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authorJohn Högberg <[email protected]>2017-08-07 16:05:30 +0200
committerJohn Högberg <[email protected]>2017-08-07 16:05:30 +0200
commitc20dbc7ee48a4193975f4351973c323c359528d7 (patch)
tree57a7ec897646e5d9027acf3ce64f7bd19d92167d /lib/compiler/src
parent74a95b3d511177a9b35c2b0272b9ca5511b6f750 (diff)
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Take fail labels into account when determining liveness in block ops
Diffstat (limited to 'lib/compiler/src')
-rw-r--r--lib/compiler/src/beam_utils.erl62
1 files changed, 36 insertions, 26 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index fbcd5de1bb..1945fadfd3 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -779,37 +779,47 @@ live_opt([{recv_mark,_}=I|Is], Regs, D, Acc) ->
live_opt([], _, _, Acc) -> Acc.
-live_opt_block([{set,Ds,Ss,Op}=I0|Is], Regs0, D, Acc) ->
+live_opt_block([{set,Ds,Ss,Op0}|Is], Regs0, D, Acc) ->
Regs1 = x_live(Ss, x_dead(Ds, Regs0)),
- {I,Regs} = case Op of
- {alloc,Live0,Alloc} ->
- %% The life-time analysis used by the code generator
- %% is sometimes too conservative, so it may be
- %% possible to lower the number of live registers
- %% based on the exact liveness information.
- %% The main benefit is that more optimizations that
- %% depend on liveness information (such as the
- %% beam_bool and beam_dead passes) may be applied.
- Live = live_regs(Regs1),
- true = Live =< Live0, %Assertion.
- I1 = {set,Ds,Ss,{alloc,Live,Alloc}},
- {I1,live_call(Live)};
- _ ->
- {I0,Regs1}
- end,
+ {Op, Regs} = live_opt_block_op(Op0, Regs1, D),
+ I = {set, Ds, Ss, Op},
+
case Ds of
- [{x,X}] ->
- case (not is_live(X, Regs0)) andalso Op =:= move of
- true ->
- live_opt_block(Is, Regs0, D, Acc);
- false ->
- live_opt_block(Is, Regs, D, [I|Acc])
- end;
- _ ->
- live_opt_block(Is, Regs, D, [I|Acc])
+ [{x,X}] ->
+ case (not is_live(X, Regs0)) andalso Op =:= move of
+ true ->
+ live_opt_block(Is, Regs0, D, Acc);
+ false ->
+ live_opt_block(Is, Regs, D, [I|Acc])
+ end;
+ _ ->
+ live_opt_block(Is, Regs, D, [I|Acc])
end;
+
live_opt_block([], Regs, _, Acc) -> {Acc,Regs}.
+live_opt_block_op({alloc,Live0,AllocOp}, Regs0, D) ->
+ Regs =
+ case AllocOp of
+ {Kind, _N, Fail} when Kind =:= gc_bif; Kind =:= put_map ->
+ live_join_label(Fail, D, Regs0);
+ _ ->
+ Regs0
+ end,
+
+ %% The life-time analysis used by the code generator is sometimes too
+ %% conservative, so it may be possible to lower the number of live
+ %% registers based on the exact liveness information. The main benefit is
+ %% that more optimizations that depend on liveness information (such as the
+ %% beam_bool and beam_dead passes) may be applied.
+ Live = live_regs(Regs),
+ true = Live =< Live0,
+ {{alloc,Live,AllocOp}, live_call(Live)};
+live_opt_block_op({bif,_N,Fail} = Op, Regs, D) ->
+ {Op, live_join_label(Fail, D, Regs)};
+live_opt_block_op(Op, Regs, _D) ->
+ {Op, Regs}.
+
live_join_labels([{f,L}|T], D, Regs0) when L =/= 0 ->
Regs = gb_trees:get(L, D) bor Regs0,
live_join_labels(T, D, Regs);