Using data-mining techniques to improve combinatorial optimization algorithms

Abstract

In this work, we show how data-mining can be used to cluster algorithmic generated data and use that data to improve algorithms that solve combinatorial optimization problems for a real-world application—the field-programmable gate array placement problem. Our methodology is a means for other algorithm engineers to improve their own algorithms for specific real-world problems that are hard to improve. In our case, the placement algorithms are difficult to improve, and to find better heuristics we analyze the results of placement solutions to find clustered information which can then be used to improve the algorithms. Specifically, we show a technique for gathering cluster information about placement, we create a new simulated annealing algorithm and a new genetic algorithm that can deal with a mixed granularity of placement objects on a virtual field-programmable gate array, and we show that these algorithms either execute faster or improve the overall quality of solution compared to their basic algorithm without this clustering data and improved heuristics. For our improved simulated annealing placer we improve the algorithms run-time by 17% across a range of benchmarks, and our genetic algorithm improves placement metrics—-critical path by 10% and channel-width by 4%.