[issue9915] speeding up sorting with a key

[Daniel Stutzbach]

Daniel Stutzbach <stutzbach at google.com> added the comment:

> Just wanted to post this so there weren't any illusions about the
> patch being a big win.

> When a key function is defined, this is all you can possibly shave
> off the time for a comparison.

I don't want to argue whether the patch is a big win or not (I recognize that it is a tradeoff), but when using a key it does shave off more than the call to sortwrapper_richcompare.

Stack with sortwrapper:

long_richcompare
do_richcompare
PyObject_RichCompare
sortwrapper_richcompare
do_richcompare
PyObject_RichCompare
PyObject_RichCompareBool
count_run
list_sort

Stack without:

long_richcompare
do_richcompare
PyObject_RichCompare
PyObject_RichCompareBool
count_run
list_sort

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue9915>
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