On 3/17/09, Raymond Toy <toy.raymond at gmail.com> wrote:
> I can reproduce this problem with current CVS using gcl 2.6.8 on
> Solaris. It's a bit slow on g(8,40), but it gets some kind of
> unrecoverable error (fault count too high) with g(9,40) and proceeds to
> dump core.
>
> This doesn't happen with cmucl. I don't know why gcl would fail in this
> way.
Looks like exp(-1/(1 - xx)) underflows in an ungraceful way ....
g(7, 40) yields a term exp(- 9.999999999712443b6) =>
1.51737304873662b-4342945, which (I guess) causes trouble.
With Clisp it triggers the error "ASH: too large shift amount 14426900".
The error is in FPPLUS. Is that the bigfloat code is trying to
normalize terms to a common basis or something? Just a guess.
The GCL build is configured to turn off all error checking, right?
So instead of triggering a Lisp error it core dumps.
Sorry I can't be more helpful,
Robert Dodier