dolphin/Source/Core/Common/Swap.h
Pierre Bourdon e149ad4f0a
treewide: convert GPLv2+ license info to SPDX tags
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
2021-07-05 04:35:56 +02:00

186 lines
3.2 KiB
C++

// Copyright 2017 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <cstring>
#include <type_traits>
#ifdef __APPLE__
#include <libkern/OSByteOrder.h>
#elif defined(__linux__)
#include <byteswap.h>
#elif defined(__FreeBSD__)
#include <sys/endian.h>
#elif defined(__OpenBSD__)
#include <endian.h>
#endif
#include "Common/CommonTypes.h"
namespace Common
{
inline u8 swap8(u8 data)
{
return data;
}
inline u32 swap24(const u8* data)
{
return (data[0] << 16) | (data[1] << 8) | data[2];
}
#if defined(ANDROID) || defined(__OpenBSD__)
#undef swap16
#undef swap32
#undef swap64
#endif
#ifdef _WIN32
inline u16 swap16(u16 data)
{
return _byteswap_ushort(data);
}
inline u32 swap32(u32 data)
{
return _byteswap_ulong(data);
}
inline u64 swap64(u64 data)
{
return _byteswap_uint64(data);
}
#elif __linux__
inline u16 swap16(u16 data)
{
return bswap_16(data);
}
inline u32 swap32(u32 data)
{
return bswap_32(data);
}
inline u64 swap64(u64 data)
{
return bswap_64(data);
}
#elif __APPLE__
inline __attribute__((always_inline)) u16 swap16(u16 data)
{
return OSSwapInt16(data);
}
inline __attribute__((always_inline)) u32 swap32(u32 data)
{
return OSSwapInt32(data);
}
inline __attribute__((always_inline)) u64 swap64(u64 data)
{
return OSSwapInt64(data);
}
#elif __FreeBSD__
inline u16 swap16(u16 data)
{
return bswap16(data);
}
inline u32 swap32(u32 data)
{
return bswap32(data);
}
inline u64 swap64(u64 data)
{
return bswap64(data);
}
#else
// Slow generic implementation.
inline u16 swap16(u16 data)
{
return (data >> 8) | (data << 8);
}
inline u32 swap32(u32 data)
{
return (swap16(data) << 16) | swap16(data >> 16);
}
inline u64 swap64(u64 data)
{
return ((u64)swap32(data) << 32) | swap32(data >> 32);
}
#endif
inline u16 swap16(const u8* data)
{
u16 value;
std::memcpy(&value, data, sizeof(u16));
return swap16(value);
}
inline u32 swap32(const u8* data)
{
u32 value;
std::memcpy(&value, data, sizeof(u32));
return swap32(value);
}
inline u64 swap64(const u8* data)
{
u64 value;
std::memcpy(&value, data, sizeof(u64));
return swap64(value);
}
template <int count>
void swap(u8*);
template <>
inline void swap<1>(u8* data)
{
}
template <>
inline void swap<2>(u8* data)
{
const u16 value = swap16(data);
std::memcpy(data, &value, sizeof(u16));
}
template <>
inline void swap<4>(u8* data)
{
const u32 value = swap32(data);
std::memcpy(data, &value, sizeof(u32));
}
template <>
inline void swap<8>(u8* data)
{
const u64 value = swap64(data);
std::memcpy(data, &value, sizeof(u64));
}
template <typename T>
inline T FromBigEndian(T data)
{
static_assert(std::is_arithmetic<T>::value, "function only makes sense with arithmetic types");
swap<sizeof(data)>(reinterpret_cast<u8*>(&data));
return data;
}
template <typename value_type>
struct BigEndianValue
{
static_assert(std::is_arithmetic<value_type>(), "value_type must be an arithmetic type");
BigEndianValue() = default;
explicit BigEndianValue(value_type val) { *this = val; }
operator value_type() const { return FromBigEndian(raw); }
BigEndianValue& operator=(value_type v)
{
raw = FromBigEndian(v);
return *this;
}
private:
value_type raw;
};
} // Namespace Common