1  /* { dg-do compile } */
       2  /* { dg-options "-O -fdump-tree-fre1" } */
       3  
       4  _Bool f1(unsigned x, unsigned y, unsigned *res)
       5  {
       6      _Bool t = __builtin_add_overflow(x, y, res);
       7      unsigned res1;
       8      _Bool t1 = __builtin_add_overflow(x, y, &res1);
       9      *res -= res1;
      10      return t==t1;
      11  }
      12  
      13  /* { dg-final { scan-tree-dump-times "ADD_OVERFLOW" 1 "fre1" } } */
      14  /* { dg-final { scan-tree-dump "return 1;" "fre1" } } */