[Openmcl-devel] Bignum speed
R. Matthew Emerson
rme at clozure.com
Fri Oct 17 00:17:53 PDT 2008
On Oct 17, 2008, at 1:22 AM, R. Matthew Emerson wrote:
> On my machine, I get 2.450994 seconds on the x86-64 lisp, and on the
> experimental x86-32 lisp, I get 0.344 seconds. (Just for grins, I can
> report that an old PowerBook G4 gets 0.909 seconds.) So, yes, the
> x86-64 lisp looks pretty bad.
> Anyway, that's just additional evidence to support gb's prior message
> that there's plenty of room for some straightforward tuning. If
> tuning the lisp code doesn't provide good enough results, it might not
> be too hard to adapt the x8632 assembly code for x8664. Maybe if I
> get some free time...
This bugged me enough that I went ahead and improved the x8664 bignum
multiply performance by replacing the inner loop of the multiply-
bignums routine with a lap function that I adapted from the x8632
This improves performance on that mini-benchmark to 0.33 seconds,
basically at parity with the experimental 32-bit lisp. Not
outstanding, but at least we won't be laughed at by all the other kids.
(This is in the trunk only, by the way. The changeset is http://trac.clozure.com/openmcl/changeset/11111
for anyone following along at home.)
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