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authorBjörn Gustavsson <[email protected]>2018-01-10 07:38:12 +0100
committerBjörn Gustavsson <[email protected]>2018-01-11 12:00:59 +0100
commit114f6de068f1cf5b0cf0cf1aacf2ff9a7f1f3650 (patch)
treec9554f654a27bada0221242bc229a778c4a00476
parent41aa951ca392e445d1ccae688f5a00662f6ca537 (diff)
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beam_bsm: Insert introduced 'move' instructions into block
If possible, when adding move/2 instructions, try to insert them into a block. That could potentially allow them to be optimized.
-rw-r--r--lib/compiler/src/beam_bsm.erl19
1 files changed, 13 insertions, 6 deletions
diff --git a/lib/compiler/src/beam_bsm.erl b/lib/compiler/src/beam_bsm.erl
index 9ea5a3eb92..9f3b9d788f 100644
--- a/lib/compiler/src/beam_bsm.erl
+++ b/lib/compiler/src/beam_bsm.erl
@@ -124,20 +124,21 @@ btb_opt_1([{test,bs_get_binary2,F,_,[Reg,{atom,all},U,Fs],Reg}=I0|Is], D, Acc0)
end,
btb_opt_1(Is, D, Acc)
end;
-btb_opt_1([{test,bs_get_binary2,F,_,[Ctx,{atom,all},U,Fs],Dst}=I0|Is], D, Acc0) ->
- case btb_reaches_match(Is, [Ctx,Dst], D) of
+btb_opt_1([{test,bs_get_binary2,F,_,[Ctx,{atom,all},U,Fs],Dst}=I0|Is0], D, Acc0) ->
+ case btb_reaches_match(Is0, [Ctx,Dst], D) of
{error,Reason} ->
Comment = btb_comment_no_opt(Reason, Fs),
- btb_opt_1(Is, D, [Comment,I0|Acc0]);
+ btb_opt_1(Is0, D, [Comment,I0|Acc0]);
{ok,MustSave} when U =:= 1 ->
Comment = btb_comment_opt(Fs),
- Acc1 = btb_gen_save(MustSave, Ctx, [Comment|Acc0]),
- Acc = [{move,Ctx,Dst}|Acc1],
+ Acc = btb_gen_save(MustSave, Ctx, [Comment|Acc0]),
+ Is = prepend_move(Ctx, Dst, Is0),
btb_opt_1(Is, D, Acc);
{ok,MustSave} ->
Comment = btb_comment_opt(Fs),
Acc1 = btb_gen_save(MustSave, Ctx, [Comment|Acc0]),
- Acc = [{move,Ctx,Dst},{test,bs_test_unit,F,[Ctx,U]}|Acc1],
+ Acc = [{test,bs_test_unit,F,[Ctx,U]}|Acc1],
+ Is = prepend_move(Ctx, Dst, Is0),
btb_opt_1(Is, D, Acc)
end;
btb_opt_1([I|Is], D, Acc) ->
@@ -150,6 +151,12 @@ btb_gen_save(true, Reg, Acc) ->
[{bs_save2,Reg,{atom,start}}|Acc];
btb_gen_save(false, _, Acc) -> Acc.
+prepend_move(Ctx, Dst, [{block,Bl0}|Is]) ->
+ Bl = [{set,[Dst],[Ctx],move}|Bl0],
+ [{block,Bl}|Is];
+prepend_move(Ctx, Dst, Is) ->
+ [{move,Ctx,Dst}|Is].
+
%% btb_reaches_match([Instruction], [Register], D) ->
%% {ok,MustSave}|{error,Reason}
%%