compiler: Fix codegen multiple updates for Maps

This fixes an error on multiple updates optimization for map pairs.
The error was introduced with moving to term order in Maps.

This also fixes an error where register life time was lost for values
and could result in erroneuos values being emitted in for map pairs.

Simplified v3_codegen by moving multiple update optimizations to v3_kernel.

1 files changed, 73 insertions, 19 deletions

diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 9a2b1605ad..0163b16715 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -274,8 +274,7 @@ expr(#c_tuple{anno=A,es=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};
+    map_split_pairs(A, Var, Ces, Sub, St1);
 expr(#c_binary{anno=A,segments=Cv}, Sub, St0) ->
     try atomic_bin(Cv, Sub, St0) of
 	{Kv,Ep,St1} ->
@@ -497,15 +496,71 @@ 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).
+    %{Kes,Ep,St2} = map_pairs(Ces, Sub, St1),
+map_split_pairs(A, Var, Ces, Sub, St0) ->
+    %% two steps
+    %% 1. force variables
+    %% 2. remove multiples
+    Pairs0 = [{Op,K,V} || #c_map_pair{op=#c_literal{val=Op},key=K,val=V} <- Ces],
+    {Pairs,Esp,St1} = foldr(fun
+	    ({Op,K0,V0}, {Ops,Espi,Sti0}) when Op =:= assoc; Op =:= exact ->
+		{K,[],Sti1} = expr(K0, Sub, Sti0),
+		{V,Ep,Sti2} = atomic(V0, Sub, Sti1),
+		{[{Op,K,V}|Ops],Ep ++ Espi,Sti2}
+	end, {[],[],St0}, Pairs0),
+
+    case map_group_pairs(Pairs) of
+	{Assoc,[]} ->
+	    Kes = [#k_map_pair{key=K,val=V}||{_,{assoc,K,V}} <- Assoc],
+	    {#k_map{anno=A,op=assoc,var=Var,es=Kes},Esp,St1};
+	{[],Exact} ->
+	    Kes = [#k_map_pair{key=K,val=V}||{_,{exact,K,V}} <- Exact],
+	    {#k_map{anno=A,op=exact,var=Var,es=Kes},Esp,St1};
+	{Assoc,Exact} ->
+	    Kes1 = [#k_map_pair{key=K,val=V}||{_,{assoc,K,V}} <- Assoc],
+	    {Mvar,Em,St2} = force_atomic(#k_map{anno=A,op=assoc,var=Var,es=Kes1},St1),
+	    Kes2 = [#k_map_pair{key=K,val=V}||{_,{exact,K,V}} <- Exact],
+	    {#k_map{anno=A,op=exact,var=Mvar,es=Kes2},Em ++ Esp,St2}
+
+    end.
+
+%% Group map by Assoc operations and Exact operations
+
+map_group_pairs(Es) ->
+    Groups = dict:to_list(map_group_pairs(Es,dict:new())),
+    partition(fun({_,{Op,_,_}}) -> Op =:= assoc end, Groups).
+
+map_group_pairs([{assoc,K,V}|Es0],Used0) ->
+    Used1 = case map_key_is_used(K,Used0) of
+	{ok, {assoc,_,_}} -> map_key_set_used(K,{assoc,K,V},Used0);
+	{ok, {exact,_,_}} -> map_key_set_used(K,{exact,K,V},Used0);
+	_                 -> map_key_set_used(K,{assoc,K,V},Used0)
+    end,
+    map_group_pairs(Es0,Used1);
+map_group_pairs([{exact,K,V}|Es0],Used0) ->
+    Used1 = case map_key_is_used(K,Used0) of
+	{ok, {assoc,_,_}} -> map_key_set_used(K,{assoc,K,V},Used0);
+	{ok, {exact,_,_}} -> map_key_set_used(K,{exact,K,V},Used0);
+	_                 -> map_key_set_used(K,{exact,K,V},Used0)
+    end,
+    map_group_pairs(Es0,Used1);
+map_group_pairs([],Used) ->
+    Used.
+
+map_key_set_used(K,How,Used) ->
+    dict:store(map_key_clean(K),How,Used).
+
+map_key_is_used(K,Used) ->
+    dict:find(map_key_clean(K),Used).
+
+%% Be explicit instead of using set_kanno(K,[])
+map_key_clean(#k_literal{val=V}) -> {k_literal,V};
+map_key_clean(#k_int{val=V})     -> {k_int,V};
+map_key_clean(#k_float{val=V})   -> {k_float,V};
+map_key_clean(#k_atom{val=V})    -> {k_atom,V};
+map_key_clean(#k_nil{})          -> k_nil;
+map_key_clean(#k_var{name=V})    -> {k_var,V}.
+
 
 %% call_type(Module, Function, Arity) -> call | bif | apply | error.
 %%  Classify the call.
@@ -664,11 +719,11 @@ pattern(#c_tuple{anno=A,es=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};
+    {#k_map{anno=A,op=exact,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};
+    {#k_map_pair{anno=A,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};
@@ -1365,9 +1420,8 @@ new_clauses(Cs0, U, St) ->
 				     [S,N|As];
 				 #k_bin_int{next=N} ->
 				     [N|As];
-				 #k_map{es=Es} ->
-				     Vals = [V ||
-						#k_map_pair{op=exact,val=V} <- Es],
+				 #k_map{op=exact,es=Es} ->
+				     Vals = [V || #k_map_pair{val=V} <- Es],
 				     Vals ++ As;
 				 _Other ->
 				     As
@@ -1467,9 +1521,9 @@ arg_val(Arg, C) ->
 		_ ->
 		    {set_kanno(S, []),U,T,Fs}
 	    end;
-	#k_map{es=Es} ->
+	#k_map{op=exact,es=Es} ->
 	    Keys = [begin
-			#k_map_pair{op=exact,key=#k_literal{val=Key}} = Pair,
+			#k_map_pair{key=#k_literal{val=Key}} = Pair,
 			Key
 		    end || Pair <- Es],
 	    %% multiple keys may have the same name
@@ -1885,7 +1939,7 @@ pat_vars(#k_tuple{es=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(#k_map_pair{val=V}) ->
     pat_vars(V).
 
 pat_list_vars(Ps) ->