1  void p1 (p) int *p;
       2  { *p &= ~0xff;
       3  }
       4  void p2 (p) int *p;
       5  { *p &= ~0xff00;
       6  }
       7  void p3 (p) int *p;
       8  { *p &= ~0xffff0000;
       9  }
      10  void p4 (p) int *p;
      11  { *p &= ~0xffff;
      12  }
      13  
      14  main ()
      15  {
      16    int a;
      17  
      18    a = 0x12345678;  p1 (&a);  printf ("%x\n", a);
      19    a = 0x12345678;  p2 (&a);  printf ("%x\n", a);
      20    a = 0x12345678;  p3 (&a);  printf ("%x\n", a);
      21    a = 0x12345678;  p4 (&a);  printf ("%x\n", a);
      22  }