Mercurial > hg > nginx
annotate src/core/ngx_crc.h @ 444:42d11f017717
nginx-0.1.0-2004-09-29-20:00:49 import; remove years from copyright
author | Igor Sysoev <igor@sysoev.ru> |
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date | Wed, 29 Sep 2004 16:00:49 +0000 |
parents | da8c5707af39 |
children | bbd6b0b4a2b1 |
rev | line source |
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1 |
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2 /* |
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3 * Copyright (C) Igor Sysoev |
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4 */ |
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7 #ifndef _NGX_CRC_H_INCLUDED_ |
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8 #define _NGX_CRC_H_INCLUDED_ |
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11 /* 32-bit crc16 */ |
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13 ngx_inline static uint32_t ngx_crc(char *data, size_t len) |
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14 { |
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15 uint32_t sum; |
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17 for (sum = 0; len; len--) { |
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19 /* |
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20 * gcc 2.95.2 x86 and icc 7.1.006 compile that operator |
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21 * into the single "rol" opcode. |
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22 * msvc 6.0sp2 compiles it into four opcodes. |
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23 */ |
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24 sum = sum >> 1 | sum << 31; |
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25 |
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26 sum += *data++; |
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27 } |
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28 |
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29 return sum; |
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30 } |
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31 |
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32 |
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33 #endif /* _NGX_CRC_H_INCLUDED_ */ |