Optimal wire retiming without binary search

The problem of retiming over a netlist of macro-blocks to achieve the minimal clock period, where the block internal structures may not be changed and flip-flops may not be inserted on some wire segments, is called the optimal wire retiming problem. To the best of our knowledge, there is no polynomial-time approach to solve it and the existence of such an approach is still an open question. In this paper, we present a brand new algorithm that solves the optimal wire retiming problem with polynomial-time worst case complexity. Since the new algorithm avoids binary search and is essentially incremental, it has the potential of being combined with other optimization techniques. Experimental results show that the new algorithm is very efficient in practice.