# qopt-matmul, Qopt-matmul

Enables or disables a compiler-generated Matrix Multiply (matmul) library call.

## Syntax

Linux: | -qopt-matmul -qno-opt-matmul

macOS: | None

Windows: | /Qopt-matmul /Qopt-matmul-

## Arguments

None

## Default

-qno-opt-matmul or /Qopt-matmul- | The matmul library call optimization does not occur unless this option is enabled or certain other compiler options are specified (see below).

## Description

This option enables or disables a compiler-generated Matrix Multiply (MATMUL) library call.

The [q or Q]opt-matmul option tells the compiler to identify matrix multiplication loop nests (if any) and replace them with a matmul library call for improved performance. The resulting executable may get additional performance gain on Intel® microprocessors than on non-Intel microprocessors.

### Note

This option is dependent upon the OpenMP* library. If your product does not support OpenMP, this option will have no effect.

This option is enabled by default at setting O2 and above. To disable this optimization, specify -qno-opt-matmul or /Qopt-matmul-.

This option has no effect unless option O2 or higher is set.

### Note

Many routines in the MATMUL library are more highly optimized for Intel® microprocessors than for non-Intel microprocessors.

## IDE Equivalent

Visual Studio: Optimization > Enable Matrix Multiply Library Call

Eclipse: Optimization > Optimize Matrix Multiplication

Xcode: None

## Alternate Options

None

Parent topic: Advanced Optimization Options

## See Also

O compiler option