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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-exception6//7//===----------------------------------------------------------------------===//8//9// This file declares generic and optimized functions to swap the byte order of10// an integral type.11//12//===----------------------------------------------------------------------===//13 14#ifndef ORC_RT_ENDIAN_H15#define ORC_RT_ENDIAN_H16 17#include <cstddef>18#include <cstdint>19#include <type_traits>20#if defined(_MSC_VER) && !defined(_DEBUG)21#include <stdlib.h>22#endif23 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 432133#define LITTLE_ENDIAN 123434#if defined(_BIG_ENDIAN)35#define BYTE_ORDER BIG_ENDIAN36#else37#define BYTE_ORDER LITTLE_ENDIAN38#endif39#elif defined(__MVS__)40#define BIG_ENDIAN 432141#define LITTLE_ENDIAN 123442#define BYTE_ORDER BIG_ENDIAN43#else44#if !defined(BYTE_ORDER) && !defined(_WIN32)45#include <machine/endian.h>46#endif47#endif48 49namespace orc_rt {50 51/// ByteSwap_16 - This function returns a byte-swapped representation of52/// 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 a56 // release build they're replaced with BSWAP instructions anyway.57 return _byteswap_ushort(value);58#else59 uint16_t Hi = value << 8;60 uint16_t Lo = value >> 8;61 return Hi | Lo;62#endif63}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#else72 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#endif78}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#else87 uint64_t Hi = ByteSwap_32(uint32_t(value));88 uint32_t Lo = ByteSwap_32(uint32_t(value >> 32));89 return (Hi << 32) | Lo;90#endif91}92 93#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN94constexpr bool IsBigEndianHost = true;95#else96constexpr bool IsBigEndianHost = false;97#endif98 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} // namespace orc_rt142 143#endif // ORC_RT_ENDIAN_H144