[quant][fx][pt2e] Refactor prepare so it's aligned better with the new API plan in pt2e (#94011)
Summary:
There are three things that happens in the current prepare code,
(1). user express their intention of how they want the model to be quantized with QConfigMapping, we translate that to
node.meta["target_dtype_info"]
(2). we validate the setting against BackendConfig
(3). insert observers based on the validated node.meta["target_dtype_info"]
previously (2) and (3) are mixed together, this PR tries to move (2) closer to (1), with one edge case left, this refactor
moves us closer to our target design for quantization in pytorch 2.0 export path
this is a follow up PR for https://github.com/pytorch/pytorch/pull/92641
Test Plan:
python test/test_quantization.py TestQuantizeFx
python test/test_quantization.py TestQuantizeFxOps
python test/test_quantization.py TestQuantizeFxModels
Reviewers:
Subscribers:
Tasks:
Tags:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94011
Approved by: https://github.com/vkuzo
