blob: 35981bc15a7c4c24878e25775f06ff695257f09e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
/* 32-bit crc16 */
static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
uint32_t sum;
for (sum = 0; len; len--) {
/*
* gcc 2.95.2 x86 and icc 7.1.006 compile
* that operator into the single "rol" opcode,
* msvc 6.0sp2 compiles it into four opcodes.
*/
sum = sum >> 1 | sum << 31;
sum += *data++;
}
return sum;
}
#endif /* _NGX_CRC_H_INCLUDED_ */
|
