error in tgammaf

[Paul Zimmermann]

sorry I fixed the subject which was misleading.
This is for tgammaf (and not tgamma), i.e.,
the single precision function.

Paul

> Date: Wed, 08 Feb 2023 16:55:51 +0100
> From: Paul Zimmermann <Paul.Zimmermann@inria.fr>
> CC: vincenzo.innocente@cern.ch
> 
>        Hi,
> 
> while testing Newlib 4.3.0, I also noticed the following regression
> with respect to 4.2.0 for tgammaf:
> 
> zimmerma@tartine:~/svn/tbd/20/src/binary32_exhaustive$ VERBOSE=-v ./doit2.newlib tgamma
> Checking tgamma with newlib-4.3.0.20230120
> Using RedHat newlib
> MPFR library: 4.2.0       
> MPFR header:  4.2.0 (based on 4.2.0)
> Checking function tgammaf with MPFR_RNDN
> ...
> libm wrong by up to nan ulp(s) [9223372036854775808] for x=-0x1p+0
> tgamma      gives inf
> mpfr_tgamma gives -nan
> 
> For a negative integer, tgamma should return NaN.
> 
> Best regards,
> Paul Zimmermann