[Bug libstdc++/11706] std::pow(T, int) implementation pessimizes code

["rguenth at tat dot physik dot uni-tuebingen dot de" <gcc-bugzilla at gcc dot gnu dot org>]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11706



------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de  2003-09-29 14:41 -------
Subject: Re:  std::pow(T, int) implementation pessimizes
 code

On 29 Sep 2003, gdr at integrable-solutions dot net wrote:

> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11706
>
>
>
> ------- Additional Comments From gdr at integrable-solutions dot net  2003-09-29 14:36 -------
> Subject: Re:  std::pow(T, int) implementation pessimizes code
>
> "rguenth at tat dot physik dot uni-tuebingen dot de" <gcc-bugzilla@gcc.gnu.org> writes:
>
> | Any progress on this? I still think this is a show stopper. What about the
> | suggested replacement of the __pow_helper() with ::pow() which is now
> | optimized by an appropriate builtin?
>
> <cmath> should not use ::pow -- it is not supposed to be available there.
> The issue should now be reevaluated with the recent work on inlining.
> I did not have time to work on it though.

Its still the very same. The (pending?) fix for PR11707 should help a
little bit, but as PR11710 will not be fixed this wont help the underlying
problem.

Why exactly should cmath not use ::pow (or __builtin_pow())? Has it to
work with other compilers than the gcc it shipped with?

Richard.

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