Issue 13623: Bytes performance regression in python3.3 vs python3.2 (original) (raw)

This issue has been migrated to GitHub: https://github.com/python/cpython/issues/57832

classification

process

Created on 2011-12-17 18:22 by Boris.FELD, last changed 2022-04-11 14:57 by admin. This issue is now closed.

Messages (7)
msg149689 - (view)	Author: Boris FELD (Boris.FELD) *	Date: 2011-12-17 18:22
Hello everyone, I juste tried to launch the stringbench on python3.2 and python3.3 dev versions and some bytes tests run slower in python3.3 than in python3.2. I cc the two raw output of both runs. I also extracted most interesting data (all the tests with more than 20% of performance regression): - (b"A"*1000).rfind(b"A") (*1000): -70.103093% - (b"A"*1000).find(b"B") (*1000): -48.372093% - (b"A"*1000).rindex(b"A") (*1000): -68.888889% - s=b"ABC"*33; (s+b"E"+(b"D"+s)*500).rfind(s+b"E") (*100): -28.982301% - (b"C"+b"AB"*300).rfind(b"CA") (*1000): -29.565217% - (b"AB"*1000).index(b"AB") (*1000): -68.539326% - b"Andrew".endswith(b"w") (*1000): -21.212121% - (b"A"*1000).index(b"A") (*1000): -71.111111% - (b"BC"+b"AB"*300).rfind(b"BC") (*1000): -42.788462% - b"Andrew".startswith(b"Andrew") (*1000): -20.588235% - (b"AB"*1000).find(b"AB") (*1000): -69.318182% - (b"AB"*1000).rfind(b"AB") (*1000): -69.791667% - (b"A"*1000).rfind(b"B") (*1000): -37.988827% - (b"AB"*300+"C").index(b"BC") (*1000): -28.750000% - b"B" in b"A"*1000 (*1000): -24.479167% - (b"AB"*300+"CA").find(b"CA") (*1000): -33.673469% - (b"AB"*1000).rindex(b"AB") (*1000): -67.777778% - (b"C"+"AB"*300).rindex(b"CA") (*1000): -29.017857% - (b"AB"*300+"C").find(b"BC") (*1000): -28.451883% - b"Andrew".startswith(b"A") (*1000): -21.212121% - b"Andrew".startswith(b"Anders") (*1000): -21.212121% - (b"A"*1000).partition(b"B") (*1000): -30.656934% - (b"AB"*1000).rfind(b"CA") (*1000): -20.603015% - (b"AB"*1000).rfind(b"BC") (*1000): -35.645472% - (b"A"*1000).find(b"A") (*1000): -70.454545% My environment is: Mac OS X 10.6.8 GCC i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5666) (dot 3) CPython3.3 revision ea421c534305 CPython3.2 revision 0b86da9d6964
msg149691 - (view)	Author: STINNER Victor (vstinner) *	Date: 2011-12-17 18:42
Grouped results. find (first): - (b"A"*1000).find(b"A") : -70% - (b"A"*1000).rfind(b"A") : -70% - (b"A"*1000).index(b"A") : -71% - (b"A"*1000).rindex(b"A") : -68% - (b"AB"*1000).index(b"AB") : -68% - (b"AB"*1000).rindex(b"AB"): -67% - (b"AB"*1000).find(b"AB") : -69% - (b"AB"*1000).rfind(b"AB") : -69% - b"Andrew".startswith(b"Andrew"): -20% - b"Andrew".startswith(b"A") : -21% - b"Andrew".startswith(b"Anders"): -21% - b"Andrew".endswith(b"w"): -21% find (last): - (b"AB"*300+"CA").find(b"CA") : -33% - (b"C"+"AB"*300).rindex(b"CA") : -29% - (b"AB"*300+"C").find(b"BC") : -28% - (b"AB"*300+"C").index(b"BC") : -28% - (b"C"+b"AB"*300).rfind(b"CA") : -29% - (b"BC"+b"AB"*300).rfind(b"BC"): -42% - s=b"ABC"*33; (s+b"E"+(b"D"+s)*500).rfind(s+b"E"): -28% find (not found): - (b"A"*1000).find(b"B") : -48% - (b"A"*1000).rfind(b"B") : -37% - (b"AB"*1000).rfind(b"CA") : -20% - (b"AB"*1000).rfind(b"BC") : -35% others: - b"B" in b"A"*1000 : -24% - (b"A"*1000).partition(b"B") : -30%
msg149693 - (view)	Author: STINNER Victor (vstinner) *	Date: 2011-12-17 18:43
See also the issue #13621 for results on Unicode.
msg149718 - (view)	Author: STINNER Victor (vstinner) *	Date: 2011-12-17 23:33
> (b"A"*1000).find(b"A") : -70% This one is a performance regression introduced by #12170. Attached patch checks object type before trying a conversion to size_t instead of catching an exception.
msg149720 - (view)	Author: STINNER Victor (vstinner) *	Date: 2011-12-18 00:00
bytes_find.patch only works for Python int, not object with the __index__ method. My new patch (bytes_find-2.patch) uses PyNumber_Check() instead of PyLong_Check() to be more generic. It fixes also a different issue: raise the same ValueError than bytes.find(-1) on overflow error.
msg149721 - (view)	Author: Roundup Robot (python-dev)	Date: 2011-12-18 00:17
New changeset 75648db1b3f3 by Victor Stinner in branch 'default': Issue #13623: Fix a performance regression introduced by issue #12170 in http://hg.python.org/cpython/rev/75648db1b3f3
msg149725 - (view)	Author: STINNER Victor (vstinner) *	Date: 2011-12-18 00:29
I checked stringbench: there is no more performance regression (difference of more than 20%).