[Bug tree-optimization/82446] New: [8 Regression] Missed equalities in dr_group_sort_cmp

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82446

            Bug ID: 82446
           Summary: [8 Regression] Missed equalities in dr_group_sort_cmp
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
            Blocks: 82397
  Target Milestone: ---

The fix for PR82397 causes a few missed equalities and thus different
vectorizer group access detections because operand_equal_p was handling
commutated operands
and data_ref_compare_tree does not.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82397
[Bug 82397] [8 Regression] qsort comparator non-negative on sorted output: 1 in
vect_analyze_data_ref_accesses