view src/core/ngx_crc.h @ 289:0750faf8d7e3

nginx-0.0.2-2004-03-15-18:26:11 import
author Igor Sysoev <igor@sysoev.ru>
date Mon, 15 Mar 2004 15:26:11 +0000
parents 0b67be7d4489
children da8c5707af39
line wrap: on
line source

#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


/* 32-bit crc16 */

ngx_inline static uint32_t ngx_crc(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_ */