[Bug middle-end/23672] New: Fold does not fold (a^b)^a to b

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

These two functions should be the same at the tree level but are not:
int f(int a, int b)
{
  return (a^b)^a;
}
int f1(int a, int b)
{
  return b;
}

---
Another one from LLVM.

-- 
           Summary: Fold does not fold  (a^b)^a to b
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P2
         Component: middle-end
        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
OtherBugsDependingO 19986
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23672