1 #ifdef __INT16_TYPE__ 2 typedef __INT16_TYPE__ int16_t; 3 #else 4 typedef short int16_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)(int16_t)(x) & (uint32_t)0x00ffff00UL) << 8) | \ 16 (((uint32_t) (x) & (uint32_t)0x00ff0000UL) >> 8) | \ 17 (((uint32_t) (x) & (uint32_t)0xff000000UL) >> 24))) 18 19 20 /* Previous version of bswap optimization failed to consider sign extension 21 and as a result would replace an expression *not* doing a bswap by a 22 bswap. */ 23 24 __attribute__ ((noinline, noclone)) uint32_t fake_bswap32(uint32_t in)25fake_bswap32 (uint32_t in) 26 { 27 return __fake_const_swab32 (in); 28 } 29 30 int main(void)31main(void) 32 { 33 if (sizeof (uint32_t) * __CHAR_BIT__ != 32) 34 return 0; 35 if (sizeof (int16_t) * __CHAR_BIT__ != 16) 36 return 0; 37 if (fake_bswap32 (0x81828384) != 0xff838281) 38 __builtin_abort (); 39 return 0; 40 } 41