Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/28620
All Tensors are Variables now, they just happen to have requires_grad=False. Tensors ALWAYS have `VariableTensorId` in their type set.
When constructing this patch, I had to make decisions about what I would fix in this patch, and what I would leave for follow up PRs. Here is the cleanup that happens in this patch:
- The `is_variable` property is removed from TensorOptions. I removed this immediately because unlike Tensor::is_variable, TensorOptions::is_variable doesn't respect our VariableTensorId thread-local state. This means that there were a bunch of places where TensorOptions::is_variable was false, which is obviously bogus in the world when tensor and variable are merged. Instead of keeping the method as a function that always returns true, I just opted to remove it entirely (it's not public API.) All places we set `is_variable` are deleted.
- Knock on effect: there is no longer a separate DeprecatedTypeProperties for the variable and non-variable versions of type.
- Knock on effect: instead of asserting on TensorOptions::is_variable, instead we just test `at::impl::variable_is_excluded()`
- There is now only one copy of the cuDNN RNN dropout cache, not two (I'm not sure why we had two to begin with)
Some cleanup that doesn't happen in this patch:
- Eliminating unnecessary uses of `make_variable`
- Eliminating `Tensor::is_variable`
The most subtle part of this patch is retaining tracing behavior: the fact that everything is a Variable means that more code gets routed to VariableType than before; this can change traces. I identified two places where we didn't appropriately turn off VariableType, mostly factory functions:
- `torch.tensor` must turn off VariableType before invoking `at::empty` to construct the tensor, as it subsequently does direct data access
- `tensor_slow` (invoked when you pass a Python scalar to a tensor argument) must turn off VariableType before calling `scalar_to_tensor` so the scalar gets traced as constant, rather than as a call to `scalar_to_tensor`.
Honestly, these are all giant hacks, and should be replaced with a more specialized guard that just toggles tracing.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: dreiss
Differential Revision: D18171156
Pulled By: ezyang
fbshipit-source-id: 5b6a045beba37492647e350190f495114e86504d
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25467
Use Layout/Device more directly in these cases.
ghstack-source-id: 89289651
Test Plan: sandcastle and ossci
Differential Revision: D17131883
fbshipit-source-id: ab3c6d1c879b7f26f20a2378364c852dc37508fc
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24393
Ability to register hook on a variable, similar to python autograd API. register_hook will take a function as argument and create a CppFunctionPreHook similar to PyFunctionPreHook.
It will return the index of the hook which can be passed to remove_hook to disable the hook.
Test Plan: Added tests.
Differential Revision: D16861722
fbshipit-source-id: d08047f932e38c7bde04283a18b2d0311c8ad604
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23618
For example: `save_for_backward({Variable(), x, Variable()})` should be allowed, so that this is consistent with the python API behaviour.
Test Plan: Added a test similar to the python test `test_save_none_for_backward` from test_autograd.py.
Differential Revision: D16589402
fbshipit-source-id: 847544ad8fc10772954d8629ad5a62bfdc1a66c1
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23572
### **(The stack from #23020 was moved into this PR)**
Adding API for custom autograd operations, with user defined forward and backward, [like in python](https://pytorch.org/docs/stable/notes/extending.html#extending-torch-autograd).
The custom operation should be a subclass of Function, with static forward and backward functions. `forward()` can accept any arguments similar to the Python API and `backward()` should accept a variable list as an argument.
Both `forward()` and `backward() `accept a AutogradContext* which can be used to share data between them.
Variables can be saved in the context using `save_for_backward()` and other data can be saved in the map `save` in the form of `<std::string, at::IValue>` pairs. Variables saved in forward can be accessed with `get_saved_variables()`.
Example usage:
```
class MyFunction : public Function<MyFunction> {
public:
static variable_list forward(AutogradContext *ctx, int n, Variable var) {
// Save data for backward in context
ctx->saved_data["n"] = n;
return {var};
}
static variable_list backward(AutogradContext *ctx, variable_list grad_output) {
// Use data saved in forward
auto n = ctx->saved_data["n"].toInt();
return {grad_output[0]*n};
}
};
```
Then, it can be used with:
```
Variable x;
MyFunction::apply(6, x);
```
Also AutogradContext has methods to mark outputs as non differentiable and mark inputs as dirty similar to the [Python API](ff23a02ac4/torch/autograd/function.py (L26)).
Test Plan: Added tests for the custom autograd function API based on test_autograd.py. Currently only the tests for the basic functionality have been added. More tests will be added later.
Differential Revision: D16583428
fbshipit-source-id: 0bd42f19ce37bcd99d3080d16195ad74d40d0413
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/22631
Test Plan:
test suite
Imported from OSS
Differential Revision: D16185040
fbshipit-source-id: 9b83749f6c9cd05d13f54a3bb4801e263293252b
