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GeezerVison is showing github.com — gh-111139: Optimize math.gcd(int, int) by vstinner · Pull Request #113887 · python/cpython

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@vstinner

@vstinner vstinner commented Jan 10, 2024 •
edited by bedevere-app Bot
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Add a fast-path for the common case.

Benchmark:

python -m pyperf timeit \
    -s 'import math; gcd=math.gcd; x=2*3; y=3*5' \
    'gcd(x,y)'

Result: 1.07x faster (-3.4 ns)

Mean +- std dev: 52.6 ns +- 4.0 ns -> 49.2 ns +- 0.4 ns: 1.07x faster
  • Issue: C API: Consider adding a public PyLong_GCD() function #111139

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@vstinner
pythongh-111139: Optimize math.gcd(int, int)
a7049b2 
Add a fast-path for the common case.

Benchmark:

    python -m pyperf timeit \
        -s 'import math; gcd=math.gcd; x=2*3; y=3*5' \
        'gcd(x,y)'

Result: 1.07x faster (-3.4 ns)

    Mean +- std dev: 52.6 ns +- 4.0 ns -> 49.2 ns +- 0.4 ns: 1.07x faster
@bedevere-app bedevere-app Bot added the awaiting core review label Jan 10, 2024
@bedevere-app bedevere-app Bot mentioned this pull request Jan 10, 2024
C API: Consider adding a public PyLong_GCD() function #111139
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@vstinner vstinner added the skip news label Jan 10, 2024
@vstinner

vstinner commented Jan 10, 2024

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@serhiy-storchaka: Would you mind to review this change?

vstinner added the skip news label

I don't think that it's worth it to document such minor micro-optimization.
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scoder
scoder approved these changes Jan 10, 2024
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Approved. This is the one use case for math.gcd(). Everything else is just random noise.

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@bedevere-app bedevere-app Bot added awaiting merge and removed awaiting core review labels Jan 10, 2024
serhiy-storchaka
serhiy-storchaka approved these changes Jan 10, 2024
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LGTM.

For larger number the difference should be much lesser than 7%.

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Comment thread Modules/mathmodule.c Resolved

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@vstinner
coding style
753d766
@vstinner
vstinner merged commit 93930ea into python:main Jan 10, 2024
@vstinner
vstinner deleted the gcd branch January 10, 2024 15:38
@bedevere-app bedevere-app Bot removed the awaiting merge label Jan 10, 2024
kulikjak pushed a commit to kulikjak/cpython that referenced this pull request Jan 22, 2024
@vstinner @kulikjak
pythongh-111139: Optimize math.gcd(int, int) (python#113887)
5cf3752 
Add a fast-path for the common case.

Benchmark:

    python -m pyperf timeit \
        -s 'import math; gcd=math.gcd; x=2*3; y=3*5' \
        'gcd(x,y)'

Result: 1.07x faster (-3.4 ns)

    Mean +- std dev: 52.6 ns +- 4.0 ns -> 49.2 ns +- 0.4 ns: 1.07x faster
aisk pushed a commit to aisk/cpython that referenced this pull request Feb 11, 2024
@vstinner @aisk
pythongh-111139: Optimize math.gcd(int, int) (python#113887)
6ea43a2 
Add a fast-path for the common case.

Benchmark:

    python -m pyperf timeit \
        -s 'import math; gcd=math.gcd; x=2*3; y=3*5' \
        'gcd(x,y)'

Result: 1.07x faster (-3.4 ns)

    Mean +- std dev: 52.6 ns +- 4.0 ns -> 49.2 ns +- 0.4 ns: 1.07x faster
Glyphack pushed a commit to Glyphack/cpython that referenced this pull request Sep 2, 2024
@vstinner @Glyphack
pythongh-111139: Optimize math.gcd(int, int) (python#113887)
f2caebc 
Add a fast-path for the common case.

Benchmark:

    python -m pyperf timeit \
        -s 'import math; gcd=math.gcd; x=2*3; y=3*5' \
        'gcd(x,y)'

Result: 1.07x faster (-3.4 ns)

    Mean +- std dev: 52.6 ns +- 4.0 ns -> 49.2 ns +- 0.4 ns: 1.07x faster
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@scoder scoder scoder approved these changes
@serhiy-storchaka serhiy-storchaka serhiy-storchaka approved these changes

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3 participants

@vstinner @scoder @serhiy-storchaka
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