From: Joe Buck <Joe.Buck@synopsys.COM>
To: Sebastian Pop <sebastian.pop@cri.ensmp.fr>
Cc: 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 16:23:00 -0000 [thread overview]
Message-ID: <20050809162344.GB11610@synopsys.com> (raw)
In-Reply-To: <20050809145928.GA4156@napoca.cri.ensmp.fr>
On Tue, Aug 09, 2005 at 04:59:28PM +0200, 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.
The problem with using time as a cutoff is that you then get results that
can't be reproduced reliably. Better to count something that is a feature
of the algorithm, e.g. number of executions of some inner loop, number of
nodes visited, or the like, so that all users get the same results.
next prev parent reply other threads:[~2005-08-09 16:23 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 [this message]
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
-- 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
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=20050809162344.GB11610@synopsys.com \
--to=joe.buck@synopsys.com \
--cc=dank@kegel.com \
--cc=gcc@gcc.gnu.org \
--cc=sebastian.pop@cri.ensmp.fr \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).