byte_swap.hpp

Go to the documentation of this file.

// Copyright (C) 2012 iwg molw5
// For conditions of distribution and use, see copyright notice in COPYING

#pragma once

#include <framework/common/common_macros.hpp>

namespace framework
{
    template <typename T>
    FRAMEWORK_ALWAYS_INLINE
    T bswap16 (T&& in)
    {
        static_assert(sizeof(T) == 2, "16-bit type expected");
        uint16_t const x = static_cast <uint16_t> (in);
        return static_cast <T> ((x >> 8) | (x << 8));
    }

    template <typename T>
    FRAMEWORK_ALWAYS_INLINE
    T bswap32 (T&& in)
    {
        static_assert(sizeof(T) == 4, "32-bit type expected");
        uint32_t x = static_cast <uint32_t> (in);
        x = ((x & 0xFF00FF00) >>  8) | ((x & 0x00FF00FF) <<  8);
        return static_cast <T> ((x >> 16) | (x << 16));
    }

    template <typename T>
    FRAMEWORK_ALWAYS_INLINE
    T bswap64 (T&& in)
    {
        static_assert(sizeof(T) == 8, "64-bit type expected");
        uint64_t x = static_cast <uint64_t> (in);
        x = ((x & 0xFF00FF00FF00FF00) >>  8) | ((x & 0x00FF00FF00FF00FF) <<  8);
        x = ((x & 0xFFFF0000FFFF0000) >> 16) | ((x & 0x0000FFFF0000FFFF) << 16);
        return static_cast <T> ((x >> 32) | (x << 32));
    }
}

#if defined(__clang__)
    // TODO - Check these definitions when 3.3 is released
    #if MAX_CLANG_VERSION(3, 2, 0)
        #define FRAMEWORK_BYTESWAP8(x) x
        #define FRAMEWORK_BYTESWAP16(x) ::framework::bswap16(x)
        #define FRAMEWORK_BYTESWAP32(x) __builtin_bswap32(x)
        #define FRAMEWORK_BYTESWAP64(x) __builtin_bswap64(x)
    #else
        #define FRAMEWORK_BYTESWAP8(x) x
        #define FRAMEWORK_BYTESWAP16(x) __builtin_bswap16(x)
        #define FRAMEWORK_BYTESWAP32(x) __builtin_bswap32(x)
        #define FRAMEWORK_BYTESWAP64(x) __builtin_bswap64(x)
    #endif
#elif defined(__GNUC__)
    #define FRAMEWORK_BYTESWAP8(x) x
    #define FRAMEWORK_BYTESWAP16(x) ::framework::bswap16(x)
    #define FRAMEWORK_BYTESWAP32(x) __builtin_bswap32(x)
    #define FRAMEWORK_BYTESWAP64(x) __builtin_bswap64(x)
#else
    #define FRAMEWORK_BYTESWAP8(x) x
    #define FRAMEWORK_BYTESWAP16(x) ::framework::bswap16(x)
    #define FRAMEWORK_BYTESWAP32(x) ::framework::bswap32(x)
    #define FRAMEWORK_BYTESWAP64(x) ::framework::bswap64(x)
#endif