Hi,

I have a FORTRAN90 code, with openmp implemented for some parts. Now to compile the fortran code using f2py with openmp support I have to pass the f90 compiler flags. Now the code should compile with openmp support only if I provide the openmp relavant flag, unless it must be compiled as a normal serial code. This works as expected for gfortran but for ifort it doesn't. Lets explain this,

if I run,

(gfortran serial mode)

f2py -c adt.f90 -m adt_module

Gives output (last few lines)

Fortran f77 compiler: /usr/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -fPIC -O3 -funroll-loops

Fortran f90 compiler: /usr/bin/gfortran -Wall -g -fno-second-underscore -fPIC -O3 -funroll-loops

Fortran fix compiler: /usr/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -Wall -g -fno-second-underscore -fPIC -O3 -funroll-loops

(gfortran parallel mode)

f2py -c adt.f90 -m adt_module --f90flags='-fopenmp' -lgomp

output

Fortran f77 compiler: /usr/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -fPIC -O3 -funroll-loops

Fortran f90 compiler: /usr/bin/gfortran -fopenmp -fPIC -O3 -funroll-loops

Fortran fix compiler: /usr/bin/gfortran -Wall -g -ffixed-form -fno-second-underscore -fopenmp -fPIC -O3 -funroll-loops

As you can clearly see there is no -fopenmp flag during the compilation in serial mode, as expected as I haven't pass the required flag

Now for ifort

(ifort parallel mode)

f2py -c adt.f90 -m adt_module --fcompiler=intelem --f90flags='-qopenmp' -liomp5

Output

Fortran f77 compiler: /opt/intel/compilers_and_libraries_2017.4.196/linux/bin/intel64/ifort -FI -fPIC -fp-model strict -O1 -qopenmp

Fortran f90 compiler: /opt/intel/compilers_and_libraries_2017.4.196/linux/bin/intel64/ifort -FR -qopenmp -fPIC -fp-model strict -O1 -qopenmp

Fortran fix compiler: /opt/intel/compilers_and_libraries_2017.4.196/linux/bin/intel64/ifort -FI -qopenmp -fPIC -fp-model strict -O1 -qopenmp

(ifort serial mode)

f2py -c adt.f90 -m adt_module --fcompiler=intelem

Output

Fortran f77 compiler: /opt/intel/compilers_and_libraries_2017.4.196/linux/bin/intel64/ifort -FI -fPIC -fp-model strict -O1 -qopenmp

Fortran f90 compiler: /opt/intel/compilers_and_libraries_2017.4.196/linux/bin/intel64/ifort -FR -fPIC -fp-model strict -O1 -qopenmp

Fortran fix compiler: /opt/intel/compilers_and_libraries_2017.4.196/linux/bin/intel64/ifort -FI -fPIC -fp-model strict -O1 -qopenmp

Now, here's the problem, see here compiling is done with -qopenmp flag for serial mode but I haven't passed it in command line. Why is it happening when compiling with ifort but not with gfortran ? And how to resolve this?