https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84482
Bug ID: 84482 Summary: 437.leslie3d regresses on Haswell and SandyBridge at -O3 and -Ofast with generic march and tuning Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: jamborm at gcc dot gnu.org Target Milestone: --- It has been brought to my attention that the run-time of benchmark 437.leslie3d from SPEC 2006 regresses on Intel Haswell by about 8% when compiled with -O3 and generic march and tuning using trunk, compared to gcc 7.2. I tried on my desktop Sandy Bridge system and actually observed a 13% regression at -Ofast (and generic march and tuning). For the record, this does not seem to be happening on Zen CPUs.