THETO - A Fast and High-Quality Partitioning Driven Global Placer

Abstract

Partitioning driven placement approaches are often preferred for fast and scalable solutions to large placement problems. However, due to the inaccuracy of representing wirelength objective by cut objective the quality of such placements often trails the quality of placements produced by pure wirelength driven placements. In this paper we present THETO, a new partitioning driven global placement algorithm that retains the speed associated with traditional partitioning driven placement algorithms but incorporates a number of novel ideas that allows it to produce solutions whose quality is better than those produced by more sophisticated and computationally expensive algorithms. The keys to THETO's success are a new terminal propagation method that allows the partitioner to better capture the characteristics of the various cut nets and a new post-bisectioning refinement step that enhances the effectiveness of the new terminal propagation. Experiments on the ISPD98 benchmarks shows that THETO produces global placement solutions that are 6% better in terms of the half perimeter wirelength than Dragon while requiring significantly less time.