Propercad: a Portable Object-oriented Parallel Environment for Vlsi Cad

Most parallel algorithms for VLSI CAD proposed to date have one important drawback: they work eeciently only on machines that they were designed for. As a result, algorithms designed to date are dependent on the architecture for which they are developed and do not port easily to other parallel architectures. This paper describes a new project under way to address this problem. We have developing a Portable object-oriented parallel environment for CAD algorithms (ProperCAD). The objectives of this research are twofold. (1) To develop new parallel algorithms that are portable. We accomplish this by writing the algorithms using a platform for portable parallel programming called CHARM 6, 12] developed at the University of Illinois. Programs written using this environment run unchanged on all parallel machines for which this environment is available. (2) To design the parallel algorithms around a good sequential algorithm with a well-deened parallel-sequential interface. This will permit the parallel algorithm to beneet from future developments in sequential algorithms. We describe one CAD application that has been implemented on the ProperCAD environment: at VLSI circuit extraction. The algorithm, its implementation, and its performance on a range of parallel machines are discussed in detail. It currently runs on an Encore Multi-max, a Sequent Symmetry, an Alliant FX2800, Intel iPSC/2 and i860 hypercubes, a NCUBE 2 hypercube, and a network of Sun Sparc workstations.