# prof-hotness-threshold, Qprof-hotness-threshold

Lets you set the hotness threshold for function grouping and function ordering. This feature is only available for ifort.

## Syntax

Linux: | -prof-hotness-threshold=n

macOS: | None

Windows: | /Qprof-hotness-threshold:n

## Arguments

n | Is the hotness threshold. n is a percentage having a value between 0 and 100 inclusive. If you specify 0, there will be no hotness threshold setting in effect for function grouping and function ordering.

## Default

OFF | The compiler's default hotness threshold setting of 10 percent is in effect for function grouping and function ordering.

## Description

This option lets you set the hotness threshold for function grouping and function ordering.

The "hotness threshold" is the percentage of functions in the application that should be placed in the application's hot region. The hot region is the most frequently executed part of the application. By grouping these functions together into one hot region, they have a greater probability of remaining resident in the instruction cache. This can enhance the application's performance.

For this option to take effect, you must specify option [Q]prof-use and one of the following:

- On Linux systems: -prof-func-groups or -prof-func-order

- On Windows systems: /Qprof-func-order

## IDE Equivalent

None

## Alternate Options

None

Parent topic: Profile Guided Optimization Options

## See Also

prof-use, Qprof-use compiler option
prof-func-groups compiler option
prof-func-order, Qprof-func-order compiler option