[Python-Dev] [ python-Patches-876206 ] scary frame speed hacks (original) (raw)

Josiah Carlson jcarlson at uci.edu
Tue Mar 2 11:56:07 EST 2004

I would be cautious about anything that slows recursive functions becasue almost any interesting data structure traversal is recursive.

Any recursion can be made iterative. Sure, it can be a pain to do, but it is always a good exercise. See this thread for a generic and involved example: http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&safe=off&th=d04dcc083dc6d219&rnum=1

hierCodeTreePanel.new_heirarchy in the PyPE source code (pype.sourceforge.net) also has an example.

Whether the patch should be made, I don't know, 20% slowdown is pretty hefty. Is this a result of the ideas for finding a fast calling convention discussed recently? If so, then it doesn't seem to be that terribly fast (10% faster for standard functions, 20% slower on recursive). Any ideas on the speed of alternating recursions (each level alternates between some small set of functions)?

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