CTD2022: Vecpar - a portable parallelization library

As High Energy Physics collider experiments continue to push the boundaries of instantaneous luminosity, the corresponding increase in particle multiplicities pose significant computing challenges. Although most of today's supercomputers provide shared-memory nodes and accelerators to boost the performance of scientific applications, the usage of latest hardware has little impact unless the code exposes parallelism. Therefore, several frameworks have been developed to support parallel execution on different architectures, but the performance gain is usually obtained by either compromising on portability or requiring significant effort to adopt, both of which can be issues for experiments' developer communities. In this talk, we introduce a new portability framework which aims to reduce the programming effort in porting and maintaining code that targets heterogeneous architectures, while ensuring improved wall-clock run times over the initial sequential implementation. Different parallelization strategies and ways of combining them are also discussed together with the known limitations. Additionally, we show preliminary performance measurements on a 4th order Runge-Kutta-Nyström stepper implementation from the ACTS GPU R&D project detray, which demonstrate the library's potential even though it is still in the early development stage