f2py and openmp on mac os x with gfortran
Hello, I'm struggling to create openmp subroutines. I've simplified the problem down to the subroutine below. -- play.f90 -- subroutine step(soln,n) implicit none integer n,i real*8 soln(n) !f2py intent(in) n !f2py intent(out) soln !f2py depend(n) soln !$OMP PARALLEL DO do i=1,n soln(i) = .1 end do !$OMP END PARALLEL DO end subroutine step I compile this with the command: f2py -c -m play play.f90 --fcompiler=gfortran --f90flags="-fopenmp" This completes successfully. When I import the module, I get the following error message. $ python -c 'import play' Traceback (most recent call last): File "<string>", line 1, in <module> ImportError: dlopen(./play.so, 2): Symbol not found: _GOMP_parallel_end Referenced from: /home/bbelson/Desktop/SOR/play.so Expected in: flat namespace in /home/bbelson/Desktop/SOR/play.so It seems to me that the linking step is broken, however I did not see any other options in the f2py documentation to change the linking step. Did I miss something? Thanks, Brandt
I'm not at my Mac to check the exact paths but see if pointing one of the environment variables LD_LIBRARY_PATH or DYLD_LIBRARY_PATH to a directory where the gfortran openmp libraries can be found - this will depend on where you got gfortran from and the version, but you should be able to find it by following the symlink that is the gfortran command and looking for an appropriate lib/ directory near the target of that. Cheers Robin On Wed, Jul 20, 2011 at 9:02 PM, Brandt Belson <bbelson@princeton.edu> wrote:
Hello, I'm struggling to create openmp subroutines. I've simplified the problem down to the subroutine below. -- play.f90 -- subroutine step(soln,n) implicit none integer n,i real*8 soln(n)
!f2py intent(in) n !f2py intent(out) soln !f2py depend(n) soln !$OMP PARALLEL DO do i=1,n soln(i) = .1 end do !$OMP END PARALLEL DO end subroutine step
I compile this with the command: f2py -c -m play play.f90 --fcompiler=gfortran --f90flags="-fopenmp" This completes successfully. When I import the module, I get the following error message. $ python -c 'import play' Traceback (most recent call last): File "<string>", line 1, in <module> ImportError: dlopen(./play.so, 2): Symbol not found: _GOMP_parallel_end Referenced from: /home/bbelson/Desktop/SOR/play.so Expected in: flat namespace in /home/bbelson/Desktop/SOR/play.so It seems to me that the linking step is broken, however I did not see any other options in the f2py documentation to change the linking step. Did I miss something? Thanks, Brandt _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Hi, I had the same problem. I think this might work: FFLAGS='-fopenmp' f2py -c (etc) The thing is that f2py doesn't let you pass the -fopenmp flag at the right time to the compiler, so you have to use some sort of environment variable trick. By the way, as far as I know, this is the case also on non-mac platforms. Did that do the trick? Cheers, Paul. On 20. juli 2011, at 21.02, Brandt Belson wrote:
Hello, I'm struggling to create openmp subroutines. I've simplified the problem down to the subroutine below.
-- play.f90 -- subroutine step(soln,n) implicit none integer n,i real*8 soln(n)
!f2py intent(in) n !f2py intent(out) soln !f2py depend(n) soln
!$OMP PARALLEL DO do i=1,n soln(i) = .1 end do !$OMP END PARALLEL DO end subroutine step
I compile this with the command:
f2py -c -m play play.f90 --fcompiler=gfortran --f90flags="-fopenmp"
This completes successfully. When I import the module, I get the following error message.
$ python -c 'import play' Traceback (most recent call last): File "<string>", line 1, in <module> ImportError: dlopen(./play.so, 2): Symbol not found: _GOMP_parallel_end Referenced from: /home/bbelson/Desktop/SOR/play.so Expected in: flat namespace in /home/bbelson/Desktop/SOR/play.so
It seems to me that the linking step is broken, however I did not see any other options in the f2py documentation to change the linking step. Did I miss something?
Thanks, Brandt _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
participants (3)
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Brandt Belson -
Paul Anton Letnes -
Robin