__bswap64
#define __bswap_64(x) __bswap64(x)
#define bswap_64(x) __bswap64(x)
#define htobe64(x) __bswap64((x))
#define be64toh(x) __bswap64((x))
#define htole64(x) __bswap64((x))
#define le64toh(x) __bswap64((x))
#define bswap64(x) __bswap64(x)
#define dtoh64(x) __bswap64(x)
#define htod64(x) __bswap64(x)
ATF_REQUIRE(O64(0x123456789abcdef0ull) == __bswap64(0x123456789abcdef0ull));
ATF_REQUIRE(O64(0x123456789abcdef0ull) == __bswap64(0x123456789abcdef0ull));
ATF_REQUIRE(O64(0x123456789abcdef0ull) == __bswap64(0x123456789abcdef0ull));
ATF_REQUIRE(O64(0x123456789abcdef0ull) == __bswap64(0x123456789abcdef0ull));