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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);

}