Initializing cell variables currently involves 2 nested loops every function call. This patch makes that process much more efficient by saving information which doesn't change every function call to the code object.

Could you possibly post a before/after timing comparison?. Some realistic code... Post the test code too.

And yes, I know that the difference will depend of code, and hardware architecture. But some references are better that not reference at all.

2011/6/24 Jesús Cea Avión <report@bugs.python.org>:
>
> Jesús Cea Avión <jcea@jcea.es> added the comment:
>
> Could you possibly post a before/after timing comparison?. Some realistic code... Post the test code too.
>
> And yes, I know that the difference will depend of code, and hardware architecture. But some references are better that not reference at all.

Well, I don't really care whether it's faster or not. It's much nicer
looking now, though.

Then change the issue title :-p.

The attached highly braindead benchmark reports about a 2% improvement.

Reviewed. General concept looks sound, just suggested a few tweaks around the edges.

And issue title updated appropriately :)

Thanks for the review.

Feel free to create a new issue about the incorrect size calculation on code objects, since it is apparently already broken.

New changeset c5b0585624ef by Benjamin Peterson in branch 'default':
map cells to arg slots at code creation time (closes #12399)
http://hg.python.org/cpython/rev/c5b0585624ef

See issue15456 for a follow-up issue.

New changeset 5093cfdff2a9 by Martin v. Löwis in branch 'default':
Issue #15456: Fix code __sizeof__ after #12399 change.
http://hg.python.org/cpython/rev/5093cfdff2a9