SPDFA: A Novel Dataflow Fusion Sparse Deep Neural Network Accelerator

Unstructured sparse pruning significantly reduces the computational and parametric complexities of deep neural network models. Nevertheless, the highly irregular nature of sparse models limits their performance and efficiency on traditional computing platforms, thereby prompting the development of specialized hardware solutions. To improve computational efficiency, we introduce the Sparse Dataflow Fusion Accelerator (SPDFA), a specialized architecture meticulously designed for sparse deep neural networks. Firstly, we present a non-blocking data distribution-computing engine that integrates inner product and column product. This engine boosts computational efficiency by decomposing matrix multiplication and convolution into rectangular matrix-vector multiplications. Secondly, we implement a computation array to further exploit the parallelism, and design an on-chip buffer structure that supports multi-line memory access mode. Lastly, to bolster the adaptability of our accelerator, we propose an innovative macroinstruction set coupled with a micro-kernel scheme. Furthermore, we refine the macroinstruction issue strategy, thereby further enhancing computational efficiency. Our evaluation results demonstrate that SPDFA achieves an average 1.29 \(\times\) –2.38 \(\times\) improvement in computational efficiency compared to the state-of-the-art SpMM accelerators when applied to unstructured sparse deep neural network models. Furthermore, its performance outperforms existing sparse neural network accelerators by a factor of 1.03 \(\times\) –1.83 \(\times\) . Additionally, SPDFA exhibits excellent scalability with a scaling efficiency exceeding 80%.