[Openmcl-devel] Is this a bug?

[Ron Garret]

On Jan 24, 2012, at 10:00 PM, Gary Byers wrote:

> I can't reproduce this

Hm, it does seem to be different on the trunk.  I'm encountering the "problem" on the App Store version (1.7-store-r15140).

FWIW, tweaking the code thusly:

(let (p)
  (setf p (MAKE-POPULATION :INITIAL-CONTENTS (LIST (COPY-LIST '(foo)))))
  (setf x 1)  ; Clobber volatile registers
  (gc)
  (POPULATION-CONTENTS p))

results in the code returning NIL on the app store version as well, which confirms your explanation.

Interestingly, the disassembly of the unmodified version seems to be identical on both the app store version and the trunk.  I say "seems to be" because one of the things that apparently changed between these two versions is the disassembly output format (!) so I can't just run the output through diff, I have to eyeball it.  But it's mostly a moot point.

Thanks for taking the time to write up that detailed explanation!

BTW, I notice a lot of NOPs in the disassembly.  Are those there for a reason?  (Feel free to treat that as a rhetorical question if you don't feel like spending more time on this.)

rg