#define UINT64_BSWAP(a) (((a) & 0x00000000000000ffull) << 56 | ((a) & 0x000000000000ff00ull) << 40 | ((a) & 0x0000000000ff0000ull) << 24 | ((a) & 0x00000000ff000000ull) << 8 | ((a) & 0x000000ff00000000ull) >> 8 | ((a) & 0x0000ff0000000000ull) >> 24 | ((a) & 0x00ff000000000000ull) >> 40 | ((a) & 0xff00000000000000ull) >> 56)