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/* ----------------------------------------------------------------------- *
*
* Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
* USA; either version 2 of the License, or (at your option) any later
* version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* ulint.h
*
* Basic operations on unaligned, littleendian integers
*/
#ifndef ULINT_H
#define ULINT_H
#include <inttypes.h>
/* These are unaligned, littleendian integer types */
typedef uint8_t le8_t; /* 8-bit byte */
typedef uint8_t le16_t[2]; /* 16-bit word */
typedef uint8_t le32_t[4]; /* 32-bit dword */
/* Read/write these quantities */
static inline unsigned char read8(le8_t * _p)
{
return *_p;
}
static inline void write8(le8_t * _p, uint8_t _v)
{
*_p = _v;
}
#if defined(__i386__) || defined(__x86_64__)
/* Littleendian architectures which support unaligned memory accesses */
static inline unsigned short read16(le16_t * _p)
{
return *((const uint16_t *)_p);
}
static inline void write16(le16_t * _p, unsigned short _v)
{
*((uint16_t *) _p) = _v;
}
static inline unsigned int read32(le32_t * _p)
{
return *((const uint32_t *)_p);
}
static inline void write32(le32_t * _p, uint32_t _v)
{
*((uint32_t *) _p) = _v;
}
#else
/* Generic, mostly portable versions */
static inline unsigned short read16(le16_t * _pp)
{
uint8_t *_p = *_pp;
uint16_t _v;
_v = _p[0];
_v |= _p[1] << 8;
return _v;
}
static inline void write16(le16_t * _pp, uint16_t _v)
{
uint8_t *_p = *_pp;
_p[0] = _v & 0xFF;
_p[1] = (_v >> 8) & 0xFF;
}
static inline unsigned int read32(le32_t * _pp)
{
uint8_t *_p = *_pp;
uint32_t _v;
_v = _p[0];
_v |= _p[1] << 8;
_v |= _p[2] << 16;
_v |= _p[3] << 24;
return _v;
}
static inline void write32(le32_t * _pp, uint32_t _v)
{
uint8_t *_p = *_pp;
_p[0] = _v & 0xFF;
_p[1] = (_v >> 8) & 0xFF;
_p[2] = (_v >> 16) & 0xFF;
_p[3] = (_v >> 24) & 0xFF;
}
#endif
#endif /* ULINT_H */
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