gcc/testsuite/gcc.c-torture/execute/pr60454.c

#ifdef __UINT32_TYPE__
typedef __UINT32_TYPE__ uint32_t;
#else
typedef unsigned uint32_t;
#endif

#define __fake_const_swab32(x) ((uint32_t)(			      \
        (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) |            \
        (((uint32_t)(x) & (uint32_t)0x0000ff00UL) <<  8) |            \
        (((uint32_t)(x) & (uint32_t)0x000000ffUL) <<  8) |            \
        (((uint32_t)(x) & (uint32_t)0x0000ff00UL)      ) |            \
        (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))

/* Previous version of bswap optimization would detect byte swap when none
   happen. This test aims at catching such wrong detection to avoid
   regressions.  */

__attribute__ ((noinline, noclone)) uint32_t
fake_swap32 (uint32_t in)
{
  return __fake_const_swab32 (in);
}

int main(void)
{
  if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
    return 0;
  if (fake_swap32 (0x12345678UL) != 0x78567E12UL)
    __builtin_abort ();
  return 0;
}