An experimental environment for design and analysis of global routing heuristics

The authors discuss the development and implementation of an object-oriented experimental environment for global routing heuristics in VLSI layout design. This experimental environment has been implemented in both common lisp (with object-oriented extensions) and Smalltalk, providing a user-friendly graphical interface for problem input, output, interaction and modification of the heuristics. Several heuristics have been implemented, some of which use only local information, while others use global information concerning the instance of the problem. All heuristics seem to have good average case performance, and from the results it is concluded that, also on average, multi-turn routings do not provide a significant improvement over one-turn routings