We now have two types of functionalization, C++ Functionalization (through the `Functionalize` dispatch key), and python functionalization (through the `FunctionalTensorMode` torch_dispatch mode).
This means that all higher order ops need custom functionalization rules for the python variant too. I added them here, as well as a helper function `dispatch_functionalize()` - equivalent to `torch.func.functionalize()`, except that it uses `FunctionalTensorMode`.
In theory we could have secretly switched `torch.func.functionalize` to use `FunctionalTensorMode`. This would be BC-breaking, though, since `FunctionalTensorMode` isn't composable with the other functorch transforms (the functorch layer-mode stack doesn't know how to re-order torch_dispatch modes arbitrarily).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108656
Approved by: https://github.com/zou3519
ghstack dependencies: #109024, #109248
Fix: #107315
This PR enables dynamo to trace through the `pytree` API by inlining its functions. In
order to do so, a few details of `pytree` had to be changed.
In summary, this PR:
- Introduces `TreeSpecVariable` for representing `TreeSpec` instances
- Specializes `<type>.__bases__` call, returning a `TupleVariable`
- Enables the call to `id` builtin function for every variable that implements
`as_python_constant` method
- Specializes `ConstantVariable.call_method` for its (un)flatten functions
- Implements `UserDefinedObjectVariable.as_python_constant`
- Modifies `pytree` by:
- Make `SUPPORTED_NODES` a map of ids (instead of types) to `NodeDef`
- Removed `functools.wraps` function, since it can't be inlined
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108533
Approved by: https://github.com/ezyang, https://github.com/voznesenskym
ghstack dependencies: #109201
