Mercurial > hg > nginx
annotate src/core/ngx_crc.h @ 201:267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
author | Igor Sysoev <igor@sysoev.ru> |
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date | Sun, 30 Nov 2003 20:03:18 +0000 |
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children | 0b67be7d4489 |
rev | line source |
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201
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
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1 #ifndef _NGX_CRC_H_INCLUDED_ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
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2 #define _NGX_CRC_H_INCLUDED_ |
267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
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3 |
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nginx-0.0.1-2003-11-30-23:03:18 import
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4 |
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nginx-0.0.1-2003-11-30-23:03:18 import
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5 /* 32-bit crc16 */ |
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6 |
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nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
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7 ngx_inline static uint32_t ngx_crc(char *data, size_t len) |
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Igor Sysoev <igor@sysoev.ru>
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8 { |
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nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
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9 uint32_t sum; |
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nginx-0.0.1-2003-11-30-23:03:18 import
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10 |
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nginx-0.0.1-2003-11-30-23:03:18 import
Igor Sysoev <igor@sysoev.ru>
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11 for (sum = 0; len; len--) { |
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12 /* |
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13 * gcc 2.95.2 x86 and icc 7.1.006 compile that operator |
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14 * into the single rol opcode. |
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15 * msvc 6.0sp2 compiles it into four opcodes. |
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16 */ |
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17 sum = sum >> 1 | sum << 31; |
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18 |
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19 sum += *data++; |
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20 } |
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21 |
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22 return sum; |
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23 } |
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24 |
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25 |
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26 #endif /* _NGX_CRC_H_INCLUDED_ */ |