According to the gFortran docs in order to enable OpenACC support it is necessary to use the -fopenacc switch. However, this does not seem to work.
gfortran: error: unrecognized command line option ‘-fopenacc’
gFortran version is GNU Fortran (GCC) 4.8.5 20150623 (Red Hat 4.8.5-28).
What is the correct way to compile Fortran code with OpenACC support?