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annotate src/core/ngx_crc.h @ 441:da8c5707af39

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nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
author Igor Sysoev <igor@sysoev.ru>
date Tue, 28 Sep 2004 08:34:51 +0000
parents 0b67be7d4489
children 42d11f017717
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da8c5707af39 nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
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2 /*
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3 * Copyright (C) 2002-2004 Igor Sysoev
da8c5707af39 nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
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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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26 sum += *data++;
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27 }
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29 return sum;
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30 }
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33 #endif /* _NGX_CRC_H_INCLUDED_ */