1  /* PR tree-optimization/20742 */
       2  
       3  int
       4  foo (int x, int y)
       5  {
       6    register int a = y + 57;
       7    register int b = y + 31;
       8  
       9    while (x-- > 0)
      10      {
      11   #define TEN(x) x x x x x x x x x x
      12        TEN (TEN (a += b; b -= a;))
      13        TEN (TEN (a += b; b -= a;))
      14      }
      15    return a + b;
      16  }