Compiling and Running Programs

Let’s consider the simple example program from Section Writing Intel® SHMEM Programs and assume the code is in a file called ishmem_example.cpp.

To compile the program, we must pass the necessary flags to the Intel® oneAPI DPC++/C++ Compiler. For example:

$ icpx -I${ISHMEM_INSTALL_DIR}/include -L${ISHMEM_INSTALL_DIR}/lib -fsycl -std=gnu++1z ishmem_example.cpp -o ishmem_example -lsma -lpmi -lze_loader -ldl

where ISHMEM_INSTALL_DIR is the path to the Intel® SHMEM installation directory.

While building Intel® SHMEM with the ENABLE_OPENSHMEM CMake option enabled, it may be convenient to use the oshc++ compiler wrapper (instead of icpx directly) to easily include the necessary compilation flags that enable the host OpenSHMEM back-end.

Intel® SHMEM provides a launcher script, ishmrun that assigns the environment variable ZE_AFFINITY_MASK so that each PE is assigned a single SYCL device. To invoke the ishmrun script, pass it as the first argument to your process launcher. The following example assumes the ISHMEM_INSTALL_DIR/bin directory is on your user path and use of the Portable Batch System launcher:

$ aprun -N 12 -n 6 ishmrun ishmem_example

This will launch the example program on 12 PEs with 6 PEs per compute node.

As described in section Building Intel® SHMEM, the following environment variables may be required for execution, depending on the Intel® SHMEM build configuration:

ISHMEM_RUNTIME
ISHMEM_SHMEM_LIB_NAME
ISHMEM_RUNTIME_USE_OSHMPI

See section Library Constants for more information about these variables.