[DORT] Reduce global configs to make enabling dynamic shape easier (#16720)
There are several global configs used by DORT.
```py
DEFAULT_ONNX_EXPORTER_OPTIONS = torch.onnx._internal.exporter.ResolvedExportOptions(
torch.onnx._internal.exporter.ExportOptions()
)
# TODO(wechi): This line must generate result identical to the call of
# _create_onnx_supports_op_overload_table(...) inside
# create_onnx_friendly_decomposition_table(...) in
# torch/onnx/_internal/fx/decomposition_table.py.
_SUPPORT_DICT = torch.onnx._internal.fx.decomposition_table._create_onnx_supports_op_overload_table(
DEFAULT_ONNX_EXPORTER_OPTIONS.onnx_registry
) # type: ignore
_EXTRA_SUPPORT_DICT: Dict[str, Any] = {
"getattr": None,
"_operator.getitem": None,
}
DORT_DECOMPOSITION_TABLE = DEFAULT_ONNX_EXPORTER_OPTIONS.decomposition_table
```
We can see all but `_EXTRA_SUPPORT_DICT` are extracted from deduced from
ONNX exporter's options. As there are many ways to configure ONNX
exporter's options, we decided to move these variables to `OrtBackend`'s
`__init__` so that the construction of `OrtBackend` becomes more
flexible (especially for enabling dynamic shape or not).
onnxruntime
b71ebf91 - [DORT] Reduce global configs to make enabling dynamic shape easier (#16720)
