Yu, Yijun and D'Hollander, E. H.
Non-uniform dependences partitioned by recurrence chains.
In: 2004 International Conference on Parallel Processing (ICPP'04), 15-18 Aug 2004, Montreal, Canada.
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Non-uniform distance loop dependences are a known obstacle to find parallel iterations. To find the outermost loop parallelism in these ï¿½irregularï¿½ loops, a novel method is presented based on recurrence chains. The scheme organizes non-uniformly dependent iterations into lexicographically ordered monotonic chains. While the initial and final iteration of monotonic chains form two parallel sets, the remaining iterations form an intermediate set that can be partitioned further. When there is only one pair of coupled array references, the non-uniform dependences are represented by a single recurrence equation. In that case, the chains in the intermediate set do not bifurcate and each can be executed as a WHILE loop. The independent iterations and the initial iterations of monotonic dependence chains constitute the outermost parallelism. The proposed approach compares favorably with other treatments of nonuniform dependences in the literature. When there are multiple recurrence equations, a dataflow parallel execution can be scheduled using the technique extensively to find maximum loop parallelism.
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||WHILE loop; data flow execution; loop parallelism; nonuniform distance loop dependence; parallel iteration; recurrence chain; recurrence equation
||Mathematics, Computing and Technology > Computing
|Interdisciplinary Research Centre:
||Centre for Research in Computing (CRC)
||22 Feb 2011 11:42
||22 Feb 2011 18:42
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