[kaffe] -Xnative-big-math should not be needed

Toad toad at amphibian.dyndns.org
Tue Jul 27 04:48:40 PDT 2004


As per our conversation on IRC:
Dalibor claimed that Kaffe would compile in both native GMP-based math
and some slow java-based math, and then only use the native if
-Xnative-big-math is enabled. This means it's even slower than Sun's
impl, by default. Please make it use native big math if it possibly can.
Personally I don't see any reason why not to just link it in if it's
available at configure time. And then fail with a dynamic linker error
if it's not available. Or link it in statically if the user asked for
that. But if you want to load it on the fly, that's fine and won't be
much performance hit.

My interest in all this: Freenet has just received a significant
reduction in its CPU usage by enclosing native GMP libs for various
x86 platforms. Sun's math is _really_ slow, simply because they don't
open source it and therefore can't use libgmp. We've had a factor of 8
or 10 gain in BigInteger modPow, and a factor of 3 in
BigInteger.doubleValue(), from using libgmp. But it means we have to
deal with platform specific native code in the extra jar, which is a
pain in the ass.

Hopefully we can get Freenet working on Kaffe soon.
-- 
Matthew J Toseland - toad at amphibian.dyndns.org
Freenet Project Official Codemonkey - http://freenetproject.org/
ICTHUS - Nothing is impossible. Our Boss says so.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://kaffe.org/pipermail/kaffe/attachments/20040727/b97e8adf/attachment-0002.pgp 


More information about the kaffe mailing list