New submission from Tim Peters <t...@python.org>:
The code could typically be faster if it did what its comments imply it does: skip the expense of PyObject_RichCompareBool() entirely for the first pair of tuple elements. It actually always calls PyObject_RichCompareBool() on the first pair, and only if that says "not equal" does it use the faster ms->tuple_elem_compare to resolve "ok, so it's less than?". Instead it could do the first pair before, and entirely apart from, the loop, along the lines of: - Use ms->tuple_elem_compare to see whether u[0] < v[0]. If so, or if an error, we're done. - Use ms->tuple_elem_compare to see whether v[0] < u[0]. If so, or if an error, we're done. Else we can assume u[0] == v[0], and go on to compare u[1:] to v[1:] via a trivial variation of the current code. In cases where the first pair does resolve it (common!), replacing a PyObject_RichCompareBool() with a ms->tuple_elem_compare can be significantly faster overall. ---------- components: Interpreter Core messages: 404360 nosy: tim.peters priority: normal severity: normal stage: needs patch status: open title: Improve listobject.c's unsafe_tuple_compare() type: performance versions: Python 3.11 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45530> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
