https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68128
Bug ID: 68128 Summary: A huge regression in Parboil v2.5 OpenMP CUTCP test (2.5 times lower performance) Product: gcc Version: 5.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: t.artem at mailcity dot com Target Milestone: --- According to Phoronix, http://www.phoronix.com/scan.php?page=article&item=fedora-2023-bench&num=4 , for Parboil v2.5 OpenMP CUTCP test GCC in Fedora 22/23 produces the code which runs 2.5 times slower than the code produced by Fedora 20. Fedora 20: GCC 4.8.2 (good performance) Fedora 21: GCC 4.9.1 (good performance) Fedora 22: GCC 5.1.1 with patches (huge regression) Fedora 23: GCC 5.1.1 with even more patches (huge regression)