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Intel® Xeon Phi™ Coprocessor DEVELOPER’S QUICK START GUIDE

Code Example 4: Using the “_Cilk_shared” and “_Cilk_offload” Keywords with Dynamic Allocation in

C/C++

Note: For more examples on using the implicit memory copy model, see:

C: /opt/intel/composerxe/Samples/en_US/C++/mic_samples/shrd_sampleC

and …/LEO_tutorial

C++: /opt/intel/composerxe/Samples/en_US/C++/mic_samples/shrd_sampleCPP

For more information, users are encouraged to read the Intel C++ Compiler User and Reference Guides and/or

the Intel Fortran Compiler User and Reference Guides.

The section “Restrictions on Offload Using Shared Virtual Memory” in the document “Intel C++ Compiler User

and Reference Guide” shows some restrictions of using this programming model.

Native Compilation

Applications can also be run natively on the Intel® Xeon Phi™ Coprocessor, in which case the coprocessor will

be treated as a standalone multicore computer. Once the binary is built on the host system, copy the binary

and other related binaries or data to the Intel® Xeon Phi™ Coprocessor’s filesystem (or make them visible over

there via NFS).

Example:

1. Copy openmp_sample.c from

/opt/intel/composerxe/Samples/en_US/C++/openmp_samples/ to your home directory

2. Build the application with the –mmic flag:

icc –mmic –vec-report3 –openmp openmp_sample.c

3. Upload the binary to the coprocessor:

scp a.out mic0:/tmp/a.out

4. Copy over any shared libraries required by your application, in this case the OpenMP* runtime library:

scp /opt/intel/composerxe/lib/mic/libiomp5.so mic0:/tmp/libiomp5.so

5. Connect to the coprocessor with ssh and export the local directory so that the application can find any

shared libraries it uses (in this case the OpenMP* runtime library):

ssh mic0

export LD_LIBRARY_PATH=/tmp

6. This application may generate a segmentation fault if the stacksize is not set correctly. To modify the

stacksize use:

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Red Hat ENTERPRISE LINUX 4 - DEVELOPER TOOLS GUIDE Informazioni Techniche Pagina 21