1  /* { dg-do compile } */
       2  /* { dg-options "-O2 -fdump-tree-optimized" } */
       3  
       4  int
       5  foo (unsigned char a, _Bool b)
       6  {
       7    return (!a & a) | (b & !b);
       8  }
       9  
      10  /* As long as comparisons aren't boolified and casts from boolean-types
      11     aren't preserved, the folding of  X & !X to zero fails.  */
      12  /* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" { xfail *-*-* } } } */