From: Steven Noonan <steven@uplinklabs.net>
To: Giuseppe Scrivano <gscrivano@gnu.org>
Cc: "Pádraig Brady" <P@draigbrady.com>,
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 08:44:30 -0700 [thread overview]
Message-ID: <f488382f0908170844h649126efxb27f87d7b319961b@mail.gmail.com> (raw)
In-Reply-To: <8763cmemsa.fsf@master.homenet>
On Mon, Aug 17, 2009 at 3:51 AM, Giuseppe Scrivano<gscrivano@gnu.org> wrote:
> Pádraig Brady <P@draigBrady.com> writes:
>
>> -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
>
> thanks. I did again all tests on my machine using these same options.
> I repeated each test 6 times and I took the median without consider the
> first result. Except the first run that it is not considered, I didn't
> report a big variance on results of the same test.
>
>
> gcc 4.3.3
>
> gnulib sha1: real 0m2.543s
> gnulib sha1 lookup: real 0m1.906s (-25%)
> linus's sha1: real 0m2.468s (-3%)
> linus's sha1 no asm: real 0m2.289s (-9%)
>
>
> gcc 4.4.1
>
> gnulib sha1: real 0m3.386s
> gnulib sha1 lookup: real 0m3.110s (-8%)
> linus's sha1: real 0m1.701s (-49%)
> linus's sha1 no asm: real 0m1.284s (-62%)
>
>
> I don't see such big differences in asm generated by gcc 4.4.1 and gcc
> 4.3.3 to explain this performance difference, what I noticed immediately
> is that in the gcc-4.4 generated asm there are more "lea" instructions
> (+30%), but I doubt this is the reason of these poor results. Anyway, I
> haven't yet looked much in details.
>
> Cheers,
> Giuseppe
Interesting. I compared Linus' implementation to the public domain one
by Steve Reid[1], which is used in OpenLDAP and a few other projects.
Anyone with some experience testing these kinds of things in a
statistically sound manner want to try it out? In my tests, I got
this:
(average of 5 runs)
Linus' sha1: 283MB/s
Steve Reid's sha1: 305MB/s
- Steven
[1] http://gpl.nas-central.org/SYNOLOGY/x07-series/514_UNTARED/source/openldap-2.3.11/libraries/liblutil/sha1.c
next prev parent reply other threads:[~2009-08-17 15:44 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
2009-08-17 10:51 ` Giuseppe Scrivano
2009-08-17 15:44 ` Steven Noonan [this message]
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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