HeLEM-GR: Heterogeneous Global Routing with Linearized Exponential Multiplier Method

Global routing (GR) plays an important role in the VLSI design flow. It not only serves as guidance for the follow-up detailed routing but also provides early design feedback for floorplanning and placement. Global routing engines are desired to provide a high-quality solution within a short time. With the design complexity growing, it becomes increasingly challenging to resolve routing overflow within affordable runtime. For example, ISPD 2024 GPU/ML-enhanced global routing contest has released large-scale industrial cases, which contain up to 50 million cells and 60 million signal nets, causing huge challenges to existing routing algorithms. In this paper, we propose HeLEM-GR, based on the linearized exponential multiplier method and heterogeneous routing kernels to achieve high-quality and ultrafast routing solutions. Our linearized exponential multiplier method can quickly reduce routing overflow. The routing process is extremely fast with GPU-enhanced massive parallelization. Experimental results demonstrate that we can achieve 4.8%-5.8% better quality scores and 1.62×-2.07× speedup compared with the top-3 winners in the ISPD 2024 contest.