//===- 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 <cstddef>

#include <cstdint>

#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 {

/// ByteSwap_16 - This function returns a byte-swapped representation of

/// the 16-bit argument.

inline uint16_t ByteSwap_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 ByteSwap_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 ByteSwap_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 = ByteSwap_32(uint32_t(value));

  uint32_t Lo = ByteSwap_32(uint32_t(value >> 32));

  return (Hi << 32) | Lo;

#endif

}

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;

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 ByteSwap_16(C); }

inline   signed short getSwappedBytes(  signed short C) { return ByteSwap_16(C); }

inline unsigned int   getSwappedBytes(unsigned int   C) { return ByteSwap_32(C); }

inline   signed int   getSwappedBytes(  signed int   C) { return ByteSwap_32(C); }

inline unsigned long getSwappedBytes(unsigned long C) {

  // Handle LLP64 and LP64 platforms.

  return sizeof(long) == sizeof(int) ? ByteSwap_32((uint32_t)C)

                                     : ByteSwap_64((uint64_t)C);

}

inline signed long getSwappedBytes(signed long C) {

  // Handle LLP64 and LP64 platforms.

  return sizeof(long) == sizeof(int) ? ByteSwap_32((uint32_t)C)

                                     : ByteSwap_64((uint64_t)C);

}

inline unsigned long long getSwappedBytes(unsigned long long C) {

  return ByteSwap_64(C);

}

inline signed long long getSwappedBytes(signed long long C) {

  return ByteSwap_64(C);

}

inline float getSwappedBytes(float C) {

  union {

    uint32_t i;

    float f;

  } in, out;

  in.f = C;

  out.i = ByteSwap_32(in.i);

  return out.f;

}

inline double getSwappedBytes(double C) {

  union {

    uint64_t i;

    double d;

  } in, out;

  in.d = C;

  out.i = ByteSwap_64(in.i);

  return out.d;

}

template <typename T>

inline std::enable_if_t<std::is_enum<T>::value, T> getSwappedBytes(T C) {

  return static_cast<T>(

      getSwappedBytes(static_cast<std::underlying_type_t<T>>(C)));

}

template<typename T>

inline void swapByteOrder(T &Value) {

  Value = getSwappedBytes(Value);

}

Unexecuted instantiation: _ZN4llvm3sys13swapByteOrderImEEvRT_

Unexecuted instantiation: _ZN4llvm3sys13swapByteOrderIjEEvRT_

Unexecuted instantiation: _ZN4llvm3sys13swapByteOrderItEEvRT_

} // end namespace sys

} // end namespace llvm

#endif