A Framework for Accelerating Transformer-Based Language Model on ReRAM-Based Architecture

Abstract

Transformer-based language models have become the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">de-facto</i> standard model for various natural language processing (NLP) applications given the superior algorithmic performances. Processing a transformer-based language model on a conventional accelerator induces the memory wall problem, and the ReRAM-based accelerator is a promising solution to this problem. However, due to the characteristics of the self-attention mechanism and the ReRAM-based accelerator, the pipeline hazard arises when processing the transformer-based language model on the ReRAM-based accelerator. This hazard issue greatly increases the overall execution time. In this article, we propose a framework to resolve the hazard issue. First, we propose the concept of window self-attention to reduce the attention computation scope by analyzing the properties of the self-attention mechanism. After that, we present a window-size search algorithm, which finds an optimal window size set according to the target application/algorithmic performance. We also suggest a hardware design that exploits the advantages of the proposed algorithm optimization on the general ReRAM-based accelerator. The proposed work successfully alleviates the hazard issue while maintaining the algorithmic performance, leading to a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.8\times $ </tex-math></inline-formula> speedup over the provisioned baseline. It also delivers up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$39.2\times /643.2\times $ </tex-math></inline-formula> speedup/higher energy efficiency over GPU, respectively.