Title
Design And Evaluation Of Smallfloat Simd Extensions To The Risc-V Isa
Abstract
RISC-V is an open-source instruction set architecture (ISA) with a modular design consisting of a mandatory base part plus optional extensions. The RISC-V 32IMFC ISA configuration has been widely adopted for the design of new-generation, low-power processors. Motivated by the important energy savings that smaller-than-32-bit FP types have enabled in several application domains and related compute platforms, some recent studies have published encouraging early results for their adoption in RISC-V processors. In this paper we introduce a set of ISA extensions for RISC-V 32IMFC, supporting scalar and SIMD operations (fitting the 32-bit register size) for 8-bit and two 16-bit FP types. The proposed extensions are enabled by exposing the new FP types to the standard C/C++ type system and an implementation for the RISC-V GCC compiler is presented. As a further, novel contribution, we extensively characterize the performance and energy savings achievable with the proposed extensions. On average, experimental results show that their adoption provide benefits in terms of performance (1.64x speedup for 16-bit and 2.18x for 8-bit types) and energy consumption (30% saving for 16-bit and 50% for 8-bit types). We also illustrate an approach based on automatic precision tuning to make effective use of the new FP types.
Year
DOI
Venue
2019
10.23919/DATE.2019.8714897
2019 DESIGN, AUTOMATION & TEST IN EUROPE CONFERENCE & EXHIBITION (DATE)
Field
DocType
ISSN
RISC-V,Computer science,Instruction set,Parallel computing,Scalar (physics),SIMD,Compiler,Modular design,Energy consumption,Speedup
Conference
1530-1591
Citations 
PageRank 
References 
0
0.34
0
Authors
5
Name
Order
Citations
PageRank
Giuseppe Tagliavini1719.36
Stefan Mach2152.83
Davide Rossi341647.47
Andrea Marongiu433739.19
Luca Benini5131161188.49