https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65494
Bug ID: 65494 Summary: [5.0 Regression] Loop is not vectorized because of operand canonicalization. Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: ysrumyan at gmail dot com 5.0 compiler is not vectorized simple loop extracted from geekbench but 4.9 compiler does. This is caused by different operand ordering after loop unrolling (I pointed out essential part of tree): 4.9 5.0 _105=_86+_1 _105=_86+_1 _109=_90+_63 _109=_63+_90 _21=_6+_82 _21=_6+_82 Test-case is attached.