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From: Giuseppe Scrivano <gscrivano@gnu.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Pádraig Brady" <P@draigBrady.com>,
	Bug-coreutils@gnu.org, "Git Mailing List" <git@vger.kernel.org>
Subject: Re: Linus' sha1 is much faster!
Date: Mon, 17 Aug 2009 00:15:49 +0200	[thread overview]
Message-ID: <87ab1ze76y.fsf@master.homenet> (raw)
In-Reply-To: <alpine.LFD.2.01.0908161306340.3162@localhost.localdomain> (Linus Torvalds's message of "Sun, 16 Aug 2009 13:10:20 -0700 (PDT)")

Linus Torvalds <torvalds@linux-foundation.org> writes:

> I pretty much can guarantee you that it improves things only because it 
> makes gcc generate crap code, which then hides some of the P4 issues.
>
> I'd also suggest you try gcc-4.4, since that apparently fixes some of the 
> oddest spill issues.


Thanks for the hint.  I tried gcc-4.4 and it produces slower code than
4.3 on the gnulib SHA1 implementation and my patch makes it even more!

I noticed that on my machine your implementation is ~30-40% faster using
SHA_ROT for rol/ror instructions than inline assembly, at least with the
test-case Pádraig wrote.  Am I the only one reporting it?

Cheers,
Giuseppe

  reply	other threads:[~2009-08-16 22:17 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 [this message]
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
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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