[Bug tree-optimization/56286] New: vectorizer does not keep loop-closed SSA up-to-date

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56286



             Bug #: 56286

           Summary: vectorizer does not keep loop-closed SSA up-to-date

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: tree-optimization

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: rgue...@gcc.gnu.org





The vectorizer relies on the bug that cfgcleaup for no changed bbs from

fix_loop_structure rewrites the whole function into loop-closed-SSA again.



Loop-closed PHI node creation in vect_create_epilog_for_reduction does

not handle outer loop uses of the reduction result properly (those uses

are not yet vectorized).  For example gcc.dg/pr50133.c.