# parallel, Qparallel

Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.

## Syntax

Linux: | -parallel

macOS: | -parallel

Windows: | /Qparallel(or /Qpar)

## Arguments

None

## Default

OFF | Multithreaded code is not generated for loops that can be safely executed in parallel.

## Description

This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.

To use this option, you must also specify option O2 or O3.

This option sets option [q or Q]opt-matmul if option O3 is also specified.

### Note

On macOS systems, when you enable automatic parallelization, you must also set the DYLD_LIBRARY_PATH environment variable within Xcode* or an error will be displayed.

### Note

Using this option enables parallelization for both Intel® microprocessors and non-Intel microprocessors. The resulting executable may get additional performance gain on Intel microprocessors than on non-Intel microprocessors. The parallelization can also be affected by certain options, such as /arch or /Qx (Windows*) or -m or -x (Linux* and macOS).

Product and Performance Information
Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex. Notice revision #20201201

## IDE Equivalent

Visual Studio: Optimization > Parallelization

Eclipse: Optimization > Parallelization

Xcode: Optimization > Parallelization

## Alternate Options

None

Parent topic: OpenMP* Options and Parallel Processing Options

## See Also

qopt-report, Qopt-report compiler option
par-affinity, Qpar-affinity compiler option
par-num-threads, Qpar-num-threads compiler option
par-runtime-control, Qpar-runtime-control compiler option
par-schedule, Qpar-schedule compiler option
qopt-matmul, Qopt-matmul compiler option