Update `register_custom_op_symbolic`'s behavior to _only register the symbolic function at a single version_. This is more aligned with the semantics of the API signature.
As a result of this change, opset 7 and opset 8 implementations are now seen as fallback when the opset_version >= 9. Previously any ops internally registered to opset < 9 are not discoverable by an export version target >= 9. Updated the test to reflect this change.
The implication of this change is that users will need to register a symbolic function to the exact version when they want to override an existing symbolic. They are not impacted if (1) an implementation does not existing for the op, or (2) they are already registering to the exact version for export.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85636
Approved by: https://github.com/BowenBao
This is the 4th PR in the series of #83787. It enables the use of `@onnx_symbolic` across `torch.onnx`.
- **Backward breaking**: Removed some symbolic functions from `__all__` because of the use of `@onnx_symbolic` for registering the same function on multiple aten names.
- Decorate all symbolic functions with `@onnx_symbolic`
- Move Quantized and Prim ops out from classes to functions defined in the modules. Eliminate the need for `isfunction` checking, speeding up the registration process by 60%.
- Remove the outdated unit test `test_symbolic_opset9.py`
- Symbolic function registration moved from the first call to `_run_symbolic_function` to init time.
- Registration is fast:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84448
Approved by: https://github.com/AllenTiTaiWang, https://github.com/BowenBao
## Summary
The change brings the new registry for symbolic functions in ONNX. The `SymbolicRegistry` class in `torch.onnx._internal.registration` replaces the dictionary and various functions defined in `torch.onnx.symbolic_registry`.
The new registry
- Has faster lookup by storing only functions in the opset version they are defined in
- Is easier to manage and interact with due to its class design
- Builds the foundation for the more flexible registration process detailed in #83787
Implementation changes
- **Breaking**: Remove `torch.onnx.symbolic_registry`
- `register_custom_op_symbolic` and `unregister_custom_op_symbolic` in utils maintain their api for compatibility
- Update _onnx_supported_ops.py for doc generation to include quantized ops.
- Update code to register python ops in `torch/csrc/jit/passes/onnx.cpp`
## Profiling results
-0.1 seconds in execution time. -34% time spent in `_run_symbolic_function`. Tested on the alexnet example in public doc.
### After
```
└─ 1.641 export <@beartype(torch.onnx.utils.export) at 0x7f19be17f790>:1
└─ 1.641 export torch/onnx/utils.py:185
└─ 1.640 _export torch/onnx/utils.py:1331
├─ 0.889 _model_to_graph torch/onnx/utils.py:1005
│ ├─ 0.478 _optimize_graph torch/onnx/utils.py:535
│ │ ├─ 0.214 PyCapsule._jit_pass_onnx_graph_shape_type_inference <built-in>:0
│ │ │ [2 frames hidden] <built-in>
│ │ ├─ 0.190 _run_symbolic_function torch/onnx/utils.py:1670
│ │ │ └─ 0.145 Constant torch/onnx/symbolic_opset9.py:5782
│ │ │ └─ 0.139 _graph_op torch/onnx/_patch_torch.py:18
│ │ │ └─ 0.134 PyCapsule._jit_pass_onnx_node_shape_type_inference <built-in>:0
│ │ │ [2 frames hidden] <built-in>
│ │ └─ 0.033 [self]
```
### Before
### Start up time
The startup process takes 0.03 seconds. Calls to `inspect` will be eliminated when we switch to using decorators for registration in #84448
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84382
Approved by: https://github.com/AllenTiTaiWang, https://github.com/BowenBao
