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/*
* This file is part of LibNSUtils.
* Licensed under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
* Copyright 2009 John-Mark Bell <jmb@netsurf-browser.org>
*/
/**
* \file
* Endianness helper functions.
*/
#ifndef NSUTILS_ENDIAN_H__
#define NSUTILS_ENDIAN_H__
#include <inttypes.h>
#include <stdbool.h>
/**
* Detect if the host is little endian.
*
* \return True if the host is little endian; false otherwise.
*/
static inline bool endian_host_is_le(void)
{
const uint16_t test = 1;
return ((const uint8_t *) &test)[0];
}
/**
* Swap the endianness of a 32bit value.
*
* \param val Value to swap endianness of
* \return Endian-swapped value
*/
static inline uint32_t endian_swap(uint32_t val)
{
return ((val & 0xff000000) >> 24) | ((val & 0x00ff0000) >> 8) |
((val & 0x0000ff00) << 8) | ((val & 0x000000ff) << 24);
}
/**
* Convert a host-endian 32bit value to its big-endian equivalent.
*
* \param host Value to convert
* \return Big endian value
*/
static inline uint32_t endian_host_to_big(uint32_t host)
{
if (endian_host_is_le())
return endian_swap(host);
return host;
}
/**
* Convert a big-endian 32bit value to its host-endian equivalent.
*
* \param host Value to convert
* \return Host endian value
*/
static inline uint32_t endian_big_to_host(uint32_t big)
{
if (endian_host_is_le())
return endian_swap(big);
return big;
}
#endif
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