https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59984
--- Comment #12 from Stupachenko Evgeny <evstupac at gmail dot com> --- Created attachment 33963 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33963&action=edit test case where pragma simd disable vectorization The following test case compiled with "-Ofast" vectorize the loop in the GetXsum function. Adding "-fopenmp" leads to failed vectorization due to: simd_issue.cpp:26:18: note: not vectorized: data ref analysis failed D.2329[_7].x = _12; It looks like before the patch in this Bug loop was vectorized with -fopenmp.
