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Date: Tue, 29 Jul 2003 13:28:00 -0000
From: Richard Guenther <rguenth@tat.physik.uni-tuebingen.de>
To: Andrew Pinski <pinskia@physics.uc.edu>
cc: Gabriel Dos Reis <gdr@integrable-solutions.net>,
   Steven Bosscher <s.bosscher@student.tudelft.nl>, <gcc@gcc.gnu.org>
Subject: Re: std::pow implementation
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On Tue, 29 Jul 2003, Andrew Pinski wrote:

> On Tuesday, Jul 29, 2003, at 08:43 US/Eastern, Richard Guenther wrote:
> > On 29 Jul 2003, Gabriel Dos Reis wrote:
> >
> > To show you some of the performance improve I get with my "hacked"
> > __pow_helper(), the average time for one iteration of my scientific
> > app dropped from 2.6s to 1.8s - this is a 30% improvement. Not to say
> > I ever expected gcc (or libstdc++) to not create x*x out of
> > std::pow(x,2).
>
> If you use ::pow instead, gcc does change it to be x*x on the mainline
> at least.

Why isnt this done for std::pow? Any particular reason?

Richard.

--
Richard Guenther <richard dot guenther at uni-tuebingen dot de>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/