https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79534
Bug ID: 79534 Summary: tree-ifcombine aarch64 regression with trunk@245151 Product: gcc Version: 7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: brzycki at gmail dot com Target Milestone: --- Created attachment 40752 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40752&action=edit Reduced test-case. Larger scores are better. I am seeing about a 6-10% performance regression on a proprietary benchmark on AArch64, depending on the target micro-architecture. # SHA d2c3261, trunk@245149, patch immediately preceding regression /gcc/2017-02-03-12-17-59-d2c3261-master/bin/aarch64-sarc-linux-gnu-g++ -O3 -mcpu=cortex-a57 -std=c++11 -c a.cpp -o a.o /gcc/2017-02-03-12-17-59-d2c3261-master/bin/aarch64-sarc-linux-gnu-g++ -o a a.o (best of 3 runs) SCORE_DIRECTION ==> larger is better SCORE ==> 1619.832509 # SHA f56c861, trunk@245151, regressing patch /gcc/2017-02-03-14-03-35-f56c861-master/bin/aarch64-sarc-linux-gnu-g++ -O3 -mcpu=cortex-a57 -std=c++11 -c a.cpp -o a.o /gcc/2017-02-03-14-03-35-f56c861-master/bin/aarch64-sarc-linux-gnu-g++ -o a a.o (best of 3 runs) SCORE_DIRECTION ==> larger is better SCORE ==> 1468.440527 # SHA e502db7, a recent 2/14/2017 tip build /gcc/2017-02-14-23-11-19-e502db7-master/bin/aarch64-sarc-linux-gnu-g++ -O3 -mcpu=cortex-a57 -std=c++11 -c a.cpp -o a.o /gcc/2017-02-14-23-11-19-e502db7-master/bin/aarch64-sarc-linux-gnu-g++ -o a a.o SCORE_DIRECTION ==> larger is better SCORE ==> 1483.952217 I do not see the slowdown when testing on x86_64.