Large-Scale Fixed-Outline Floorplanning Design Using Convex Optimization

A two-stage optimization methodology is proposed to solve the fixed-outline floorplanning problem that is a global optimization problem for wirelength minimization. In the first stage, an attractor-repeller convex optimization model provides the relative positions of the modules on the floorplan. The second stage places and sizes the modules using second-order cone optimization. With the relative positions of modules obtained from the first stage, a Voronoi diagram is employed to obtain a planar graph and thus a relative position matrix to connect the two stages. An efficient approach to generate sparse relative position matrices and an interchange-free algorithm for local improvement of the floorplan are also presented in this paper. Overlap-free and deadspace-free floorplans are achieved in a fixed outline and floorplans with any specified percentage of whitespace can be produced. Experimental results on MCNC and GSRC benchmarks demonstrate that we obtain significant improvements on the best results in the literature for these benchmarks. Most importantly, our methodology provides greater improvement over other floorplanners as the number of modules increases.