Re: What to do about tgammal?

On Tue, Dec 14, 2021 at 06:26:13PM +0000, Mark Murray wrote:
> 
> This is now visible for review at
> https://reviews.freebsd.org/D33444 <https://reviews.freebsd.org/D33444>
> 

I see imp lamented that that fact that he is not sufficiently
versed in the numerical methods used (neither am I!).  bde
use to be my go-to reviewer, but he's no longer with us.  To
allay fears, I've tested 5 million values distributed in the
intervals of the various approximations.  Here's the result

 Interval          max ULP          x at Max ULP
[6,1755.1]        0.873414 at 1.480588145237629047468e+03
[1.0662,6]        0.861508 at 1.999467927053585410537e+00
[1.01e-17,1.0661] 0.938041 at 1.023286481537296307856e+00
[-1.9999,-1.0001] 3.157770 at -1.246957268051453610329e+00
[-2.9999,-2.0001] 2.987659 at -2.220949465449893090070e+00 

Note, 1.01e-17 can be reduced to soemthing like 1.01e-19 or
1.01e-20.

-- 
Steve