From: Aaron Lehmann <aaronl@vitelus.com>
To: Willy Tarreau <willy@w.ods.org>
Cc: Daniel Phillips <dphillips@sistina.com>,
Linus Torvalds <torvalds@transmeta.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] Faster generic_fls
Date: Wed, 30 Apr 2003 01:36:07 -0700 [thread overview]
Message-ID: <20030430083607.GA6035@vitelus.com> (raw)
In-Reply-To: <20030430071907.GA30999@alpha.home.local>
On Wed, Apr 30, 2003 at 09:19:07AM +0200, Willy Tarreau wrote:
> But gcc's optimizer seems to be even worse with each new version. The NIL
> checksum takes 3 times more to complete on gcc3/athlon than gcc2/athlon !!!
> And on some test, the P4 goes faster when the code is optimized for athlon
> than for P4 !
It would be interesting to compare the assembly output of the
compilers to see what's happening. The gcc folks appreciate test cases
and this function seems simple and sensitive enough to make a good one.
> ===== gcc-2.95.3 -march=i686 -O2 / athlon MP/2200 (1.8 GHz) =====
-march=athlon would give gcc a chance to make better scheduling
decisions, which could make the results more sensible.
> ==== gcc 3.2.3 -march=i686 -O3 / Pentium 4 / 2.0 GHz ====
This version of gcc accepts -march=pentium4, which again might make
gcc's behavior less bizarre.
next prev parent reply other threads:[~2003-04-30 8:25 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-30 2:46 [RFC][PATCH] Faster generic_fls Daniel Phillips
2003-04-30 7:19 ` Willy Tarreau
2003-04-30 8:36 ` Aaron Lehmann [this message]
2003-04-30 8:43 ` Aaron Lehmann
2003-04-30 8:52 ` Aaron Lehmann
2003-04-30 8:51 ` P
2003-04-30 13:51 ` Daniel Phillips
2003-04-30 11:14 ` Falk Hueffner
2003-04-30 13:03 ` Daniel Phillips
2003-04-30 13:17 ` Falk Hueffner
2003-04-30 14:07 ` Daniel Phillips
2003-04-30 14:11 ` Linus Torvalds
2003-04-30 14:53 ` Falk Hueffner
2003-04-30 15:28 ` Linus Torvalds
2003-04-30 16:03 ` Falk Hueffner
2003-04-30 16:16 ` Linus Torvalds
2003-04-30 16:43 ` Falk Hueffner
2003-04-30 20:25 ` Alan Cox
2003-04-30 21:59 ` Falk Hueffner
2003-04-30 22:22 ` Alan Cox
2003-04-30 23:41 ` Linus Torvalds
2003-04-30 22:47 ` Alan Cox
2003-05-01 0:12 ` Falk Hueffner
2003-05-01 1:07 ` Linus Torvalds
2003-04-30 19:15 ` Daniel Phillips
2003-04-30 20:59 ` Willy Tarreau
2003-05-01 1:02 ` Daniel Phillips
2003-05-01 9:19 ` Willy Tarreau
2003-05-01 16:02 ` Linus Torvalds
2003-04-30 20:55 ` Andrew Morton
2003-05-01 5:03 ` hugang
2003-05-01 5:11 ` Andrew Morton
2003-05-01 5:33 ` hugang
2003-05-01 7:05 ` hugang
2003-05-01 13:52 ` Willy TARREAU
2003-05-01 14:14 ` Falk Hueffner
2003-05-01 14:26 ` Willy TARREAU
2003-05-01 14:53 ` hugang
2003-05-01 15:54 ` Thomas Schlichter
2003-05-02 0:33 ` hugang
2003-05-01 17:16 ` Willy TARREAU
2003-05-01 23:27 ` Thomas Schlichter
2003-05-02 0:10 ` Willy Tarreau
2003-05-02 0:43 ` Daniel Phillips
2003-05-02 0:54 ` Andrew Morton
2003-05-02 12:21 ` Daniel Phillips
2003-05-02 1:47 ` Thomas Schlichter
2003-05-02 13:24 ` Willy Tarreau
2003-05-02 0:13 ` Daniel Phillips
2003-05-02 0:13 ` Lincoln Dale
2003-05-01 5:16 ` hugang
2003-05-01 10:22 ` Willy TARREAU
2003-05-01 11:17 ` hugang
2003-05-01 11:45 ` Willy TARREAU
[not found] <87d6j34jad.fsf@student.uni-tuebingen.de.suse.lists.linux.kernel>
[not found] ` <Pine.LNX.4.44.0304301801210.20283-100000@home.transmeta.com.suse.lists.linux.kernel>
2003-05-01 1:46 ` Andi Kleen
2003-05-01 4:40 ` Linus Torvalds
2003-05-01 12:00 ` David S. Miller
2003-05-02 5:14 ` Linus Torvalds
-- strict thread matches above, loose matches on Subject: below --
2003-05-01 13:31 linux
2003-05-01 17:15 Chuck Ebbert
2003-05-02 8:50 Chuck Ebbert
2003-05-02 9:37 ` Peter Osterlund
2003-05-02 10:04 Chuck Ebbert
2003-05-02 22:55 ` David S. Miller
2003-05-03 2:21 Chuck Ebbert
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20030430083607.GA6035@vitelus.com \
--to=aaronl@vitelus.com \
--cc=dphillips@sistina.com \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@transmeta.com \
--cc=willy@w.ods.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox