Mercurial > hg > nginx-ranges
comparison src/core/ngx_crc.h @ 0:f0b350454894 NGINX_0_1_0
nginx 0.1.0
*) The first public version.
| author | Igor Sysoev <http://sysoev.ru> |
|---|---|
| date | Mon, 04 Oct 2004 00:00:00 +0400 |
| parents | |
| children | 74b1868dd3cd |
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| -1:000000000000 | 0:f0b350454894 |
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| 1 | |
| 2 /* | |
| 3 * Copyright (C) Igor Sysoev | |
| 4 */ | |
| 5 | |
| 6 | |
| 7 #ifndef _NGX_CRC_H_INCLUDED_ | |
| 8 #define _NGX_CRC_H_INCLUDED_ | |
| 9 | |
| 10 | |
| 11 /* 32-bit crc16 */ | |
| 12 | |
| 13 ngx_inline static uint32_t ngx_crc(char *data, size_t len) | |
| 14 { | |
| 15 uint32_t sum; | |
| 16 | |
| 17 for (sum = 0; len; len--) { | |
| 18 | |
| 19 /* | |
| 20 * gcc 2.95.2 x86 and icc 7.1.006 compile that operator | |
| 21 * into the single "rol" opcode. | |
| 22 * msvc 6.0sp2 compiles it into four opcodes. | |
| 23 */ | |
| 24 sum = sum >> 1 | sum << 31; | |
| 25 | |
| 26 sum += *data++; | |
| 27 } | |
| 28 | |
| 29 return sum; | |
| 30 } | |
| 31 | |
| 32 | |
| 33 #endif /* _NGX_CRC_H_INCLUDED_ */ |