Inverter Redistribution through Self-Dual and Self-Anti-Dual Function Transformation
For digital design automation, this work offers a modest incremental improvement in delay optimization for AIG-based synthesis flows.
The paper addresses the overlooked impact of complemented edges in AIG-based logic synthesis and introduces a pre-processing stage to redistribute inverters before technology mapping. Experimental results show an average delay reduction of 0.49% and a maximum improvement of 3.86% on arithmetic logic in EPFL benchmarks.
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.