Re: weird optimization in sin+cos, x86 backend

[Vincent Lefevre <vincent+gcc at vinc17 dot org>]

On 2012-02-09 16:01:48 +0000, Andrew Haley wrote:
> On 02/09/2012 03:59 PM, Richard Guenther wrote:
> > On Thu, Feb 9, 2012 at 4:57 PM, Andrew Haley <aph@redhat.com> wrote:
> >> On 02/09/2012 03:56 PM, Michael Matz wrote:
> >>> Hi,
> >>>
> >>> On Thu, 9 Feb 2012, Andrew Haley wrote:
> >>>
> >>>> On 02/09/2012 03:28 PM, Richard Guenther wrote:
> >>>>> So - do you have an idea what routines we can start off with to get
> >>>>> a full C99 set of routines for float, double and long double?  The last
> >>>>> time I was exploring the idea again I was looking at the BSD libm.
> >>>>
> >>>> I'd start with INRIA's crlibm.
> >>>
> >>> Not complete.  Too slow.
> >>
> >> Not complete, fair enough.  But it's the fastest accurate one,
> >> isn't it?
> > 
> > Maybe.  Nothing would prevent us from composing from multiple sources
> > of course.  crlibm also only provides double precision routines.
> 
> Okay, but the crlibm algorithms could be extended to long
> doubles and, presumably, floats.  Where's Vincent Lefevre
> when you need him?   :-)

I'm a bit late at reading and answering all my mail. :)

Our team has new tools to support other precisions, so that
long double would be possible.

Also note that CRlibm supports the 4 rounding modes, while the
IBM Accurate Mathematical Library currently used in glibc behaves
erratically (e.g. can even crash) on directed rounding modes.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <http://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)