lib/compiler/src/cerl_trees.erl
@@ -55,7 +55,15 @@
 	       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_es/1, 
+	       ann_c_map/2,
+	       update_c_map/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 +137,12 @@ 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_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 +249,14 @@ 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)),
@@ -349,6 +371,14 @@ mapfold(F, S0, T) ->
  	tuple ->
 	    {Ts, S1} = mapfold_list(F, S0, tuple_es(T)),
 	    F(update_c_tuple_skel(T, Ts), S1);
+	map ->
+	    {Ts, S1} = mapfold_list(F, S0, map_es(T)),
+	    F(update_c_map(T, Ts), S1);
+	map_pair ->
+	    {Op,  S1} = mapfold(F, S0, map_pair_op(T)),
+	    {Key, S2} = mapfold(F, S1, map_pair_key(T)),
+	    {Val, S3} = mapfold(F, S2, map_pair_val(T)),
+	    F(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)),
@@ -488,6 +518,10 @@ variables(T, S) ->
 			  variables(cons_tl(T), S));
 	tuple ->
 	    vars_in_list(tuple_es(T), S);
+	map ->
+	    vars_in_list(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)),
@@ -688,6 +722,16 @@ 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 ->
+	    {Ts, N1} = label_list(map_es(T), N, Env),
+	    {As, N2} = label_ann(T, N1),
+	    {ann_c_map(As, Ts), N2};
+	map_pair ->
+	    {Op,  N1} = label(map_pair_op(T), N, Env),
+	    {Val, N2} = label(map_pair_key(T), N1, Env),
+	    {Key, 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 3db7ffc4d2..0bb4de6f17 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -230,12 +230,25 @@ 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_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, erlang:get_stacktrace(), StackFun, FormatFun)];
+format_error_reason(Reason) ->
+    io_lib:format("~tp", [Reason]).
 
 %% The compile state record.
 -record(compile, {filename="" :: file:filename(),
diff --git a/lib/compiler/src/core_lib.erl b/lib/compiler/src/core_lib.erl
index 824be9ff7f..f506901099 100644
--- a/lib/compiler/src/core_lib.erl
+++ b/lib/compiler/src/core_lib.erl
@@ -105,6 +105,10 @@ 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{es=Es}) ->
+    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}) ->
diff --git a/lib/compiler/src/core_lint.erl b/lib/compiler/src/core_lint.erl
index 67d37ff1fc..36165245a6 100644
--- a/lib/compiler/src/core_lint.erl
+++ b/lib/compiler/src/core_lint.erl
@@ -254,6 +254,10 @@ 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_map{es=Es}, Def, _Rt, St) ->
+    gexpr_list(Es, Def, St);
+gexpr(#c_map_pair{key=K,val=V}, Def, _Rt, St) ->
+    gexpr_list([K,V], Def, St);
 gexpr(#c_binary{segments=Ss}, Def, _Rt, St) ->
     gbitstr_list(Ss, Def, St);
 gexpr(#c_seq{arg=Arg,body=B}, Def, Rt, St0) ->
@@ -278,6 +282,7 @@ 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.
@@ -303,6 +308,10 @@ 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_map{es=Es}, Def, _Rt, St) ->
+    expr_list(Es, Def, St);
+expr(#c_map_pair{key=K,val=V},Def,_Rt,St) ->
+    expr_list([K,V],Def,St);
 expr(#c_binary{segments=Ss}, Def, _Rt, St) ->
     bitstr_list(Ss, Def, St);
 expr(#c_fun{vars=Vs,body=B}, Def, Rt, St0) ->
@@ -355,7 +364,7 @@ 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 +463,19 @@ 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..d54715ef59 100644
--- a/lib/compiler/src/core_parse.hrl
+++ b/lib/compiler/src/core_parse.hrl
@@ -96,3 +96,12 @@
 -record(c_values, {anno=[], es}).	% es :: [Tree]
 
 -record(c_var, {anno=[], name :: cerl:var_name()}).
+
+-record(c_map_pair, {anno=[],
+	             op :: #c_literal{val::'assoc'} | #c_literal{val::'exact'},
+		     key,
+		     val}).
+
+-record(c_map, {anno=[],
+		var=#c_literal{val=[]} :: #c_var{} | #c_literal{},
+		es :: [#c_map_pair{}]}).
diff --git a/lib/compiler/src/core_parse.yrl b/lib/compiler/src/core_parse.yrl
index 4e98a8c2da..b8db0f683a 100644
--- a/lib/compiler/src/core_parse.yrl
+++ b/lib/compiler/src/core_parse.yrl
@@ -21,6 +21,8 @@
 %% Have explicit productions for annotated phrases named anno_XXX.
 %% This just does an XXX and adds the annotation.
 
+Expect 1.
+
 Nonterminals
 
 module_definition module_export module_attribute module_defs
@@ -44,6 +46,9 @@ receive_expr timeout try_expr
 sequence catch_expr
 variable clause clause_pattern
 
+map_expr map_pairs map_pair map_pair_assoc map_pair_exact
+map_pattern map_pair_patterns map_pair_pattern
+
 annotation anno_fun anno_expression anno_expressions
 anno_variable anno_variables anno_pattern anno_patterns
 anno_function_name
@@ -53,7 +58,7 @@ Terminals
 
 %% Separators
 
-'(' ')' '{' '}' '[' ']' '|' ',' '->' '=' '/' '<' '>' ':' '-|' '#'
+'(' ')' '{' '}' '[' ']' '|' ',' '->' '=' '/' '<' '>' ':' '-|' '#' '~' '::'
 
 %% Keywords (atoms are assumed to always be single-quoted).
 
@@ -166,6 +171,7 @@ 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 :
@@ -176,6 +182,16 @@ atomic_pattern -> atomic_literal : '$1'.
 tuple_pattern -> '{' '}' : c_tuple([]).
 tuple_pattern -> '{' anno_patterns '}' : c_tuple('$2').
 
+map_pattern -> '~' '{' '}' '~' : #c_map{es=[]}.
+map_pattern -> '~' '{' map_pair_patterns '}' '~' :
+		   #c_map{es=lists:sort('$3')}.
+
+map_pair_patterns -> map_pair_pattern : ['$1'].
+map_pair_patterns -> map_pair_pattern ',' map_pair_patterns : ['$1' | '$3'].
+
+map_pair_pattern -> '~' '<' anno_pattern ',' anno_pattern '>' :
+			#c_map_pair{op=#c_literal{val=exact},key='$3',val='$5'}.
+
 cons_pattern -> '[' anno_pattern tail_pattern :
 		    #c_cons{hd='$2',tl='$3'}.
 
@@ -240,6 +256,7 @@ 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'.
@@ -267,6 +284,22 @@ tail_literal -> ',' literal tail_literal : #c_cons{hd='$2',tl='$3'}.
 tuple -> '{' '}' : c_tuple([]).
 tuple -> '{' anno_expressions '}' : c_tuple('$2').
 
+map_expr -> '~' '{' '}' '~' : #c_map{es=[]}.
+map_expr -> '~' '{' map_pairs  '}' '~' : #c_map{es='$3'}.
+map_expr -> variable '~' '{' '}' '~' : #c_map{var='$1',es=[]}.
+map_expr -> variable '~' '{' map_pairs  '}' '~' : #c_map{var='$1',es='$4'}.
+
+map_pairs -> map_pair : ['$1'].
+map_pairs -> map_pair ',' map_pairs : ['$1' | '$3'].
+
+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='$3',val='$5'}.
+map_pair_exact -> '~' '<' anno_expression ',' anno_expression'>' :
+		#c_map_pair{op=#c_literal{val=exact},key='$3',val='$5'}.
+
 cons -> '[' anno_expression tail : c_cons('$2', '$3').
 
 tail -> ']' : #c_literal{val=[]}.
@@ -381,3 +414,5 @@ Erlang code.
 
 tok_val(T) -> element(3, T).
 tok_line(T) -> element(2, T).
+
+%% vim: syntax=erlang
diff --git a/lib/compiler/src/core_pp.erl b/lib/compiler/src/core_pp.erl
index 1f91a52be3..faa26ec6df 100644
--- a/lib/compiler/src/core_pp.erl
+++ b/lib/compiler/src/core_pp.erl
@@ -161,6 +161,27 @@ format_1(#c_tuple{es=Es}, Ctxt) ->
      format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
      $}
     ];
+format_1(#c_map{var=#c_var{}=Var,es=Es}, Ctxt) ->
+    [format_1(Var, Ctxt),
+     "~{",
+     format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
+     "}~"
+    ];
+format_1(#c_map{es=Es}, Ctxt) ->
+    ["~{",
+     format_hseq(Es, ",", add_indent(Ctxt, 1), fun format/2),
+     "}~"
+    ];
+format_1(#c_map_pair{op=#c_literal{val=assoc},key=K,val=V}, Ctxt) ->
+    ["::<",
+     format_hseq([K,V], ",", add_indent(Ctxt, 1), fun format/2),
+     ">"
+    ];
+format_1(#c_map_pair{op=#c_literal{val=exact},key=K,val=V}, Ctxt) ->
+    ["~<",
+     format_hseq([K,V], ",", add_indent(Ctxt, 1), fun format/2),
+     ">"
+    ];
 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)))];
diff --git a/lib/compiler/src/core_scan.erl b/lib/compiler/src/core_scan.erl
index a4fe920258..b7799b373a 100644
--- a/lib/compiler/src/core_scan.erl
+++ b/lib/compiler/src/core_scan.erl
@@ -271,6 +271,8 @@ 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/genop.tab b/lib/compiler/src/genop.tab
index ebc9b1c85b..79b467f949 100755
--- a/lib/compiler/src/genop.tab
+++ b/lib/compiler/src/genop.tab
@@ -528,3 +528,11 @@ BEAM_FORMAT_NUMBER=0
 # R15A
 
 153: line/1
+
+# R16
+
+154: put_map_assoc/5
+155: put_map_exact/5
+156: is_map/2
+157: has_map_field/3
+158: get_map_element/4
diff --git a/lib/compiler/src/sys_core_dsetel.erl b/lib/compiler/src/sys_core_dsetel.erl
index f6696992b9..60d83763f8 100644
--- a/lib/compiler/src/sys_core_dsetel.erl
+++ b/lib/compiler/src/sys_core_dsetel.erl
@@ -102,6 +102,13 @@ visit(Env, #c_literal{}=R) ->
 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),
@@ -212,6 +219,11 @@ visit_pat(Env0, #c_var{name=V}, Vs) ->
     {[V|Vs], dict:store(V, 0, Env0)};
 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);
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index a388960312..1cdbac5693 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -246,6 +246,16 @@ expr(#c_tuple{anno=Anno,es=Es0}=Tuple, Ctxt, Sub) ->
 	value ->
 	    ann_c_tuple(Anno, Es)
     end;
+expr(#c_map{var=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),
+	    Map#c_map{var=V,es=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.
@@ -408,6 +418,16 @@ 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].
 
@@ -677,7 +697,7 @@ 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.
 
@@ -1500,6 +1520,9 @@ 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};
@@ -1509,6 +1532,15 @@ 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,Osub1} = pattern(K0, Isub, Osub0),
+    {V,Osub} = pattern(V0, Isub, Osub1),
+    {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}.
@@ -2987,6 +3019,9 @@ format_error(result_ignored) ->
 	"(suppress the warning by assigning the expression to the _ variable)";
 format_error(useless_building) ->
     "a term is constructed, but never used";
+format_error({map_pair_key_overloaded,K}) ->
+    M = io_lib:format("the key ~p is used multiple times in map value association",[K]),
+    flatten(M);
 format_error(bin_opt_alias) ->
     "INFO: the '=' operator will prevent delayed sub binary optimization";
 format_error(bin_partition) ->
diff --git a/lib/compiler/src/sys_pre_expand.erl b/lib/compiler/src/sys_pre_expand.erl
index 48d9c16718..9998043013 100644
--- a/lib/compiler/src/sys_pre_expand.erl
+++ b/lib/compiler/src/sys_pre_expand.erl
@@ -228,6 +228,13 @@ 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) ->
+    {K,St1} = pattern(K0, St0),
+    {V,St2} = pattern(V0, St1),
+    {{map_field_exact,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 +328,20 @@ 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,Var,Es0}, St0) ->
+    {Es1,St1} = expr_list(Es0, St0),
+    {{map,Line,Var,Es1},St1};
+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};
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index f534500671..c8735a76e8 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -210,6 +210,8 @@ 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 +455,11 @@ 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)};
@@ -594,14 +599,13 @@ top_level_block(Keis, Bef, MaxRegs, _St) ->
 %%   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(El-1,setelement(El,Tp,turn_yreg(element(El,Tp),MaxY)),MaxY).
+
+turn_yreg({yy,YY},MaxY) -> {y,MaxY-YY};
+turn_yreg({list,Ls},MaxY) -> {list, turn_yreg(Ls,MaxY)};
+turn_yreg(Ts,MaxY) when is_list(Ts) -> [turn_yreg(T,MaxY)||T<-Ts];
+turn_yreg(Other,_MaxY) -> Other.
 
 %% select_cg(Sclause, V, TypeFail, ValueFail, StackReg, State) ->
 %%      {Is,StackReg,State}.
@@ -623,6 +627,8 @@ 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}) ->
@@ -637,6 +643,10 @@ select_val_cg(tuple, R, [Arity,{f,Lbl}], Tf, Vf, [{label,Lbl}|Sis]) ->
     [{test,is_tuple,{f,Tf},[R]},{test,test_arity,{f,Vf},[R,Arity]}|Sis];
 select_val_cg(tuple, R, Vls, Tf, Vf, Sis) ->
     [{test,is_tuple,{f,Tf},[R]},{select_tuple_arity,R,{f,Vf},{list,Vls}}|Sis];
+select_val_cg(map, R, [_Val,{f,Lbl}], Fail, Fail, [{label,Lbl}|Sis]) ->
+    [{test,is_map,{f,Fail},[R]}|Sis];
+select_val_cg(map, R, [_Val,{f,Lbl}|_], Tf, _Vf, [{label,Lbl}|Sis]) ->
+    [{test,is_map,{f,Tf},[R]}|Sis];
 select_val_cg(Type, R, [Val, {f,Lbl}], Fail, Fail, [{label,Lbl}|Sis]) ->
     [{test,is_eq_exact,{f,Fail},[R,{Type,Val}]}|Sis];
 select_val_cg(Type, R, [Val, {f,Lbl}], Tf, Vf, [{label,Lbl}|Sis]) ->
@@ -915,6 +925,36 @@ 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,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(Src, Vs, Fail, I, Vdb, Bef, St) ->
+    F = fun ({map_pair,Key,{var,V}}, Int0) ->
+		Rsrc = fetch_var(Src, Int0),
+		case vdb_find(V, Vdb) of
+		    {V,_,L} when L =< I ->
+			{[{test,has_map_field,{f,Fail},[Rsrc,Key]}],Int0};
+		    _Other ->
+			Reg1 = put_reg(V, Int0#sr.reg),
+			Int1 = Int0#sr{reg=Reg1},
+			{[{get_map_element,{f,Fail},
+			   Rsrc,Key,fetch_reg(V, Reg1)}],
+			 Int1}
+		end
+	end,
+    {Es,Aft} = flatmapfoldl(F, Bef, Vs),
+    {Es,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 ->
@@ -1408,7 +1448,7 @@ 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) ->
@@ -1448,6 +1488,55 @@ set_cg([{var,R}], {binary,Segs}, Le, Vdb, Bef,
     %% Now generate the complete code for constructing the binary.
     Code = cg_binary(PutCode, Target, Temp, Fail, MaxRegs, Le#l.a),
     {Sis++Code,Aft,St};
+set_cg([{var,R}], {map,SrcMap,Es0}, Le, Vdb, Bef,
+       #cg{in_catch=InCatch,bfail=Bfail}=St) ->
+    Fail = {f,Bfail},
+    {Sis,Int0} =
+	case InCatch of
+	    true -> adjust_stack(Bef, Le#l.i, Le#l.i+1, Vdb);
+	    false -> {[],Bef}
+	end,
+    Line = line(Le#l.a),
+    SrcReg = case SrcMap of
+		 {var,SrcVar} -> fetch_var(SrcVar, Int0);
+		 _ -> SrcMap
+	     end,
+    {Assoc,Exact} =
+	try
+	    cg_map_pairs(Es0)
+	catch
+	    throw:badarg ->
+		{[],[{{float,0.0},{atom,badarg}},
+		     {{integer,0},{atom,badarg}}]}
+	end,
+    F = fun ({K,{var,V}}) -> [K,fetch_var(V, Int0)];
+	    ({K,E}) -> [K,E]
+	end,
+    AssocList = flatmap(F, Assoc),
+    ExactList = flatmap(F, Exact),
+    Live0 = max_reg(Bef#sr.reg),
+    Int1 = clear_dead(Int0, Le#l.i, Vdb),
+    Aft = Bef#sr{reg=put_reg(R, Int1#sr.reg)},
+    Target = fetch_reg(R, Aft#sr.reg),
+    Code = [Line] ++
+	case {AssocList,ExactList} of
+	    {[_|_],[]} ->
+		[{put_map_assoc,Fail,SrcReg,Target,Live0,{list,AssocList}}];
+	    {[_|_],[_|_]} ->
+		Live = case Target of
+			   {x,TargetX} when TargetX =:= Live0 ->
+			       Live0 + 1;
+			   _ ->
+			       Live0
+		       end,
+		[{put_map_assoc,Fail,SrcReg,Target,Live0,{list,AssocList}},
+		 {put_map_exact,Fail,Target,Target,Live,{list,ExactList}}];
+	    {[],[_|_]} ->
+		[{put_map_exact,Fail,SrcReg,Target,Live0,{list,ExactList}}];
+	    {[],[]} ->
+		[{put_map_assoc,Fail,SrcReg,Target,Live0,{list,[]}}]
+	end,
+    {Sis++Code,Aft,St};
 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)},
@@ -1460,6 +1549,71 @@ set_cg([{var,R}], Con, Le, Vdb, Bef, St) ->
 	  end,
     {Ais,clear_dead(Int, Le#l.i, Vdb),St}.
 
+%% cg_map_pairs(MapPairs) -> {Assoc,Exact}
+%%  Assoc = Exact = [{K,V}]
+%%
+%%  Remove multiple assignments to the same key, and return
+%%  one list key-value list with all keys that may or may not exist
+%%  (Assoc), and one with keys that must exist (Exact).
+%%
+
+cg_map_pairs(Es0) ->
+    Es = cg_map_pairs_1(Es0, 0),
+    R0 = sofs:relation(Es),
+    R1 = sofs:relation_to_family(R0),
+    R2 = sofs:to_external(R1),
+
+    %% R2 is now [{KeyValue,[{Order,Op,OriginalKey,Value}]}]
+    R3 = [begin
+	      %% The value for the last pair determines the value.
+	      {_,_,_,V} = lists:last(Vs),
+	      {Op,{_,SortOrder}=K} = map_pair_op_and_key(Vs),
+	      {Op,{SortOrder,K,V}}
+	  end || {_,Vs} <- R2],
+
+    %% R3 is now [{Op,{Key,Value}}]
+    R = termsort(R3),
+
+    %% R4 is now sorted with all alloc first in the list, followed by
+    %% all exact.
+    {Assoc,Exact} = lists:partition(fun({Op,_}) -> Op =:= assoc end, R),
+    {[{K,V} || {_,{_,K,V}} <- Assoc],
+     [{K,V} || {_,{_,K,V}} <- Exact]}.
+
+cg_map_pairs_1([{map_pair_assoc,{_,Kv}=K,V}|T], Order) ->
+    [{Kv,{Order,assoc,K,V}}|cg_map_pairs_1(T, Order+1)];
+cg_map_pairs_1([{map_pair_exact,{_,Kv}=K,V}|T], Order) ->
+    [{Kv,{Order,exact,K,V}}|cg_map_pairs_1(T, Order+1)];
+cg_map_pairs_1([], _) -> [].
+
+%% map_pair_op_and_key({_,Op,K,_}) -> {Operator,Key}
+%%  Determine the operator and key to use. Throw a 'badarg'
+%%  exception if there are contradictory exact updates.
+
+map_pair_op_and_key(L) ->
+    case [K || {_,exact,K,_} <- L] of
+	[K] ->
+	    %% There is a single ':=' operator. Use that key.
+	    {exact,K};
+	[K|T] ->
+	    %% There is more than one ':=' operator. All of them
+	    %% must have the same key.
+	    case lists:all(fun(E) -> E =:= K end, T) of
+		true ->
+		    {exact,K};
+		false ->
+		    %% Some keys are different, e.g. 1 and 1.0.
+		    throw(badarg)
+	    end;
+	[] ->
+	    %% Only '=>' operators. Use the first key in the list.
+	    [{_,assoc,K,_}|_] = L,
+	    {assoc,K}
+    end.
+
+termsort(Ls) ->
+    lists:sort(fun(A,B) -> erts_internal:cmp_term(A,B) < 0 end, Ls).
+
 %%%
 %%% Code generation for constructing binaries.
 %%%
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index a5f31f3844..e30bfa729c 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -487,6 +487,17 @@ expr({tuple,L,Es0}, St0) ->
     {Es1,Eps,St1} = safe_list(Es0, St0),
     A = lineno_anno(L, St1),
     {ann_c_tuple(A, Es1),Eps,St1};
+expr({map,L,Es0}, St0) ->
+    % erl_lint should make sure only #{ K => V } are allowed
+    % in map construction.
+    {Es1,Eps,St1} = map_pair_list(Es0, St0),
+    A = lineno_anno(L, St1),
+    {#c_map{anno=A,es=Es1},Eps,St1};
+expr({map,L,M0,Es0}, St0) ->
+    {M1,Mps,St1} = safe(M0, St0),
+    {Es1,Eps,St2} = map_pair_list(Es0, St1),
+    A = lineno_anno(L, St2),
+    {#c_map{anno=A,var=M1,es=Es1},Mps++Eps,St2};
 expr({bin,L,Es0}, St0) ->
     try expr_bin(Es0, lineno_anno(L, St0), St0) of
 	{_,_,_}=Res -> Res
@@ -695,6 +706,21 @@ make_bool_switch_guard(L, E, V, T, F) ->
       {clause,NegL,[V],[],[V]}
      ]}.
 
+map_pair_list(Es, St) ->
+    foldr(fun
+	    ({map_field_assoc,L,K0,V0}, {Ces,Esp,St0}) ->
+		{K,Ep0,St1} = safe(K0, St0),
+		{V,Ep1,St2} = safe(V0, St1),
+		A = lineno_anno(L, St2),
+		Pair = #c_map_pair{op=#c_literal{val=assoc},anno=A,key=K,val=V},
+		{[Pair|Ces],Ep0 ++ Ep1 ++ Esp,St2};
+	    ({map_field_exact,L,K0,V0}, {Ces,Esp,St0}) ->
+		{K,Ep0,St1} = safe(K0, St0),
+		{V,Ep1,St2} = safe(V0, St1),
+		A = lineno_anno(L, St2),
+		Pair = #c_map_pair{op=#c_literal{val=exact},anno=A,key=K,val=V},
+		{[Pair|Ces],Ep0 ++ Ep1 ++ Esp,St2}
+	end, {[],[],St}, Es).
 
 %% try_exception([ExcpClause], St) -> {[ExcpVar],Handler,St}.
 
@@ -1478,6 +1504,26 @@ pattern({cons,L,H,T}, St) ->
     ann_c_cons(lineno_anno(L, St), pattern(H, St), pattern(T, St));
 pattern({tuple,L,Ps}, St) ->
     ann_c_tuple(lineno_anno(L, St), pattern_list(Ps, St));
+pattern({map,L,Ps}, St) ->
+    #c_map{anno=lineno_anno(L, St), es=sort(pattern_list(Ps, St))};
+pattern({map_field_exact,L,K,V}, St) ->
+    %% FIXME: Better way to construct literals? or missing case
+    %% {Key,_,_} = expr(K, St),
+    Key = case K of
+	{bin,L,Es0} ->
+	    case constant_bin(Es0) of
+		error ->
+		    throw(badmatch);
+		Bin ->
+		    #c_literal{anno=lineno_anno(L,St),val=Bin}
+	    end;
+	_ ->
+	    pattern(K,St)
+    end,
+    #c_map_pair{anno=lineno_anno(L, St),
+                op=#c_literal{val=exact},
+		key=Key,
+		val=pattern(V, St)};
 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.
@@ -1823,6 +1869,12 @@ 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},val=V0}=MapPair, Ks, St0) ->
+    {V,Vg,Vv,Vu,St1} = upattern(V0, Ks, St0),
+    {MapPair#c_map_pair{val=V},Vg,Vv,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};
@@ -2152,6 +2204,9 @@ 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().
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 65f1251099..9a2b1605ad 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -272,6 +272,10 @@ 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,var=Var0,es=Ces}, Sub, St0) ->
+    {Var,[],St1} = expr(Var0, Sub, St0),
+    {Kes,Ep,St2} = map_pairs(Ces, Sub, St1),
+    {#k_map{anno=A,var=Var,es=Kes},Ep,St2};
 expr(#c_binary{anno=A,segments=Cv}, Sub, St0) ->
     try atomic_bin(Cv, Sub, St0) of
 	{Kv,Ep,St1} ->
@@ -493,6 +497,16 @@ translate_match_fail_1(Anno, As, Sub, #kern{ff=FF}) ->
 translate_fc(Args) ->
     [#c_literal{val=function_clause},make_list(Args)].
 
+%% FIXME: Not completed
+map_pairs(Es, Sub, St) ->
+    foldr(fun
+	    (#c_map_pair{op=#c_literal{val=Op},key=K0,val=V0}, {Kes,Esp,St0}) when
+                                           Op =:= assoc; Op =:= exact -> %% assert Op
+		{K,[],St1} = expr(K0, Sub, St0),
+		{V,Ep,St2} = atomic(V0, Sub, St1),
+		{[#k_map_pair{op=Op,key=K,val=V}|Kes],Ep ++ Esp,St2}
+	end, {[],[],St}, Es).
+
 %% call_type(Module, Function, Arity) -> call | bif | apply | error.
 %%  Classify the call.
 call_type(#c_literal{val=M}, #c_literal{val=F}, Ar) when is_atom(M), is_atom(F) ->
@@ -648,6 +662,13 @@ 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_list(Ces, Isub, Osub0, St0),
+    {#k_map{anno=A,es=Kes},Osub1,St1};
+pattern(#c_map_pair{op=#c_literal{val=exact},anno=A,key=Ck,val=Cv},Isub, Osub0, St0) ->
+    {Kk,Osub1,St1} = pattern(Ck, Isub, Osub0, St0),
+    {Kv,Osub2,St2} = pattern(Cv, Isub, Osub1, St1),
+    {#k_map_pair{anno=A,op=exact,key=Kk,val=Kv},Osub2,St2};
 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};
@@ -1015,7 +1036,8 @@ 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 +1273,9 @@ 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 +1288,12 @@ 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 +1342,13 @@ 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{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{es=Es},Mes,St1};
 get_match(M, St) ->
     {M,[],St}.
 
@@ -1331,7 +1365,12 @@ new_clauses(Cs0, U, St) ->
 				     [S,N|As];
 				 #k_bin_int{next=N} ->
 				     [N|As];
-				 _Other -> As
+				 #k_map{es=Es} ->
+				     Vals = [V ||
+						#k_map_pair{op=exact,val=V} <- Es],
+				     Vals ++ As;
+				 _Other ->
+				     As
 			     end,
 		      Vs = arg_alias(Arg),
 		      Osub1 = foldl(fun (#k_var{name=V}, Acc) ->
@@ -1406,6 +1445,7 @@ 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;
@@ -1426,7 +1466,15 @@ arg_val(Arg, C) ->
 		    {#k_var{name=get_vsub(V, Isub)},U,T,Fs};
 		_ ->
 		    {set_kanno(S, []),U,T,Fs}
-	    end
+	    end;
+	#k_map{es=Es} ->
+	    Keys = [begin
+			#k_map_pair{op=exact,key=#k_literal{val=Key}} = Pair,
+			Key
+		    end || Pair <- Es],
+	    %% multiple keys may have the same name
+	    %% do not use ordsets
+	    lists:sort(Keys)
     end.
 
 %% ubody_used_vars(Expr, State) -> [UsedVar]
@@ -1795,6 +1843,10 @@ 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}) ->
@@ -1830,7 +1882,11 @@ 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{op=exact,val=V}) ->
+    pat_vars(V).
 
 pat_list_vars(Ps) ->
     foldl(fun (P, {Used0,New0}) ->
diff --git a/lib/compiler/src/v3_kernel.hrl b/lib/compiler/src/v3_kernel.hrl
index fb8baf398b..c7886a070d 100644
--- a/lib/compiler/src/v3_kernel.hrl
+++ b/lib/compiler/src/v3_kernel.hrl
@@ -38,6 +38,8 @@
 -record(k_nil, {anno=[]}).
 
 -record(k_tuple, {anno=[],es}).
+-record(k_map, {anno=[],var,es}).
+-record(k_map_pair, {anno=[],op,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..edbd3f74f8 100644
--- a/lib/compiler/src/v3_kernel_pp.erl
+++ b/lib/compiler/src/v3_kernel_pp.erl
@@ -104,6 +104,21 @@ format_1(#k_tuple{es=Es}, Ctxt) ->
      format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
      $}
     ];
+format_1(#k_map{var=#k_var{}=Var,es=Es}, Ctxt) ->
+    [$~,${,
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     " | ",format_1(Var, Ctxt),
+     $},$~
+    ];
+format_1(#k_map{es=Es}, Ctxt) ->
+    [$~,${,
+     format_hseq(Es, ",", ctxt_bump_indent(Ctxt, 1), fun format/2),
+     $},$~
+    ];
+format_1(#k_map_pair{op=assoc,key=K,val=V}, Ctxt) ->
+    ["~<",format(K, Ctxt),",",format(V, Ctxt),">"];
+format_1(#k_map_pair{op=exact,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..ae928e955c 100644
--- a/lib/compiler/src/v3_life.erl
+++ b/lib/compiler/src/v3_life.erl
@@ -323,7 +323,9 @@ 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;
+type(k_map_pair) -> map_pair.
 
 %% variable(Klit) -> Lit.
 %% var_list([Klit]) -> [Lit].
@@ -365,6 +367,12 @@ literal(#k_bin_end{}, Ctxt) ->
     {bin_end,Ctxt};
 literal(#k_tuple{es=Es}, Ctxt) ->
     {tuple,literal_list(Es, Ctxt)};
+literal(#k_map{var=Var,es=Es}, Ctxt) ->
+    {map,literal(Var, Ctxt),literal_list(Es, Ctxt)};
+literal(#k_map_pair{op=assoc,key=K,val=V}, Ctxt) ->
+    {map_pair_assoc,literal(K, Ctxt),literal(V, Ctxt)};
+literal(#k_map_pair{op=exact,key=K,val=V}, Ctxt) ->
+    {map_pair_exact,literal(K, Ctxt),literal(V, Ctxt)};
 literal(#k_literal{val=V}, _Ctxt) ->
     {literal,V}.
 
@@ -393,7 +401,11 @@ literal2(#k_bin_int{size=S,unit=U,flags=Fs,val=Int,next=N}, Ctxt) ->
 literal2(#k_bin_end{}, Ctxt) ->
     {bin_end,Ctxt};
 literal2(#k_tuple{es=Es}, Ctxt) ->
-    {tuple,literal_list2(Es, Ctxt)}.
+    {tuple,literal_list2(Es, Ctxt)};
+literal2(#k_map{es=Es}, Ctxt) ->
+    {map,literal_list2(Es, Ctxt)};
+literal2(#k_map_pair{key=K,val=V}, Ctxt) ->
+    {map_pair,literal2(K, Ctxt),literal2(V, Ctxt)}.
 
 literal_list2(Ks, Ctxt) ->
     [literal2(K, Ctxt) || K <- Ks].
diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index 4ec75d015e..de35ebc7bd 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -415,11 +415,11 @@ encrypted_abstr(Config) when is_list(Config) ->
     ?line {Simple,Target} = files(Config, "encrypted_abstr"),
 
     Res = case has_crypto() of
-	      no ->
+	      false ->
 		  %% No crypto.
 		  ?line encrypted_abstr_no_crypto(Simple, Target),
 		  {comment,"The crypto application is missing or broken"};
-	      yes ->
+	      true ->
 		  %% Simulate not having crypto by removing
 		  %% the crypto application from the path.
 		  ?line OldPath = code:get_path(),
@@ -511,6 +511,7 @@ write_crypt_file(Contents0) ->
     ok = file:write_file(".erlang.crypt", Contents).
 
 encrypted_abstr_no_crypto(Simple, Target) ->
+    io:format("simpe: ~p~n", [Simple]),
     ?line TargetDir = filename:dirname(Target),
     ?line Key = "ablurf123BX#$;3",
     ?line error = compile:file(Simple,
@@ -525,11 +526,11 @@ verify_abstract(Target) ->
 has_crypto() ->
     try
 	crypto:start(),
-	crypto:info(),
+	<<_,_,_,_,_>> = crypto:rand_bytes(5),
 	crypto:stop(),
-	yes
+	true
     catch
-	error:_ -> no
+	error:_ -> false
     end.
 
 install_crypto_key(Key) ->
diff --git a/lib/compiler/test/core_SUITE.erl b/lib/compiler/test/core_SUITE.erl
index a40dc32d59..1a521c3591 100644
--- a/lib/compiler/test/core_SUITE.erl
+++ b/lib/compiler/test/core_SUITE.erl
@@ -23,7 +23,8 @@
 	 init_per_testcase/2,end_per_testcase/2,
 	 dehydrated_itracer/1,nested_tries/1,
 	 seq_in_guard/1,make_effect_seq/1,eval_is_boolean/1,
-	 unsafe_case/1,nomatch_shadow/1,reversed_annos/1]).
+	 unsafe_case/1,nomatch_shadow/1,reversed_annos/1,
+	 map_core_test/1]).
 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -48,7 +49,9 @@ all() ->
 groups() -> 
     [{p,test_lib:parallel(),
       [dehydrated_itracer,nested_tries,seq_in_guard,make_effect_seq,
-       eval_is_boolean,unsafe_case,nomatch_shadow,reversed_annos]}].
+       eval_is_boolean,unsafe_case,nomatch_shadow,reversed_annos,
+       map_core_test
+   ]}].
 
 
 init_per_suite(Config) ->
@@ -72,6 +75,7 @@ end_per_group(_GroupName, Config) ->
 ?comp(unsafe_case).
 ?comp(nomatch_shadow).
 ?comp(reversed_annos).
+?comp(map_core_test).
 
 try_it(Mod, Conf) ->
     Src = filename:join(?config(data_dir, Conf), atom_to_list(Mod)),
diff --git a/lib/compiler/test/core_SUITE_data/map_core_test.core b/lib/compiler/test/core_SUITE_data/map_core_test.core
new file mode 100644
index 0000000000..7ece8a8bbd
--- /dev/null
+++ b/lib/compiler/test/core_SUITE_data/map_core_test.core
@@ -0,0 +1,95 @@
+module 'map_core_test' ['map_core_test'/0,
+			'module_info'/0,
+			'module_info'/1]
+    attributes []
+'map_core_test'/0 =
+    %% Line 14
+    fun () ->
+	let <_cor0> =
+	    %% Line 15
+	    ~{::<'check','ok'>,::<1337,#{#<104>(8,1,'integer',['unsigned'|['big']]),
+				      #<101>(8,1,'integer',['unsigned'|['big']]),
+				      #<108>(8,1,'integer',['unsigned'|['big']]),
+				      #<108>(8,1,'integer',['unsigned'|['big']]),
+				      #<111>(8,1,'integer',['unsigned'|['big']])}#>,::<'val',0>}~
+	in  let <M> =
+		%% Line 15
+		apply 'id'/1
+		    (_cor0)
+	    in  let <_cor2> =
+		    %% Line 16
+		    apply 'id'/1
+			([1|[2|[3|[4|[5|[6]]]]]])
+		in  %% Line 16
+		    case apply 'call'/2
+			     (M, _cor2) of
+		      <~{~<1337,#{#<104>(8,1,'integer',['unsigned'|['big']]),
+				#<101>(8,1,'integer',['unsigned'|['big']]),
+				#<108>(8,1,'integer',['unsigned'|['big']]),
+				#<108>(8,1,'integer',['unsigned'|['big']]),
+				#<111>(8,1,'integer',['unsigned'|['big']]),
+				#<32>(8,1,'integer',['unsigned'|['big']]),
+				#<49>(8,1,'integer',['unsigned'|['big']]),
+				#<32>(8,1,'integer',['unsigned'|['big']]),
+				#<50>(8,1,'integer',['unsigned'|['big']]),
+				#<32>(8,1,'integer',['unsigned'|['big']]),
+				#<51>(8,1,'integer',['unsigned'|['big']]),
+				#<32>(8,1,'integer',['unsigned'|['big']]),
+				#<52>(8,1,'integer',['unsigned'|['big']]),
+				#<32>(8,1,'integer',['unsigned'|['big']]),
+				#<53>(8,1,'integer',['unsigned'|['big']]),
+				#<32>(8,1,'integer',['unsigned'|['big']]),
+				#<54>(8,1,'integer',['unsigned'|['big']])}#>,~<'check','ok'>,~<'val',21>}~> when 'true' ->
+			  %% Line 17
+			  'ok'
+		      ( <_cor3> when 'true' ->
+			    primop 'match_fail'
+				({'badmatch',_cor3})
+			-| ['compiler_generated'] )
+		    end
+'call'/2 =
+    %% Line 20
+    fun (_cor1,_cor0) ->
+	case <_cor1,_cor0> of
+	  <M = ~{~<1337,Bin>,~<'check',_cor8>,~<'val',Val>}~,[V|Vs]> when 'true' ->
+	      let <_cor3> =
+		  %% Line 21
+		  call 'erlang':'+'
+		      (V, 48)
+	      in  let <_cor4> =
+		      %% Line 21
+		      #{#<Bin>('all',8,'binary',['unsigned'|['big']]),
+			#<32>(8,1,'integer',['unsigned'|['big']]),
+			#<_cor3>(8,1,'integer',['unsigned'|['big']])}#
+		  in  let <_cor2> =
+			  %% Line 21
+			  call 'erlang':'+'
+			      (Val, V)
+		      in  let <_cor5> =
+			      %% Line 21
+			      M~{~<1337,_cor4>,~<'val',_cor2>}~
+			  in  %% Line 21
+			      apply 'call'/2
+				  (_cor5, Vs)
+	  %% Line 22
+	  <M,[]> when 'true' ->
+	      M
+	  ( <_cor7,_cor6> when 'true' ->
+		( primop 'match_fail'
+		      ({'function_clause',_cor7,_cor6})
+		  -| [{'function_name',{'call',2}}] )
+	    -| ['compiler_generated'] )
+	end
+'id'/1 =
+    %% Line 24
+    fun (_cor0) ->
+	_cor0
+'module_info'/0 =
+    fun () ->
+	call 'erlang':'get_module_info'
+	    ('map_core_test')
+'module_info'/1 =
+    fun (_cor0) ->
+	call 'erlang':'get_module_info'
+	    ('map_core_test', _cor0)
+end
\ No newline at end of file
diff --git a/lib/compiler/test/inline_SUITE.erl b/lib/compiler/test/inline_SUITE.erl
index e5c2d4f73a..47851e680b 100644
--- a/lib/compiler/test/inline_SUITE.erl
+++ b/lib/compiler/test/inline_SUITE.erl
@@ -37,7 +37,7 @@ all() ->
 groups() -> 
     [{p,test_lib:parallel(),
       [attribute,bsdecode,bsdes,barnes2,decode1,smith,fname,
-       itracer,pseudoknot,comma_splitter,lists,really_inlined,otp_7223,
+       itracer,pseudoknot,maps_inline_test,comma_splitter,lists,really_inlined,otp_7223,
        coverage]}].
 
 init_per_suite(Config) ->
@@ -85,6 +85,7 @@ attribute(Config) when is_list(Config) ->
 ?comp(pseudoknot).
 ?comp(comma_splitter).
 ?comp(fname).
+?comp(maps_inline_test).
 
 try_inline(Mod, Config) ->
     Node = ?config(testing_node, Config),
diff --git a/lib/compiler/test/inline_SUITE_data/maps_inline_test.erl b/lib/compiler/test/inline_SUITE_data/maps_inline_test.erl
new file mode 100644
index 0000000000..d9762e2647
--- /dev/null
+++ b/lib/compiler/test/inline_SUITE_data/maps_inline_test.erl
@@ -0,0 +1,70 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2013. 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.
+%% 
+%% %CopyrightEnd%
+%%
+
+-module(maps_inline_test).
+
+-export([?MODULE/0]).
+
+?MODULE() ->
+    21 = mval(#{val => 1}) +
+	 mval(#{val => 2}) +
+	 mval(#{val => 3}) +
+	 mval(#{val => 4}) +
+	 mval(#{val => 5}) +
+	 mval(#{val => 6}),
+
+    21 = gval(#{id => 1}) +
+	 gval(#{id => 2}) +
+	 gval(#{id => 3}) +
+	 gval(#{id => 4}) +
+	 gval(#{id => 5}) +
+	 gval(#{id => 6}),
+
+    21 = sval(#{id => 1}) +
+	 sval(#{id => 2}) +
+	 sval(#{id => 3}) +
+	 sval(#{id => 4}) +
+	 sval(#{id => 5}) +
+	 sval(#{id => 6}),
+
+    M = #{v => 1, m => #{v => 21, m => #{v => 7, m => 13}}},
+
+    42 = decompose(M).
+
+% switch key orders
+decompose(#{ m := M, v := V}) when is_map(M) ->
+    V + decompose(M);
+decompose(#{ v := V, m := M}) -> V + M.
+
+
+mval(#{val := V}) -> V.
+
+sval(#{id := 1}) -> 6;
+sval(#{id := 2}) -> 5;
+sval(#{id := 3}) -> 4;
+sval(#{id := 4}) -> 3;
+sval(#{id := 5}) -> 2;
+sval(#{id := 6}) -> 1.
+
+gval(M) when is_map(M) andalso M =:= #{ id => 1} -> 1;
+gval(M) when is_map(M) andalso M =:= #{ id => 2} -> 4;
+gval(M) when is_map(M) andalso M =:= #{ id => 3} -> 2;
+gval(M) when is_map(M) andalso M =:= #{ id => 4} -> 5;
+gval(M) when is_map(M) andalso M =:= #{ id => 5} -> 3;
+gval(M) when is_map(M) andalso M =:= #{ id => 6} -> 6.