GRIP: Global Routing via Integer Programming

Abstract—This work introduces GRIP, a global routing technique via integer programming. GRIP optimizes wirelength and via cost directly without going through a traditional layer assignment phase. Candidate routes spanning all the metal layers are generated using a linear programming pricing phase that formally accounts for the impact of existing candidate routes when generating new ones. To make an integer-programmingbased approach applicable for today’s large-scale global routing instances, the original problem is decomposed into smaller subproblems corresponding to rectangular subregions on the chip together with their net assignments. Route fragments of nets that fall in adjacent subproblems are connected in a flexible manner. In case of overflow, GRIP applies a second-phase optimization that explicitly minimizes overflow. By using integer programming in an effective manner, GRIP obtains high-quality solutions. Specifically, for the ISPD 2007 and 2008 benchmarks, GRIP obtain...

• Type: Journal
• Year: 2011
• Where: TCAD
• Authors: Tai-Hsuan Wu, Azadeh Davoodi, Jeffrey T. Linderoth
• Keywords: Candidate Routes, Global Routing, Integer Programming, Software Engineering, TCAD 2011