modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/pr61306-1.c (about)

     1  #ifdef __INT32_TYPE__
     2  typedef __INT32_TYPE__ int32_t;
     3  #else
     4  typedef int int32_t;
     5  #endif
     6  
     7  #ifdef __UINT32_TYPE__
     8  typedef __UINT32_TYPE__ uint32_t;
     9  #else
    10  typedef unsigned uint32_t;
    11  #endif
    12  
    13  #define __fake_const_swab32(x) ((uint32_t)(		      \
    14  	(((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) |    \
    15  	(((uint32_t)(x) & (uint32_t)0x0000ff00UL) <<  8) |    \
    16  	(((uint32_t)(x) & (uint32_t)0x00ff0000UL) >>  8) |    \
    17  	(( (int32_t)(x) &  (int32_t)0xff000000UL) >> 24)))
    18  
    19  /* Previous version of bswap optimization failed to consider sign extension
    20     and as a result would replace an expression *not* doing a bswap by a
    21     bswap.  */
    22  
    23  __attribute__ ((noinline, noclone)) uint32_t
    24  fake_bswap32 (uint32_t in)
    25  {
    26    return __fake_const_swab32 (in);
    27  }
    28  
    29  int
    30  main(void)
    31  {
    32    if (sizeof (int32_t) * __CHAR_BIT__ != 32)
    33      return 0;
    34    if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
    35      return 0;
    36    if (fake_bswap32 (0x87654321) != 0xffffff87)
    37      __builtin_abort ();
    38    return 0;
    39  }