NOVA-microhypervisor/inc/endian.hpp

65 lines
2.1 KiB
C++

/*
* Endianness
*
* Copyright (C) 2019-2025 Udo Steinberg, BlueRock Security, Inc.
*
* This file is part of the NOVA microhypervisor.
*
* NOVA is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* NOVA is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License version 2 for more details.
*/
#pragma once
#include "types.hpp"
/*
* Aligned Big/Little-Endian Integral Type T
*/
template<typename T, bool B> class Aligned
{
private:
T val { 0 };
static constexpr auto bswap (uint128_t v) { return B ? __builtin_bswap128 (v) : v; }
static constexpr auto bswap (uint64_t v) { return B ? __builtin_bswap64 (v) : v; }
static constexpr auto bswap (uint32_t v) { return B ? __builtin_bswap32 (v) : v; }
static constexpr auto bswap (uint16_t v) { return B ? __builtin_bswap16 (v) : v; }
static constexpr auto bswap (uint8_t v) { return v; }
public:
constexpr Aligned() = default;
explicit constexpr Aligned (T v) : val { bswap (v) } {}
operator T() const { return bswap (val); }
};
template<typename T> using Aligned_be = Aligned<T, __BYTE_ORDER__ != __ORDER_BIG_ENDIAN__>;
template<typename T> using Aligned_le = Aligned<T, __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__>;
/*
* Unaligned Big/Little-Endian Integral Type T
*/
template<typename T, bool B> class Unaligned
{
private:
char val[sizeof (T)] { 0 };
public:
constexpr Unaligned() = default;
Unaligned (T v) { Aligned<T, B> tmp { v }; __builtin_memcpy (val, &tmp, sizeof (T)); }
operator T() const { Aligned<T, B> tmp; __builtin_memcpy (&tmp, val, sizeof (T)); return tmp; }
};
template<typename T> using Unaligned_be = Unaligned<T, __BYTE_ORDER__ != __ORDER_BIG_ENDIAN__>;
template<typename T> using Unaligned_le = Unaligned<T, __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__>;