| /* Bytes swap functions, reverse order of bytes: |
| |
| - _Py_bswap16(uint16_t) |
| - _Py_bswap32(uint32_t) |
| - _Py_bswap64(uint64_t) |
| */ |
| |
| #ifndef Py_INTERNAL_BSWAP_H |
| #define Py_INTERNAL_BSWAP_H |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #ifndef Py_BUILD_CORE |
| # error "this header requires Py_BUILD_CORE define" |
| #endif |
| |
| #if defined(__GNUC__) \ |
| && ((__GNUC__ >= 5) || (__GNUC__ == 4) && (__GNUC_MINOR__ >= 8)) |
| /* __builtin_bswap16() is available since GCC 4.8, |
| __builtin_bswap32() is available since GCC 4.3, |
| __builtin_bswap64() is available since GCC 4.3. */ |
| # define _PY_HAVE_BUILTIN_BSWAP |
| #endif |
| |
| #ifdef _MSC_VER |
| /* Get _byteswap_ushort(), _byteswap_ulong(), _byteswap_uint64() */ |
| # include <intrin.h> |
| #endif |
| |
| static inline uint16_t |
| _Py_bswap16(uint16_t word) |
| { |
| #if defined(_PY_HAVE_BUILTIN_BSWAP) || _Py__has_builtin(__builtin_bswap16) |
| return __builtin_bswap16(word); |
| #elif defined(_MSC_VER) |
| Py_BUILD_ASSERT(sizeof(word) == sizeof(unsigned short)); |
| return _byteswap_ushort(word); |
| #else |
| // Portable implementation which doesn't rely on circular bit shift |
| return ( ((word & UINT16_C(0x00FF)) << 8) |
| | ((word & UINT16_C(0xFF00)) >> 8)); |
| #endif |
| } |
| |
| static inline uint32_t |
| _Py_bswap32(uint32_t word) |
| { |
| #if defined(_PY_HAVE_BUILTIN_BSWAP) || _Py__has_builtin(__builtin_bswap32) |
| return __builtin_bswap32(word); |
| #elif defined(_MSC_VER) |
| Py_BUILD_ASSERT(sizeof(word) == sizeof(unsigned long)); |
| return _byteswap_ulong(word); |
| #else |
| // Portable implementation which doesn't rely on circular bit shift |
| return ( ((word & UINT32_C(0x000000FF)) << 24) |
| | ((word & UINT32_C(0x0000FF00)) << 8) |
| | ((word & UINT32_C(0x00FF0000)) >> 8) |
| | ((word & UINT32_C(0xFF000000)) >> 24)); |
| #endif |
| } |
| |
| static inline uint64_t |
| _Py_bswap64(uint64_t word) |
| { |
| #if defined(_PY_HAVE_BUILTIN_BSWAP) || _Py__has_builtin(__builtin_bswap64) |
| return __builtin_bswap64(word); |
| #elif defined(_MSC_VER) |
| return _byteswap_uint64(word); |
| #else |
| // Portable implementation which doesn't rely on circular bit shift |
| return ( ((word & UINT64_C(0x00000000000000FF)) << 56) |
| | ((word & UINT64_C(0x000000000000FF00)) << 40) |
| | ((word & UINT64_C(0x0000000000FF0000)) << 24) |
| | ((word & UINT64_C(0x00000000FF000000)) << 8) |
| | ((word & UINT64_C(0x000000FF00000000)) >> 8) |
| | ((word & UINT64_C(0x0000FF0000000000)) >> 24) |
| | ((word & UINT64_C(0x00FF000000000000)) >> 40) |
| | ((word & UINT64_C(0xFF00000000000000)) >> 56)); |
| #endif |
| } |
| |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| #endif /* !Py_INTERNAL_BSWAP_H */ |
| |
