Hi, Konstantinos. On Sep 09 2008, Konstantinos Margaritis wrote: > ???????? Tuesday 09 September 2008 01:00:42 ??/?? Rogério Brito ????????????: > > This might explain my impression in a private mail to Charles Plessy > > that my iBook G3 was quite faster under Linux than under MacOS X. > > Apparently, MacOS X is *made* *for* altivec machines. > > True, Altivec is quite extensively used in MacOS X, which is not sth I > can say for any core component of Linux, sadly. This was exactly the > reason I started libfreevec in the first place.
Right. What I meant with my previous e-mail was to say that if your libfreevec provides just better scheduling or better algorithms than what is available for G3 machines, that would be *very* welcome. > > This would be very welcome addition to glibc. Especially for the > > "weaker" chips that don't have any vectorial part. > > These won't be accelerated though, only in the case that the original > algorithm was optimised as well, I think that you meant "was not optimised"? > > This part about not using altivec is interesting, since I would like to, > > say, be able to watch DVDs with my iBook and not have them drop so many > > frames. Decoding theora videos is also quite CPU intensive... :-( > > Well, I can't really say how much faster decoding will be with faster libm > functions, but 3D definitely will be faster. Anything that makes the current situation better is very welcome. > > > > just by choosing a different approximation method (Taylor > > > > approximation is pretty dumb if you ask me anyway). > > > > What are you using, BTW? CORDIC? > > No, Pade approximations. CORDIC iirc, is also not that much faster than > Taylor. I thought that CORDIC converged faster than Taylor series and that was the reason why it is (was?) used on scientific calculators. > I have some relevant paper around but I can't seem to find it right > now, but I could look it up if you really like. I'd like to see it, if you could find it. It is a pity that the Wikipedia article on Padé approximations is way too short (it only gives the definition of a Padé approximation of order (m, n)). > Anyway, the libm rewrites will be accompanied by a math paper full with proof > and benchmarks, so I guess you will see the method used :) I have to say that I'm a little bit more interested on the paper than on the implementation per-se. :-) Thanks for your work, Rogério Brito. -- Rogério Brito : [EMAIL PROTECTED],ime.usp}.br : GPG key 1024D/7C2CAEB8 http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
