mex setup for openMP using Intel parallel_studio_xe?

I have successfully used openMP in FORTRAN code compiled previously as mex files under gfortran (having edited the mex.sh file appropriately). I have now updated to the latest versions of matlab and Intel parallel_studio_xe. I can compile and execute mex files. However, the openMP parallelization is not happening. Can anyone tell me the required modifications of the mex setup that will provide the correct compiler and linker options?

Answer 1

[James Tursa]

How do you currently do the compile? Have you added the appropriate OpenMP directive to the mex compiler options? E.g., see this link for the directive (looks like it is /qopenmp or /Qopenmp):

https://software.intel.com/en-us/node/692392

[Michael Brown]

I edited the mexopts.sh to include -openmp as a compiler option. It does not "take" despite efforts to restart matlab and do the mex -startup again. Where else are the compiler options being set? Here is the line from the verbose output: FFLAGS="-fexceptions -fpp -mp1 -fp-model source -assume bscc -D__LP64__ -i8 -DUSE_MEX_CMD " within the mexopts.sh file I've defined the FFLAGS to include -openmp

[James Tursa]

Does it need to be -qopenmp instead of -openmp?

Is there a COMPFLAGS line in your setup files?

[Michael Brown]

Thanks for responding. (1) I don't know whether -qopenmp or -openmp is correct. I could try both if I solved point (2) below.

(2) I am creating the mex file within matlab after running the "mex -setup FORTRAN" command. This correctly sets all the environments so that the mex command then builds a functioning mex code (without the openmp optimization. In earlier versions of matlab, I just went into the matlab app package and hand edited the mexopts.sh file to change compiler flags. I've done that now in R2017b but the changes are not showing up when I "mex" a file - ie. the FFLAGS still show the default list. Therefore, the mex setup script must be reading from a different source file in setting up the environment. As soon as I know where to go to edit a file, I can try to modify with different versions (-openmp vs -qopenmp).