From: Richard Guenther <richard.guenther@gmail.com>
To: Kenneth Hoste <kenneth.hoste@ugent.be>
Cc: Martin Guy <martinwguy@gmail.com>, ami_stuff <ami_stuff@o2.pl>,
gcc@gcc.gnu.org
Subject: Re: GCC 4..4.x speed regression - help?
Date: Mon, 17 Aug 2009 10:00:00 -0000 [thread overview]
Message-ID: <84fc9c000908170153mbe73f2bia10d3c513ba78974@mail.gmail.com> (raw)
In-Reply-To: <E8DE22EF-5BAF-4093-B997-2283810A9BAE@ugent.be>
On Mon, Aug 17, 2009 at 9:19 AM, Kenneth Hoste<kenneth.hoste@ugent.be> wrote:
>
> On Aug 16, 2009, at 18:02 , Martin Guy wrote:
>
>> Yes, GCC is bigger and slower and for several architectures generates
>> bigger, slower code with every release, though saying so won't make
>> you very popular on this list! :)
>>
>> One theory is that there are now so many different optimization passes
>> (and, worse, clever case-specific hacks hidden in the backends) that
>> the interaction between the lot of them is now chaotic. Selecting
>> optimization flags by hand is no longer humanly possible.
>
> That, and the fact that GCC supports so many (quite different) targets
> while keeping the set of optimization passes roughly equal across
> these targets probably also doesn't help...
>
> I'm aware there are (good) reasons to try and keep it that way, but it seems
> the reasons against it are getting stronger.
The main reason for it is scalability of maintainance - while I bet it
would work well for popular architectures like x86 or ppc (hey, but
those don't exhibit the problems anyway...) less popular architectures
would even less benefit from the bugfixing in general code.
Richard.
>
> Just my 2 cents.
>
> Kenneth
>
> PS: There's MILEPOST, but there are other projects too. Check out Acovea
> (http://www.coyotegulch.com/products/acovea) and my very own
> pet COLE (http://users.elis.ugent.be/~kehoste/, see the publications
> section).
>
> --
>
> Kenneth Hoste
> Paris research group - ELIS - Ghent University, Belgium
> email: kenneth.hoste@elis.ugent.be
> website: http://www.elis.ugent.be/~kehoste
> blog: http://boegel.kejo.be
>
>
next prev parent reply other threads:[~2009-08-17 8:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-16 16:02 ami_stuff
2009-08-16 22:46 ` Bernd Roesch
2009-08-17 0:39 ` ami_stuff
2009-08-17 6:42 ` Martin Guy
2009-08-17 8:53 ` Kenneth Hoste
2009-08-17 10:00 ` Richard Guenther [this message]
2009-08-17 9:03 ` Paolo Bonzini
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