/* * 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)); } static inline uint64_t default_bswap64(uint64_t val) { return (((val & (uint64_t)0x00000000000000ffULL) << 56) | ((val & (uint64_t)0x000000000000ff00ULL) << 40) | ((val & (uint64_t)0x0000000000ff0000ULL) << 24) | ((val & (uint64_t)0x00000000ff000000ULL) << 8) | ((val & (uint64_t)0x000000ff00000000ULL) >> 8) | ((val & (uint64_t)0x0000ff0000000000ULL) >> 24) | ((val & (uint64_t)0x00ff000000000000ULL) >> 40) | ((val & (uint64_t)0xff00000000000000ULL) >> 56)); } #undef bswap32 #undef bswap64 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) #define bswap32 git_bswap32 static inline uint32_t git_bswap32(uint32_t x) { uint32_t result; if (__builtin_constant_p(x)) result = default_swab32(x); else __asm__("bswap %0" : "=r" (result) : "0" (x)); return result; } #define bswap64 git_bswap64 #if defined(__x86_64__) static inline uint64_t git_bswap64(uint64_t x) { uint64_t result; if (__builtin_constant_p(x)) result = default_bswap64(x); else __asm__("bswap %q0" : "=r" (result) : "0" (x)); return result; } #else static inline uint64_t git_bswap64(uint64_t x) { union { uint64_t i64; uint32_t i32[2]; } tmp, result; if (__builtin_constant_p(x)) result.i64 = default_bswap64(x); else { tmp.i64 = x; result.i32[0] = git_bswap32(tmp.i32[1]); result.i32[1] = git_bswap32(tmp.i32[0]); } return result.i64; } #endif #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64)) #include <stdlib.h> #define bswap32(x) _byteswap_ulong(x) #define bswap64(x) _byteswap_uint64(x) #endif #if defined(bswap32) #undef ntohl #undef htonl #define ntohl(x) bswap32(x) #define htonl(x) bswap32(x) #endif #if defined(bswap64) #undef ntohll #undef htonll #define ntohll(x) bswap64(x) #define htonll(x) bswap64(x) #else #undef ntohll #undef htonll #if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN) # define GIT_BYTE_ORDER __BYTE_ORDER # define GIT_LITTLE_ENDIAN __LITTLE_ENDIAN # define GIT_BIG_ENDIAN __BIG_ENDIAN #elif defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && defined(BIG_ENDIAN) # define GIT_BYTE_ORDER BYTE_ORDER # define GIT_LITTLE_ENDIAN LITTLE_ENDIAN # define GIT_BIG_ENDIAN BIG_ENDIAN #else # define GIT_BIG_ENDIAN 4321 # define GIT_LITTLE_ENDIAN 1234 # if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN) # define GIT_BYTE_ORDER GIT_BIG_ENDIAN # elif defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN) # define GIT_BYTE_ORDER GIT_LITTLE_ENDIAN # elif defined(__THW_BIG_ENDIAN__) && !defined(__THW_LITTLE_ENDIAN__) # define GIT_BYTE_ORDER GIT_BIG_ENDIAN # elif defined(__THW_LITTLE_ENDIAN__) && !defined(__THW_BIG_ENDIAN__) # define GIT_BYTE_ORDER GIT_LITTLE_ENDIAN # else # error "Cannot determine endianness" # endif #endif #if GIT_BYTE_ORDER == GIT_BIG_ENDIAN # define ntohll(n) (n) # define htonll(n) (n) #else # define ntohll(n) default_bswap64(n) # define htonll(n) default_bswap64(n) #endif #endif /* * Performance might be improved if the CPU architecture is OK with * unaligned 32-bit loads and a fast ntohl() is available. * Otherwise fall back to byte loads and shifts which is portable, * and is faster on architectures with memory alignment issues. */ #if !defined(NO_UNALIGNED_LOADS) && ( \ defined(__i386__) || defined(__x86_64__) || \ defined(_M_IX86) || defined(_M_X64) || \ defined(__ppc__) || defined(__ppc64__) || \ defined(__powerpc__) || defined(__powerpc64__) || \ defined(__s390__) || defined(__s390x__)) #define get_be16(p) ntohs(*(unsigned short *)(p)) #define get_be32(p) ntohl(*(unsigned int *)(p)) #define put_be32(p, v) do { *(unsigned int *)(p) = htonl(v); } while (0) #else #define get_be16(p) ( \ (*((unsigned char *)(p) + 0) << 8) | \ (*((unsigned char *)(p) + 1) << 0) ) #define get_be32(p) ( \ (*((unsigned char *)(p) + 0) << 24) | \ (*((unsigned char *)(p) + 1) << 16) | \ (*((unsigned char *)(p) + 2) << 8) | \ (*((unsigned char *)(p) + 3) << 0) ) #define put_be32(p, v) do { \ unsigned int __v = (v); \ *((unsigned char *)(p) + 0) = __v >> 24; \ *((unsigned char *)(p) + 1) = __v >> 16; \ *((unsigned char *)(p) + 2) = __v >> 8; \ *((unsigned char *)(p) + 3) = __v >> 0; } while (0) #endif