[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: unassigned@gcc.gnu.org
        ReportedBy: rguenth@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.