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https://github.com/RfidResearchGroup/proxmark3.git
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42 lines
1 KiB
C
42 lines
1 KiB
C
//-----------------------------------------------------------------------------
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// This code is licensed to you under the terms of the GNU GPL, version 2 or,
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// at your option, any later version. See the LICENSE.txt file for the text of
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// the license.
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//-----------------------------------------------------------------------------
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// Generic CRC calculation code.
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//-----------------------------------------------------------------------------
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#ifndef __PARITY_H
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#define __PARITY_H
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#include <stdint.h>
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extern const uint8_t OddByteParity[256];
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#define oddparity8(x) (OddByteParity[(x)])
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extern const uint8_t EvenByteParity[256];
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static inline bool /*__attribute__((always_inline))*/ evenparity8(const uint8_t x) {
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#if !defined __i386__ || !defined __GNUC__
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return EvenByteParity[x];
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#else
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uint8_t y;
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__asm( "testb $255, %1\n"
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"setpo %0\n" : "=r"(y) : "r"(x): );
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return y;
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#endif
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}
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static inline uint8_t evenparity32(uint32_t x)
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{
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x ^= x >> 16;
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x ^= x >> 8;
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return EvenByteParity[x & 0xff];
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}
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#endif /* __PARITY_H */
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