114 lines
3.9 KiB
Python
114 lines
3.9 KiB
Python
"""Helpers for OpenMP support during the build."""
|
|
|
|
# This code is adapted for a large part from the astropy openmp helpers, which
|
|
# can be found at: https://github.com/astropy/astropy-helpers/blob/master/astropy_helpers/openmp_helpers.py # noqa
|
|
|
|
|
|
import os
|
|
import sys
|
|
import textwrap
|
|
import warnings
|
|
import subprocess
|
|
|
|
from distutils.errors import CompileError, LinkError
|
|
|
|
from .pre_build_helpers import compile_test_program
|
|
|
|
|
|
def get_openmp_flag(compiler):
|
|
if hasattr(compiler, 'compiler'):
|
|
compiler = compiler.compiler[0]
|
|
else:
|
|
compiler = compiler.__class__.__name__
|
|
|
|
if sys.platform == "win32" and ('icc' in compiler or 'icl' in compiler):
|
|
return ['/Qopenmp']
|
|
elif sys.platform == "win32":
|
|
return ['/openmp']
|
|
elif sys.platform == "darwin" and ('icc' in compiler or 'icl' in compiler):
|
|
return ['-openmp']
|
|
elif sys.platform == "darwin" and 'openmp' in os.getenv('CPPFLAGS', ''):
|
|
# -fopenmp can't be passed as compile flag when using Apple-clang.
|
|
# OpenMP support has to be enabled during preprocessing.
|
|
#
|
|
# For example, our macOS wheel build jobs use the following environment
|
|
# variables to build with Apple-clang and the brew installed "libomp":
|
|
#
|
|
# export CPPFLAGS="$CPPFLAGS -Xpreprocessor -fopenmp"
|
|
# export CFLAGS="$CFLAGS -I/usr/local/opt/libomp/include"
|
|
# export CXXFLAGS="$CXXFLAGS -I/usr/local/opt/libomp/include"
|
|
# export LDFLAGS="$LDFLAGS -Wl,-rpath,/usr/local/opt/libomp/lib
|
|
# -L/usr/local/opt/libomp/lib -lomp"
|
|
return []
|
|
# Default flag for GCC and clang:
|
|
return ['-fopenmp']
|
|
|
|
|
|
def check_openmp_support():
|
|
"""Check whether OpenMP test code can be compiled and run"""
|
|
code = textwrap.dedent(
|
|
"""\
|
|
#include <omp.h>
|
|
#include <stdio.h>
|
|
int main(void) {
|
|
#pragma omp parallel
|
|
printf("nthreads=%d\\n", omp_get_num_threads());
|
|
return 0;
|
|
}
|
|
""")
|
|
|
|
extra_preargs = os.getenv('LDFLAGS', None)
|
|
if extra_preargs is not None:
|
|
extra_preargs = extra_preargs.strip().split(" ")
|
|
extra_preargs = [
|
|
flag for flag in extra_preargs
|
|
if flag.startswith(('-L', '-Wl,-rpath', '-l'))]
|
|
|
|
extra_postargs = get_openmp_flag
|
|
|
|
try:
|
|
output = compile_test_program(code,
|
|
extra_preargs=extra_preargs,
|
|
extra_postargs=extra_postargs)
|
|
|
|
if 'nthreads=' in output[0]:
|
|
nthreads = int(output[0].strip().split('=')[1])
|
|
openmp_supported = len(output) == nthreads
|
|
else:
|
|
openmp_supported = False
|
|
|
|
except (CompileError, LinkError, subprocess.CalledProcessError):
|
|
openmp_supported = False
|
|
|
|
if not openmp_supported:
|
|
if os.getenv("SKLEARN_FAIL_NO_OPENMP"):
|
|
raise CompileError("Failed to build with OpenMP")
|
|
else:
|
|
message = textwrap.dedent(
|
|
"""
|
|
|
|
***********
|
|
* WARNING *
|
|
***********
|
|
|
|
It seems that scikit-learn cannot be built with OpenMP.
|
|
|
|
- Make sure you have followed the installation instructions:
|
|
|
|
https://scikit-learn.org/dev/developers/advanced_installation.html
|
|
|
|
- If your compiler supports OpenMP but you still see this
|
|
message, please submit a bug report at:
|
|
|
|
https://github.com/scikit-learn/scikit-learn/issues
|
|
|
|
- The build will continue with OpenMP-based parallelism
|
|
disabled. Note however that some estimators will run in
|
|
sequential mode instead of leveraging thread-based
|
|
parallelism.
|
|
|
|
***
|
|
""")
|
|
warnings.warn(message)
|
|
|
|
return openmp_supported
|