SWIG and Ctypes

SWIG and Ctypes#

Interfacing Fortran code through C interface

I found this reference with good examples.

Problem: Collatz conjecture#

Choose \(u_0\)
If \(u_k\) even, \(u_{k+1} \rightarrow \frac{u_k}{2}\) ;
If \(u_k\) odd, \(u_{k+1} \rightarrow 3 u_k+1\)
The Collatz conjecture is: For all \(u_0>0\) , the process will eventually reach \(u_k=1\).
The programs below compute number of steps (named flight) to reach \(f(u_0)\) for \(1\leq u_0 \leq N\), \(N\) given.

C program#

%%file syracuse.c
#include <stdlib.h> 
#include <stdio.h>
long syracuse(long n) { 
   long count = 0L ; 
   while (n > 1) {
      if ((n&1)==0) 
          n /= 2; 
      else 
          n = 3*n+1; 
      count++;   
   }
   return count ; 
}

int main() {
   const long N = 1000000; 
   double t1, t2;
   long i , *flights ;
   flights = (long*)malloc(N*sizeof(long));
   for (i = 0; i <N; i++) flights[i] = syracuse(i+1); 
   return EXIT_SUCCESS;
}

Writing syracuse.c

%%bash
gcc -O3 syracuse.c 
time ./a.out

real	0m0.001s

user	0m0.001s

sys	0m0.000s

Python program#

%%time

from itertools import count

def syracuse(n):
    x = n
    for steps in count() :
        if x & 1 : 
            x = 3*x+1
        else:
            x = x // 2
            
        if x == 1:
            return steps

N = 1000000
flights = [syracuse(i) for i in range(1,N+1)]

CPU times: user 9.44 s, sys: 6.5 ms, total: 9.45 s
Wall time: 9.45 s

Performances#

The python syntax is simpler.
100 times slower
Solution : call the C function from python.

Ctypes#

This is the C function we will call from python

%%file syrac.c

long syracuse(long n)
{ 
   long count = 0L ; 
   while (n > 1)
   {
      if ((n&1)==0) 
         n /= 2; 
      else 
         n = 3*n+1; 
      count++;   
   }
   return count ; 
}

Writing syrac.c

Build the shared library

%%bash
gcc -fPIC -shared -O3 \
    -o syrac.so syrac.c

%%time

import time
from ctypes import *

syracDLL = CDLL("./syrac.so")
syracuse = syracDLL.syracuse

flights = [syracuse(i) for i in range(1,N+1)]

CPU times: user 364 ms, sys: 1 µs, total: 364 ms
Wall time: 364 ms

Ctypes with Fortran module#

If you change the fortran file you have to restart the kernel

%%file syrac.F90

module syrac_f90
  use iso_c_binding
  implicit none

contains

  function f_syrac(n) bind(c, name='c_syrac') result(f)
    
    integer(c_long) :: f
    integer(c_long), intent(in), value :: n
    integer(c_long) :: x
    x = n
    f = 0_8
    do while(x>1)
       if (iand(x,1_8) == 0) then
          x = x / 2
       else
          x = 3*x+1
       end if
       f = f + 1_8
    end do

  end function f_syrac

end module syrac_f90

Writing syrac.F90

%%bash
rm -f *.o *.so *.dylib
gfortran -fPIC -shared -O3 -o syrac.dylib syrac.F90

from ctypes import *

syrac_f90 = CDLL('./syrac.dylib')

syrac_f90.c_syrac.restype = c_long

syrac_f90.c_syrac(1000)

%%time
N = 1000000
flights = [syrac_f90.c_syrac(i) for i in range(1,N+1)]

CPU times: user 397 ms, sys: 0 ns, total: 397 ms
Wall time: 397 ms

Faster than pure Python
We can call function from DLL windows libraries.
Unfortunately you need to adapt the syntax to the operating system.

http://docs.python.org/library/ctypes.html}

SWIG#

Interface file syrac.i for C function in syrac.c

%%file syrac.i

%module syracuseC
%{
   extern long syracuse(long n);
%}
extern long syracuse(long n);

Writing syrac.i

%%bash
swig -python syrac.i

Build the python module#

Using command line

swig -python syrac.i

gcc `python3-config --cflags` -fPIC \
  -shared -O3 -o _syracuseC.so syrac_wrap.c syrac.c `python3-config --ldflags`

With distutils

%%file setup.py
from numpy.distutils.core import Extension, setup


module_swig = Extension('_syracuseC', sources=['syrac_wrap.c', 'syrac.c'])

setup( name='Syracuse',
       version = '0.1.0',
       author      = "Pierre Navaro",
       description = """Simple C Fortran interface example """,
       ext_modules = [module_swig],
)

Writing setup.py

import sys, os

if sys.platform == "darwin":
    os.environ["CC"] = "gcc-10"
    
!{sys.executable} setup.py build_ext --inplace --quiet

/home/runner/work/python-fortran/python-fortran/notebooks/setup.py:1: DeprecationWarning: 

  `numpy.distutils` is deprecated since NumPy 1.23.0, as a result
  of the deprecation of `distutils` itself. It will be removed for
  Python >= 3.12. For older Python versions it will remain present.
  It is recommended to use `setuptools < 60.0` for those Python versions.
  For more details, see:
    https://numpy.org/devdocs/reference/distutils_status_migration.html 


  from numpy.distutils.core import Extension, setup

running build_ext
running build_src
INFO: build_src
INFO: building extension "_syracuseC" sources
INFO: build_src: building npy-pkg config files
/usr/share/miniconda/envs/python-fortran/lib/python3.9/site-packages/setuptools/_distutils/cmd.py:66: SetuptoolsDeprecationWarning: setup.py install is deprecated.
!!

        ********************************************************************************
        Please avoid running ``setup.py`` directly.
        Instead, use pypa/build, pypa/installer or other
        standards-based tools.

        See https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html for details.
        ********************************************************************************

!!
  self.initialize_options()
INFO: customize UnixCCompiler
INFO: customize UnixCCompiler using build_ext
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-march=native)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

creating /tmp/tmp8i1jwcjd/usr/share/miniconda/envs/python-fortran/lib/python3.9/site-packages/numpy/distutils/checks
INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-march=native'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-O3)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-O3'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-Werror)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-Werror'
INFO: CCompilerOpt.__init__[1795] : check requested baseline
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-msse)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-msse2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse2'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'SSE' with flags (-msse -msse2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'SSE2' with flags (-msse -msse2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-msse3)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse3'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'SSE3' with flags (-msse -msse2 -msse3)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -Werror'

INFO: CCompilerOpt.__init__[1804] : check requested dispatch-able features
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mssse3)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mssse3'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-msse4.1)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse4.1'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'SSE41' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mpopcnt)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mpopcnt'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'POPCNT' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-msse4.2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse4.2'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'SSE42' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'SSSE3' with flags (-msse -msse2 -msse3 -mssse3)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -Werror'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mf16c)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mf16c'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'F16C' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx2'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX2' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mavx2)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mavx2 -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mfma)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mfma'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512f -mno-mmx)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512f -mno-mmx'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512cd)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512cd'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512vl -mavx512bw -mavx512dq)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512vl -mavx512bw -mavx512dq'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512vnni)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512vnni'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_CLX' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512vnni)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512vnni -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512F' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512ifma -mavx512vbmi)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512ifma -mavx512vbmi'
INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512vbmi2 -mavx512bitalg -mavx512vpopcntdq)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512vbmi2 -mavx512bitalg -mavx512vpopcntdq'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_ICL' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512vnni -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx512bitalg -mavx512vpopcntdq)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512vnni -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx512bitalg -mavx512vpopcntdq -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_CNL' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512ifma -mavx512vbmi)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512ifma -mavx512vbmi -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'FMA3' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_SKX' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -Werror'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512CD' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512fp16)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512fp16'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_SPR' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512vnni -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx512bitalg -mavx512vpopcntdq -mavx512fp16)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -mavx512vnni -mavx512ifma -mavx512vbmi -mavx512vbmi2 -mavx512bitalg -mavx512vpopcntdq -mavx512fp16 -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx512er -mavx512pf)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx512er -mavx512pf'
INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_KNL' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512er -mavx512pf)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512er -mavx512pf -Werror'

INFO: CCompilerOpt.cc_test_flags[1086] : testing flags (-mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq'

INFO: CCompilerOpt.feature_test[1560] : testing feature 'AVX512_KNM' with flags (-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512er -mavx512pf -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512er -mavx512pf -mavx5124fmaps -mavx5124vnniw -mavx512vpopcntdq -Werror'

INFO: CCompilerOpt.__init__[1816] : skip features (SSE2 SSE SSE3) since its part of baseline
INFO: CCompilerOpt.__init__[1820] : initialize targets groups
INFO: CCompilerOpt.__init__[1822] : parse target group simd_test
INFO: CCompilerOpt._parse_target_tokens[2033] : skip targets (VXE2 XOP NEON VXE VX VSX3 FMA4 VSX VSX4 VSX2 ASIMD) not part of baseline or dispatch-able features
INFO: CCompilerOpt._parse_policy_not_keepbase[2145] : skip baseline features (SSE2)
INFO: CCompilerOpt.generate_dispatch_header[2366] : generate CPU dispatch header: (build/src.linux-x86_64-3.9/numpy/distutils/include/npy_cpu_dispatch_config.h)
WARN: CCompilerOpt.generate_dispatch_header[2375] : dispatch header dir build/src.linux-x86_64-3.9/numpy/distutils/include does not exist, creating it
INFO: CCompilerOpt.feature_extra_checks[1640] : Testing extra checks for feature 'AVX512F' (AVX512F_REDUCE)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -Werror'

INFO: CCompilerOpt.feature_extra_checks[1640] : Testing extra checks for feature 'AVX512_SKX' (AVX512BW_MASK AVX512DQ_MASK)
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -Werror'

INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3 -mssse3 -msse4.1 -mpopcnt -msse4.2 -mavx -mf16c -mfma -mavx2 -mavx512f -mno-mmx -mavx512cd -mavx512vl -mavx512bw -mavx512dq -Werror'

INFO: building '_syracuseC' extension
INFO: compiling C sources
INFO: C compiler: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -Wno-unused-result -Wsign-compare -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC -O2 -isystem /usr/share/miniconda/envs/python-fortran/include -fPIC

INFO: compile options: '-I/usr/share/miniconda/envs/python-fortran/lib/python3.9/site-packages/numpy/_core/include -Ibuild/src.linux-x86_64-3.9/numpy/distutils/include -I/usr/share/miniconda/envs/python-fortran/include/python3.9 -c'
extra options: '-msse -msse2 -msse3'
INFO: gcc: syrac_wrap.c
INFO: gcc: syrac.c

INFO: gcc -pthread -B /usr/share/miniconda/envs/python-fortran/compiler_compat -shared -Wl,--allow-shlib-undefined -Wl,-rpath,/usr/share/miniconda/envs/python-fortran/lib -Wl,-rpath-link,/usr/share/miniconda/envs/python-fortran/lib -L/usr/share/miniconda/envs/python-fortran/lib -Wl,--allow-shlib-undefined -Wl,-rpath,/usr/share/miniconda/envs/python-fortran/lib -Wl,-rpath-link,/usr/share/miniconda/envs/python-fortran/lib -L/usr/share/miniconda/envs/python-fortran/lib build/temp.linux-x86_64-cpython-39/syrac_wrap.o build/temp.linux-x86_64-cpython-39/syrac.o -o _syracuseC.cpython-39-x86_64-linux-gnu.so
INFO: 
########### EXT COMPILER OPTIMIZATION ###########
INFO: Platform      : 
  Architecture: x64
  Compiler    : gcc

CPU baseline  : 
  Requested   : 'min'
  Enabled     : SSE SSE2 SSE3
  Flags       : -msse -msse2 -msse3
  Extra checks: none

CPU dispatch  : 
  Requested   : 'max -xop -fma4'
  Enabled     : SSSE3 SSE41 POPCNT SSE42 AVX F16C FMA3 AVX2 AVX512F AVX512CD AVX512_KNL AVX512_KNM AVX512_SKX AVX512_CLX AVX512_CNL AVX512_ICL AVX512_SPR
  Generated   : none
INFO: CCompilerOpt.cache_flush[864] : write cache to path -> /home/runner/work/python-fortran/python-fortran/notebooks/build/temp.linux-x86_64-cpython-39/ccompiler_opt_cache_ext.py

import _syracuseC

syracuse = _syracuseC.syracuse
syracuse(1000)

%%time
N=1000000

flights = [syracuse(i) for i in range(1,N+1)]

CPU times: user 206 ms, sys: 17 µs, total: 206 ms
Wall time: 206 ms

References#

Interfacage C-Python par Xavier Juvigny
Optimizing and interfacing with Cython par Konrad Hinsen
Python Scripting for Computational Science de Hans Petter Langtangen chez Springer