1  /* { dg-do run } */
       2  /* { dg-options "-O2" } */
       3  
       4  extern int memcmp (const void *, const void *, __SIZE_TYPE__);
       5  
       6  void *x (void *pdst, const void *psrc, unsigned int pn)
       7  {
       8    register void *return_dst = pdst;
       9    register unsigned char *dst = pdst;
      10    register unsigned const char *src = psrc;
      11    register int n __asm__ ("ebx") = pn;
      12  
      13    if (src < dst && dst < src + n)
      14      {
      15        src += n;
      16        dst += n;
      17        while (n--)
      18          *--dst = *--src;
      19        return return_dst;
      20      }
      21  
      22    while (n >= 16) n--;
      23  
      24    return return_dst;
      25  }
      26  extern void abort ();
      27  extern void exit (int);
      28  char xx[30] = "abc";
      29  int main (void)
      30  {
      31    char yy[30] = "aab";
      32  
      33    if (x (xx + 1, xx, 2) != xx + 1 || memcmp (xx, yy, sizeof (yy)) != 0)
      34      abort ();
      35    exit (0);
      36  }