[debbugs-tracker] bug#17350: closed ([PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset)

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Your message dated Sat, 26 Apr 2014 18:08:12 -0700
with message-id <address@hidden>
and subject line Re: bug#17350: [PATCH] grep: speed up for a case to repeat 
failure in DFA after success in kwset
has caused the debbugs.gnu.org bug report #17350,
regarding [PATCH] grep: speed up for a case to repeat failure in DFA after 
success in kwset
to be marked as done.

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17350: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=17350
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--- Begin Message --- Subject: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset Date: Sat, 26 Apr 2014 20:25:43 +0900

Patch#17230 causes slowdown for a case to repeat failure in DFA after
success in kwset, although it improves the performance for many cases.

In fact, the master without this patch is 3.5x slower than grep 2.18 for
below.

    $ yes abcdabc | head -50000000 >k
    $ env LC_ALL=C time -p src/grep -i 'abcd.bd' k

This patch fixes the degradation of the performance for such cases.  See
the commit log for details.

Norihiro

patch.txt
Description: Text document

--- End Message ---

--- Begin Message --- Subject: Re: bug#17350: [PATCH] grep: speed up for a case to repeat failure in DFA after success in kwset Date: Sat, 26 Apr 2014 18:08:12 -0700 User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 Thanks, I installed that patch with minor reworking of the ChangeLog entry and am marking this as done. By the way, a minor point -- nowadays we prefer single-quoting 'like this' rather than the old style `like this' -- the GNU coding standards changed recently in this regard.

I noticed a mostly-theoretical read buffer overrun in the patch, along with some other opportunities for simplification and tuning, and installed the attached fixup patch as well.

0001-dfa-fix-index-bug-in-previous-patch-and-simplify.patch
Description: Text document

--- End Message ---