[Bug tree-optimization/20130] New: Fold a * -1 - 1 into ~a;

["kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

Consider

int
foo (int a)
{
  return a * -1 - 1;
}

CSE folds a * -1 into -a;
combine folds -a - 1 into ~a;

Obviously, we should do both of these in tree.

-- 
           Summary: Fold a * -1 - 1 into ~a;
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: gcc-bugs at gcc dot gnu dot org
OtherBugsDependingO 19721
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20130