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| author | Björn Gustavsson <[email protected]> | 2013-05-29 13:48:52 +0200 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2013-05-29 15:10:23 +0200 |
| commit | 2b1bf52eb71f0305247f95d4b10ba49a271a458c (patch) | |
| tree | 5cdd5aa757b6bfd746bf94dabc71875a6444f459 | |
| parent | 59fc364f7426d1a05d916900b42ba7aa0fda32bc (diff) | |
| download | otp-2b1bf52eb71f0305247f95d4b10ba49a271a458c.tar.gz otp-2b1bf52eb71f0305247f95d4b10ba49a271a458c.tar.bz2 otp-2b1bf52eb71f0305247f95d4b10ba49a271a458c.zip | |
compiler: Correct liveness optimization for wait/1
The live optimization in beam_utils:live_opt/4 did not take into
account that the wait/1 instruction *never* falls through to
the next instruction (it has the same effect on the control flow
as the jump/1 instruction).
| -rw-r--r-- | lib/compiler/src/beam_utils.erl | 4 | ||||
| -rw-r--r-- | lib/compiler/test/receive_SUITE.erl | 21 |
2 files changed, 21 insertions, 4 deletions
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl index 554c14f57a..e623bcc6a5 100644 --- a/lib/compiler/src/beam_utils.erl +++ b/lib/compiler/src/beam_utils.erl @@ -734,6 +734,8 @@ live_opt([{loop_rec,_Fail,_Dst}=I|Is], _, D, Acc) -> live_opt(Is, 0, D, [I|Acc]); live_opt([timeout=I|Is], _, D, Acc) -> live_opt(Is, 0, D, [I|Acc]); +live_opt([{wait,_}=I|Is], _, D, Acc) -> + live_opt(Is, 0, D, [I|Acc]); %% Transparent instructions - they neither use nor modify x registers. live_opt([{deallocate,_}=I|Is], Regs, D, Acc) -> @@ -744,8 +746,6 @@ live_opt([{try_end,_}=I|Is], Regs, D, Acc) -> live_opt(Is, Regs, D, [I|Acc]); live_opt([{loop_rec_end,_}=I|Is], Regs, D, Acc) -> live_opt(Is, Regs, D, [I|Acc]); -live_opt([{wait,_}=I|Is], Regs, D, Acc) -> - live_opt(Is, Regs, D, [I|Acc]); live_opt([{wait_timeout,_,{Tag,_}}=I|Is], Regs, D, Acc) when Tag =/= x -> live_opt(Is, Regs, D, [I|Acc]); live_opt([{line,_}=I|Is], Regs, D, Acc) -> diff --git a/lib/compiler/test/receive_SUITE.erl b/lib/compiler/test/receive_SUITE.erl index e60584d4ab..ec49267ded 100644 --- a/lib/compiler/test/receive_SUITE.erl +++ b/lib/compiler/test/receive_SUITE.erl @@ -23,7 +23,8 @@ -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, init_per_group/2,end_per_group/2, init_per_testcase/2,end_per_testcase/2, - export/1,recv/1,coverage/1,otp_7980/1,ref_opt/1]). + export/1,recv/1,coverage/1,otp_7980/1,ref_opt/1, + wait/1]). -include_lib("test_server/include/test_server.hrl"). @@ -44,7 +45,7 @@ all() -> groups() -> [{p,test_lib:parallel(), - [recv,coverage,otp_7980,ref_opt,export]}]. + [recv,coverage,otp_7980,ref_opt,export,wait]}]. init_per_suite(Config) -> @@ -252,4 +253,20 @@ export_1(Reference) -> id({build,self()}), Result. +wait(Config) when is_list(Config) -> + self() ! <<42>>, + <<42>> = wait_1(r, 1, 2), + {1,2,3} = wait_1(1, 2, 3), + ok. + +wait_1(r, _, _) -> + receive + B when byte_size(B) > 0 -> + B + end; +%% beam_utils would wrongly assume that wait/1 could fall through +%% to the next clause. +wait_1(A, B, C) -> + {A,B,C}. + id(I) -> I. |