Pragmas are directives that provide instructions to the compiler for use in specific cases. For example, you can use the novector pragma to specify that a loop should never be vectorized. The keyword #pragma is standard in the C++ language, but individual pragmas are machine-specific or operating system-specific, and vary by compiler.

Some pragmas provide the same functionality as compiler options. Pragmas override behavior specified by compiler options.

Some pragmas are available for both Intel® and non-Intel microprocessors but they may perform additional optimizations for Intel® microprocessors than they perform for non-Intel microprocessors. Refer to the individual pragma name for detailed description.

The Intel® C++ Compiler pragmas are categorized as follows:

  • Intel-specific Pragmas - pragmas developed or modified by Intel to work specifically with the Intel® C++ Compiler

  • Intel Supported Pragmas - pragmas developed by external sources that are supported by the Intel® C++ Compiler for compatibility reasons

Using Pragmas

You enter pragmas into your C++ source code using the following syntax:

#pragma <pragma name>

Individual Pragma Descriptions

Each pragma description has the following details:



Short Description

Contains a brief description of what the pragma does.


Contains the pragma syntax.


Contains a list of the arguments (parameters).


Contains a detailed description of what the pragma does.


Contains typical usage example/s.

See Also

Contains links or paths to other pragmas or related topics.

Para obtener información más completa sobre las optimizaciones del compilador, consulte nuestro Aviso de optimización.