> How did it get *faster* than the original (in the case with no 
> key-function)?

I was able to shave off some instructions in countrun(), binarysort(), and the setup and cleanup code in listsort() proper.  For small n, these made a difference.

> Is there any chance you can persuade Uncle Timmy to review this?  This
> is all his code and he's likely to have some good insights.

Any suggestions on how he might be persuaded? ;-)

> Also, is there anyone else who is knowledgeable about Python on less
> common platforms?  ISTM part of the optimization is dependent on the
> branch-prediction and other nuances that vary from environment to
> environment.  That being said, doing fewer memory allocations is
> always a win.

I do have a Windows machine I can test on.  It's not exactly a "less common" platform, but at least it's a completely different compiler.  I'll post the results once I have them.


The Rietveld issue is here:
http://codereview.appspot.com/3269041

I ended up loading my incremental patches in, but it's easy enough to diff the base with the last patch.  If for some reasons it doesn't work as conveniently as I expect, let me know and I will upload it to Rietveld again as one big patch.

If there's anything else I can do to make reviewing easier, please let me know.  For that matter, if there's other code you'd like me to review in exchange or straightforward bugs you'd like to pawn off, I would be happy to help out.