Compiling Parallel Codes on Triton Resource

The default compiler/mpi stack combination is the Portland compiler (pgf90, pgf77, pgcc, pgCC) and openmpi. Other compilers and mpi variants may be accessed by loading the appropriate modules. The commands mpicc, mpiCC, mpif77, mpif90 will access a particular compiler/mpi combination based on the module choices. Read about modules to learn how Triton Resource manages compiler configurations.

A simple MPI C program is given below (mpi_c.c):

#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
main(int argc,char *argv[])
{
   int myproc,numproc;
   MPI_Status status;

   MPI_Init(&argc,&argv);

   MPI_Comm_rank(MPI_COMM_WORLD,&myproc);
   MPI_Comm_size(MPI_COMM_WORLD,&numproc);

   if(myproc == 0)
        printf("NUMPROC %d\n",numproc);
   printf("Process %d\n running",myproc);
   MPI_Finalize();
}

This program can be compiled with the following command

• mpicc -o mpi_c mpic.c

The program will print the total number of MPI processes initiated and a message printed by each process (see Submitting a job)

Following is the Fortran equivalent of the above program (mpi_f.f):

program mpi
implicit double precision (a-h,o-z)
include "mpif.h"

call mpi_init(ierror)

call mpi_comm_rank(MPI_COMM_WORLD,myproc,ierror)
call mpi_comm_size(MPI_COMM_WORLD,numproc,ierror)
if(myproc.eq.0) write(6,*) 'NUMPROC ',numproc
write(6,*) 'Process ',myproc,' running'
call mpi_finalize();
end

and can be compiled as follows :

• mpif77 -o mpi_f mpi_f.f

More information about compiling can be found on the Compiler Jobs page.