Practical experiences with standard-cell based datapath design tools. Do we really need regular layouts?

Commercial tools for standard-cell based datapath design are here classed according to design flows, and the advantages of each class are discussed with the results of two test circuits. Algorithmic generation of netlists and of relative cell placement can help reducing area but, contrary to common belief appears often detrimental to speed. Extraction of regularity from synthesized netlists is difficult and requires counterproductive simplifications to the synthesis process. Most promising are synthesis tools which can generate placement data; yet, no tool of this class appears ready today.