1//===- endian.h - Endianness support ----------------------------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file declares generic and optimized functions to swap the byte order of 10// an integral type. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef ORC_RT_ENDIAN_H 15#define ORC_RT_ENDIAN_H 16 17#include <cstddef> 18#include <cstdint> 19#include <type_traits> 20#if defined(_MSC_VER) && !defined(_DEBUG) 21#include <stdlib.h> 22#endif 23 24#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__) || \ 25 defined(__Fuchsia__) || defined(__EMSCRIPTEN__) 26#include <endian.h> 27#elif defined(_AIX) 28#include <sys/machine.h> 29#elif defined(__sun) 30/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */ 31#include <sys/types.h> 32#define BIG_ENDIAN 4321 33#define LITTLE_ENDIAN 1234 34#if defined(_BIG_ENDIAN) 35#define BYTE_ORDER BIG_ENDIAN 36#else 37#define BYTE_ORDER LITTLE_ENDIAN 38#endif 39#elif defined(__MVS__) 40#define BIG_ENDIAN 4321 41#define LITTLE_ENDIAN 1234 42#define BYTE_ORDER BIG_ENDIAN 43#else 44#if !defined(BYTE_ORDER) && !defined(_WIN32) 45#include <machine/endian.h> 46#endif 47#endif 48 49namespace __orc_rt { 50 51/// ByteSwap_16 - This function returns a byte-swapped representation of 52/// the 16-bit argument. 53inline uint16_t ByteSwap_16(uint16_t value) { 54#if defined(_MSC_VER) && !defined(_DEBUG) 55 // The DLL version of the runtime lacks these functions (bug!?), but in a 56 // release build they're replaced with BSWAP instructions anyway. 57 return _byteswap_ushort(value); 58#else 59 uint16_t Hi = value << 8; 60 uint16_t Lo = value >> 8; 61 return Hi | Lo; 62#endif 63} 64 65/// This function returns a byte-swapped representation of the 32-bit argument. 66inline uint32_t ByteSwap_32(uint32_t value) { 67#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC)) 68 return __builtin_bswap32(value); 69#elif defined(_MSC_VER) && !defined(_DEBUG) 70 return _byteswap_ulong(value); 71#else 72 uint32_t Byte0 = value & 0x000000FF; 73 uint32_t Byte1 = value & 0x0000FF00; 74 uint32_t Byte2 = value & 0x00FF0000; 75 uint32_t Byte3 = value & 0xFF000000; 76 return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24); 77#endif 78} 79 80/// This function returns a byte-swapped representation of the 64-bit argument. 81inline uint64_t ByteSwap_64(uint64_t value) { 82#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC)) 83 return __builtin_bswap64(value); 84#elif defined(_MSC_VER) && !defined(_DEBUG) 85 return _byteswap_uint64(value); 86#else 87 uint64_t Hi = ByteSwap_32(uint32_t(value)); 88 uint32_t Lo = ByteSwap_32(uint32_t(value >> 32)); 89 return (Hi << 32) | Lo; 90#endif 91} 92 93#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN 94constexpr bool IsBigEndianHost = true; 95#else 96constexpr bool IsBigEndianHost = false; 97#endif 98 99static const bool IsLittleEndianHost = !IsBigEndianHost; 100 101inline unsigned char getSwappedBytes(unsigned char C) { return C; } 102inline signed char getSwappedBytes(signed char C) { return C; } 103inline char getSwappedBytes(char C) { return C; } 104 105inline unsigned short getSwappedBytes(unsigned short C) { 106 return ByteSwap_16(C); 107} 108inline signed short getSwappedBytes(signed short C) { return ByteSwap_16(C); } 109 110inline unsigned int getSwappedBytes(unsigned int C) { return ByteSwap_32(C); } 111inline signed int getSwappedBytes(signed int C) { return ByteSwap_32(C); } 112 113inline unsigned long getSwappedBytes(unsigned long C) { 114 // Handle LLP64 and LP64 platforms. 115 return sizeof(long) == sizeof(int) ? ByteSwap_32((uint32_t)C) 116 : ByteSwap_64((uint64_t)C); 117} 118inline signed long getSwappedBytes(signed long C) { 119 // Handle LLP64 and LP64 platforms. 120 return sizeof(long) == sizeof(int) ? ByteSwap_32((uint32_t)C) 121 : ByteSwap_64((uint64_t)C); 122} 123 124inline unsigned long long getSwappedBytes(unsigned long long C) { 125 return ByteSwap_64(C); 126} 127inline signed long long getSwappedBytes(signed long long C) { 128 return ByteSwap_64(C); 129} 130 131template <typename T> 132inline std::enable_if_t<std::is_enum<T>::value, T> getSwappedBytes(T C) { 133 return static_cast<T>( 134 getSwappedBytes(static_cast<std::underlying_type_t<T>>(C))); 135} 136 137template <typename T> inline void swapByteOrder(T &Value) { 138 Value = getSwappedBytes(Value); 139} 140 141} // end namespace __orc_rt 142 143#endif // ORC_RT_ENDIAN_H 144