GNU bug report logs - #38322
GCC optimize levels makes huge impact on performance

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Message #13 received at 38322-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Balázs Vinarz <vinibali1 <at> gmail.com>
Cc: 38322-done <at> debbugs.gnu.org
Subject: Re: bug#38322: GCC optimize levels makes huge impact on performance
Date: Thu, 2 Jan 2020 02:08:27 -0800

On 11/22/19 5:52 PM, Paul Eggert wrote:
> If we do want to tune grep for set-like operations, that suggests doing some
> surgery to its internals rather than merely fiddling with -O flags.

Since I last wrote, some of that surgery has been done by another grep
contributor, and a simple 'grep -f file1 file2' benchmark that I just now tried
sped up from 47 seconds (for grep 3.1) to 2.3 seconds (for the next version of
grep). So this algorithmic change should far outweigh any GCC optimization level
change.

Anyway, the topic seems to have died down so I'm closing the bug report.

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