Dynamic Fetch Engine for Simultaneous Multithreaded Processors

Abstract. While the fetch unit has been identified as one of the major bottlenecks of Simultaneous Multithreading architecture, several fetch schemes were proposed by prior works to enhance the fetching efficiency. Among these schemes, ICOUNT, proposed by Tullsen et al. were considered to be a great scheme. The ICOUNT scheme works mainly because it favors the thread which fast moving through the pipeline, thus use the resource effectively. We think it is better letting the thread which tends to have more long latency instructions to get the priority at adequate time since long latency instructions are very likely on program's critical path. We proposed a dynamic fetch scheme which gives the long latency bound thread higher priority while the RUU or LSQ is under low usage. Our motivation is to gain further performance by not only use the resource effectively but also by the urgency of the instructions.

• Type: Conference
• Year: 2004
• Where: APCSAC
• Authors: Tzung-Rei Yang, Jong-Jiann Shieh
• Keywords: APCSAC 2004, Computer Architecture, Fetch Scheme, Long Latency, Long Latency Instructions