progress on powl.
Steve Kargl
sgk at troutmask.apl.washington.edu
Sat Dec 16 01:33:31 UTC 2017
All,
As expect no one elase is working on powl, I have
dusted off my work-in-progress that is now some
1+ year in the works. I've now got a sort of
working version in very limited testing.
% ./testl -a 1.2345 3.124
libmu = LD80C(0xf7303d48d62e9df4, 0, 1.93115964943387024991e+00L),
mpfru = LD80C(0xf7303d48d62e9df5, 0, 1.93115964943387025002e+00L),
ulp = 0.73609
I'm still slowing working out some thresholds and
few other kinks. The biggest problem is that
src/e_pow.c may be the worse commented code that
I've had the pleasure to read. There are 3 polynomial
approximations. One is easy to work. The other two
are gaint mysteries at moment.
I'll note that src/e_powf.c uses the same polynomials
and it appears that these use naively rounded coefficients.
I suspect that these polynomials can be reduced to
lower order, but have pursued that yet.
--
Steve
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