Re: [Grep-devel] [PATCH 2/2] grep: speed up Aho-Corasick when at most 2 bytes

[Paul Eggert]

Norihiro Tanaka wrote:
> However, Slight slowdown may be caused in following case.
>
>   yes $(printf 0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c) | head -1000000 >inp
>   time -p src/grep -F -e 0b -e ab inp
>
> I think that it is not enough to mind.

It'd be a pain to attack that problem seriously, and perhaps you're right it's 
not worth worrying about. Still, we can do minor tuning that should be 
relatively simple and trouble-free. How about the attached patch? On my platform 
it improves CPU performance on the above benchmark by about 23%.

0001-grep-tune-to-avoid-memchr2-sometimes.patch
Description: Text Data