Inverter Redistribution through Self-Dual and Self-Anti-Dual Function Transformation

TL;DR

This paper presents a delay-driven pre-processing technique for AIG-based logic synthesis that redistributes complemented edges to improve delay performance during technology mapping.

Contribution

It introduces a novel inverter redistribution method using self-dual and self-anti-dual function transformations to optimize delay in logic synthesis.

Findings

Achieved an average delay reduction of 0.49% on benchmarks.

Maximum delay improvement of 3.86% on the sqrt case.

Method preserves original delay characteristics while enhancing performance.

Abstract

And-Inverter Graph (AIG)-based logic synthesis has been a cornerstone of digital design automation for several decades. While numerous optimization techniques have been developed for both technology-independent and technology-dependent synthesis stages, existing technology mapping approaches predominantly employ graph-covering strategies directly on AIG representations without adequately addressing complemented edge distribution. Neglecting inverters creates a significant disconnect: complemented edges are systematically overlooked in technology-independent cost functions, yet they abruptly become critical during technology-dependent mapping. In this work, we introduce a delay-driven pre-processing stage that operates prior to technology mapping, designed to strategically redistribute complemented edges and mitigate the inverter-induced costs on critical paths. Experimental validation demonstrates that our delay-targeted methodology not only preserves original delay characteristics but also enables performance improvements. Notably, arithmetic logic in the EPFL combinational benchmark exhibits particular sensitivity to this approach, with our method achieving an average delay reduction of 0.49% and a maximum improvement of 3.86% on the case sqrt.