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Diffstat (limited to 'third_party/llvm-project/include/llvm/Support/SwapByteOrder.h')
-rw-r--r-- | third_party/llvm-project/include/llvm/Support/SwapByteOrder.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/third_party/llvm-project/include/llvm/Support/SwapByteOrder.h b/third_party/llvm-project/include/llvm/Support/SwapByteOrder.h new file mode 100644 index 000000000..6cec87006 --- /dev/null +++ b/third_party/llvm-project/include/llvm/Support/SwapByteOrder.h @@ -0,0 +1,160 @@ +//===- 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 <cstddef> +#include <type_traits> +#if defined(_MSC_VER) && !defined(_DEBUG) +#include <stdlib.h> +#endif + +#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__) +#include <endian.h> +#elif defined(_AIX) +#include <sys/machine.h> +#elif defined(__sun) +/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */ +#include <sys/types.h> +#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 <machine/endian.h> +#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 <typename T> +inline typename std::enable_if<std::is_enum<T>::value, T>::type +getSwappedBytes(T C) { + return static_cast<T>( + getSwappedBytes(static_cast<typename std::underlying_type<T>::type>(C))); +} + +template<typename T> +inline void swapByteOrder(T &Value) { + Value = getSwappedBytes(Value); +} + +} // end namespace sys +} // end namespace llvm + +#endif |