From: Daniel Berlin <dberlin@dberlin.org>
To: Sebastian Pop <sebastian.pop@cri.ensmp.fr>
Cc: Joe Buck <Joe.Buck@synopsys.com>, Dan Kegel <dank@kegel.com>,
GCC Mailing List <gcc@gcc.gnu.org>
Subject: Re: [GCC 4.2 Project] Omega data dependence test
Date: Tue, 09 Aug 2005 22:57:00 -0000 [thread overview]
Message-ID: <Pine.LNX.4.63.0508091854290.32564@localhost.localdomain> (raw)
In-Reply-To: <20050809145928.GA4156@napoca.cri.ensmp.fr>
On Tue, 9 Aug 2005, Sebastian Pop wrote:
> Joe Buck wrote:
>> Algorithms that are sometimes exponential can still be used if there is
>> a cutoff mechanism, to abort the algorithm if it exceeds a budget. This
>> assumes that we can then fall back to an algorithm that might produce
>> inferior results, but will produce something usable in reasonable time.
>>
>
> Okay, I stand corrected. As a practical implementation we can have a
> mechanism as push/pop timevar, that would monitor the time and space
> of an algorithm and that can cancel the computation for failing on a
> safe approximation. As a first concretization, I was thinking to use
> threads, but I'm not sure whether this is suitable for GCC.
A lot of data dependence related algorithms are exponential in the worst
case, and work fine in production compilers, without cutoffs.
XLC uses fourier motzkin without any cutoffs, for example (as does intel,
i believe) :)
>
>
next prev parent reply other threads:[~2005-08-09 22:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-08 15:51 Dan Kegel
2005-08-08 16:12 ` Daniel Berlin
2005-08-08 16:27 ` Dave Korn
2005-08-08 18:39 ` Sebastian Pop
2005-08-08 18:31 ` Sebastian Pop
2005-08-08 22:48 ` Joe Buck
2005-08-09 14:55 ` Sebastian Pop
2005-08-09 16:23 ` Joe Buck
2005-08-13 23:07 ` Sebastian Pop
2005-08-14 1:36 ` Daniel Berlin
2005-08-14 11:10 ` Sebastian Pop
2005-08-14 15:40 ` Daniel Berlin
2005-08-14 1:49 ` Ian Lance Taylor
2005-08-09 22:57 ` Daniel Berlin [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-08-09 22:14 Daniel Kegel
2005-08-09 18:01 Daniel Kegel
2005-08-09 18:03 ` Andrew Pinski
2005-08-08 12:29 Sebastian Pop
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