# pch-use

Tells the compiler to use a precompiled header file.

## Syntax

Linux and macOS: | -pch-use filename

Windows: | None

## Arguments

filename | Is the name of the precompiled header file to use. A space must appear before the file name. It can include a path.

## Default

OFF | The compiler does not create or use precompiled headers unless you tell it to do so.

## Description

This option tells the compiler to use a precompiled header (PCH) file.

It is supported for multiple source files when all source files use the same .pchi file.

This option cannot be used in the same compilation as the -pch-create option.

To learn how to optimize compile times using the PCH options, see "Using Precompiled Header Files" in the User's Guide.

On Windows* systems, option -pch-use is equivalent to the /Yu option.

## IDE Equivalent

None

## Alternate Options

Linux and macOS: None

Windows: /Yu

## Example

Consider the following command line:

    icpc -pch-use /pch/source32.pchi source.cpp

It produces the following output:

    "source.cpp": using precompiled header file /pch/source32.pchi

Parent topic: Output, Debug, and Precompiled Header Options

## See Also

-pch-create compiler option