[Bug tree-optimization/49984] New: VRP does not handle BIT_XOR_EXPR

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49984

           Summary: VRP does not handle BIT_XOR_EXPR
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: rgue...@gcc.gnu.org


In

int f(int x)
{
  if (x >= 0 && x <= 3)
    {
      x = x ^ 3;
      x = x & 3;
    }
  return x;
}

the x = x & 3 statement should be removed by simplify_bit_ops_using_ranges,
but propagation does not handle BIT_XOR_EXPR and thus the input range to
this statement is VARYING.