Title
Hybrid multithreading for VLIW processors
Abstract
Several multithreading techniques have been proposed to reduce resource underutilization in Very Long Instruction Word (VLIW) processors. Simultaneous MultiThreading (SMT) is a popular technique that improves processor performance by issuing multiple instructions from different threads. In VLIW processors, SMT requires extra hardware to merge instructions from different threads. The complexity of this hardware increases substantially with the number of threads. On the other hand, techniques like Interleaved MultiThreading (IMT) do not need any merging hardware, and support a larger number of threads at reasonable cost. In this paper, we propose Hybrid MultiThreading (HMT), a technique that at each cycle merges instructions from only a subset of threads. HMT supports a reasonable number of threads with a low merging hardware cost. For instance, it is possible to support 8 hardware threads with a merging hardware for only 2 threads. The experimental results show that using HMT improves the multithreading performance significantly. Further, supporting 8 hardware threads with HMT but using a 4-thread merging hardware achieves a performance similar to merging 8 threads simultaneously with a significantly lower merging hardware cost.
Year
DOI
Venue
2009
10.1145/1629395.1629403
Compilers, Architecture, and Synthesis for Embedded Systems
Keywords
Field
DocType
hybrid multithreading,extra hardware,different thread,processor performance,clustered vliw processors,hardware cost,simultaneous multithreading,multithreading,vliw processor,multithreading performance,larger number,hardware thread,interleaved multithreading,very long instruction word
Multithreading,Very long instruction word,Computer science,Parallel computing,Real-time computing,Thread (computing),Simultaneous multithreading,Process (computing),Temporal multithreading,Merge (version control),Barrel processor
Conference
Citations 
PageRank 
References 
2
0.40
15
Authors
3
Name
Order
Citations
PageRank
Manoj Gupta17612.47
Fermín Sánchez2235.45
Josep Llosa357439.30