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

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.

-- 
Steve