Summary:
The goal is to implement cross layer equalization as described in section 4.1 in this paper: https://arxiv.org/pdf/1906.04721.pdf
Given two adjacent submodules in a trained model, A,B quantization might hurt one of the submodules more than the other. The paper poses the idea that a loss in accuracy from quantizing can be due to a difference in the channel ranges between the two submodules (the output channel range of A can be small, while the input channel range of B can be large). To minimize this source of error, we want to scale the tensors of A,B s.t. their channel ranges are equal (them being equal means no difference in ranges and minimizes this source of error).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41685
Test Plan: Imported from OSS
Reviewed By: z-a-f
Differential Revision: D22630219
Pulled By: edmundw314
fbshipit-source-id: ccc91ba12c10b652d7275222da8b85455b8a7cd5
