#include int main() { uint16_t u16 = __builtin_bswap16(0x9812U); uint32_t u32 = __builtin_bswap32(0x9812ad81U); uint64_t u64 = __builtin_bswap64(0x9812ad81f61a890dU); return (u16 > 0 && u32 > 0 && u64 > 0) ? 0 : 1; }