Evaluation of the RISC-V Floating Point Extensions

Abstract:
Designing an Instruction Set Architecture (ISA) is a challenging task that plays a crucial role in shaping the characteristics of compute systems. However, the process of designing an ISA is often shrouded in secrecy, as many relevant ISAs are proprietary standards developed behind closed doors. In recent years, a disruptive newcomer has emerged in the ISA landscape, known as RISC-V. Unlike other ISAs, RISC-V adopts an open-standard approach, embracing open discussions and decision-making through online forums. The goal of this work is to shed light on the design rationale behind the RISCV Floating-Point (FP) extensions F and D. To complement our analysis, we conducted a practical assessment using a profiling RISC-V Virtual Platform (VP) and a comprehensive set of 78 Floating Point (FP) benchmarks and applications. Using this VP, we were able to track and analyze instruction distributions, FP value distributions, and other data of interest. This allows us to draw well-grounded conclusions and gain valuable insights into the characteristics of the RISC-V F/D extensions.