SpMT WaveCache: Exploiting Speculative Multithreading for Dataflow Computer

Abstract

Speculative Multithreading(SpMT) increases the performance by means of executing multithreads speculatively to exploit thread-level parallelism. The authors expanded the transactional memory system of WaveCache by adding extra hardware components,such as Thread Synchronization Unit(TSU),Thread Context Table(TCT) and Thread Memory History(TMH),to improve the performance of SpMT WaveCache which is built on WaveScalar instruction set architecture(ISA). Furthermore,a novel two-levels commit method is proposed to support submitting thread-level transactions. Finally,the SpMT WaveCache is evaluated with 6 real benchmarks selected from SPEC,Mediabench and Mibench benchmarks. According to the experimental results,the SpMT WaveCache outperforms superscalar architecture ranging from 2X to 3X,and it also performs greater gain over original WaveCache and Transactional WaveCache. Therefore,the SpMT WaveCache is a good way to exploit thread-level parallelism of dynamic dataflow computer.