//===- SwapByteOrder.h - Generic and optimized byte swaps -------*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file declares generic and optimized functions to swap the byte order of // an integral type. // //===----------------------------------------------------------------------===// #ifndef LLVM_SUPPORT_SWAPBYTEORDER_H #define LLVM_SUPPORT_SWAPBYTEORDER_H #include "llvm/Support/Compiler.h" #include "llvm/Support/DataTypes.h" #include #include #if defined(_MSC_VER) && !defined(_DEBUG) #include #endif #if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__) #include #elif defined(_AIX) #include #elif defined(__sun) /* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */ #include #define BIG_ENDIAN 4321 #define LITTLE_ENDIAN 1234 #if defined(_BIG_ENDIAN) #define BYTE_ORDER BIG_ENDIAN #else #define BYTE_ORDER LITTLE_ENDIAN #endif #else #if !defined(BYTE_ORDER) && !defined(_WIN32) #include #endif #endif namespace llvm { namespace sys { #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN constexpr bool IsBigEndianHost = true; #else constexpr bool IsBigEndianHost = false; #endif static const bool IsLittleEndianHost = !IsBigEndianHost; /// SwapByteOrder_16 - This function returns a byte-swapped representation of /// the 16-bit argument. inline uint16_t SwapByteOrder_16(uint16_t value) { #if defined(_MSC_VER) && !defined(_DEBUG) // The DLL version of the runtime lacks these functions (bug!?), but in a // release build they're replaced with BSWAP instructions anyway. return _byteswap_ushort(value); #else uint16_t Hi = value << 8; uint16_t Lo = value >> 8; return Hi | Lo; #endif } /// This function returns a byte-swapped representation of the 32-bit argument. inline uint32_t SwapByteOrder_32(uint32_t value) { #if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC)) return __builtin_bswap32(value); #elif defined(_MSC_VER) && !defined(_DEBUG) return _byteswap_ulong(value); #else uint32_t Byte0 = value & 0x000000FF; uint32_t Byte1 = value & 0x0000FF00; uint32_t Byte2 = value & 0x00FF0000; uint32_t Byte3 = value & 0xFF000000; return (Byte0 << 24) | (Byte1 << 8) | (Byte2 >> 8) | (Byte3 >> 24); #endif } /// This function returns a byte-swapped representation of the 64-bit argument. inline uint64_t SwapByteOrder_64(uint64_t value) { #if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC)) return __builtin_bswap64(value); #elif defined(_MSC_VER) && !defined(_DEBUG) return _byteswap_uint64(value); #else uint64_t Hi = SwapByteOrder_32(uint32_t(value)); uint32_t Lo = SwapByteOrder_32(uint32_t(value >> 32)); return (Hi << 32) | Lo; #endif } inline unsigned char getSwappedBytes(unsigned char C) { return C; } inline signed char getSwappedBytes(signed char C) { return C; } inline char getSwappedBytes(char C) { return C; } inline unsigned short getSwappedBytes(unsigned short C) { return SwapByteOrder_16(C); } inline signed short getSwappedBytes( signed short C) { return SwapByteOrder_16(C); } inline unsigned int getSwappedBytes(unsigned int C) { return SwapByteOrder_32(C); } inline signed int getSwappedBytes( signed int C) { return SwapByteOrder_32(C); } #if __LONG_MAX__ == __INT_MAX__ inline unsigned long getSwappedBytes(unsigned long C) { return SwapByteOrder_32(C); } inline signed long getSwappedBytes( signed long C) { return SwapByteOrder_32(C); } #elif __LONG_MAX__ == __LONG_LONG_MAX__ inline unsigned long getSwappedBytes(unsigned long C) { return SwapByteOrder_64(C); } inline signed long getSwappedBytes( signed long C) { return SwapByteOrder_64(C); } #else #error "Unknown long size!" #endif inline unsigned long long getSwappedBytes(unsigned long long C) { return SwapByteOrder_64(C); } inline signed long long getSwappedBytes(signed long long C) { return SwapByteOrder_64(C); } inline float getSwappedBytes(float C) { union { uint32_t i; float f; } in, out; in.f = C; out.i = SwapByteOrder_32(in.i); return out.f; } inline double getSwappedBytes(double C) { union { uint64_t i; double d; } in, out; in.d = C; out.i = SwapByteOrder_64(in.i); return out.d; } template inline typename std::enable_if::value, T>::type getSwappedBytes(T C) { return static_cast( getSwappedBytes(static_cast::type>(C))); } template inline void swapByteOrder(T &Value) { Value = getSwappedBytes(Value); } } // end namespace sys } // end namespace llvm #endif