libm lacks C99 functions -> no c++11 cmath in libstdc++

[Steve Kargl]

On Wed, Jan 29, 2014 at 08:41:36PM +0400, Dmitry Marakasov wrote:
> 
> Gerald haven't responded yet, so I though I'd better post in on the
> list as well for wider discussion.
> 
> In short:
> - our libm lacks some C99 functions: erfl erfcl lgammal tgammal

I have code for erfl and erfcl, and I've done
some work on lgammal.  See freebsd-numerics list archive.
No, I do not have an ETA for when the code may land in the tree.

> - bad enough by itself, it affects libstdc++ from ports' gcc in such a
>   way that it disables C++11 math completely (along with a lot more
>   other more widely used math functions)
>
>
> - we may probably implement these by calling less-precise
>   erf erfc lgamma tgamma as we do with other functions as we alredy
>   do with some others

This, unfortuantely, has already been done, although it may only 
be available in FreeBSD-current.  See src/lib/msun/src/imprecise.c.

-- 
Steve