1  extern void abort ();
       2  extern int abs (int __x) __attribute__ ((__nothrow__, __leaf__)) __attribute__ ((__const__));
       3  
       4  static int
       5  foo (unsigned char *w, int i, unsigned char *x, int j)
       6  {
       7    int tot = 0;
       8    for (int a = 0; a < 16; a++)
       9      {
      10        for (int b = 0; b < 16; b++)
      11  	tot += abs (w[b] - x[b]);
      12        w += i;
      13        x += j;
      14      }
      15    return tot;
      16  }
      17  
      18  void
      19  bar (unsigned char *w, unsigned char *x, int i, int *result)
      20  {
      21    *result = foo (w, 16, x, i);
      22  }
      23  
      24  int
      25  main (void)
      26  {
      27    unsigned char m[256];
      28    unsigned char n[256];
      29    int sum, i;
      30  
      31    for (i = 0; i < 256; ++i)
      32      if (i % 2 == 0)
      33        {
      34  	m[i] = (i % 8) * 2 + 1;
      35  	n[i] = -(i % 8);
      36        }
      37      else
      38        {
      39  	m[i] = -((i % 8) * 2 + 2);
      40  	n[i] = -((i % 8) >> 1);
      41        }
      42  
      43    bar (m, n, 16, &sum);
      44  
      45    if (sum != 32384)
      46      abort ();
      47  
      48    return 0;
      49  }