1  /* { dg-do compile } */
       2  /* { dg-options "-O1" } */
       3  
       4  int m;
       5  
       6  int
       7  undefined (int);
       8  
       9  __attribute__ ((pure, returns_twice)) int
      10  bar (void)
      11  {
      12    m = 1;
      13    while (m)
      14      m = 2;
      15  
      16    return m;
      17  }
      18  
      19  int
      20  foo (void)
      21  {
      22    return undefined (bar ());
      23  }