1  typedef union
       2  {
       3    struct
       4      {
       5        char h, l;
       6      } b;
       7  } T;
       8  
       9  f (x)
      10       int x;
      11  {
      12    int num = 0;
      13    T reg;
      14  
      15    reg.b.l = x;
      16    while ((reg.b.l & 1) == 0)
      17      {
      18        num++;
      19        reg.b.l >>= 1;
      20      }
      21    return num;
      22  }
      23  
      24  main ()
      25  {
      26    if (f (2) != 1)
      27      abort ();
      28    exit (0);
      29  }
      30