1  p1 (int b, int *p, int a)
       2  {
       3    p[0] = p[1];
       4    return p[0];
       5  }
       6  p2 (int b, int *p, int a)
       7  {
       8    p[0] = p[1];
       9    return p[0] == 0;
      10  }
      11  p3 (int b, int *p, int a)
      12  {
      13    p[0] = p[1];
      14    a = p[0];
      15    if (a)
      16      return 0;
      17    return a;
      18  }
      19  p4 (int b, int *p, int a)
      20  {
      21    a = p[1];
      22    p[0] = p[1];
      23    if (a)
      24      return 0;
      25    return a;
      26  }