view src/core/ngx_crc.h @ 5036:6e374742043e stable-1.2

Merge of r4944: removed GLOB_NOSORT glob option. This will result in alphabetical sorting of included files if the "include" directive with wildcards is used. Note that the behaviour is now different from that on Windows, where alphabetical sorting is not guaranteed for FindFirsFile()/FindNextFile() (used to be alphabetical on NTFS, but not on FAT). Approved by Igor Sysoev, prodded by many.
author Maxim Dounin <mdounin@mdounin.ru>
date Sat, 09 Feb 2013 21:27:37 +0000
parents d620f497c50f
children
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/*
 * 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_ */