mirror of
https://github.com/libretro/RetroArch
synced 2024-12-26 21:29:08 +00:00
120 lines
3.0 KiB
C++
120 lines
3.0 KiB
C++
#pragma once
|
|
#include <cstring>
|
|
#include <type_traits>
|
|
|
|
#if defined(WIN32) || defined(_WIN32) || defined(_MSC_VER)
|
|
#define PLATFORM_WINDOWS
|
|
#elif __APPLE__
|
|
#define PLATFORM_APPLE
|
|
#define PLATFORM_POSIX
|
|
#elif __linux__
|
|
#define PLATFORM_LINUX
|
|
#define PLATFORM_POSIX
|
|
#endif
|
|
|
|
#ifdef PLATFORM_LINUX
|
|
#include <byteswap.h>
|
|
#endif
|
|
|
|
/* reinterpret_cast for value types */
|
|
template<typename DstType, typename SrcType>
|
|
inline DstType
|
|
bit_cast(const SrcType& src)
|
|
{
|
|
static_assert(sizeof(SrcType) == sizeof(DstType), "bit_cast must be between same sized types");
|
|
static_assert(std::is_trivially_copyable<SrcType>::value, "SrcType is not trivially copyable.");
|
|
static_assert(std::is_trivially_copyable<DstType>::value, "DstType is not trivially copyable.");
|
|
|
|
DstType dst;
|
|
std::memcpy(&dst, &src, sizeof(SrcType));
|
|
return dst;
|
|
}
|
|
|
|
/* Utility class to swap endian for types of size 1, 2, 4, 8 */
|
|
/* other type sizes are not supported */
|
|
template<typename Type, unsigned Size = sizeof(Type)>
|
|
struct byte_swap_t;
|
|
|
|
template<typename Type>
|
|
struct byte_swap_t<Type, 1>
|
|
{
|
|
static Type swap(Type src)
|
|
{
|
|
return src;
|
|
}
|
|
};
|
|
|
|
template<typename Type>
|
|
struct byte_swap_t<Type, 2>
|
|
{
|
|
static Type swap(Type src)
|
|
{
|
|
#ifdef PLATFORM_WINDOWS
|
|
return bit_cast<Type>(_byteswap_ushort(bit_cast<uint16_t>(src)));
|
|
#elif defined(PLATFORM_APPLE)
|
|
/* Apple has no 16-bit byteswap intrinsic */
|
|
const uint16_t data = bit_cast<uint16_t>(src);
|
|
return bit_cast<Type>((uint16_t)((data >> 8) | (data << 8)));
|
|
#elif defined(PLATFORM_LINUX)
|
|
return bit_cast<Type>(bswap_16(bit_cast<uint16_t>(src)));
|
|
#endif
|
|
}
|
|
};
|
|
|
|
template<typename Type>
|
|
struct byte_swap_t<Type, 4>
|
|
{
|
|
static Type swap(Type src)
|
|
{
|
|
#ifdef PLATFORM_WINDOWS
|
|
return bit_cast<Type>(_byteswap_ulong(bit_cast<uint32_t>(src)));
|
|
#elif defined(PLATFORM_APPLE)
|
|
return bit_cast<Type>(__builtin_bswap32(bit_cast<uint32_t>(src)));
|
|
#elif defined(PLATFORM_LINUX)
|
|
return bit_cast<Type>(bswap_32(bit_cast<uint32_t>(src)));
|
|
#endif
|
|
}
|
|
};
|
|
|
|
template<typename Type>
|
|
struct byte_swap_t<Type, 8>
|
|
{
|
|
static Type swap(Type src)
|
|
{
|
|
#ifdef PLATFORM_WINDOWS
|
|
return bit_cast<Type>(_byteswap_uint64(bit_cast<uint64_t>(src)));
|
|
#elif defined(PLATFORM_APPLE)
|
|
return bit_cast<Type>(__builtin_bswap64(bit_cast<uint64_t>(src)));
|
|
#elif defined(PLATFORM_LINUX)
|
|
return bit_cast<Type>(bswap_64(bit_cast<uint64_t>(src)));
|
|
#endif
|
|
}
|
|
};
|
|
|
|
/* Swaps endian of src */
|
|
template<typename Type>
|
|
inline Type
|
|
byte_swap(Type src)
|
|
{
|
|
return byte_swap_t<Type>::swap(src);
|
|
}
|
|
|
|
/* Alignment helpers */
|
|
template<typename Type>
|
|
constexpr inline Type
|
|
align_up(Type value, size_t alignment)
|
|
{
|
|
return static_cast<Type>((static_cast<size_t>(value) + (alignment - 1)) & ~(alignment - 1));
|
|
}
|
|
|
|
template<typename Type>
|
|
constexpr inline Type
|
|
align_down(Type value, size_t alignment)
|
|
{
|
|
return static_cast<Type>(static_cast<size_t>(value) & ~(alignment - 1));
|
|
}
|
|
|
|
#define CHECK_SIZE(Type, Size) \
|
|
static_assert(sizeof(Type) == Size, \
|
|
#Type " must be " #Size " bytes")
|