ProperCAD: A portable object-oriented parallel environment for VLSI CAD

Most parallel algorithms for VLSI CAD proposed to date work efficiently only on machines that they were designed for. As a result, these algorithms are dependent on the architecture for which they are developed and do not port easily to other parallel architectures. In an effort to address this problem, we are developing a Portable object-oriented parallel environment for CAD algorithms (ProperCAD). The objectives of this research are two-fold: 1) To develop new parallel algorithms that run in a portable object-oriented environment. We accomplish this in two stages. First, we develop CAD algorithms using a general purpose platform for portable parallel programming called CHARM developed at the University of Illinois. Concurrently, we are developing a C++ environment that is truly object-oriented and specialized for CAD applications; and 2) To design the parallel algorithms around a good sequential algorithm with a well-defined parallel-sequential interface. This will permit the parallel algorithm to benefit from future developments in sequential algorithms. This approach is described using one CAD application that has been implemented as part of this project-ProperEXT: a flat extractor for VLSI circuits. The algorithm, its implementation, and performance of ProperEXT on a range of parallel machines is presented. The implementation is portable across a variety of parallel platforms without change. It currently runs on an Encore Multimax, a Sequent Symmetry, Inter iPSC/2 and i860 hypercubes, a NCUBE 2 hypercube and a network of Sun Sparc workstations