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author | Björn Gustavsson <[email protected]> | 2016-04-06 06:29:49 +0200 |
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committer | Björn Gustavsson <[email protected]> | 2016-04-11 13:57:26 +0200 |
commit | 8a659704161705fb838447cb6aa54627e12a8910 (patch) | |
tree | 349511b0921b58ceb9189fd03cf2808493622a23 /lib/compiler | |
parent | 9d2dde09689246cd61a5e7bfdc8ca37884043a9c (diff) | |
download | otp-8a659704161705fb838447cb6aa54627e12a8910.tar.gz otp-8a659704161705fb838447cb6aa54627e12a8910.tar.bz2 otp-8a659704161705fb838447cb6aa54627e12a8910.zip |
beam_peep: Help out beam_jump
beam_jump fails to optimize the following:
jump 2
label 1
label 2
Since this situation is rare, instead of complicating beam_jump,
add the optimization to beam_peep. It will always succeed, since
adjacent labels have been coalesced.
Diffstat (limited to 'lib/compiler')
-rw-r--r-- | lib/compiler/src/beam_peep.erl | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/lib/compiler/src/beam_peep.erl b/lib/compiler/src/beam_peep.erl index 0c1abfe6a0..5a02626642 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 [] -> |