[Bug middle-end/31096] New: a*C == b*C where C is a constant is not optimized to a == b

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

The following two functions should be equzlivant when overflow is undefined:
int f(int a, int b)
{
  return a * 10 == b*10;
}

int f1(int a, int b)
{
  return a==b;
}


-- 
           Summary: a*C == b*C where C is a constant is not optimized to a
                    == b
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31096