XKOMP

An experimental OpenMP runtime-library implementation built on top of the XKaapi runtime system, and an extended LLVM's Clang ABI.

Installation

You must have an installation of

• XKRT
• LLVM(ANL) - and compile your openmp program with it

Example of LLVM build

cmake ../llvm -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_ENABLE_RUNTIMES="openmp;offload" -DLLVM_TARGETS_TO_BUILD="NVPTX;X86" -DCMAKE_INSTALL_PREFIX=~/install/llvm/debug

Example of XKOMP build

cmake -DCMAKE_BUILD_TYPE=Debug ../

Example of application build

xkcc main.c -o main

Remarks

• Pass -fopenmp-task-jit-abi=[pointers|packed] to xkcxx so that the LLVM-IR/PTX of tasks/targets is kept after compile-time, and passed to the XKOMP runtime for JIT during taskgraph optimizations. With pointers, all arguments (firstprivate, shared, etc.) are stored in a void ** args array, referenced within the outlined region. With packed, they are packed in a void * args, size_t size compact structure.
• The OMP_TASKGRAPH_OPT=opt1,opt2,...,optn can be used to enable taskgraph optimizations. Available optimizations are: copy-fuse, reduce-node, transitive-reduction, prog-fuse, jit, sequence, batch (applied in that order, whatever the order they are listed in)

Bits of history

XKRT is a fork of XKaapi, that it extended with support for task dependencies over intersecting regions of memory (https://gitlab.inria.fr/xkaapi/dev-v2) This repo is an abstraction layer to OpenMP through LLVM and GCC ABIs. It partial support of OpenMP 6.0 on taskgraphs (6.0) and original extensions for multi-devices dataflow.

If you are looking for the old version of kaapi/komp, refer to:

• https://gitlab.inria.fr/openmp/kaapi
• https://gitlab.inria.fr/openmp/libkomp

References

[1] XKRT: a Runtime System for Macro-Dataflow Programming on Multi-Devices Architectures. DOI: 10.2139/ssrn.6460634