| /* | |
| * Copyright (C) Igor Sysoev | |
| */ | |
| #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_ */ |