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arXiv · 2012.15701

BinaryBERT: Pushing the Limit of BERT Quantization

Haoli Bai·Wei Zhang·Lu Hou·Lifeng Shang·Jing Jin·Xin Jiang·Qun Liu·Michael Lyu·Irwin King
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Abstract

The rapid development of large pre-trained language models has greatly increased the demand for model compression techniques, among which quantization is a popular solution. In this paper, we propose BinaryBERT, which pushes BERT quantization to the limit by weight binarization. We find that a binary BERT is hard to be trained directly than a ternary counterpart due to its complex and irregular loss landscape. Therefore, we propose ternary weight splitting, which initializes BinaryBERT by equivalently splitting from a half-sized ternary network. The binary model thus inherits the good performance of the ternary one, and can be further enhanced by fine-tuning the new architecture after splitting. Empirical results show that our BinaryBERT has only a slight performance drop compared with the full-precision model while being 24x smaller, achieving the state-of-the-art compression results on the GLUE and SQuAD benchmarks.

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Haoli Bai, Wei Zhang, Lu Hou, Lifeng Shang, Jing Jin, Xin Jiang, Qun Liu, Michael Lyu, Irwin King. 2021-07-22. BinaryBERT: Pushing the Limit of BERT Quantization. https://arxiv.org/abs/2012.15701

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