[Python-Dev] Re: [Python-checkins] python/nondist/peps pep-0329.txt, 1.2, 1.3 (original) (raw)

Phillip J. Eby pje at telecommunity.com
Wed Apr 21 10:50:15 EDT 2004

At 09:31 PM 4/20/04 -0400, Jeremy Hylton wrote:

On Tue, 2004-04-20 at 17:21, Phillip J. Eby wrote: > I think it would be helpful for the language spec to include the rules for > potential optimizing of built-ins, and cover what happens if you attempt to > replace a builtin whose dynamic nature has been optimized away.

I'm not opposed to that, but it isn't required to get good performance for globals.

I could be wrong, but it seems to me that globals shouldn't be nearly as bad for performance as builtins. A global only does one dict lookup, while builtins do two. Also, builtins can potentially be optimized away altogether (e.g. 'while True:') or converted to fast LOAD_CONST, or perhaps even a new CALL_BUILTIN opcode, assuming that adding the opcode doesn't blow the cacheability of the eval loop.

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