FPGAN: An FPGA Accelerator for Graph Attention Networks With Software and Hardware Co-Optimization

The Graph Attention Networks (GATs) exhibit outstanding performance in multiple authoritative node classification benchmark tests (including transductive and inductive). The purpose of this research is to implement an FPGA-based accelerator called FPGAN for graph attention networks that achieves significant improvement on performance and energy efficiency without losing accuracy compared with PyTorch baseline. It eliminates the dependence on digital signal processors (DSPs) and large amounts of on-chip memory and can even work well on low-end FPGA devices. We design FPGAN with software and hardware co-optimization across the full stack from algorithm through architecture. Specifically, we compress model to reduce the model size, quantify features to perform fixed-point calculation, replace multiplication addition cell (MAC) with shift addition units (SAUs) to eliminate the dependence on DSPs, and design an efficient algorithm to approximate SoftMax function. We also adjust the activation functions and fuse operations to further reduce the computation requirement. Moreover, all data is vectorized and aligned for scalable vector computation and efficient memory access. All the above optimizations are integrated into a universal hardware pipeline for various structures of GATs. We evaluate our design on an Inspur F10A board with an Intel Arria 10 GX1150 and 16 GB DDR3 memory. Experimental results show that FPGAN can achieve 7.34 times speedup over Nvidia Tesla V100 and 593 times over Xeon CPU Gold 5115 while maintaining accuracy, and 48 times and 2400 times on energy efficiency respectively.