Mercurial > hg > nginx-quic
diff src/core/ngx_crc.h @ 201:267ea1d98683
nginx-0.0.1-2003-11-30-23:03:18 import
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Sun, 30 Nov 2003 20:03:18 +0000 |
parents | |
children | 0b67be7d4489 |
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new file mode 100644 --- /dev/null +++ b/src/core/ngx_crc.h @@ -0,0 +1,26 @@ +#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_ */