https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74881
Bug ID: 74881 Summary: re-align optimization blocks vectorization on powerpc Product: gcc Version: 7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: amker at gcc dot gnu.org Target Milestone: --- Hi, gcc.dg/vect/vect-117.c starts failing with patch at r238301. After investigation I think it exposed a latent vectorizer issue. Before patch, the loop is vectorized but guarded by alias check that is always false. That is, the vectorized loop will never be executed in reality. The patch only skips known to be false alias check. Detailed analysis and possible fix is at https://gcc.gnu.org/ml/gcc-patches/2016-08/msg01035.html