Inspired by recent success of analytical placers that use a logarithmsum-exponential (LSE) to smooth half-perimeter wirelength (HPWL), we consider in this paper two alternative smoothing methods for HPWL by recursive extension of two-variable max functions. A limited memory Quasi-Newton solver is applied to solve the objective function combining both the smoothing function of HPWL and the penalty function that arises from cell density constraints. Experimental results show that our flow using these two smoothing functions and the solver produces placements with comparable HPWL compared to LSE smoothing-based methods. Our placement flow also produces placements with comparable routability and routed wirelength but with shorter runtime. 1.

APlace is a high quality, scalable analytical placer. This paper describes our recent efforts to improve APlace for speed and scalability. We explore various wirelength and density approximation functions. We speed up the placer using a hybrid usage of wirelength and density approximations during the course of multi-level placement, and obtain 2-2.5 times speedup of global placement on the IBM ISPD04 and ISPD05 benchmarks. Recent applications of the APlace framework to supply voltage degradation-aware placement and lens aberration-aware timing-driven placement are also briefly described.