Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

ID 767251
Date 7/13/2023
Public

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Document Table of Contents

qopt-prefetch, Qopt-prefetch

Enables or disables prefetch insertion optimization.

Syntax

Linux:

-qopt-prefetch[=n]

-qno-opt-prefetch

macOS:

-qopt-prefetch[=n]

-qno-opt-prefetch

Windows:

/Qopt-prefetch[:n]

/Qopt-prefetch-

Arguments

n

Is the level of software prefetching optimization desired. Possible values are:

0

Disables software prefetching. This is the same as specifying -qno-opt-prefetch (Linux* and macOS) or /Qopt-prefetch- (Windows*).

1 to 5

Enables different levels of software prefetching. If you do not specify a value for n, the default is -qopt-prefetch=2 or /Qopt-prefetch:2. Use lower values to reduce the amount of prefetching.

Default

ifort: -qno-opt-prefetch
or /Qopt-prefetch-

Prefetch insertion optimization is disabled.

ifx: varies

The default can change depending on certain option settings.

If you specify option -qno-opt-prefetch (or /Qopt-prefetch-), or you specify option O0 or O1 explicitly or implicitly, prefetch insertion optimization is disabled.

If you specify option O2 or above explicitly or implicitly, the default is option -qopt-prefetch=2 (or /Qopt-prefetch:2).

Description

This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.

This option enables prefetching when higher optimization levels are specified.

IDE Equivalent

Visual Studio: Optimization > Prefetch Insertion

Alternate Options

None