ecb_bswap16
#define ecb_bswap16(x) __builtin_bswap16 (x)
#define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
#define ecb_bswap16(x) ((uint16_t)_byteswap_ushort ((uint16_t)(x)))
ecb_bswap16 (uint16_t x)