# vec, Qvec

Enables or disables vectorization.

## Syntax

Linux: | -vec -no-vec

macOS: | -vec -no-vec

Windows: | /Qvec /Qvec-

## Arguments

None

## Default

-vec or /Qvec | Vectorization is enabled if option O2 or higher is in effect.

## Description

This option enables or disables vectorization.

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

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

To disable all compiler vectorization, use the "-no-vec -no-simd" (Linux* and macOS) 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. The vectorization can also be affected by certain options, such as /arch (Windows), -m (Linux and macOS), 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

Parent topic: Advanced Optimization Options

## See Also

simd, Qsimd compiler option
ax, Qax compiler option
x, Qx compiler option
vec-guard-write, Qvec-guard-write compiler option
vec-threshold, Qvec-threshold compiler option