An Efficient Approximate Node Merging with an Error Rate Guarantee

Abstract

Approximate computing is an emerging design paradigm for error-tolerant applications. e.g., signal processing and machine learning. In approximate computing, the area, delay, or power consumption of an approximate circuit can be improved by trading off its accuracy. In this paper, we propose an approximate logic synthesis approach based on a node-merging technique with an error rate guarantee. The ideas of our approach are to replace internal nodes by constant values and to merge two similar nodes in the circuit in terms of functionality. We conduct experiments on a set of IWLS 2005 and MCNC benchmarks. The experimental results show that our approach can reduce area by up to 80%, and 31% on average. As compared with the state-of-the-art method, our approach has a speedup of 51 under the same 5% error rate constraint.