| 1 | /* ----------------------------------------------------------------------- * |
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| 2 | * |
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| 3 | * Copyright 2001-2008 H. Peter Anvin - All Rights Reserved |
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| 4 | * |
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| 5 | * This program is free software; you can redistribute it and/or modify |
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| 6 | * it under the terms of the GNU General Public License as published by |
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| 7 | * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139, |
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| 8 | * USA; either version 2 of the License, or (at your option) any later |
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| 9 | * version; incorporated herein by reference. |
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| 10 | * |
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| 11 | * ----------------------------------------------------------------------- */ |
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| 12 | |
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| 13 | /* |
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| 14 | * ulint.h |
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| 15 | * |
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| 16 | * Basic operations on unaligned, littleendian integers |
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| 17 | */ |
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| 18 | |
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| 19 | #ifndef ULINT_H |
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| 20 | #define ULINT_H |
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| 21 | |
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| 22 | #include <inttypes.h> |
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| 23 | |
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| 24 | /* These are unaligned, littleendian integer types */ |
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| 25 | |
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| 26 | typedef uint8_t le8_t; /* 8-bit byte */ |
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| 27 | typedef uint8_t le16_t[2]; /* 16-bit word */ |
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| 28 | typedef uint8_t le32_t[4]; /* 32-bit dword */ |
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| 29 | |
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| 30 | /* Read/write these quantities */ |
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| 31 | |
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| 32 | static inline unsigned char read8(le8_t * _p) |
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| 33 | { |
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| 34 | return *_p; |
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| 35 | } |
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| 36 | |
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| 37 | static inline void write8(le8_t * _p, uint8_t _v) |
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| 38 | { |
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| 39 | *_p = _v; |
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| 40 | } |
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| 41 | |
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| 42 | #if defined(__i386__) || defined(__x86_64__) |
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| 43 | |
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| 44 | /* Littleendian architectures which support unaligned memory accesses */ |
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| 45 | |
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| 46 | static inline unsigned short read16(le16_t * _p) |
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| 47 | { |
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| 48 | return *((const uint16_t *)_p); |
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| 49 | } |
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| 50 | |
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| 51 | static inline void write16(le16_t * _p, unsigned short _v) |
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| 52 | { |
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| 53 | *((uint16_t *) _p) = _v; |
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| 54 | } |
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| 55 | |
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| 56 | static inline unsigned int read32(le32_t * _p) |
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| 57 | { |
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| 58 | return *((const uint32_t *)_p); |
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| 59 | } |
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| 60 | |
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| 61 | static inline void write32(le32_t * _p, uint32_t _v) |
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| 62 | { |
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| 63 | *((uint32_t *) _p) = _v; |
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| 64 | } |
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| 65 | |
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| 66 | #else |
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| 67 | |
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| 68 | /* Generic, mostly portable versions */ |
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| 69 | |
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| 70 | static inline unsigned short read16(le16_t * _pp) |
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| 71 | { |
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| 72 | uint8_t *_p = *_pp; |
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| 73 | uint16_t _v; |
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| 74 | |
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| 75 | _v = _p[0]; |
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| 76 | _v |= _p[1] << 8; |
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| 77 | return _v; |
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| 78 | } |
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| 79 | |
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| 80 | static inline void write16(le16_t * _pp, uint16_t _v) |
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| 81 | { |
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| 82 | uint8_t *_p = *_pp; |
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| 83 | |
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| 84 | _p[0] = _v & 0xFF; |
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| 85 | _p[1] = (_v >> 8) & 0xFF; |
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| 86 | } |
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| 87 | |
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| 88 | static inline unsigned int read32(le32_t * _pp) |
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| 89 | { |
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| 90 | uint8_t *_p = *_pp; |
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| 91 | uint32_t _v; |
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| 92 | |
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| 93 | _v = _p[0]; |
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| 94 | _v |= _p[1] << 8; |
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| 95 | _v |= _p[2] << 16; |
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| 96 | _v |= _p[3] << 24; |
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| 97 | return _v; |
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| 98 | } |
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| 99 | |
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| 100 | static inline void write32(le32_t * _pp, uint32_t _v) |
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| 101 | { |
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| 102 | uint8_t *_p = *_pp; |
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| 103 | |
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| 104 | _p[0] = _v & 0xFF; |
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| 105 | _p[1] = (_v >> 8) & 0xFF; |
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| 106 | _p[2] = (_v >> 16) & 0xFF; |
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| 107 | _p[3] = (_v >> 24) & 0xFF; |
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| 108 | } |
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| 109 | |
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| 110 | #endif |
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| 111 | |
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| 112 | #endif /* ULINT_H */ |
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