@inproceedings{hoerold_raptor_2025, title = {{{RAPTOR}}: {{Practical Numerical Profiling}} of {{Scientific Applications}}}, booktitle = {Proceedings of the {{International Conference}} for {{High Performance Computing}}, {{Networking}}, {{Storage}} and {{Analysis}}}, author = {Hoerold, Faveo and Ivanov, Ivan Radanov and Dhruv, Akash and Moses, William S. and Dubey, Anshu and Wahib, Mohamed and Domke, Jens}, date = {2025-11}, series = {{{SC}} '25}, pages = {661--680}, publisher = {Association for Computing Machinery}, location = {New York, NY, USA}, doi = {10.1145/3712285.3759810}, abstract = {The proliferation of low-precision units in modern high-performance architecture increasingly burdens the domain scientists. Historically, the choice in HPC was easy: can we get away with 32bit floating-point operations and lower bandwidth requirements, or is FP64 necessary? Driven by Artificial Intelligence, vendors introduced novel low-precision units for vector and tensor operations. Technology roadmaps point to a future of stagnating, or even a reduction in, FP64 support. Hence, scientists have to re-evaluate their codes, but a simple search-and-replace approach to go from FP64 to FP16 will not work. Hence, we introduce RAPTOR: a numerical profiling tool to guide the scientists in their search for code regions where precision lowering is feasible. Using LLVM, we transparently replace high-precision computations using low-precision units, or emulate user-defined lengths of exponent and mantissa. Our RAPTOR is the first feature-rich approach---with focus on ease of use---to change, profile, and reason about numerical requirements and instabilities.}, isbn = {979-8-4007-1466-5}, keywords = {deep neural networks,error tracking,GPUs,LLVM,low precision,Mixed precision,MPFR,multiphysics,numerical profiling,out-of-core,simulation accuracy}, annotation = {wins Reproducibility Advancement Award at SC25}, }