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

ID 767251
Date 3/22/2024
Public

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Document Table of Contents

vec, Qvec

Enables or disables loop vectorization.

Syntax

Linux:

-vec

-no-vec

Windows:

/Qvec

/Qvec-

Arguments

None

Default

-vec
or /Qvec

Loop vectorization is enabled if option O2 or higher is in effect.

Description

This option enables or disables loop vectorization.

To disable loop vectorization, specify -no-vec (Linux*) or /Qvec- (Windows*).

On ifort:

  • To disable interpretation of SIMD directives, specify -no-simd (Linux*) or /Qsimd- (Windows*).

  • To disable all compiler vectorization, use the "-no-vec -no-simd" (Linux*) or "/Qvec- /Qsimd-" (Windows*) compiler options. The option -no-vec (and /Qvec-) disables all auto-vectorization, including vectorization of array notation statements. The option -no-simd (and /Qsimd-) disables vectorization of loops that have SIMD directives.

NOTE:

Using this option enables vectorization at default optimization levels for both Intel® microprocessors and non-Intel microprocessors. Vectorization may call library routines that can result in additional performance gain on Intel microprocessors than on non-Intel microprocessors.

On ifort, the vectorization can also be affected by certain options, such as /arch (Windows), -m (Linux), or [Q]x.

NOTE:

This option only applies to host compilation. When offloading is enabled, it does not impact device-specific compilation. Offloading can only be enabled when using ifx.

IDE Equivalent

None

Alternate Options

None

See Also