Re: Use of C99 extra long double math functions after r236148

On Jul 8, 2012, at 8:01 PM, Steve Kargl wrote:
> Not to mention, I've seen way too many examples of 'x - y'
> where cancellation of significant digits causes
> problems.  Throw in rather poor estimates of function
> results with real poor ULP and you have problems.

Are these problems significantly more or less than the usual #define I talked about before?  If the functions are so so, but much better than the double version, we have a significant win, even if things aren't perfect.

If we weren't 13 past the publication date of the c99 standard, I'd be more sympathetic to the 'we need a high quality implementation' arguments.  However, we can't let the perfect be the enemy of the good here.  We claim c99 conformance, yet don't have these functions. 

After all, many of the original functions that were in our library had sub-optimial performance which bruce optimized over many years.  Why can't we use this model here?

Warner