An Effective Fixed-Outline Floorplanning Algorithm for Rectilinear Soft Modules

The increasing demand for flexible module integration necessitates the placement of rectilinear soft modules, which pose significant challenges in floorplanning, particularly under fixed-outline constraints and with pre-placed modules. In this paper, we propose an effective fixed-outline floorplanning algorithm for rectilinear soft modules. We first present electrostatics-based global floorplanning with a module-area-growing strategy to optimize the positions and dimensions of soft modules. Then, a negotiation-based legalization method is proposed to eliminate overlaps between modules, where a polygonal shape determination method for rectilinear soft modules is presented to minimize wirelength while considering polygonal shape constraints. Finally, a polygon-clipping-based refinement method is developed to further optimize both shape and wirelength. Based on the GSRC and MCNC benchmarks, experimental results demonstrate that our algorithm achieves a smaller half-perimeter wirelength (HPWL) in a reasonable runtime.