1 /* ----------------------------------------------------------------------- *
3 * Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
8 * USA; either version 2 of the License, or (at your option) any later
9 * version; incorporated herein by reference.
11 * ----------------------------------------------------------------------- */
16 * Basic operations on unaligned, littleendian integers
24 /* These are unaligned, littleendian integer types */
26 typedef uint8_t le8_t; /* 8-bit byte */
27 typedef uint8_t le16_t[2]; /* 16-bit word */
28 typedef uint8_t le32_t[4]; /* 32-bit dword */
30 /* Read/write these quantities */
32 static inline unsigned char read8(le8_t * _p)
37 static inline void write8(le8_t * _p, uint8_t _v)
42 #if defined(__i386__) || defined(__x86_64__)
44 /* Littleendian architectures which support unaligned memory accesses */
46 static inline unsigned short read16(le16_t * _p)
48 return *((const uint16_t *)_p);
51 static inline void write16(le16_t * _p, unsigned short _v)
53 *((uint16_t *) _p) = _v;
56 static inline unsigned int read32(le32_t * _p)
58 return *((const uint32_t *)_p);
61 static inline void write32(le32_t * _p, uint32_t _v)
63 *((uint32_t *) _p) = _v;
68 /* Generic, mostly portable versions */
70 static inline unsigned short read16(le16_t * _pp)
80 static inline void write16(le16_t * _pp, uint16_t _v)
85 _p[1] = (_v >> 8) & 0xFF;
88 static inline unsigned int read32(le32_t * _pp)
100 static inline void write32(le32_t * _pp, uint32_t _v)
105 _p[1] = (_v >> 8) & 0xFF;
106 _p[2] = (_v >> 16) & 0xFF;
107 _p[3] = (_v >> 24) & 0xFF;