fix comment

This commit is contained in:
Igor Sysoev 2007-01-12 18:05:41 +00:00
parent b1d65e50d6
commit 8f6a00c3ef

View File

@ -13,11 +13,11 @@
* described at http://www.w3.org/TR/PNG/
*
* The 256 element lookup table takes 1024 bytes, and it may be completely
* cached after processing about 30-60 bytes. So for short messages
* cached after processing about 30-60 bytes of data. So for short data
* we use the 16 element lookup table that takes only 64 bytes and align it
* to CPU cache line size. Of course, the small table adds code inside
* CRC32 cycle, but cache misses overhead is bigger than overhead of
* the additional code. For example, ngx_crc32_short() of 16 byte message
* CRC32 loop, but the cache misses overhead is bigger than overhead of
* the additional code. For example, ngx_crc32_short() of 16 bytes of data
* takes half as much CPU clocks than ngx_crc32_long().
*/