[kaffe] Removed GMP math?

Alan Eliasen eliasen at mindspring.com
Wed Feb 27 16:40:14 PST 2008

Jim Pick wrote:
> What's New In Kaffe 1.1.9
> ----------------------------
> * Removed support for native big math.

   I have to admit, I was *very* disappointed when I saw this.  The fact
that Kaffe could use the best-of-breed GMP libraries to perform
operations with very large BigIntegers was the sole reason that I used
and advocated Kaffe.  It was the one place where programs run under
Kaffe could be enormously, incredibly faster than other JVMs, often by
factors of 1000 or even 100,000.  The algorithms that replaced it are
*vastly* slower for very large numbers.

   Why was this done?  It constitutes a severe performance regression
for many programs, and was already switchable so that it could be
compiled in and used or not used at runtime if desired, or completely
omitted from compilation if you didn't want it.

   While I am working very hard at implementing faster algorithms for
the OpenJDK project, my best algorithms are still factors of about 100
times slower than Kaffe/GMP for many large numbers, and nothing one
could do in Java could ever match their performance.

   How much trouble would it be for whoever removed these parts to
revert those changes?  I think they were removed without concern for the
people who use Kaffe for this very reason, and this reason alone.  For
me, and the people that use Kaffe/GMP for work in number theory, this is
a heartbreaking regression, and one that, quite frankly, makes Kaffe
rather unsuitable for my use, as it tends to be about 20-25 times slower
than other JVMs for most other programs.

  Alan Eliasen              |  "Furious activity is no substitute
  eliasen at mindspring.com    |    for understanding."
  http://futureboy.us/      |           --H.H. Williams

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