[Bug tree-optimization/17671] New: PHI-OPT is not smart enough

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

Here is an example of where PHI-OPT could be smarter and do top down instead of bottom up.  
Looking at COND_EXPR instead of looking at the PHI nodes
int f(int a, int b)
{
  if (a == 0)
   return 0;
  if (a != b)
   return a;
 return a;
}

-- 
           Summary: PHI-OPT is not smart enough
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17671