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From: "tprince at computer dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/66740] New: omp simd reduction miscompiles at -O3 with AVX (recent regression) Date: Thu, 02 Jul 2015 12:42:00 -0000 [thread overview] Message-ID: <bug-66740-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66740 Bug ID: 66740 Summary: omp simd reduction miscompiles at -O3 with AVX (recent regression) Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: tprince at computer dot org Target Milestone: --- Created attachment 35897 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35897&action=edit f2c include file This regression is new in the last 2 weeks. gcc -O3 -march=sandybridge -std=c99 -D__assume_aligned= -fopenmp -c s115.c is miscompiled (bad numerical results when run under test harness). It is OK at -O2 or with -march=westmere, or with the omp directive disabled. It doesn't vectorize without the omp directive. It fails the same with -march=haswell. Similar versions using inner_product or Fortran dot_product are vectorizing correctly without omp simd.
next reply other threads:[~2015-07-02 12:42 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-07-02 12:42 tprince at computer dot org [this message] 2015-07-02 12:43 ` [Bug c/66740] " tprince at computer dot org 2015-07-02 12:46 ` tprince at computer dot org 2015-07-02 12:48 ` tprince at computer dot org 2015-07-02 13:57 ` [Bug tree-optimization/66740] [6 Regression] " rguenth at gcc dot gnu.org 2015-07-10 23:25 ` tprince at computer dot org
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