RISC-V Streaming Extension Support on the Spike Simulator

João Pedro Rosa Baptista

Key information

Authors:

João Pedro Rosa Baptista (João Pedro Rosa Baptista)

Supervisors:

Nuno Filipe Simões Santos Moraes da Silva Neves (Nuno Filipe Simões Santos Moraes Neves); Nuno Filipe Valentim Roma (Nuno Filipe Valentim Roma)

Published in

11/22/2023

Abstract

Vectorial and Single-Instruction-Multiple-Data (SIMD) instruction-set extensions have gained added attention in the last decade, as a result of an increased prevalence of computational demanding application domains, pushing the need to exploit as much data-level parallelism as possible. The numerous Streaming SIMD Extensions (SSE) and Advanced Vector Extensions (AVX) extensions from Intel/AMD or the NEON and Scalable Vector Extension (SVE) extensions from ARM are some well-known examples of these Instruction Set Architecture (ISA) extensions. Following these same steps, the well-known RISC-V ISA has recently established a comparable vectorial extension, known as the RISC-V Vector (RVV). Other ISA extensions have also been developed to enhance the performance and power/energy efficiency of computing systems. The extremely successful Unlimited Vector Extension (UVE), developed at the INESC-ID HPCAS lab, is one of those extensions. Its prime objective is to provide consolidated support for data-stream processing, alleviating the Central Processing Unit (CPU) from the memory indexing/addressing tasks, while also simplifying loop control. Spike is recognized as the golden reference functional RISC-V ISA software simulator. Making justice to its title, Spike already supports a large collection of extensions including the pertinent RVV extension. However, it still lacks accompany the recent arise of stream-based ISA extensions. Having what was stated in mind, this Thesis proposal aims to define a new RISC-V stream-based extension, integrate it with the rest of the RISC-V ISA and introduce support for the defined extension on the Spike functional simulator. As a result, users will be able to explore such extension on C/C++ applications.