Fine-grained parallel VLSI synthesis for commercial CAD on a network of workstations

We present a fine-grained parallel processing scheme for speeding up an industrial VLSI synthesis tool on a network of workstations without sacrificing the quality of results. The synthesis tool is Ambit BuildGates, a high-capacity ASIC logic synthesis software from Cadence Design Systems. We examine some necessary operating conditions for a practical parallel implementation of such a software, and propose a parallel approach which accommodates for the highly-irregular computation requirements in synthesis and the high-latency, low-bandwidth conditions of the target environment. For pragmatic as well as performance concerns, we designed a parallel algorithm which produces results (synthesized logic) that are identical to those of the original uniprocessor algorithm. We employ heuristic load assessment and adaptive cyclic distribution in order to actively balance the unpredictable load throughout execution, which enables a considerable reduction in runtime (i.e. 51.3 hours down to 23.4 hours) on actual customer design benchmarks.