Re: Use of C99 extra long double math functions after r236148

On Monday, May 28, 2012 7:02:18 pm Steve Kargl wrote:
> On Tue, May 29, 2012 at 07:05:07AM +1000, Peter Jeremy wrote:
> > On 2012-May-28 11:01:24 -0500, Stephen Montgomery-Smith 
<stephen_at_missouri.edu> wrote:
> > >One thing that could be done is to have a "math/cephes" port that adds 
> > >the extra C99 math functions.  This is already done in the math/sage 
> > >port, using a rather clever patch due to Peter Jeremy, that applies to 
> > >the cephes code.
> > >
> > >What it would do is to create a /usr/local/lib/libm.so that would 
> > >provide the extra functions not currently included in /lib/libm.so, and 
> > >then link in /lib/libm.so as well.  It would also create its own 
> > >/usr/local/include/math.h and /usr/local/include/complex.h as well.
> > 
> > Basically, as long as the compiler searches /usr/local/{include,lib}
> > before the base include/lib then <math.h>, <complex.h> and -lm give
> > the application a complete C99 math implementation by using base
> > functions where they exist and cephes functions where they don't.
> > 
> > The patch I wrote for sage can be found at
> > http://trac.sagemath.org/sage_trac/ticket/9543
> > If there's any interest, I could produce a port for this.
> > 
> > Another option would be to import cephes into base and use it to
> > provide the missing C99 functions.  Cephes includes copyright notices
> > but the closest I can find to a license is:
> > "   Some software in this archive may be from the book _Methods and
> >  Programs for Mathematical Functions_ (Prentice-Hall or Simon & Schuster
> >  International, 1989) or from the Cephes Mathematical Library, a
> >  commercial product. In either event, it is copyrighted by the author.
> >  What you see here may be used freely but it comes with no support or
> >  guarantee."
> 
> Please talk to das_at_ (although I believe he's finishing up his
> dissertation).  I recall that he's stated that he looked into
> using cephes, and concluded that it is not suitable for libm.
> 
> Note there is also
> 
> http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/147599
> 
> which I've also objected to importing into libm.

I do think we should provide something in ports as an interim solution.
There are other 3rd party applications looking to drop FreeBSD support
because we are missing APIs that almost all other OS's have.  I'm fine
if the interim lives in ports and that we don't import substandard
routines into the base.  I would even be fine with calling it 
/usr/local/lib/libm_inaccurate.so.  However, I do think we need an option.

-- 
John Baldwin