Thanks for putting up the hg repo, makes it much easier to follow.

Getting back to the performance regression I reported in msg124904:

I've verified that if I take the hg commit 7abd9f9bb1 , and I back out the guards changes manually, while leaving the FAST_INIT changes in, the performance is back to normal on my full regression suite (i.e. the 30-40% penalty disappears).

I've repeated my tests a few times to make sure I'm not mistaken;  since the guard changes doesn't look like it should impact performance much, but it does.

I've attached the diff that restored the speed for me (as usual, using Python 2.6.5 on Linux x86_64)

BTW, now that we have the code on google code, can we log individual issues over there?  Might make it easier for those interested to follow certain issues than trying to comb through every individual detail in this super-issue-thread...?