SyCLDslash MiniApp

This git repository contains the SyCLDslash package. SyCLDslash depends for its testing reference implementatins on QDP++. To build this code it is recommended to perform a recursive checkout of the repository:

github.com:bjoo/SyCLDslashWorkspace.git

which contains QDP++ and its dependencies

In addition SyCLDslash depends on googletest and includes it as a sub-module.

Checking out this repository

It is highly recommended that this library be checked out using the --recursive option to Git so that the googletest submodule is checked out. Alternatively consider checking out SyCLDslashWorkspace.

Building

This code builds with CMake.

Useful CMake options are:

• -DQDPXX_DIR=<qdp-install-location>/share - points to the share directory of an installation of QDP++ which contains a FindQDPXX.cmake file.

• -DMG_FORTRANLIKE_COMPLEX=ON enables (RIRIRIRI) storage for complex numbers in vectors. Turning it to 'OFF' selects a more vector oriented storage order of (RRRR...)(IIII...)

• -DMG_USE_NEIGHBOR_TABLE=OFF (if set to 'ON` would use a neighbour table that is actualy a lookup table. This option is not currently implemented properly, neighbor indices are explicitly computed, and this option should remain 'OFF')

• -DMG_USE_LAYOUT_LEFT=OFF ( if set to ON selects left index fastest indexing for View objects, if set to OFF uses right fastest indexing, following Kokkos. )

• -DMG_USE_COMPUTE_CPP=ON ( set this to ON if using the ComputeCPP compiler from codeplay, and specify the ComputeCpp install directory using -DComputeCpp_DIR -- this sets some extra CMake magic to drive their compiler chain )

• -DComputeCpp_DIR=<path> - set this to the install location of the ComputeCPP compiler if using.

Running The Mini-App:

Once building is complete the executables will be in build/build_sycl_dslash/tests Two executables are of primary interest: test_dslash_sycl and test_dslash_sycl_vperf.

The test_dslash_sycl app performs some unit testing of the dslash operator for a selection of vector lenghts.

The performance test is test_dslash_sycl_vperf which will first apply a dslash for the purposes of JIT-compiling all the components, and then it will apply dslash again to time a single application. It will use this timing to choose a number of iterations commensurate to 5 seconds of runtime or minimally 1 iteration if it takes longer than 5 seconds. It will then perform 5 timing loops.

Known issues

• The code has been tested only with the Intel LLVM/SyCL compiler which is in development, on a system running an OpenCL runtime. It occasionally crashes OpenCL with the error message:

OpenCL API failed. OpenCL API returns: -34 (CL_INVALID_CONTEXT)

This issue needs to be chased down still.

To Do Items

• Need to figure out how to run this code with other SyCL Compilers e.g. CodePlay etc

Licensing and copyright

The Jefferson Lab License under which this workspace is distributed is in the file LICENSE Licenses for dependencies are included in their source code and/or in the LICENSES directory.