User Guide

Contents

Enable
OpenMP* in your Build Environment

OpenMP* is supported by certain versions of the Microsoft Visual C++* compiler, the GNU* compilers, the
Intel® C++ Compiler Classic
,
Intel® Fortran Compiler Classic
, and
Intel® oneAPI
DPC++/C++
Compiler
:
  • Most recent versions of the Microsoft Visual C++* compiler include OpenMP support.
  • Certain editions of the
    Intel® C++ Compiler Classic
    and the
    Intel® Fortran Compiler Classic
    support the
    TASK
    feature introduced with OpenMP 3.0.
For information about OpenMP support for the Microsoft compilers, see your Microsoft Visual Studio help.
For information about OpenMP support for the GNU compilers, see your compiler help or the appropriate man page, such as
gcc(1)
.
To enable OpenMP on the command line, specify the appropriate compiler option (see your compiler documentation), such as the
-openmp
(for Linux* OS) or
/Qopenmp (for Windows* OS)
option when using the Intel compilers.
To enable OpenMP on a
Windows OS system
using Microsoft Visual Studio*:
  1. In Solution Explorer, select (click) the name of one or more projects. To select multiple projects, hold down the
    Ctrl
    key.
  2. Select
    Project
    >
    Properties
    or right-click the project name and select
    Properties
    from the pop-up menu.
  3. Specify the Configuration Properties for your C/C++ or Fortran project(s):
    C/C++
    >
    Language
    Specify
    OpenMP Support
    as
    Yes
    Fortran
    >
    Language
    Specify
    OpenMP Support
    as
    Yes
  4. Click
    OK
    to save the specified properties.
  5. Repeat the steps above for other configurations.
  6. You should check your startup project properties before starting a build.
You have set up your environment for OpenMP support on a Windows OS system.
After you rewrite your code to use OpenMP* parallel framework, you can analyze its performance with
Intel® Advisor
perspectives. Use the
Vectorization and Code Insights
perspective to analyze how well you OpenMP code is vectorized or use the
Offload Modeling
perspective to model its performance on a GPU.
Even if you are only using the
#pragma omp
pragmas within your source, Visual C++ sources compiled with the Microsoft compilers need to
#include <omp.h>.
Otherwise, running the application will be missing a
.dll
at load time.
To include the appropriate OpenMP environment when using the
Intel® Fortran Compiler Classic
, specify the
use omp_lib
statement.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.