OMP_PROC_BIND is Now Supported on Compatible Non-Intel Processors

By Kenneth M Craft, published on October 16 , 2012

The newest versions of the Intel® C++ and Fortran compilers now support OpenMP* environment variable OMP_PROC_BIND on compatible non-Intel processors for Linux* and Windows* platforms.  The compilers containing the fixes are Intel® Composer XE 2011 Update 13 and Intel® Composer XE 2013 Update 1.  Previous versions of these compilers do not support OMP_PROC_BIND, as defined by the OpenMP* Version 3.1 API specification, on non-Intel processors.  Setting OMP_PROC_BIND={true, false} on a non-Intel processor and running a program linked against the Intel® OpenMP* runtime would produce warnings about affinity not being supported. This has now been corrected, and setting OMP_PROC_BIND=true will bind OpenMP* threads to processors.  Setting OMP_PROC_BIND=false will allow OpenMP* threads to migrate between processors.

On Linux* systems only, GOMP_CPU_AFFINITY may be used to define a specfic set of OS processor IDs to bind OpenMP* threads to.  Note that GOMP_CPU_AFFINITY takes precedence over OMP_PROC_BIND.  If both are set in the execution environment and an Intel-compiled OpenMP* program is run, the following warning will be seen:

OMP: Warning #181: OMP_PROC_BIND: ignored because GOMP_CPU_AFFINITY has been defined

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Product and Performance Information

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Intel's compilers 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 SSE2, SSE3, and 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. Certain optimizations not specific to Intel microarchitecture are reserverd for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804