Custom Query (1030 matches)

in the current trunk CCL (and likely earlier) pm x8664

? (upgraded-array-element-type '(signed-byte 60))
FIXNUM

ok. but

? (upgraded-array-element-type '(unsigned-byte 59))
(UNSIGNED-BYTE 64)

does not seem to be ok

I think that the problem is likely in the order in which CASE clauses are tested by CCL::CTYPE-SUBTYPE

See ​http://clozure.com/pipermail/openmcl-devel/2012-May/013568.html

I was unable to reproduce this after doing:

? (progn
    (egc nil)
    (set-lisp-heap-gc-threshold (ash 512 20))
    (gc))

before calling (RUN), even when TEST/RUN created threads and RUN ran for 2500 iterations instead of 25. That suggests pretty strongly that this is a GC bug (or that the code involved in BIGNUM * FIXNUM multiplication doesn't follow register conventions correctly and that the failure occurs when such code is interrupted by GC in another thread.)

When a failure occurs, several words (in the "middle" of the result bignum) have incorrect values; the bignum is of the correct size and the words near both ends seem to be correct. This is also consistent with GC-related memory corruption.

I'm too lazy to submit another bug report, but (on x8664):

? (defun foo ()
  (let* ((x most-negative-fixnum)
         (y 1))
    (- x y)))
FOO
? (foo)
1152921504606846975
? 

Hmm. I expected something more ... negative.

(This is broken on 1.2 as well. I haven't checked ppc64, but I'd be suspicious.)