Towards Efficient Utilization of RISC-V Long Vector Register Files: A Characterization Study
2026-06-11 , Poster Island C

As RISC-V "Vector" (RVV 1.0) architectures scale, the Vector Register File (VRF) becomes a primary bottleneck in area and power. This work characterizes data residency and redundancy patterns in a distributed, long-vector VRF using the gem5 simulator. We identify two primary inefficiencies: resource fragmentation and an entropy-capacity mismatch in active data. Our evaluation of lightweight compression schemes reveals that a 2-entry dictionary-based approach consistently yields a 2.5x compression ratio of the computed vector elements. These results demonstrate that hardware-level data compaction is an interesting path for optimizing the area of future long-vector RISC-V accelerators

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Computer Architecture Researcher at Barcelona Supercomputing Center & PHD student at Universitat Politècnica de Catalunya.