[issue13622] Bytes performance regression in python3.3 vs python3.2

[Boris FELD]

New submission from Boris FELD <lothiraldan at gmail.com>:

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).find(b"B") (*1000): -30.379747%
- b"Hello\t   \t".rstrip() (*1000): -33.333333%
- b"this\nis\na\ntest\n".rsplit(b"\n") (*1000): -23.437500%
- b"\nHello!\n".strip() (*1000): -33.333333%
- dna.split(b"ACTAT") (*10): -21.066667%
- b"Andrew".endswith(b"w") (*1000): -23.529412%
- b"...text.with.2000.lines...replace(b"\n", b" ") (*10): -37.668161%
- b"\t   \tHello".rstrip() (*1000): -33.333333%
- (b"A"*1000).rpartition(b"A") (*1000): -21.212121%
- (b"Here are some words. "*2).split() (*1000): -22.105263%
- b"this\nis\na\ntest\n".split(b"\n") (*1000): -23.437500%
- b"Hello!\n".rstrip() (*1000): -35.714286%
- b"B" in b"A"*1000 (*1000): -32.089552%
- b"Hello!\n".strip() (*1000): -35.714286%
- b"\nHello!".strip() (*1000): -28.571429%
- b"Andrew".startswith(b"A") (*1000): -20.588235%
- b"\nHello!".rstrip() (*1000): -35.714286%
- b"Andrew".endswith(b"Andrew") (*1000): -22.857143%
- b"Andrew".endswith(b"Anders") (*1000): -23.529412%
- b"Andrew".startswith(b"Anders") (*1000): -23.529412%
- b"this--is--a--test--of--the--emergency--broadcast--system".split(b"--") (*1000): -22.429907%
- b"Andrew"+b"Dalke" (*1000): -23.076923%

Hope it help

----------
assignee: collinwinter
components: Benchmarks
files: stringbench_log_cpython3.2
messages: 149683
nosy: Boris.FELD, collinwinter
priority: normal
severity: normal
status: open
title: Bytes performance regression in python3.3 vs python3.2
type: performance
versions: Python 3.2, Python 3.3
Added file: http://bugs.python.org/file23995/stringbench_log_cpython3.2

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<http://bugs.python.org/issue13622>
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