Compiling Hybrid Programs

A hybrid program combines both MPI and shared-memory to take advantage of compute clusters with multi-core compute nodes. Libraries for OpenMPI, Intel MPI (IMPI) and MVAPICH2 and compilers which include OpenMP for C, C++, and Fortran are available.

Hybrid programs require including header files:
Language	Header Files
Fortran 77	`INCLUDE 'omp_lib.h' INCLUDE 'mpif.h'`
Fortran 90	`use omp_lib INCLUDE 'mpif.h'`
Fortran 95	`use omp_lib INCLUDE 'mpif.h'`
C	`#include <mpi.h> #include <omp.h>`
C++	`#include <mpi.h> #include <omp.h>`

A few examples illustrate hybrid programs with task parallelism of OpenMP:

This example illustrates a hybrid program with loop-level (data) parallelism of OpenMP:

hybrid_loop.c

To see the available MPI libraries:

$ module avail impi
$ module avail openmpi
$ module avail mvapich2

The following tables illustrate how to compile your hybrid (MPI/OpenMP) program. Any compiler flags accepted by Intel ifort/icc compilers are compatible with their respective MPI compiler.
Language	Intel Compiler with Intel MPI (IMPI)	Intel/GNU/AOCC Compiler with OpenMPI/MVAPICH2
Fortran 77	`$ mpiifort -qopenmp myprogram.f -o myprogram`	`$ mpif77 -fopenmp myprogram.f -o myprogram`
Fortran 90	`$ mpiifort -qopenmp myprogram.f90 -o myprogram`	`$ mpif90 -fopenmp myprogram.f90 -o myprogram`
Fortran 95	`$ mpiifort -qopenmp myprogram.f90 -o myprogram`	`$ mpif90 -fopenmp myprogram.f90 -o myprogram`
C	`$ mpiicc -qopenmp myprogram.c -o myprogram`	`$ mpicc -fopenmp myprogram.c -o myprogram`
C++	`$ mpiicpc -qopenmp myprogram.C -o myprogram`	`$ mpicxx -fopenmp myprogram.C -o myprogram`

The Intel, GNU and AOCC compilers will not output anything for a successful compilation. Also, the Intel compiler does not recognize the suffix ".f95". You may use ".f90" to stand for any Fortran code regardless of version as it is a free-formatted form.

Compiling Hybrid Programs

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