Presentation
Assessing a RISC-V Accelerator for Cross-Section Lookup in Chipyard
DescriptionHigh-fidelity nuclear reactor simulations using Monte Carlo
neutron transport face bottlenecks in neutron cross-section
lookups. We designed a custom RISC-V accelerator for
RSBench, integrated with a RocketCore in Chipyard. The
pipelined design employs Humlíček’s 8th-order rational ap-
proximation to efficiently compute the Faddeeva function
during Doppler broadening of multipole cross section data,
which forms the inner loop of the program, achieving a 17×
cycle reduction for Faddeeva computations and 34.2× for
the loop compared to RISC-V software, with similar gains
over Intel Core i5 Tiger Lake-U, yielding a 10× wall-clock
time improvement. Chipyard’s software-based environment
benefits the HPC community by enabling accelerator eval-
uation. These results highlight RISC-V’s potential for HPC
through custom accelerators and code portability. Future work
will optimize operating frequency and extend to additional
simulation kernels.
neutron transport face bottlenecks in neutron cross-section
lookups. We designed a custom RISC-V accelerator for
RSBench, integrated with a RocketCore in Chipyard. The
pipelined design employs Humlíček’s 8th-order rational ap-
proximation to efficiently compute the Faddeeva function
during Doppler broadening of multipole cross section data,
which forms the inner loop of the program, achieving a 17×
cycle reduction for Faddeeva computations and 34.2× for
the loop compared to RISC-V software, with similar gains
over Intel Core i5 Tiger Lake-U, yielding a 10× wall-clock
time improvement. Chipyard’s software-based environment
benefits the HPC community by enabling accelerator eval-
uation. These results highlight RISC-V’s potential for HPC
through custom accelerators and code portability. Future work
will optimize operating frequency and extend to additional
simulation kernels.
Event Type
Workshop
TimeMonday, 17 November 202512:10pm - 12:20pm CST
Location242