Intel® Fortran Compiler 16.0 User and Reference Guide

OpenMP* Support Overview

The Intel® compiler supports most of OpenMP* Version 4.0. For the complete OpenMP specification, see the OpenMP* Application Program Interface Version 4.0 specification, which is available from the OpenMP* web site (http://www.openmp.org, see OpenMP Specifications). The descriptions of OpenMP* language characteristics in this documentation often use terms defined in the specification.

The OpenMP* API provides symmetric multiprocessing (SMP) with the following major features:

The compiler performs transformations to generate multithreaded code based on your placement of OpenMP* directives in the source program, making it simple to add threading to existing software. The Intel compiler compiles parallel programs and supports the industry-standard OpenMP* directives.

The compiler provides Intel-specific extensions to the OpenMP* specification including run-time library routines and environment variables. A summary of the compiler options appear in the OpenMP* Options Quick Reference.

Parallel Processing with OpenMP*

To compile with the OpenMP* API, add the directives in the form of the Fortran program comments to your code. The compiler processes the code and internally produces a multithreaded version which is then compiled into an executable with the parallelism implemented by threads that execute parallel regions or constructs.

Using Other Compilers

The OpenMP* specification does not define interoperability of multiple implementations, so the OpenMP* implementation supported by other compilers and OpenMP* support in the Intel compiler might not be interoperable. Even if you compile and build the entire application with one compiler, be aware that different compilers might not provide OpenMP* source compatibility that enable you to compile and link the same set of application sources with a different compiler and get the expected parallel execution results.

The Intel compiler includes two sets of OpenMP* libraries, as described in OpenMP* Source Compatibility and Interoperability with Other Compilers.