1  /* { dg-do compile } */
       2  /* { dg-options "-O1 -fno-ipa-pure-const -Wuninitialized" } */
       3  
       4  int n;
       5  
       6  void
       7  empty (int)
       8  {
       9  }
      10  
      11  int
      12  bar (int x)
      13  {
      14    return n + x + 1;
      15  }
      16  
      17  __attribute__ ((pure, returns_twice)) int
      18  foo (void)
      19  {
      20    int uninitialized;
      21  
      22    if (n)
      23      {
      24        if (bar (0))
      25          return 0;
      26  
      27        __builtin_unreachable ();
      28      }
      29  
      30    while (uninitialized < 1) /* { dg-warning "uninitialized" } */
      31      {
      32        foo ();
      33        empty (bar (0) == foo ());
      34        ++uninitialized;
      35      }
      36  
      37    return 0;
      38  }