gcc/testsuite/gcc.target/i386/pr20204.c

   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 }