From: "Pádraig Brady" <P@draigBrady.com>
To: Giuseppe Scrivano <gscrivano@gnu.org>
Cc: Bug-coreutils@gnu.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Git Mailing List <git@vger.kernel.org>
Subject: Re: Linus' sha1 is much faster!
Date: Mon, 17 Aug 2009 02:53:17 +0100 [thread overview]
Message-ID: <4A88B80D.40804@draigBrady.com> (raw)
In-Reply-To: <87eirbef3c.fsf@master.homenet>
Giuseppe Scrivano wrote:
> Hi Pádraig,
>
> I tried to reproduce your results but I wasn't able to do it. The
> biggest difference on a 300MB file I noticed was approximately 15% using
> on both implementations -O2, and 5% using -O3.
> My GCC version is "gcc (Debian 4.3.3-14) 4.3.3" and the CPU is: Intel(R)
> Pentium(R) D CPU 3.20GHz.
>
> I also spent some time trying to improve the gnulib SHA1 implementation
> and it seems a lookup table can improve things a bit.
>
> Can you please try the patch that I have attached and tell me which
> performance difference (if any) you get?
Thanks for looking at this Giuseppe
and sorry for not mentioning my GCC and CPU.
Note the binaries below is compiled with
$(rpm -q --qf="%{OPTFLAGS}\n" coreutils)
for consistency, which on my F11 machines is:
-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
-fstack-protector --param=ssp-buffer-size=4 -m32 -march=i586
-mtune=generic -fasynchronous-unwind-tables -D_GNU_SOURCE=1
Testing on 2 machines I have here:
$ rpm -q gcc
gcc-4.4.1-2.fc11.i586
$ grep "model name" /proc/cpuinfo | head -n1 | tr -s '[:blank:]' ' '
model name : Intel(R) Pentium(R) M processor 1.70GHz
$ truncate -s300MB sha1.test
$ time sha1sum sha1.test
real 0m3.540s
$ time linus-sha1 sha1.test
real 0m2.319s (-34%)
$ time giuseppe-sha1sum sha1.test
real 0m3.513s (-.8%)
$ rpm -q gcc
gcc-4.4.1-2.fc11.i586
$ grep "model name" /proc/cpuinfo | head -n1 | tr -s '[:blank:]' ' '
model name : Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz
$ truncate -s300MB sha1.test
$ time sha1sum sha1.test
real 0m1.857s
$ time linus-sha1 sha1.test
real 0m1.102s (-40%)
$ time giuseppe-sha1sum sha1.test
real 0m1.932s (+ 4%)
cheers,
Pádraig.
next prev parent reply other threads:[~2009-08-17 1:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-14 23:25 Linus' sha1 is much faster! Pádraig Brady
2009-08-15 20:02 ` Bryan Donlan
2009-08-15 20:12 ` John Tapsell
2009-08-15 20:23 ` Linus Torvalds
2009-08-15 20:54 ` Linus Torvalds
2009-08-17 1:55 ` Nicolas Pitre
2009-08-26 11:39 ` Pádraig Brady
2017-04-20 21:35 ` galt
2017-04-20 21:38 ` galt
2009-08-17 8:22 ` Andreas Ericsson
2009-08-16 0:06 ` Theodore Tso
2009-08-16 19:25 ` Giuseppe Scrivano
2009-08-16 20:10 ` Linus Torvalds
2009-08-16 22:15 ` Giuseppe Scrivano
2009-08-16 22:47 ` Linus Torvalds
2009-08-17 1:53 ` Pádraig Brady [this message]
2009-08-17 10:51 ` Giuseppe Scrivano
2009-08-17 15:44 ` Steven Noonan
2009-08-17 16:22 ` Linus Torvalds
2009-08-17 21:43 ` Steven Noonan
2009-08-17 17:32 ` Giuseppe Scrivano
-- strict thread matches above, loose matches on Subject: below --
2009-08-17 7:23 George Spelvin
2009-08-17 14:20 ` Nicolas Pitre
2009-08-17 17:06 ` Nicolas Pitre
2009-08-17 17:20 ` Paolo Bonzini
2009-08-17 18:54 ` George Spelvin
2009-08-17 19:34 ` Nicolas Pitre
2009-08-17 23:12 ` George Spelvin
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