[quant][core] Add Embedding and EmbeddingBag reference module (#73436)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73436
This PR adds support reference module support for Embedding and EmbeddingBag, following https://github.com/pytorch/rfcs/blob/master/RFC-0019-Extending-PyTorch-Quantization-to-Custom-Backends.md
* the reference module inherits from the corresponding float module (e.g. nn.Embedding), and the ReferenceQuantizedModule (which defines some utility functions to store qparms for a single weight)
* in forward, we first quantize and then dequantize weight (to generate the pattern) and then feed the weight to the original fp32 op
We'll connect this with fx grpah mode quantization later, in the final PR that deprecates the current convert implementation. Since current convert doesn't
support emitting quantize_per_tensor_dynamic ops, we don't want to implement it and immediately throw away the code, so might be better to just implement this
in the final flow.
Test Plan:
Will be tested later, in the final PR that deprecates the current convert implementation
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D34480325
fbshipit-source-id: bc353f3be035a364e013fa9132d0422f19120ac3
(cherry picked from commit 1722ec2f8d82e9763ef252fed5796fd09d120e34)
