1 #ifndef COMPAT_BSWAP_H 2 #define COMPAT_BSWAP_H 3 4 /* 5 * Let's make sure we always have a sane definition for ntohl()/htonl(). 6 * Some libraries define those as a function call, just to perform byte 7 * shifting, bringing significant overhead to what should be a simple 8 * operation. 9 */ 10 11 /* 12 * Default version that the compiler ought to optimize properly with 13 * constant values. 14 */ default_swab32(uint32_t val)15static inline uint32_t default_swab32(uint32_t val) 16 { 17 return (((val & 0xff000000) >> 24) | 18 ((val & 0x00ff0000) >> 8) | 19 ((val & 0x0000ff00) << 8) | 20 ((val & 0x000000ff) << 24)); 21 } 22 default_bswap64(uint64_t val)23static inline uint64_t default_bswap64(uint64_t val) 24 { 25 return (((val & (uint64_t)0x00000000000000ffULL) << 56) | 26 ((val & (uint64_t)0x000000000000ff00ULL) << 40) | 27 ((val & (uint64_t)0x0000000000ff0000ULL) << 24) | 28 ((val & (uint64_t)0x00000000ff000000ULL) << 8) | 29 ((val & (uint64_t)0x000000ff00000000ULL) >> 8) | 30 ((val & (uint64_t)0x0000ff0000000000ULL) >> 24) | 31 ((val & (uint64_t)0x00ff000000000000ULL) >> 40) | 32 ((val & (uint64_t)0xff00000000000000ULL) >> 56)); 33 } 34 35 #undef bswap32 36 #undef bswap64 37 38 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) 39 40 #define bswap32 git_bswap32 git_bswap32(uint32_t x)41static inline uint32_t git_bswap32(uint32_t x) 42 { 43 uint32_t result; 44 if (__builtin_constant_p(x)) 45 result = default_swab32(x); 46 else 47 __asm__("bswap %0" : "=r" (result) : "0" (x)); 48 return result; 49 } 50 51 #define bswap64 git_bswap64 52 #if defined(__x86_64__) git_bswap64(uint64_t x)53static inline uint64_t git_bswap64(uint64_t x) 54 { 55 uint64_t result; 56 if (__builtin_constant_p(x)) 57 result = default_bswap64(x); 58 else 59 __asm__("bswap %q0" : "=r" (result) : "0" (x)); 60 return result; 61 } 62 #else git_bswap64(uint64_t x)63static inline uint64_t git_bswap64(uint64_t x) 64 { 65 union { uint64_t i64; uint32_t i32[2]; } tmp, result; 66 if (__builtin_constant_p(x)) 67 result.i64 = default_bswap64(x); 68 else { 69 tmp.i64 = x; 70 result.i32[0] = git_bswap32(tmp.i32[1]); 71 result.i32[1] = git_bswap32(tmp.i32[0]); 72 } 73 return result.i64; 74 } 75 #endif 76 77 #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64) || defined(_M_ARM64)) 78 79 #include <stdlib.h> 80 81 #define bswap32(x) _byteswap_ulong(x) 82 #define bswap64(x) _byteswap_uint64(x) 83 84 #endif 85 86 #if defined(bswap32) 87 88 #undef ntohl 89 #undef htonl 90 #define ntohl(x) bswap32(x) 91 #define htonl(x) bswap32(x) 92 93 #endif 94 95 #if defined(bswap64) 96 97 #undef ntohll 98 #undef htonll 99 #define ntohll(x) bswap64(x) 100 #define htonll(x) bswap64(x) 101 102 #else 103 104 #undef ntohll 105 #undef htonll 106 107 #if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN) 108 109 # define GIT_BYTE_ORDER __BYTE_ORDER 110 # define GIT_LITTLE_ENDIAN __LITTLE_ENDIAN 111 # define GIT_BIG_ENDIAN __BIG_ENDIAN 112 113 #elif defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && defined(BIG_ENDIAN) 114 115 # define GIT_BYTE_ORDER BYTE_ORDER 116 # define GIT_LITTLE_ENDIAN LITTLE_ENDIAN 117 # define GIT_BIG_ENDIAN BIG_ENDIAN 118 119 #else 120 121 # define GIT_BIG_ENDIAN 4321 122 # define GIT_LITTLE_ENDIAN 1234 123 124 # if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN) 125 # define GIT_BYTE_ORDER GIT_BIG_ENDIAN 126 # elif defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN) 127 # define GIT_BYTE_ORDER GIT_LITTLE_ENDIAN 128 # elif defined(__THW_BIG_ENDIAN__) && !defined(__THW_LITTLE_ENDIAN__) 129 # define GIT_BYTE_ORDER GIT_BIG_ENDIAN 130 # elif defined(__THW_LITTLE_ENDIAN__) && !defined(__THW_BIG_ENDIAN__) 131 # define GIT_BYTE_ORDER GIT_LITTLE_ENDIAN 132 # else 133 # error "Cannot determine endianness" 134 # endif 135 136 #endif 137 138 #if GIT_BYTE_ORDER == GIT_BIG_ENDIAN 139 # define ntohll(n) (n) 140 # define htonll(n) (n) 141 #else 142 # define ntohll(n) default_bswap64(n) 143 # define htonll(n) default_bswap64(n) 144 #endif 145 146 #endif 147 get_be16(const void * ptr)148static inline uint16_t get_be16(const void *ptr) 149 { 150 const unsigned char *p = ptr; 151 return (uint16_t)p[0] << 8 | 152 (uint16_t)p[1] << 0; 153 } 154 get_be32(const void * ptr)155static inline uint32_t get_be32(const void *ptr) 156 { 157 const unsigned char *p = ptr; 158 return (uint32_t)p[0] << 24 | 159 (uint32_t)p[1] << 16 | 160 (uint32_t)p[2] << 8 | 161 (uint32_t)p[3] << 0; 162 } 163 get_be64(const void * ptr)164static inline uint64_t get_be64(const void *ptr) 165 { 166 const unsigned char *p = ptr; 167 return (uint64_t)get_be32(&p[0]) << 32 | 168 (uint64_t)get_be32(&p[4]) << 0; 169 } 170 put_be32(void * ptr,uint32_t value)171static inline void put_be32(void *ptr, uint32_t value) 172 { 173 unsigned char *p = ptr; 174 p[0] = value >> 24; 175 p[1] = value >> 16; 176 p[2] = value >> 8; 177 p[3] = value >> 0; 178 } 179 put_be64(void * ptr,uint64_t value)180static inline void put_be64(void *ptr, uint64_t value) 181 { 182 unsigned char *p = ptr; 183 p[0] = value >> 56; 184 p[1] = value >> 48; 185 p[2] = value >> 40; 186 p[3] = value >> 32; 187 p[4] = value >> 24; 188 p[5] = value >> 16; 189 p[6] = value >> 8; 190 p[7] = value >> 0; 191 } 192 193 #endif /* COMPAT_BSWAP_H */ 194