Short Biography

In 2015 I have obtained a bachelor's degree in physics, followed in 2018 by a master's degree in physics with specialization on computational astrophysics (both from Heidelberg University). During my studies, I have designed and developed teralens, an OpenCL-based tree code for gravitational quasar microlensing, which, to this day, is the fastest known code in its field.

Afterwards, I increasingly focused on developing tools for HPC, and most notably created AdaptiveCpp (formerly known as hipSYCL). AdaptiveCpp is one of the two major SYCL implementations in use today, and the very first SYCL implementation to pioneer an interpretation of SYCL without OpenCL. In late 2018, I joined Heidelberg University Computing Centre's HPC team and EMCL.

Since 2019, I am a member of the Khronos SYCL working group.

Research Interests

• High performance computing
• Heterogeneous computing, GPU computing
• Parallel programming models, compilers and runtime systems

Teaching

At Heidelberg University

• Supervisor of the Heidelberg University team for the ISC19 Student Cluster Competition
• Supervisor of the Heidelberg University team for the ISC20 Student Cluster Competition
• Supervisor of the Heidelberg University team for the ISC21 Student Cluster Competition
• Supervisor of the Heidelberg University team for the ISC22 Student Cluster Competition
• Advanced Practical Accelerating applications using BLAS libraries with unified memory on GPUs
• Supervisor of the bachelor thesis: SYCL 2020 work group parallel primitives: Optimized algorithms for GPUs and CPUs in hipSYCL (H. Wünsche, 2021)
• Supervisor of the bachelor thesis: Task parallelism in hipSYCL (B. Soproni, 2021)
• Supervisor of the master thesis: Compiler-assisted optimizations for data-parallel paradigms in hipSYCL (J. Meyer, 2021)

At Conferences

• Rod Burns, Gordon Brown, Ronan Keryell, Aksel Alpay and Igor Vorobstov. 2020. Tutorial: A Hands-On Introduction to SYCL and Application Development with SYCL. International Workshop on OpenCL (IWOCL '20). (watch tutorial on YouTube. Note: YouTube seems to have mixed up the original order of the videos in the playlist)
• Tim Mattson, Michael Wong, Ronan Keryell, Rod Burns, Aksel Alpay, Gordon Brown. 2020. HPC Application Development Using C++ and SYCL. SC20.
• Rod Burns, Igor Vorobtsov, Aksel Alpay, Ronan Keryell, Michael Steyer, and Gordon Brown. 2021. A Hands-On Introduction To SYCL. In International Workshop on OpenCL (IWOCL'21).
• Rod Burns, Aksel Alpay, Gordon Brown, James Reinders, Michael Wong, Peter Zuzek, and Ronan Keryell. 2021: Heterogeneous Programming in Modern C++ with SYCL. CppCon 2021.
• Rod Burns, Ronan Keryell, Igor Vorobtsov, Aksel Alpay, Hugh Delaney, and Peter Zuzek. 2022. Tutorial: Application Development with SYCL. In International Workshop on OpenCL (IWOCL'22).
• Aksel Alpay, Igor Baratta, Tom Deakin, Peter Žužek, Igor Vorobtsov. Heterogeneous Programming in Modern C++ with SYCL. ISC22.
• Aksel Alpay, Igor Baratta, Tom Deakin, Peter Žužek, Heterogeneous Programming in Modern C++ with SYCL. IEEE Cluster 2022.
• Rod Burns, Hugh Delaney, Aksel Alpay, Ronan Keryell, and Igor Vorobtsov. 2023. Tutorial: SYCL Techniques and Best Practices. In Proceedings of the 2023 International Workshop on OpenCL (IWOCL '23).
• Rod Burns, Aksel Alpay, Igor Baratta, Tom Deakin, Igor Vorobtsov, Peter Žužek. Heterogeneous Programming in Modern C++ with SYCL. ISC23.

Publications

• Joachim Meyer, Aksel Alpay, Sebastian Hack, Holger Fröning, and Vincent Heuveline. 2023. Implementation Techniques for SPMD Kernels on CPUs. In Proceedings of the 2023 International Workshop on OpenCL (IWOCL '23). Association for Computing Machinery, New York, NY, USA, Article 1, 1–12. https://doi.org/10.1145/3585341.3585342
• Aksel Alpay and Vincent Heuveline. 2023. One Pass to Bind Them: The First Single-Pass SYCL Compiler with Unified Code Representation Across Backends. In Proceedings of the 2023 International Workshop on OpenCL (IWOCL '23). Association for Computing Machinery, New York, NY, USA, Article 7, 1–12. https://doi.org/10.1145/3585341.3585351
• Aksel Alpay, Bálint Soproni, Holger Wünsche, and Vincent Heuveline. 2022. Exploring the possibility of a hipSYCL-based implementation of oneAPI. In International Workshop on OpenCL (IWOCL'22). Association for Computing Machinery, New York, NY, USA, Article 10, 1–12. https://doi.org/10.1145/3529538.3530005
• George S. Markomanolis, Aksel Alpay, Jeffrey Young, Michael Klemm, Nicholas Malaya, Aniello Esposito, Jussi Heikonen, Sergei Bastrakov, Alexander Debus, Thomas Kluge, Klaus Steiniger, Jan Stephan, Rene Widera and Michael Bussmann. 2022. Evaluating GPU Programming Models for the LUMI Supercomputer, Supercomputing Frontiers Asia 2022, Singapore
• Tom Deakin, Simon McIntosh-Smith, Aksel Alpay, Vincent Heuveline. 2021. Benchmarking and Extending SYCL Hierarchical Parallelism. 2nd Workshop on Hierarchical Parallelism for Exascale Computing.
• Sohan Lal, Aksel Alpay, Philip Salzmann, Biagio Cosenza, Alexander Hirsch, Nicolai Stawinoga, Peter Thoman, Thomas Fahringer, Vincent Heuveline. 2020. SYCL-Bench: A Versatile Cross-Platform Benchmark Suite for Heterogeneous Computing. In: Malawski M., Rzadca K. (eds) Euro-Par 2020: Parallel Processing. Euro-Par 2020. Lecture Notes in Computer Science, vol 12247. Springer, Cham. https://doi.org/10.1007/978-3-030-57675-2_39

Conference Contributions and Talks

• Aksel Alpay. 2022. Pushing the boundaries of SYCL with hipSYCL. Keynote. International Workshop on OpenCL (IWOCL'22).
• Aksel Alpay and Vincent Heuveline. 2022. How much SYCL does a compiler need? Experiences from the implementation of SYCL as a library for nvc++. In International Workshop on OpenCL (IWOCL'22). Association for Computing Machinery, New York, NY, USA, Article 11, 1. https://doi.org/10.1145/3529538.3529556
• Thomas Applencourt, Abhishek Bagusetty, Ajay Panyala, and Aksel Alpay. 2022. SYCL Concurrency on GPU Platforms: Empirical Measurement. In International Workshop on OpenCL (IWOCL'22). Association for Computing Machinery, New York, NY, USA, Article 31, 1. https://doi.org/10.1145/3529538.3529989
• Aksel Alpay, Thomas Applencourt, Gordon Brown, Ronan Keryell, and Gregory Lueck. 2022. Using interoperability mode in SYCL 2020. In International Workshop on OpenCL (IWOCL'22). Association for Computing Machinery, New York, NY, USA, Article 21, 1. https://doi.org/10.1145/3529538.3529997
• Joachim Meyer, Aksel Alpay, Holger Fröning, and Vincent Heuveline. 2022. Compiler-aided nd-range parallel-for implementations on CPU in hipSYCL. In International Workshop on OpenCL (IWOCL'22). Association for Computing Machinery, New York, NY, USA, Article 28, 1–3. https://doi.org/10.1145/3529538.3530216
• Aksel Alpay. 2021. SYCL 2020 in hipSYCL: DPC++ features on AMD GPUs, NVIDIA GPUs and CPUs. Keynote. oneAPI Developer Summit at IWOCL'21.
• Aksel Alpay and Vincent Heuveline. 2021. HipSYCL in 2021: Peculiarities, unique features and SYCL 2020. In International Workshop on OpenCL (IWOCL'21). Association for Computing Machinery, New York, NY, USA, Article 18, 1. DOI:https://doi.org/10.1145/3456669.3456691
• Aksel Alpay and Vincent Heuveline. 2020. SYCL beyond OpenCL: The architecture, current state and future direction of hipSYCL. In Proceedings of the International Workshop on OpenCL (IWOCL '20). Association for Computing Machinery, New York, NY, USA, Article 8, 1. DOI:https://doi.org/10.1145/3388333.3388658 (watch recording on YouTube)
• Sohan Lal, Aksel Alpay, Philip Salzmann, Biagio Cosenza, Nicolai Stawinoga, Peter Thoman, Thomas Fahringer, and Vincent Heuveline. 2020. SYCL-Bench: A Versatile Single-Source Benchmark Suite for Heterogeneous Computing. In Proceedings of the International Workshop on OpenCL (IWOCL '20). Association for Computing Machinery, New York, NY, USA, Article 10, 1. DOI:https://doi.org/10.1145/3388333.3388669 (watch recording on YouTube)