Using Intel® Math Kernel Library on Intel® Xeon Phi™ Coprocessors

Intel® Math Kernel Library (Intel® MKL) offers two sets of libraries to support Intel® Many Integrated Core (Intel® MIC) Architecture:

• For the host computer based on Intel® 64 or compatible architecture and running a Linux* operating system
• For Intel® Xeon Phi™ coprocessors

You can control how Intel MKL offloads computations to Intel® Xeon Phi™ coprocessors. Either you can offload computations automatically or use Compiler Assisted Offload:

• Automatic Offload.

  On Linux* OS running on Intel® 64 or compatible architecture systems, Automatic Offload automatically detects the presence of coprocessors based on Intel MIC Architecture and automatically offloads computations that may benefit from additional computational resources available. This usage model enables you to call Intel MKL routines as you would normally do with minimal changes to your program. The only change needed to enable Automatic Offload is either the setting of an environment variable or a single function call. For details see Automatic Offload.

• Compiler Assisted Offload.

  This usage model enables you to use the Intel compiler and its offload pragma support to manage the functions and data offloaded to a coprocessor. Within an offload region, you should specify both the input and output data for the Intel MKL functions to be offloaded. After linking with the Intel MKL libraries for Intel MIC Architecture, the compiler provided run-time libraries transfer the functions along with their data to a coprocessor to carry out the computations. For details see Compiler Assisted Offload.

In addition to offloading computations to coprocessors, you can call Intel MKL functions from an application that runs natively on a coprocessor. Native execution occurs when an application runs entirely on Intel MIC Architecture. Native mode is a fast way to make an existing application run on Intel MIC Architecture with minimal changes to the source code. For more information, see Running Intel MKL on an Intel Xeon Phi Coprocessor in Native Mode.

Intel MKL ScaLAPACK and Cluster FFT can benefit from yet another usage model offered by the Intel® MPI Library. The Intel MPI Library treats each Intel Xeon Phi coprocessor as a regular node in a cluster of Intel® Xeon® processors and Intel Xeon Phi coprocessors. To run your application on a coprocessor, you can specify an MPI rank on the coprocessor, build the application for Intel MIC Architecture, and launch the built executable from the host computer or the coprocessor. For usage details of the MPI on coprocessors, see documentation for the Intel MPI Library, available in the Intel Software Documentation Library. For details of building MPI applications that use Intel MKL, see Using ScaLAPACK and Cluster FFT on Intel Xeon Phi Coprocessors.

Intel MKL functionality offers different levels of support for Intel MIC Architecture:

• Optimized

• Supported

Please see the Intel MKL Release Notes for details.