116 lines
2.1 KiB
C
116 lines
2.1 KiB
C
#ident "$Id: ulint.h,v 1.3 2004/12/20 04:57:44 hpa Exp $"
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/* ----------------------------------------------------------------------- *
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*
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* Copyright 2001-2004 H. Peter Anvin - All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
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* USA; either version 2 of the License, or (at your option) any later
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* version; incorporated herein by reference.
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*
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* ----------------------------------------------------------------------- */
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/*
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* ulint.h
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*
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* Basic operations on unaligned, littleendian integers
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*/
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#ifndef ULINT_H
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#define ULINT_H
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#include <inttypes.h>
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/* These are unaligned, littleendian integer types */
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typedef uint8_t le8_t; /* 8-bit byte */
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typedef uint8_t le16_t[2]; /* 16-bit word */
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typedef uint8_t le32_t[4]; /* 32-bit dword */
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/* Read/write these quantities */
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static inline unsigned char
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read8(le8_t *_p)
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{
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return *_p;
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}
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static inline void
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write8(le8_t *_p, uint8_t _v)
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{
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*_p = _v;
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}
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#if defined(__i386__) || defined(__x86_64__)
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/* Littleendian architectures which support unaligned memory accesses */
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static inline unsigned short
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read16(le16_t *_p)
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{
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return *((const uint16_t *)_p);
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}
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static inline void
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write16(le16_t *_p, unsigned short _v)
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{
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*((uint16_t *)_p) = _v;
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}
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static inline unsigned int
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read32(le32_t *_p)
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{
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return *((const uint32_t *)_p);
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}
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static inline void
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write32(le32_t *_p, uint32_t _v)
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{
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*((uint32_t *)_p) = _v;
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}
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#else
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/* Generic, mostly portable versions */
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static inline unsigned short
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read16(le16_t *_p)
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{
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uint16_t _v;
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_v = p[0];
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_v |= p[1] << 8;
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return _v;
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}
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static inline void
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write16(le16_t *_p, uint16_t _v)
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{
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_p[0] = _v & 0xFF;
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_p[1] = (_v >> 8) & 0xFF;
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}
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static inline unsigned int
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read32(le32_t *_p)
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{
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_v = _p[0];
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_v |= _p[1] << 8;
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_v |= _p[2] << 16;
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_v |= _p[3] << 24;
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return _v;
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}
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static inline void
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write32(le32_t *_p, uint32_t _v)
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{
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_p[0] = _v & 0xFF;
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_p[1] = (_v >> 8) & 0xFF;
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_p[2] = (_v >> 16) & 0xFF;
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_p[3] = (_v >> 24) & 0xFF;
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}
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#endif
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#endif /* ULINT_H */
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