1  /* { dg-do compile } */ 
       2  /* { dg-options "-O2 -fdump-tree-reassoc1" } */
       3  int main(int a, int b, int c, int d)
       4  {
       5    /* All the xor's cancel each other out, leaving 0  */
       6    int e = (a ^ b) ^ (c ^ d);
       7    int f = (c ^ a) ^ (b ^ d);
       8    return e ^ f;
       9  }
      10  /* { dg-final { scan-tree-dump-times "= 0" 1 "reassoc1"} } */