MP-trees: A Packing-Based Macro Placement Algorithm for Mixed-Size Designs

In this paper, we present a new multi-packing tree (MP-tree) representation for macro placement to handle mixed-size designs. Based on binary trees, the MP-tree is very efficient, effective, and flexible for handling macro placement with various constraints. Given a global placement, our MP-tree-based macro placer optimizes macro positions, minimizes the macro displacement from the initial macro positions, and maximizes the area of the chip center for standard-cell placement and routing. Experiments based on the eight ISPD´06 placement contest benchmarks show that our macro placer combined with Capo 10.2, NTUplace3, or mPL6 for standard-cell placement outperforms these state-of-the-art academic mixed-size placers alone by large margins in both robustness and quality. In addition to wirelength, experimented on five real industrial designs show that our method significantly reduce the average HPWL by 35%, the average routed wirelength by 55%, and the routing overflows than the counterpart with Capo 10.2, implying that our macro placer leads to much higher routability.