# Language extensions

The Hexagon LLVM compilers support language features that are not defined in the standard LLVM compilers. These features are specific to the Hexagon processor and are known as *language extensions*.

The compilers predefine several symbols to simplify the development of portable software. For example:

#if __hexagon__
    ...                    // Hexagon processor-specific code
    #endif
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## Predefined symbols for processor versions

The Hexagon compiler defines these macros:

__hexagon__
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Defined when compiling code for any version of the Hexagon processor. This macro allows you to ascertain that the compiler is being asked to generate Hexagon code.

__HEXAGON_V<NN>__
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Indicate the Hexagon version, where `NN` is the specific Hexagon processor number described in [Processor version](https://docs.qualcomm.com/doc/80-N3040-23/topic/use-the-compilers.html#hccpp-compiler-options-processor-version-sub). For example, if the compiler is generating code for Hexagon V73, `NN` is set to `73`.

## Predefined symbols for HVX coprocessor versions

When compiling code for specific versions of the HVX coprocessor, the compiler defines three symbols:

__HVX__
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Set to 1 if HVX is enabled. For information on how to enable HVX and select an HVX coprocessor version, see [Processor version](https://docs.qualcomm.com/doc/80-N3040-23/topic/use-the-compilers.html#hccpp-compiler-options-processor-version-sub).

__HVX_<ARCH>__
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Numerical value set to the version of the Hexagon processor. For example, if codes is being compiled for Hexagon V68, `ARCH` is set to `68`.

__HVX_LENGTH__
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Set to either 64 or 128, based on the vector length that is selected for compilation.

Last Published: Oct 06, 2026

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