glibc math improvements

[Pedro Giffuni]

> Il giorno 03/gen/2015, alle ore 23:37, Steve Kargl <sgk at troutmask.apl.washington.edu> ha scritto:
> 
> On Sat, Jan 03, 2015 at 10:00:58PM -0500, Pedro Giffuni wrote:
>> 
>> This blog post was covered by Phoronix:
>> http://developerblog.redhat.com/2015/01/02/improving-math-performance-in-glibc/ <http://developerblog.redhat.com/2015/01/02/improving-math-performance-in-glibc/>
>> 
>> Not sure any of that stuff is applicable to our implementation but it looks like an interesting link to share nevertheless.
>> 
> 
> AFAICT, it is not applicable.   The improvements are in
> a 768-bit multi-precision computation of pow() to get an
> accurate answer.  The article mentions that the technique
> may be applied to exp() and log(), but the table-driven
> methods that Bruce, David, and I used for logl, expl, and
> exp2l are quite accurate (somewhere around ulp < 0.55 or so).
> 

OK, I see, apparently the improvements only apply for worst-case
scenarios but we never hit them.

A test suite would have been interesting but there is no trace of
them in the blog.

thanks,

Pedro.