On 8/14/10 3:53 AM, Leo Butler wrote:
>
> On Fri, 13 Aug 2010, Raymond Toy wrote:
>
> < On 8/13/10 4:51 PM, Leo Butler wrote:
> < > After building 5.22.1 with cmucl 19d, I've
> < > got the following errors:
> < Perhaps these are bugs in 19d. Cmucl 2010-08 gives no errors in the
> < testsuite.
> < >
> < >
> < > Error found in
> < > /knoppix-home/work/maxima/sandbox/maxima-5.22.1/tests/rtest4.mac,
> < > problem:
> < > (86)
> < According to the logs, this test was added in Dec 2007. This might be
> < an issue with that version of cmucl. IIRC, maxima sometimes computes
> < 1^N for very large N. Cmucl would warn about raising a number to a
> < large N. At some point cmucl added a test so that 1^N doesn't produce
> < that warning, since, obviously, it's not a problem for any N.
>
> The issue here is that the CMUCL from the Ubuntu repositories has a
> ridiculously low maximum exponent:
>
> (%i1) is(errcatch(rat(x^2^128)) = []);
Yes, you can make it larger. But that just moves the problem out. If
this must be solved by maxima, then maxima should handle the case of 1^N
itself, or maxima should include the code from cmucl that fixes it there.
Or better yet, upgrade to a newer version of cmucl. :-) Getting and
installing the official binaries from common-lisp.net is not hard.
Just untar somewhere.
>
> If anything, it is greater than expected:
I guess those tests need to be more careful and use closeto or
something. Perhaps it's an issue with cmucl 19d that is using 80-bit
floats in some operations. (It's supposed to use double floats, but
there might some cases where it isn't.)
I am rather troubled by these results. You said these didn't occur in
5.22.0 but do appear in 5.22.1. But the tests have been there for much
longer than 5.22.0. And I assume you've been using 19d for all of the
tests. Something else may have changed?
Ray