How to Use OpenMP
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Basics
This will give you a general overview of how to compile and execute a program that has been parallelized with MPI. Many of the options listed below are the same for both Open MPI and Intel MPI, however, be care if they do differentiate.
How to Compile OpenMP Code
As opposed to MPI, you do not have to load any modules to use OpenMP, but set an additional compiler flags to tell the compiler to enable OpenMP. Otherwise, the OpenMP pragmas in the code will be ignored by the compiler.
Depending on which compiler you have loaded, use one of the flags below to compile your code.
| Compiler | Flag |
| GNU | -fopenmp |
| Intel | -openmp |
| Oracle | -xopenmp |
For example: if you plan to use an Intel compiler for your OpenMP code written in C, you have to type this to create an application called "omp_code.exe":
$ icc -fopenmp omp_code.c -o omp_code.exe