Faster minimization of linear wirelength for global placement

A linear wirelength objective more e ectively captures timing, congestion, and other global placement considerations than a squared wirelength objective. The GORDIAN-L cell placement tool 19 minimizes linear wirelength by rst approximating the linear wirelength objective by a modi ed squared wirelength objective, then executing the following loop 1 minimize the current objective to yield some approximate solution, and 2 use the resulting solution to construct a more accurate objective until the solution converges. This paper shows how to apply a generalization 5, 6 of a 1937 algorithm due to Weiszfeld 22 to placement with a linear wirelength objective, and that the main GORDIAN-L loop is actually a special case of this algorithm. We then propose applying a regularization parameter to the generalized Weiszfeld algorithm to control the tradeo between convergence and solution accuracy; the GORDIAN-L iteration is equivalent to setting this regularization parameter to zero. We also app...

• Type: Conference
• Year: 1997
• Where: ISPD
• Authors: Charles J. Alpert, Tony F. Chan, Dennis J.-H. Huang, Andrew B. Kahng, Igor L. Markov, Pep Mulet, Kenneth Yan
• Keywords: Hardware, ISPD 1997, Linear Wirelength Objective, Minimizes Linear Wirelength, Squared Wirelength Objective