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nico-zck/parallelsort.md

Last active February 1, 2023 05:58
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Make Python could access c++ built-in parallel in-place sort via Cython.
Raw
parallelsort.md

build:

python3 setup.py build_ext -if

using:

from parallelsort import parallelsort
import numpy as np

arr = np.random.uniform(0,100,100000000)

%timeit np.sort(arr)
%timeit parallelsort(arr)
Raw
parallelsort.pyx
import cython
cimport cython
ctypedef fused real:
cython.short
cython.ushort
cython.int
cython.uint
cython.long
cython.ulong
cython.longlong
cython.ulonglong
cython.float
cython.double
cdef extern from "<parallel/algorithm>" namespace "__gnu_parallel":
cdef void sort[T](T first, T last) nogil
@cython.boundscheck(False) # turn off bounds-checking for entire function
@cython.wraparound(False) # turn off negative index wrapping for entire function
def parallelsort(real[:] a):
"""
In-place parallel sort for numpy types
"""
sort(&a[0], &a[a.shape[0]])
Raw
setup.py
from setuptools import Extension, setup
from Cython.Build import cythonize
ext_modules = [
Extension(
"parallelsort",
["parallelsort.pyx"],
language="c++",
extra_compile_args=['-fopenmp'],
extra_link_args=['-fopenmp'],
)
]
setup(
name='parallelsort',
ext_modules=cythonize(ext_modules, compiler_directives={'language_level': "3"}),
)
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