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Author ztane
Recipients ztane
Date 2016-03-12.22:45:45
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1457822745.22.0.972836245522.issue26549@psf.upfronthosting.co.za>
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When answering a question on StackOverflow, I noticed that a function that only loads a constant tuple to a local variable still has a large `co_stacksize` as if it was built with BUILD_TUPLE.

e.g.

    >>> def foo():
    ...     a = (1,2,3,4,5,6,7,8,9,10)
    ...
    >>> foo.__code__.co_stacksize
    10
    >>> dis.dis(foo)
      2           0 LOAD_CONST              11 ((1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
                  3 STORE_FAST               0 (a)
                  6 LOAD_CONST               0 (None)
                  9 RETURN_VALUE

I suspect it is because in the `makecode` the stack usage is calculated from the unoptimized assembler output instead of the actual optimized bytecode. I do not know if there is any optimization that would increase the stack usage, but perhaps it should be calculated from the resulting output.
History
Date User Action Args
2016-03-12 22:45:45ztanesetrecipients: + ztane
2016-03-12 22:45:45ztanesetmessageid: <1457822745.22.0.972836245522.issue26549@psf.upfronthosting.co.za>
2016-03-12 22:45:45ztanelinkissue26549 messages
2016-03-12 22:45:45ztanecreate