Floorplanning with graph attention

Floorplanning has long been a critical physical design task with high computation complexity. Its key objective is to determine the initial locations of macros and standard cells with optimized wirelength for a given area constraint. This paper presents Flora, a graph attention-based floorplanner to learn an optimized mapping between circuit connectivity and physical wirelength, and produce a chip floorplan using efficient model inference. Flora has been integrated with two state-of-the-art mixed-size placers. Experimental studies using both academic benchmarks and industrial designs demonstrate that compared to state-of-the-art mixed-size placers alone, Flora improves placement runtime by 18%, with 2% wirelength reduction on average.