SwapByteOrder.h

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//===- 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/ADT/STLForwardCompat.h"
#include "llvm/ADT/bit.h"
#include <cstdint>
#include <type_traits>
 
namespace llvm {
 
namespace sys {
 
constexpr bool IsBigEndianHost =
    llvm::endianness::native == llvm::endianness::big;
 
constexpr bool IsLittleEndianHost = !IsBigEndianHost;
 
inline unsigned char      getSwappedBytes(unsigned char      C) { return llvm::byteswap(C); }
inline   signed char      getSwappedBytes( signed  char      C) { return llvm::byteswap(C); }
inline          char      getSwappedBytes(         char      C) { return llvm::byteswap(C); }
 
inline unsigned short     getSwappedBytes(unsigned short     C) { return llvm::byteswap(C); }
inline   signed short     getSwappedBytes(  signed short     C) { return llvm::byteswap(C); }
 
inline unsigned int       getSwappedBytes(unsigned int       C) { return llvm::byteswap(C); }
inline   signed int       getSwappedBytes(  signed int       C) { return llvm::byteswap(C); }
 
inline unsigned long      getSwappedBytes(unsigned long      C) { return llvm::byteswap(C); }
inline   signed long      getSwappedBytes(  signed long      C) { return llvm::byteswap(C); }
 
inline unsigned long long getSwappedBytes(unsigned long long C) { return llvm::byteswap(C); }
inline   signed long long getSwappedBytes(  signed long long C) { return llvm::byteswap(C); }
 
inline float getSwappedBytes(float C) {
  return llvm::bit_cast<float>(llvm::byteswap(llvm::bit_cast<uint32_t>(C)));
}
 
inline double getSwappedBytes(double C) {
  return llvm::bit_cast<double>(llvm::byteswap(llvm::bit_cast<uint64_t>(C)));
}
 
template <typename T>
inline std::enable_if_t<std::is_enum_v<T>, T> getSwappedBytes(T C) {
  return static_cast<T>(llvm::byteswap(llvm::to_underlying(C)));
}
 
template<typename T>
inline void swapByteOrder(T &Value) {
  Value = getSwappedBytes(Value);
}
 
} // end namespace sys
} // end namespace llvm
 
#endif