I found that grep -Fw is extremely slow in spite of whether in
multibyte locales or not.
$ yes 'abcdefg hijklmn opqrstu vwxyz' | head -10 >k
$ time -p env LC_ALL=C grep -Fw vwxy k
real 14.03
user 12.51
sys 0.74
$ time -p env LC_ALL=ja_JP.eucJP grep -Fw vwxy k
real 14.29
user 12.67
sys 0.50
$
Thanks for those performance improvements. I installed them, with some minor
changes to commentary. I also installed a couple of minor tweaks to the code, to
use memrchr and to simplify the multibyte test. Attached are the revised set of
patches.
From a341e981fec14f3a76e88bca3e40fdbc98539cf8 Mon
