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Very Long Instruction Word architectures and the ELI-512

Published: 13 June 1983 Publication History

Abstract

By compiling ordinary scientific applications programs with a radical technique called trace scheduling, we are generating code for a parallel machine that will run these programs faster than an equivalent sequential machine—we expect 10 to 30 times faster.
Trace scheduling generates code for machines called Very Long Instruction Word architectures. In Very Long Instruction Word machines, many statically scheduled, tightly coupled, fine-grained operations execute in parallel within a single instruction stream. VLIWs are more parallel extensions of several current architectures.
These current architectures have never cracked a fundamental barrier. The speedup they get from parallelism is never more than a factor of 2 to 3. Not that we couldn't build more parallel machines of this type; but until trace scheduling we didn't know how to generate code for them. Trace scheduling finds sufficient parallelism in ordinary code to justify thinking about a highly parallel VLIW.
At Yale we are actually building one. Our machine, the ELI-512, has a horizontal instruction word of over 500 bits and will do 10 to 30 RISC-level operations per cycle [Patterson 82]. ELI stands for Enormously Longword Instructions; 512 is the size of the instruction word we hope to achieve. (The current design has a 1200-bit instruction word.)
Once it became clear that we could actually compile code for a VLIW machine, some new questions appeared, and answers are presented in this paper. How do we put enough tests in each cycle without making the machine too big? How do we put enough memory references in each cycle without making the machine too slow?

References

[1]
A. V. Aho and J. D. Ullman. Principles of Compiler Design. Addison-Wesley, 1977.
[2]
Dasgupta, S. The Organization of Microprogram Stores. ACM Comp. Surv. 11(1):39-65, Mar. 1979.
[3]
J. A. Fisher. An effective packing method for use with 2n-way jump instruction hardware. In 13th annual microprogramming workshop, pages 64-75. ACM Special Interest Group on Microprogramming, November 1980.
[4]
J. A. Fisher. Trace scheduling: A technique for global microcode compaction. IEEE Transactions on Computers c-30(7):478-490, July 1981.
[5]
C. C. Foster and E. M. Riseman. Percolation of code to enhance parallel dispatching and execution. IEEE Transactions on Computers 21(12):1411-1415, December 1972.
[6]
T. R. Gross and J. L. Hennessy. Optimizing Delayed Branches. In 15th annual workshop on microprogramming, pages 114-120. ACM Special Interest Group on Microprogramming, October 1982.
[7]
J. Hennessy, N. Jouppi, S. Przbyski, C. Rowen, T. Gross, F. Baskett, and J. Gill. MIPS: A Microprocessor Architecture. In 15th annual workshop on microprogramming, pages 17-22. ACM Special Interest Group on Microprogramming, October 1982.
[8]
D. Jacobs, J. Prins, P. Siegel and K. Wilson. Monte carlo techniques in code optimization. In 15th annual workshop on microprogramming, pages 143-148. ACM Special Interest Group on Microprogramming, October 1982.
[9]
Alexandru Nicolau and Joseph A. Fisher. Using an oracle to measure parallelism in single instruction stream programs. In 14th annual microprogramming workshop, pages 171-182. ACM Special Interest Group on Microprogramming, October 1981.
[10]
D. A. Padua, D. J. Kuck, and D. H. Lawrie. High speed multiprocessors and compilation techniques. IEEE Transactions on Computers 29(9):763-776, September 1980.
[11]
D. A. Patterson, K. Lew, and R. Tuck. Towards an efficient machine-independent language for microprogramming. In 12th annual microprogramming workshop, pages 22-35. ACM Special Interest Group on Microprogramming, 1979.
[12]
D. A. Patterson and C. H. Sequin. A VLSI RISC. Computer 15(9):8-21, SEPT 1982.
[13]
E. M. Riseman and C. C. Foster. The inhibition of potential parallelism by conditional jumps. IEEE Transactions on Computers 21(12):1405-1411, December 1972.
[14]
G. S. Tjaden and M. J. Flynn. Detection and parallel execution of independent instructions. IEEE Transactions on Computers 19(10):889-895, October 1970.
[15]
Tokoro, M.; Takizuka, T.; Tamura E. and Yamaura, I. Towards an Efficient Machine-Independent Language for Microprogramming. In 11th Annual Microprogramming Workshop, pages 41-50. SIGMICRO, 1978.

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cover image ACM Conferences
ISCA '83: Proceedings of the 10th annual international symposium on Computer architecture
June 1983
424 pages
  • cover image ACM SIGARCH Computer Architecture News
    ACM SIGARCH Computer Architecture News  Volume 11, Issue 3
    June 1983
    413 pages
    ISSN:0163-5964
    DOI:10.1145/1067651
    Issue’s Table of Contents

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Published: 13 June 1983

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