2010 19th International Conference on Parallel Architectures and Compilation Techniques (PACT) (2010)
Sept. 11, 2010 to Sept. 15, 2010
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Santhosh Sharma Ananthramu , Indian Institute of Technology, Kanpur, India
Deepak Majeti , Dept. of Comp. Sci., Rice University, USA
Sanjeev Kumar Aggarwal , Indian Institute of Technology, Kanpur, India
Mainak Chaudhuri , Indian Institute of Technology, Kanpur, India
Speculative parallelization is a powerful technique to parallelize loops with irregular data dependencies. In this poster, we present a value-based selective squash protocol and an optimistic speculation reuse technique that leverages an extended notion of silent stores. These optimizations focus on reducing the number of squashes due to dependency violations. Our proposed optimizations, when applied to loops selected from standard benchmark suites, demonstrate an average (geometric mean) 2.5x performance improvement. This improvement is attributed to a 94% success in speculation reuse and a 77% reduction in the number of squashed threads compared to an implementation that, in such cases of squashes, would have squashed all the successors starting from the oldest offending one.
Mis-speculation overhead, Thread-level speculation
S. S. Ananthramu, D. Majeti, S. K. Aggarwal and M. Chaudhuri, "Improving speculative loop parallelization via selective squash and speculation reuse," 2010 19th International Conference on Parallel Architectures and Compilation Techniques (PACT), Vienna, Austria, 2010, pp. 543-544.