Uh oh!
There was an error while loading.Please reload this page.
- Notifications
You must be signed in to change notification settings - Fork32.4k
Open
Assignees
Description
Bug report
Bug description:
I don't see measurable difference on pure-Python level, e.g. for
# a.pyimportpyperfdeff1(x):return1deff2(x,/):return1runner=pyperf.Runner()runner.bench_func("f1(1)",f1,1)runner.bench_func("f2(1)",f2,1)
I got on 3.13:
$ python a.py -qf1(1): Mean +- std dev: 233 ns +- 2 nsf2(1): Mean +- std dev: 232 ns +- 2 nsBut for functions, implemented in C, using the Argument Clinic - the difference is bigger:
$ python bench.py -q -o patch.jsonisfinite(1.0): Mean +- std dev: 152 ns +- 1 ns$ git checkout master && make -sChecked 114 modules (35 built-in, 78 shared, 1 n/a on linux-x86_64, 0 disabled, 0 missing, 0 failed on import)$ python bench.py -q -o ref.jsonisfinite(1.0): Mean +- std dev: 136 ns +- 1 ns| Benchmark | ref | patch |
|---|---|---|
| isfinite(1.0) | 136 ns | 152 ns: 1.12x slower |
(In the second version - the math.isfinite() accept also keyword argumentx)
a patch
(run ./python Tools/clinic/clinic.py Modules/mathmodule.c !)
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.cindex 7c2a421dd6..e33281ac8b 100644--- a/Modules/mathmodule.c+++ b/Modules/mathmodule.c@@ -3156,14 +3156,13 @@ math_radians_impl(PyObject *module, double x) math.isfinite x: double- / Return True if x is neither an infinity nor a NaN, and False otherwise. [clinic start generated code]*/ static PyObject * math_isfinite_impl(PyObject *module, double x)-/*[clinic end generated code: output=8ba1f396440c9901 input=46967d254812e54a]*/+/*[clinic end generated code: output=8ba1f396440c9901 input=a47ad6e72998b81d]*/ { return PyBool_FromLong((long)isfinite(x)); }
This performance penalty affects API decisions (e.g.#131886) and that looks as a bug.
CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux