On Thu, Feb 09, 2012 at 04:59:55PM +0100, Richard Guenther wrote:
> On Thu, Feb 9, 2012 at 4:57 PM, Andrew Haley <a...@redhat.com> wrote:
> > On 02/09/2012 03:56 PM, Michael Matz wrote:
> >> 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.
We don't want just a single libm, we need several different ones,
one accurrate (crlibm/IBM ulp based for doubles, unclear what to base it
on for the rest, if we don't have something 0.5ulp precise for
float and long double (__float80/__float128/IBM double double formats),
at least something as precise as possible, perhaps glibc sources), one
or more faster/less precise variants, ideally ABI compatible with glibc
and then vectorized variants.
If it can't live in GCC tree, it could be a separate project, which then
certainly could use glibc/crlibm/AMD vector library etc. sources.
Jakub
