IntelĀ® MPI Library Reference Manual for Linux* OS
Use the following options to enable the ILP64 interface
Use the Fortran compiler driver option -i8 for separate compilation and the -ilp64 option for separate linkage. For example,
$ mpiifort -i8 -c test.f
$ mpiifort -ilp64 -o test test.o
For simple programs, use the Fortran compiler driver option -i8 for compilation and linkage. Specifying -i8 will automatically assume the ILP64 library. For example,
$ mpiifort -i8 test.f
Use the mpirun -ilp64 option to preload the ILP64 interface. For example,
$ mpirun -ilp64 -n 2 ./myprog