DynaFlow: An ML Framework for Dynamic Dataflow Selection in SpGEMM Accelerators

Sparse matrix-matrix multiplication (SpGEMM) is a critical operation in numerous fields, including scientific computing, graph analytics, and deep learning, leveraging matrix sparsity to reduce both storage and computation costs. However, the irregular structure of sparse matrices poses significant challenges for performance optimization. Existing hardware accelerators often employ fixed dataflows designed for specific sparsity patterns, leading to performance degradation when the input deviates from these assumptions. As SpGEMM adoption expands across a broad spectrum of sparsity workloads, the demand grows for accelerators capable of dynamically adapting their dataflow schemes to diverse sparsity patterns. To address this, we propose DynaFlow, a machine learning-based framework that trains on the set of dataflows supported by any given accelerator and learns to predict the optimal dataflow based on the input sparsity pattern. By leveraging decision trees and deep reinforcement learning, DynaFlow surpasses static dataflow selection approaches, achieving up to a 50× speedup.