Microarchitectural support for precomputation microthreads

ABSTRACT

Research has shown that precomputation microthreads can be useful for improving branch prediction and prefetching. However, it is not obvious how to provide the necessary microarchitectural support, and few details have been given in the literature. By judiciously constraining microthreads, we can easily adapt a superscalar machine to support many simultaneous microthreads. The nature of precomputation microthreads also requires efficient usage of resources. Our proposed implementation addresses this issue by dynamically identifying and aborting useless microthreads.

REFERENCES

• 1: Robert S. Chappell , Jared Stark , Sangwook P. Kim , Steven K. Reinhardt , Yale N. Patt, Simultaneous subordinate microthreading (SSMT), Proceedings of the 26th annual international symposium on Computer architecture, p.186-195, May 01-04, 1999, Atlanta, Georgia, United States
• 2: Robert S. Chappell , Francis Tseng , Adi Yoaz , Yale N. Patt, Difficult-path branch prediction using subordinate microthreads, Proceedings of the 29th annual international symposium on Computer architecture, p.307, May 25-29, 2002, Anchorage, Alaska
• 3: Jamison D. Collins , Dean M. Tullsen , Hong Wang , John P. Shen, Dynamic speculative precomputation, Proceedings of the 34th annual ACM/IEEE international symposium on Microarchitecture, December 01-05, 2001, Austin, Texas
• 4: Jamison D. Collins , Hong Wang , Dean M. Tullsen , Christopher Hughes , Yong-Fong Lee , Dan Lavery , John P. Shen, Speculative precomputation: long-range prefetching of delinquent loads, Proceedings of the 28th annual international symposium on Computer architecture, p.14-25, June 30-July 04, 2001, Göteborg, Sweden
• 5: Erik Jacobsen , Eric Rotenberg , J. E. Smith, Assigning confidence to conditional branch predictions, Proceedings of the 29th annual ACM/IEEE international symposium on Microarchitecture, p.142-152, December 02-04, 1996, Paris, France
• 6: Andreas Moshovos , Dionisios N. Pnevmatikatos , Amirali Baniasadi, Slice-processors: an implementation of operation-based prediction, Proceedings of the 15th international conference on Supercomputing, p.321-334, June 2001, Sorrento, Italy [doi>10.1145/377792.377856]
• 7: Amir Roth , Gurindar S. Sohi, Speculative Data-Driven Multithreading, Proceedings of the 7th International Symposium on High-Performance Computer Architecture, p.37, January 20-24, 2001
• 8: U. Weiser. Personal Communication, 1995.
• 9: Craig Zilles , Gurindar Sohi, Execution-based prediction using speculative slices, Proceedings of the 28th annual international symposium on Computer architecture, p.2-13, June 30-July 04, 2001, Göteborg, Sweden

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.0 GENERAL
      Subjects: System architectures

Additional Classification:
  D. Software
  D.4 OPERATING SYSTEMS
      D.4.1 Process Management
          Subjects: Threads

General Terms:
Reliability