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1 | //----------------------------------------------------------------------------- |
2 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, |
3 | // at your option, any later version. See the LICENSE.txt file for the text of |
4 | // the license. |
5 | //----------------------------------------------------------------------------- |
6 | // Generic CRC calculation code. |
7 | //----------------------------------------------------------------------------- |
8 | |
9 | #ifndef __PARITY_H |
10 | #define __PARITY_H |
11 | |
12 | #include <stdint.h> |
13 | |
14 | extern const uint8_t OddByteParity[256]; |
15 | |
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16 | #define oddparity8(x) (OddByteParity[(x)]) |
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17 | |
18 | |
19 | extern const uint8_t EvenByteParity[256]; |
20 | |
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21 | static inline bool /*__attribute__((always_inline))*/ evenparity8(const uint8_t x) { |
22 | #if !defined __i386__ || !defined __GNUC__ |
23 | return EvenByteParity[x]; |
24 | #else |
25 | uint8_t y; |
26 | __asm( "testb $255, %1\n" |
27 | "setpo %0\n" : "=r"(y) : "r"(x): ); |
28 | return y; |
29 | #endif |
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30 | } |
31 | |
32 | |
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33 | static inline uint8_t evenparity32(uint32_t x) |
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34 | { |
35 | x ^= x >> 16; |
36 | x ^= x >> 8; |
37 | return EvenByteParity[x & 0xff]; |
38 | } |
39 | |
40 | |
41 | #endif /* __PARITY_H */ |