[PATCH libstdc++/66689] comp_ellint_3 and ellint_3 return garbage values

[Jonathan Wakely]

On 17/11/17 15:05 -0500, Ed Smith-Rowland wrote:
>This is an embarrassment actually, after the excellent analysis in the 
>PR trail.
>
>We've (I've) been using the wrong sign convention for the nu parameter 
>in comp_ellint_3 and in ellint_3 in tr1 and now std for years.  In my 
>defence the World seems about evenly split on this with GSL, 
>Abramowitz&Stegun (and DLMF) and Carlson (that's what actually got me 
>here) on the +nu side, and tr1/std, boost on the other -nu side.
>
>We need to get this into 8.
>
>I'm not sure about backporting to 7.  I don't think we should change 
>this breaking in the middle of a release series.

Hmm, you're probably right. I'd be tempted to though.

>I'll write a Mea Culpa warning about changing ellint_3, comp_ellint_3 
>in the release notes and in the libstdc++ pages and the tr29124 
>conformance page later.
>
>This builds and passes on x86-64-linux.
>
>OK for 8?

OK, thanks.