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/* Duff's device is legal C; test to make sure the compiler
   doesn't complain about it.
 
   Jason Thorpe <thorpej@wasabisystems.com>
   Derived from Tom Duff's original usenet message about the device.  */
 
/* { dg-do run } */
/* { dg-options "-O2" } */
 
extern void abort (void);
extern void exit (int);
 
typedef __SIZE_TYPE__ size_t;
extern int memcmp (const void *, const void *, size_t);
 
void
duffcpy (char *dst, const char *src, unsigned long size)
{
  unsigned long n = (size + 7) / 8;
 
  switch (size % 8)
    {
    case 0:	do {	*dst++ = *src++;
    case 7:		*dst++ = *src++;
    case 6:		*dst++ = *src++;
    case 5:		*dst++ = *src++;
    case 4:		*dst++ = *src++;
    case 3:		*dst++ = *src++;
    case 2:		*dst++ = *src++;
    case 1:		*dst++ = *src++;
		} while (--n > 0);
    }
}
 
const char testpat[] = "The quick brown fox jumped over the lazy dog.";
 
int
main()
{
  char buf[64];
 
  duffcpy (buf, testpat, sizeof (testpat));
  if (memcmp (buf, testpat, sizeof (testpat)) != 0)
    abort ();
 
  exit (0);
}