OpenMP* Support Overview

The Intel® compiler supports the OpenMP* Version 2.5 API specification. For complete Fortran language support for OpenMP, see the OpenMP Application Program Interface Version 2.5 specification, which is available from the OpenMP web site (http://www.openmp.org/).

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

The compiler performs transformations to generate multithreaded code based on a developer's placement of OpenMP directives in the source program making it easy to add threading to existing software. The Intel compiler supports all of the current industry-standard OpenMP directives and compiles parallel programs annotated with OpenMP directives.

The compiler provides Intel-specific extensions to the OpenMP Version 2.5 specification including run-time library routines and environment variables.

Parallel Processing with OpenMP

To compile with OpenMP, you need to prepare your program by annotating the code with OpenMP directives in the form of the Fortran program comments. The Intel compiler processes the application and internally produces a multithreaded version of the code which is then compiled. The output is an executable with the parallelism implemented by threads that execute parallel regions or constructs. See Programming with OpenMP.

Interoperability

The OpenMP specification does not define interoperability of multiple implementations; therefore, the OpenMP implementation supported by other compilers and OpenMP support in Intel compilers might not be interoperable. To avoid possible linking or run-time problems, keep the following guidelines in mind: