Recursive bisection based placement is well known, and recent advances in partitioning have made the approach more attractive. While partitioners can optimize a placement from a local perspective, high performance design requires consideration of global issues as well. We focus on aspects of the placement problem which cannot be captured with bisection, addressing them through a new approach derived from recent work on k-way partitioning. We consider large values of k, and objective functions which are more complex than the traditional min-cut. Our placement tool, Feng Shui, integrates this new k-way partitioning method into a traditional recursive bisection framework. Experimental results show the effect of the approach; there is reduced variation in solution quality, in 8 of 11 benchmarks best case wire length is improved, and for 9 of 11 benchmarks, average wire length is improved. These improvements are obtained with negligible impact to total run time.
This paper considers parallelizing a placement tool (called Feng Shui REF ) developed by two of the authors.
Global objectives for standard cell placement
GLSVLSI '01
Computer Science