19. The apparatus of claim 15 , wherein said partitioning the circuit design comprises creating a set of partitions corresponding to the set of clusters and assigning each cell to a partition in the set of partitions based on the set of probability values.
19. The apparatus of claim 15 , wherein said partitioning the circuit design comprises creating a set of partitions corresponding to the set of clusters and assigning each cell to a partition in the set of partitions based on the set of probability values. 20. The apparatus of claim 19 , wherein said optimizing the placed circuit design comprises performing an iterative optimization process to optimize an objective function based on the placed circuit design, wherein in each iteration of the iterative optimization process at least one cell is reassigned to a different layout bin based on the set of probability values, and wherein the iterative optimization process is terminated when the optimization function improves less than a minimum improvement threshold between two consecutive iterations or a maximum iteration limit is reached.