/* * Let's make sure we always have a sane definition for ntohl()/htonl(). * Some libraries define those as a function call, just to perform byte * shifting, bringing significant overhead to what should be a simple * operation. */ /* * Default version that the compiler ought to optimize properly with * constant values. */ static inline uint32_t default_swab32(uint32_t val) { return (((val & 0xff000000) >> 24) | ((val & 0x00ff0000) >> 8) | ((val & 0x0000ff00) << 8) | ((val & 0x000000ff) << 24)); } #undef bswap32 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) #define bswap32(x) ({ \ uint32_t __res; \ if (__builtin_constant_p(x)) { \ __res = default_swab32(x); \ } else { \ __asm__("bswap %0" : "=r" (__res) : "0" ((uint32_t)(x))); \ } \ __res; }) #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64)) #include #define bswap32(x) _byteswap_ulong(x) #endif #ifdef bswap32 #undef ntohl #undef htonl #define ntohl(x) bswap32(x) #define htonl(x) bswap32(x) #endif