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Concurrency Extraction Via Hardware Methods Executing the Static Instruction Stream
July 1992 (vol. 41 no. 7)
pp. 826-841

Hardware solutions to low-level (semantic) concurrency extraction are presented, focusing on the reduction of both control-flow and dataflow inhibitors of concurrency in general-purpose and scientific instruction streams. In the first model, CONDEL-1, an input code control flow model based on the code's branch domains is used in the algorithm to detect the reduced procedural dependencies in the input code. This model allows branches to execute concurrently. The cost and delay of the model's concurrency hardware are demonstrated to be relatively low, especially for the detection of concurrency beyond branches. The reduced procedural dependence techniques of CONDEL-1 are combined with high-speed reduced data dependency techniques to yield a machine model, CONDEL-2, executing standard sequential code in a manner beyond data-flow. Simulation results are presented and analyzed, showing the model's functionality and performance improvement. The beneficial effects of limited software optimizations are also reviewed.

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Index Terms:
concurrency extraction; general-purpose streams; semantic extraction; hardware methods; static instruction stream; control-flow; dataflow inhibitors; scientific instruction streams; CONDEL-1; input code control flow model; procedural dependencies; delay; data dependency; machine model; standard sequential code; performance improvement; software optimizations; computer architecture; concurrency control; performance evaluation.
Citation:
A.K. Uht, "Concurrency Extraction Via Hardware Methods Executing the Static Instruction Stream," IEEE Transactions on Computers, vol. 41, no. 7, pp. 826-841, July 1992, doi:10.1109/12.256451
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