Adaptable Register File Organization for Vector Processors

Cristobal Ramirez Lazo, Enrico Reggiani, Carlos Rojas Morales, Roger Figueras Bague, Luis A. Villa Vargas, Marco A. Ramirez Salinas, Mateo Valero Cortes, Osman Sabri Unsal, Adrian Cristal

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Contemporary Vector Processors (VPs) are de-signed either for short vector lengths, e.g., Fujitsu A64FX with 512-bit ARM SVE vector support, or long vectors, e.g., NEC Aurora Tsubasa with 16Kbits Maximum Vector Length (MVL1). Unfortunately, both approaches have drawbacks. On the one hand, short vector length VP designs struggle to provide high efficiency for applications featuring long vectors with high Data Level Parallelism (DLP). On the other hand, long vector VP designs waste resources and underutilize the Vector Register File (VRF) when executing low DLP applications with short vector lengths. Therefore, those long vector VP implementations are limited to a specialized subset of applications, where relatively high DLP must be present to achieve excellent performance with high efficiency. Modern scientific applications are getting more diverse, and the vector lengths in those applications vary widely. To overcome these limitations, we propose an Adaptable Vector Architecture (AVA) that leads to having the best of both worlds. AVA is designed for short vectors (MVL=16 elements) and is thus area and energy-efficient. However, AVA has the functionality to reconfigure the MVL, thereby allowing to exploit the benefits of having a longer vector of up to 128 elements microarchitecture when abundant DLP is present. We model AVA on the gem5 simulator and evaluate AVA performance with six applications taken from the RiVEC Benchmark Suite. To obtain area and power consumption metrics, we model AVA on McPAT for 22nm technology. Our results show that by reconfiguring our small VRF (8KB) plus our novel issue queue scheme, AVA yields a 2X speedup over the default configuration for short vectors. Additionally, AVA shows competitive performance when compared to a long vector VP, while saving 50% of area.

Original languageEnglish
Title of host publicationProceedings - 2022 IEEE International Symposium on High-Performance Computer Architecture, HPCA 2022
PublisherIEEE Computer Society
Number of pages14
ISBN (Electronic)9781665420273
StatePublished - 2022
Event28th Annual IEEE International Symposium on High-Performance Computer Architecture, HPCA 2022 - Virtual, Online, Korea, Republic of
Duration: 2 Apr 20226 Apr 2022

Publication series

NameProceedings - International Symposium on High-Performance Computer Architecture
ISSN (Print)1530-0897


Conference28th Annual IEEE International Symposium on High-Performance Computer Architecture, HPCA 2022
Country/TerritoryKorea, Republic of
CityVirtual, Online


  • data-level parallelism
  • vector architectures
  • vector register file


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