6 files changed, 75 insertions, 19 deletions

diff --git a/lib/compiler/src/beam_block.erl b/lib/compiler/src/beam_block.erl
index 7a30c68593..5626aa34ab 100644
--- a/lib/compiler/src/beam_block.erl
+++ b/lib/compiler/src/beam_block.erl
@@ -155,7 +155,8 @@ 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_elements,F,S,{list,Gets}}) ->
-    {set,Gets,[S],{get_map_elements,F}};
+    {Ss,Ds} = beam_utils:spliteven(Gets),
+    {set,Ds,[S|Ss],{get_map_elements,F}};
 collect({'catch',R,L})       -> {set,[R],[],{'catch',L}};
 collect(fclearerror)         -> {set,[],[],fclearerror};
 collect({fcheckerror,{f,0}}) -> {set,[],[],fcheckerror};
diff --git a/lib/compiler/src/beam_flatten.erl b/lib/compiler/src/beam_flatten.erl
index 46835bece1..05d067dc48 100644
--- a/lib/compiler/src/beam_flatten.erl
+++ b/lib/compiler/src/beam_flatten.erl
@@ -63,7 +63,8 @@ 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,Gets,[S],{get_map_elements,F}}) ->
+norm({set,Ds,[S|Ss],{get_map_elements,F}}) ->
+    Gets = beam_utils:joineven(Ss,Ds),
     {get_map_elements,F,S,{list,Gets}};
 norm({set,[],[],remove_message})   -> remove_message;
 norm({set,[],[],fclearerror}) -> fclearerror;
diff --git a/lib/compiler/src/beam_split.erl b/lib/compiler/src/beam_split.erl
index 688bba9a94..f5dba314ae 100644
--- a/lib/compiler/src/beam_split.erl
+++ b/lib/compiler/src/beam_split.erl
@@ -53,8 +53,9 @@ 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,Gets,[S],{get_map_elements,{f,Lbl}=Fail}}|Is], Bl, Acc)
+split_block([{set,Ds,[S|Ss],{get_map_elements,{f,Lbl}=Fail}}|Is], Bl, Acc)
   when Lbl =/= 0 ->
+    Gets = beam_utils:joineven(Ss,Ds),
     split_block(Is, [], [{get_map_elements,Fail,S,{list,Gets}}|make_block(Bl, Acc)]);
 split_block([{set,[R],[],{'catch',L}}|Is], Bl, Acc) ->
     split_block(Is, [], [{'catch',R,L}|make_block(Bl, Acc)]);
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index 8ca368c167..e82ba82d38 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -26,6 +26,8 @@
 	 code_at/2,bif_to_test/3,is_pure_test/1,
 	 live_opt/1,delete_live_annos/1,combine_heap_needs/2]).
 
+-export([joineven/2,spliteven/1]).
+
 -import(lists, [member/2,sort/1,reverse/1,splitwith/2]).
 
 -record(live,
@@ -832,3 +834,15 @@ x_live([_|Rs], Regs) -> x_live(Rs, Regs);
 x_live([], Regs) -> Regs.
 
 is_live(X, Regs) -> ((Regs bsr X) band 1) =:= 1.
+
+%% spliteven/1
+%% [1,2,3,4,5,6] -> {[1,3,5],[2,4,6]}
+spliteven(Rs) -> spliteven(Rs,[],[]).
+spliteven([],Ss,Ds) -> {reverse(Ss),reverse(Ds)};
+spliteven([S,D|Rs],Ss,Ds) ->
+    spliteven(Rs,[S|Ss],[D|Ds]).
+
+%% joineven/1
+%% {[1,3,5],[2,4,6]} -> [1,2,3,4,5,6]
+joineven([],[]) -> [];
+joineven([S|Ss],[D|Ds]) -> [S,D|joineven(Ss,Ds)].
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index 9d5563d13b..0acc7a227f 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -1123,7 +1123,9 @@ assert_freg_set(Fr, _) -> error({bad_source,Fr}).
 %%% Maps
 
 %% ensure that a list of literals has a strict
-%% ascending term order (also meaning unique literals)
+%% ascending term order (also meaning unique literals).
+%% Single item lists may have registers.
+assert_strict_literal_termorder([_]) -> ok;
 assert_strict_literal_termorder(Ls) ->
     Vs = lists:map(fun (L) -> get_literal(L) end, Ls),
     case check_strict_value_termorder(Vs) of
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index d0c337e3ca..7cfc8d8197 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -943,27 +943,34 @@ select_extract_map(Src, Vs, Fail, I, Vdb, Bef, St) ->
     %% Assume keys are term-sorted
     Rsrc = fetch_var(Src, Bef),
 
-    {{HasKs,GetVs},Aft} = lists:foldr(fun
-	    ({map_pair,Key,{var,V}},{{HasKsi,GetVsi},Int0}) ->
+    {{HasKs,GetVs,HasVarKs,GetVarVs},Aft} = lists:foldr(fun
+	    ({map_pair,{var,K},{var,V}},{{HasKsi,GetVsi,HasVarVsi,GetVarVsi},Int0}) ->
 		case vdb_find(V, Vdb) of
 		    {V,_,L} when L =< I ->
-			{{[Key|HasKsi],GetVsi},Int0};
+			RK = fetch_var(K,Int0),
+			{{HasKsi,GetVsi,[RK|HasVarVsi],GetVarVsi},Int0};
 		    _Other ->
 			Reg1 = put_reg(V, Int0#sr.reg),
 			Int1 = Int0#sr{reg=Reg1},
-			{{HasKsi,[Key,fetch_reg(V, Reg1)|GetVsi]},Int1}
+			RK = fetch_var(K,Int0),
+			RV = fetch_reg(V,Reg1),
+			{{HasKsi,GetVsi,HasVarVsi,[[RK,RV]|GetVarVsi]},Int1}
+		end;
+	    ({map_pair,Key,{var,V}},{{HasKsi,GetVsi,HasVarVsi,GetVarVsi},Int0}) ->
+		case vdb_find(V, Vdb) of
+		    {V,_,L} when L =< I ->
+			{{[Key|HasKsi],GetVsi,HasVarVsi,GetVarVsi},Int0};
+		    _Other ->
+			Reg1 = put_reg(V, Int0#sr.reg),
+			Int1 = Int0#sr{reg=Reg1},
+			{{HasKsi,[Key,fetch_reg(V, Reg1)|GetVsi],HasVarVsi,GetVarVsi},Int1}
 		end
-	end, {{[],[]},Bef}, Vs),
-
-    Code = case {HasKs,GetVs} of
-	{HasKs,[]} ->
-	    [{test,has_map_fields,{f,Fail},Rsrc,{list,HasKs}}];
-	{[],GetVs} ->
-	    [{get_map_elements,   {f,Fail},Rsrc,{list,GetVs}}];
-	{HasKs,GetVs} ->
-	    [{test,has_map_fields,{f,Fail},Rsrc,{list,HasKs}},
-	     {get_map_elements,   {f,Fail},Rsrc,{list,GetVs}}]
-    end,
+	end, {{[],[],[],[]},Bef}, Vs),
+
+    Code = [{test,has_map_fields,{f,Fail},Rsrc,{list,HasKs}} || HasKs =/= []] ++
+	   [{test,has_map_fields,{f,Fail},Rsrc,{list,[K]}}   || K <- HasVarKs] ++
+	   [{get_map_elements,   {f,Fail},Rsrc,{list,GetVs}} || GetVs =/= []] ++
+	   [{get_map_elements,   {f,Fail},Rsrc,{list,[K,V]}} || [K,V] <- GetVarVs],
     {Code, Aft, St}.
 
 
@@ -1500,9 +1507,39 @@ 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};
+% Map single variable key
+set_cg([{var,R}], {map,Op,Map,[{map_pair,{var,_}=K,V}]}, 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,
+    SrcReg = cg_reg_arg(Map,Int0),
+    Line = line(Le#l.a),
+
+    List = [cg_reg_arg(K,Int0),cg_reg_arg(V,Int0)],
+
+    Live = max_reg(Bef#sr.reg),
+    Int1 = Int0#sr{reg=put_reg(R, Int0#sr.reg)},
+    Aft = clear_dead(Int1, Le#l.i, Vdb),
+    Target = fetch_reg(R, Int1#sr.reg),
+
+    I = case Op of
+	assoc -> put_map_assoc;
+	exact -> put_map_exact
+    end,
+    {Sis++[Line]++[{I,Fail,SrcReg,Target,Live,{list,List}}],Aft,St};
+
+% Map (possibly) multiple literal keys
 set_cg([{var,R}], {map,Op,Map,Es}, Le, Vdb, Bef,
        #cg{in_catch=InCatch,bfail=Bfail}=St) ->
 
+    %% assert key literals
+    [] = [Var||{map_pair,{var,_}=Var,_} <- Es],
+
     Fail = {f,Bfail},
     {Sis,Int0} =
 	case InCatch of