Challenges of cell selection algorithms in industrial high performance microprocessor designs

• State-of-the-art cell selection algorithm applied in an industrial design flow.
• The challenges found, some solutions and preliminary results.
• Experiments using high-performance microprocessor blocks with modern cell library.
• Discuss challenges and requirements yet to be solved to further stimulate research.
• Results show how usual formulations fail when directly applied to industrial flows.
• Also show that current industrial algorithms do not provide near-optimal solutions.

Timing-constrained power-driven gate sizing has aroused lot of research interest after the recent discrete gate sizing contests organized by International Symposium on Physical Design. Since then, there are plenty of research papers published and new algorithms are proposed based on the contest formulation. However, almost all (new and old) papers in the literature ignore the details of how power-driven gate sizing fits in industrial physical synthesis flows, which limits their practical usage. This paper aims at filling this knowledge gap. We explain our approach to integrate a state-of-the-art Lagrangian Relaxation-based gate sizing into our actual physical synthesis framework, and explain the challenges and issues we observed from the point of view of VLSI design flows.