Mercurial > hg > nginx-vendor-0-8
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> |
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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_ */ |