https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108752
Bug ID: 108752 Summary: word_mode vectorization is pessimized by hard limit on nunits Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: rguenth at gcc dot gnu.org Target Milestone: --- r13-5771-gdc87e1391c55c6 re-introduced a hard nunits limit to the vectorizer when using emulated vectors (aka word_mode vectorization). That's because this feature relies on vector lowering to implement plus, minus and negate with bit operations and that has such limit in place for when dealing with user written code that didn't have any cost modeling applied. The fix is to emit supported operations from the vectorizer.