[issue2183] optimize list comprehensions

Antoine Pitrou added the comment: Committed to py3k in r67839. -- resolution: accepted -> fixed status: open -> closed ___ Python tracker ___

[issue2183] optimize list comprehensions

Raymond Hettinger added the comment: Recommend having both MAP_ADD and STORE_MAP. The latter is repeated often in a typical dict literal so it needs to be compact and fast. The former needs the flexibility of the offset argument to be workable in a dict comprehension. I also like that MAP_ADD

[issue2183] optimize list comprehensions

Raymond Hettinger added the comment: Will take a look in the morning and get back to you on the MAP_ADD question. -- assignee: pitrou -> rhettinger ___ Python tracker ___ ___

[issue2183] optimize list comprehensions

Antoine Pitrou added the comment: FWIW, here's the py3k patch. -- versions: -Python 2.7 Added file: http://bugs.python.org/file12372/py3k-comps.patch ___ Python tracker ___

[issue2183] optimize list comprehensions

Antoine Pitrou added the comment: I have started porting to py3k and I've applied the same optimizations to set and dict comprehensions. I just have a question: I have created an opcode MAP_ADD which is very similar to STORE_MAP, except that it takes as argument the stack offset to the dict obje

[issue2183] optimize list comprehensions

Antoine Pitrou added the comment: I've fixed the Python compiler package and committed it all in r67818. Will port to py3k. ___ Python tracker ___

[issue2183] optimize list comprehensions

Changes by Jeffrey Yasskin : -- nosy: +jyasskin ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.pyth

[issue2183] optimize list comprehensions

Raymond Hettinger added the comment: This is a nice cleanup. Marking as accepted. Go ahead and apply. -- assignee: nnorwitz -> pitrou resolution: -> accepted ___ Python tracker

[issue2183] optimize list comprehensions

Antoine Pitrou added the comment: > I presume it has been tested with nested and conditional variants? The whole test suite runs fine. test_iter and test_grammar seem to cover all possible cases. As for performance, the new benches in #4677 show a moderate improvement (~ 10%). __

[issue2183] optimize list comprehensions

Raymond Hettinger added the comment: This looks like a major improvement, not just for speed, but for getting rid of the _[1] arguments setup, retrieval, and deletion. I presume it has been tested with nested and conditional variants? def f(): return [x for t in s for x in t if x] -

[issue2183] optimize list comprehensions

Antoine Pitrou added the comment: Here is a new patch against trunk and fixing the documentation for LIST_APPEND. -- nosy: +pitrou stage: -> patch review versions: +Python 2.7, Python 3.1 -Python 2.6 Added file: http://bugs.python.org/file12369/list-comp-opt3.patch ___

[issue2183] optimize list comprehensions

Neal Norwitz <[EMAIL PROTECTED]> added the comment: Ya, I'll get around to it...hopefully soon. But if someone wants to do it for me, I won't complain. :-) __ Tracker <[EMAIL PROTECTED]> __ __

[issue2183] optimize list comprehensions

Sean Reifschneider <[EMAIL PROTECTED]> added the comment: Neal: Can you make that doc change? -- assignee: -> nnorwitz nosy: +jafo priority: -> normal __ Tracker <[EMAIL PROTECTED]> __ _

[issue2183] optimize list comprehensions

Alexander Belopolsky added the comment: The patch looks reasonable to me. Bytecode docs need to be changed. At minimum like this: === --- Doc/library/dis.rst (revision 61097) +++ Doc/library/dis.rst (working copy) @@ -463,9 +463,9

[issue2183] optimize list comprehensions

New submission from Neal Norwitz: Optimize list comprehensions by using the list on the stack, rather than storing in a (local/global) variable. This reduces the size of the stack by one pointer, reduces the bytecode size by 8, and reduces the iterations in the eval loop by 2 + # of iterations t