1  int
       2  test_endianness()
       3  {
       4    union doubleword
       5      {
       6        double d;
       7        unsigned long u[2];
       8      } dw;
       9    dw.d = 10;
      10    return dw.u[0] != 0 ? 1 : 0;
      11  }
      12  
      13  int
      14  test_endianness_vol()
      15  {
      16    union doubleword
      17      {
      18        volatile double d;
      19        volatile long u[2];
      20      } dw;
      21    dw.d = 10;
      22    return dw.u[0] != 0 ? 1 : 0;
      23  }
      24  
      25  main ()
      26  {
      27    if (test_endianness () != test_endianness_vol ())
      28      abort ();
      29    exit (0);
      30  }