[Bug tree-optimization/37573] gcc-4.4 regression: incorrect code generation with -O1 -ftree-vectorize

["edwintorok at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #1 from edwintorok at gmail dot com  2008-09-18 17:30 -------
Testcase:
extern int printf (__const char *__restrict __format, ...);
extern int strcmp (__const char *__s1, __const char *__s2);
extern int puts (__const char *__s);
typedef unsigned char uint8_t;
typedef unsigned int uint32_t;
struct MT
{
  uint32_t *next;
  uint32_t items;
  uint32_t mt[624];
};
static uint8_t
MT_getnext (struct MT *MT)
{
  uint32_t r;
  if (!--MT->items)
    {
      uint32_t *mt = MT->mt;
      unsigned int i;
      MT->next = mt;
      for (i = 0; i < 227; i++)
        mt[i] =
         ((((mt[i] ^ mt[i + 1]) & 0x7ffffffe) ^ mt[i]) >> 1) ^
           ((0 - (mt[i + 1] & 1)) & 0x9908b0df) ^ mt[i + 397];
    }
  r = *(MT->next++);
  r ^= (r >> 11);
  r ^= ((r & 0xff3a58ad) << 7);
  r ^= ((r & 0xffffdf8c) << 15);
  r ^= (r >> 18);
  return (uint8_t) (r >> 1);
}

static void
MT_decrypt (uint8_t * buf, unsigned int size, uint32_t seed)
{
  struct MT MT;
  unsigned int i;
  uint32_t *mt = MT.mt;
  *mt = seed;
  for (i = 1; i < 624; i++)
    mt[i] = i + 0x6c078965 * ((mt[i - 1] >> 30) ^ mt[i - 1]);
  MT.items = 1;
  while (size--)
    *buf++ ^= MT_getnext (&MT);
};

static uint8_t buf[23] = {
  0xc0, 0x49, 0x17, 0x32, 0x62, 0x1e, 0x2e, 0xd5, 0x4c, 0x19, 0x28, 0x49,
    0x91, 0xe4, 0x72, 0x83, 0x91, 0x3d, 0x93, 0x83, 0xb3, 0x61, 0x38
};

int
main (void)
{
  uint32_t s;
  s = 23;
  MT_decrypt (buf, s, s + 0xa25e);
  if (!strcmp (">AUTOIT UNICODE SCRIPT<", buf))
    {
      puts ("OK");
      return 0;
    }
  else
    {
      printf ("Failed:%s\n", buf);
      return 1;
    }
}


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37573