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-multiple-gather-scatter-by-shuffles, Qopt-multiple-gather-scatter-by-shuffles

Enables or disables the optimization for multiple adjacent gather/scatter type vector memory references.

Syntax

Linux:

-qopt-multiple-gather-scatter-by-shuffles

-qno-opt-multiple-gather-scatter-by-shuffles

macOS:

-qopt-multiple-gather-scatter-by-shuffles

-qno-opt-multiple-gather-scatter-by-shuffles

Windows:

/Qopt-multiple-gather-scatter-by-shuffles

/Qopt-multiple-gather-scatter-by-shuffles-

Arguments

None

Default

varies

When this option is not specified, the compiler uses default heuristics for optimization.

Description

This option controls the optimization for multiple adjacent gather/scatter type vector memory references. This optimization hint is useful for performance tuning. It tries to generate more optimal software sequences using shuffles.

If you specify this option, the compiler will apply the optimization heuristics. If you specify -qno-opt-multiple-gather-scatter-by-shuffles or /Qopt-multiple-gather-scatter-by-shuffles-, the compiler will not apply the optimization.

NOTE:

Optimization is affected by optimization compiler options, such as [Q]x, -march (Linux* or macOS), and /arch (Windows*).

To override the effect of this option (or the default) per loop basis, you can use directive VECTOR [NO]MULTIPLE_GATHER_SCATTER_BY_SHUFFLE.

Product and Performance Information

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.

Notice revision #20201201

IDE Equivalent

None

Alternate Options

None

See Also