Tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
IDE Equivalent
Windows: Optimization > Parallelization
Linux: Optimization > Parallelization
Mac OS X: Optimization > Parallelization
Architectures
IA-32, Intel® 64 architectures
Syntax
Linux and Mac OS X: | -parallel |
Windows: | /Qparallel |
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.
On Linux and Windows systems, this option sets option -opt-matmul (Linux*) or /Qopt-matmul (Windows*) if option O3 is also specified.
Note
On Mac OS* X 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 Mac OS X).
Optimization Notice |
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Intel® Compiler includes compiler options that optimize for instruction sets that are available in both Intel® and non-Intel microprocessors (for example SIMD instruction sets), but do not optimize equally for non-Intel microprocessors. In addition, certain compiler options for Intel® Compiler are reserved for Intel microprocessors. For a detailed description of these compiler options, including the instruction sets they implicate, please refer to "Intel® Compiler User and Reference Guides > Compiler Options". Many library routines that are part of Intel® Compiler are more highly optimized for Intel microprocessors than for other microprocessors. While the compilers and libraries in Intel® Compiler offer optimizations for both Intel and Intel-compatible microprocessors, depending on the options you select, your code and other factors, you likely will get extra performance on Intel microprocessors. While the paragraph above describes the basic optimization approach for Intel® Compiler, with respect to Intel's compilers and associated libraries as a whole, Intel® Compiler may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include Intel® Streaming SIMD Extensions 2 (Intel® SSE2), Intel® Streaming SIMD Extensions 3 (Intel® SSE3), and Supplemental Streaming SIMD Extensions 3 (Intel® SSSE3) instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Intel recommends that you evaluate other compilers to determine which best meet your requirements. |
Alternate Options
None