From: Toon Moene <moene@knmi.nl>
To: Andi Kleen <ak@suse.de>
Cc: gcc@gcc.gnu.org, starlex@eng.sun.com
Subject: Re: contribution
Date: Fri, 12 Apr 2002 05:58:00 -0000 [thread overview]
Message-ID: <3CB6D8E2.66047055@knmi.nl> (raw)
In-Reply-To: <p73ads9axvo.fsf@oldwotan.suse.de>
Andi Kleen wrote:
> > > You could compiled 172.mgrid with gcc twice this way and it showed
> > > 48% improvement ? Or did you use a different compiler as backend?
> > > If you used gcc - is it known where that huge difference comes
> > > from?
> To be honest I don't believe that he got that result with multiple runs
> of gcc. If yes that would be a very bad bug in the optimizer. More likely
> it was reached with the proprietary Sun compiler as backend (that would
> make the patch more a porting tool for GNU C programs to Sun C)
Hmm, I wouldn't be surprised at all ... When g77 came out (in February
'95) we had a hard time beating the f2c+gcc combo. It might still be
the case that, e.g., multi-rank array code (as in mgrid) is treated more
optimally by the gcc middle-end when first "squashed" by a Fortran to C
converter into a linear array.
--
Toon Moene, KNMI, PO Box 201, 3730 AE De Bilt, The Netherlands.
Tel. +31302206443, Fax +31302210407, e-mail moene@knmi.nl
URL: http://www.knmi.nl/hirlam
next prev parent reply other threads:[~2002-04-12 12:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <3CB6D448.45A4FE3E@knmi.nl.suse.lists.egcs>
2002-04-12 5:54 ` contribution Andi Kleen
2002-04-12 5:58 ` Toon Moene [this message]
2022-12-14 15:32 Contribution Mohamed Atef
2022-12-15 14:47 ` Contribution Jason Merrill
2022-12-15 16:42 ` Contribution Paul Smith
[not found] <CAOw3FZBzjtxEmbSMJDviD-td4bDM_mCMs9BQpk0SvK4EpR8N5g@mail.gmail.com>
2022-03-14 8:35 ` Fwd: Contribution farhad
2022-03-14 16:51 ` Contribution David Edelsohn
-- strict thread matches above, loose matches on Subject: below --
2002-04-12 5:45 contribution Toon Moene
[not found] <Pine.GSO.4.31.0204112030350.15026-101000@boojum.suse.lists.egcs-patches>
2002-04-12 1:28 ` contribution Andi Kleen
2002-04-12 11:42 ` contribution Alexey Starovoytov
2002-04-12 15:15 ` contribution Toon Moene
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