Merge branch 'bjorn/compiler/misc-opt'

* bjorn/compiler/misc-opt:
  v3_kernel: Construct literal lists properly
  Use the register map in %live in beam_utils:is_killed_block/2
  Teach beam_utils to check liveness for put_map instructions
  beam_peep: Help out beam_jump

4 files changed, 21 insertions, 12 deletions

diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index c08b4a8759..879daaca0a 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -532,9 +532,9 @@ i_put_tuple x I
 i_put_tuple y I
 
 #
-# The instruction "put_list Const [] Dst" will not be generated by
-# the current BEAM compiler. But until R15A, play it safe by handling
-# that instruction with the following transformation.
+# The instruction "put_list Const [] Dst" were generated in rare
+# circumstances up to and including OTP 18. Starting with OTP 19,
+# AFAIK, it should never be generated.
 #
 put_list Const=c n Dst => move Const x | put_list x n Dst
 
diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl
index 1e430b4ed5..c8bef31824 100644
--- a/lib/compiler/src/beam_peep.erl
+++ b/lib/compiler/src/beam_peep.erl
@@ -83,6 +83,9 @@ peep([{gc_bif,_,_,_,_,Dst}=I|Is], SeenTests0, Acc) ->
     %% Kill all remembered tests that depend on the destination register.
     SeenTests = kill_seen(Dst, SeenTests0),
     peep(Is, SeenTests, [I|Acc]);
+peep([{jump,{f,L}},{label,L}=I|Is], _, Acc) ->
+    %% Sometimes beam_jump has missed this optimization.
+    peep(Is, gb_sets:empty(), [I|Acc]);
 peep([{select,Op,R,F,Vls0}|Is], _, Acc) ->
     case prune_redundant_values(Vls0, F) of
 	[] ->
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index b338286a16..37f89dd677 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -484,6 +484,17 @@ check_liveness(R, [{get_map_elements,{f,Fail},S,{list,L}}|Is], St0) ->
 		    Other
 	    end
     end;
+check_liveness(R, [{put_map,{f,_},_,Src,_D,Live,{list,_}}|_], St0) ->
+    case R of
+	Src ->
+	    {used,St0};
+	{x,X} when X < Live ->
+	    {used,St0};
+	{x,_} ->
+	    {killed,St0};
+	{y,_} ->
+	    {unknown,St0}
+    end;
 check_liveness(R, [{test_heap,N,Live}|Is], St) ->
     I = {block,[{set,[],[],{alloc,Live,{nozero,nostack,N,[]}}}]},
     check_liveness(R, [I|Is], St);
@@ -570,9 +581,9 @@ check_killed_block(R, [{set,Ds,Ss,_Op}|Is]) ->
 		false -> check_killed_block(R, Is)
 	    end
     end;
-check_killed_block(R, [{'%live',Live,_}|Is]) ->
+check_killed_block(R, [{'%live',_,Regs}|Is]) ->
     case R of
-	{x,X} when X >= Live -> killed;
+	{x,X} when (Regs bsr X) band 1 =:= 0 -> killed;
 	_ -> check_killed_block(R, Is)
     end;
 check_killed_block(_, []) -> transparent.
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 4446d5ff1d..4a6330fce4 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -401,7 +401,7 @@ expr(#c_call{anno=A,module=M0,name=F0,args=Cargs}, Sub, St0) ->
 	    Call = #c_call{anno=A,
 			   module=#c_literal{val=erlang},
 			   name=#c_literal{val=apply},
-			   args=[M0,F0,make_list(Cargs)]},
+			   args=[M0,F0,cerl:make_list(Cargs)]},
 	    expr(Call, Sub, St1);
 	_ ->
 	    {[M1,F1|Kargs],Ap,St} = atomic_list([M0,F0|Cargs], Sub, St1),
@@ -496,7 +496,7 @@ translate_match_fail_1(Anno, As, Sub, #kern{ff=FF}) ->
     end.
 
 translate_fc(Args) ->
-    [#c_literal{val=function_clause},make_list(Args)].
+    [#c_literal{val=function_clause},cerl:make_list(Args)].
 
 expr_map(A,Var0,Ces,Sub,St0) ->
     {Var,Mps,St1} = expr(Var0, Sub, St0),
@@ -1988,11 +1988,6 @@ pat_list_vars(Ps) ->
 		  {union(Used0, Used),union(New0, New)} end,
 	  {[],[]}, Ps).
 
-make_list(Es) ->
-    foldr(fun(E, Acc) ->
- 		  #c_cons{hd=E,tl=Acc}
- 	  end, #c_literal{val=[]}, Es).
-
 %% List of integers in interval [N,M]. Empty list if N > M.
 
 integers(N, M) when N =< M ->