[ONNX] Convert dynamic_shapes to dynamic_axes when fallback is triggered in torch.onnx.export #139320
Description
torch.onnx.export fallback to torchscript graph when dynamo exporting fails:
pytorch/torch/onnx/__init__.py
Line 157 in 24c9683
However, users typically does not provide both dynamic_shapes (for torch.onnx.export(..., dynamo=True)) and dynamic_axes (torch.onnx.export(..., dynamo=False)) at the same time. A conversion from dynamic_shapes to dynamic axes is needed to improve fallback user experience.
pytorch/torch/onnx/__init__.py
Line 150 in 24c9683
pytorch/torch/onnx/__init__.py
Lines 143 to 145 in 24c9683
cc @xadupre