New submission from Sergey Fedoseev <fedoseev.ser...@gmail.com>:
Currently _Py_bytes_capitalize() checks case before using conversion table, performance can be improved by using conversion table unconditionally. Benchmarks: $ python -m perf timeit --compare-to ~/tmp/cpython-master-venv/bin/python -s "b = b'0'*10000000" "b.capitalize()" /home/sergey/tmp/cpython-master-venv/bin/python: ..................... 7.26 ms +- 0.03 ms /home/sergey/tmp/cpython-dev-venv/bin/python: ..................... 7.27 ms +- 0.04 ms Mean +- std dev: [/home/sergey/tmp/cpython-master-venv/bin/python] 7.26 ms +- 0.03 ms -> [/home/sergey/tmp/cpython-dev-venv/bin/python] 7.27 ms +- 0.04 ms: 1.00x slower (+0%) Not significant! $ python -m perf timeit --compare-to ~/tmp/cpython-master-venv/bin/python -s "b = b'a'*10000000" "b.capitalize()" /home/sergey/tmp/cpython-master-venv/bin/python: ..................... 7.25 ms +- 0.03 ms /home/sergey/tmp/cpython-dev-venv/bin/python: ..................... 7.26 ms +- 0.03 ms Mean +- std dev: [/home/sergey/tmp/cpython-master-venv/bin/python] 7.25 ms +- 0.03 ms -> [/home/sergey/tmp/cpython-dev-venv/bin/python] 7.26 ms +- 0.03 ms: 1.00x slower (+0%) $ python -m perf timeit --compare-to ~/tmp/cpython-master-venv/bin/python -s "b = b'A'*10000000" "b.capitalize()" /home/sergey/tmp/cpython-master-venv/bin/python: ..................... 18.1 ms +- 0.0 ms /home/sergey/tmp/cpython-dev-venv/bin/python: ..................... 7.31 ms +- 0.13 ms Mean +- std dev: [/home/sergey/tmp/cpython-master-venv/bin/python] 18.1 ms +- 0.0 ms -> [/home/sergey/tmp/cpython-dev-venv/bin/python] 7.31 ms +- 0.13 ms: 2.47x faster (-60%) ---------- components: Interpreter Core messages: 324707 nosy: sir-sigurd priority: normal severity: normal status: open title: improve performance of _Py_bytes_capitalize() type: performance versions: Python 3.8 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue34599> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
