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From: Richard Guenther <richard.guenther@gmail.com>
To: Toon Moene <toon@moene.org>
Cc: Daniel Kraft <d@domob.eu>, Tobias Burnus <burnus@net-b.de>,
	Jerry DeLisle <jvdelisle@verizon.net>,
		Thomas Koenig <tkoenig@netcologne.de>,
	fortran@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: Re: [patch, fortran] PR 40628, front-end optimization pass
Date: Tue, 20 Jul 2010 09:58:00 -0000	[thread overview]
Message-ID: <AANLkTimKRPiqDKNUYKiVNI2R5NFMLdPyoW7Wk8j-k9FQ@mail.gmail.com> (raw)
In-Reply-To: <4C456FE6.7010805@moene.org>

On Tue, Jul 20, 2010 at 11:44 AM, Toon Moene <toon@moene.org> wrote:
> Daniel Kraft wrote:
>
>> I just wonder if there is not yet any way to tell the middle-end that it
>> is allowed to optimize function calls away (like marking the functions
>> "pure" -- according to the c.l.f thread, this should be allowed for all
>> Fortran functions (if I understood it correctly)).
>
> No, that's not sufficient, as I argued in my 2007 GCC Summit paper (see
> paragraph 6.3 - you also have to get rid of the temporaries that are
> allocated to hold the function results, which can be quite large (i.e., when
> eliding MATMUL calls).
>
> It is hard to see how the middle end could do this.

It generally can't if it doesn't know that MATMUL is MATMUL.
Middle-end arrays would help, but they keep being below the top
of my TODO list ;)

Richard.

  reply	other threads:[~2010-07-20  9:58 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-17 18:38 Thomas Koenig
2010-07-18  8:41 ` Daniel Kraft
2010-07-18 10:18   ` Thomas Koenig
2010-07-19 18:59     ` Toon Moene
2010-07-19 19:11       ` Thomas Koenig
2010-07-19  4:12   ` Jerry DeLisle
2010-07-19 18:21     ` Richard Henderson
2010-07-19 19:06     ` Jakub Jelinek
2010-07-19 22:31     ` Thomas Koenig
2010-07-20  1:19       ` Jerry DeLisle
2010-07-20  2:08         ` Steve Kargl
2010-07-20  2:39         ` Diego Novillo
2010-07-20  2:54           ` Jerry DeLisle
2010-07-20  8:05         ` Tobias Burnus
2010-07-20  8:21           ` Daniel Kraft
2010-07-20  9:44             ` Toon Moene
2010-07-20  9:58               ` Richard Guenther [this message]
2010-07-20 22:01                 ` Thomas Koenig
2010-07-25 15:52                   ` Tobias Burnus
2010-07-25 19:35                     ` Thomas Koenig
2010-07-25 21:15                       ` Paolo Bonzini
2010-07-26 19:24                         ` Thomas Koenig

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