- `FakeContext` hides all fields other than ctx.saved_tensors, this dynamo errors when the autograd.Function.backward uses other attrs on ctx and it also doesn't allow fallback to eager.
- If we remove it, we still can't fallback to eager: node variables are already freed (ctx.saved_tensors throws)
- However, we can fallback to "pseudo-eager" by using a duck-typed ctx and routing the ctx.saved_tensors to lifted tensors
- Dynamo tries to inline external_utils.call_backward, treats BackwardCFunction as a AutogradFunctionContextVariable (only used up until we create the fake context: FakeBackwardCFunction)
- we call_function backward from the forward class AutogradFunctionVariable, and we still pass in the fake context as a UserDefinedObjectVariable (can later use AutogradFunctionContextVariable + HOO graph speculate)
Fixes#125489#124827
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125661
Approved by: https://github.com/jansel
This allows `associative_scan` to take an arbitrary pytree of tensors,
which is flattened to their leaves before calling the `associative_scan`
higher order operator.
I also add support in inductor to generate code for scanning over sequences
of tensors.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/122137
Approved by: https://github.com/lezcano, https://github.com/Chillee
ghstack dependencies: #119430
While there are some similarities, they are also quite different (one
handles Numpy numbers while the other handles ints. I am also going to
add a wrap_symfloat soon which will do even more different behavior.
So split these out for clarity.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125483
Approved by: https://github.com/lezcano
ghstack dependencies: #125395, #125419
A common complaint when working with data-dependent code in PyTorch is that it's hard to tell how far you are from the finish line: every time a GuardOnDataDependentSymNode error is hit, you have to somehow fix or workaround it to see the next one.
This PR adds a new mode `torch._functorch.config.fake_tensor_propagate_real_tensors` which modifies fake tensors to also propagate real tensors. This means that when we try to guard on a data-dependent SymNode, we can actually produce a real result. We also produce a warning which you should consult to figure out what the crux points are.
I ran this on vision_maskrcnn. In the baseline (without this mode), the model has 27 graph breaks, resulting in 40 graphs. With this mode on, the model has only 11 graph breaks, resulting in 15 graphs (the remaining graph breaks are due to missing functionality for item() on float tensor and some other Dynamo missing features.) You get a list of things that would have errored like this:
```
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Max(1, u1) < 2) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u1), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u1), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Ne(Max(1, u1), 1)) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Max(1, u0) < 2) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u0), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u0), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Ne(Max(1, u0), 1)) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Max(1, u1) < 2) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u1), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u1), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Ne(Max(1, u1), 1)) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Max(1, u0) < 2) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u0), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u0), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Ne(Max(1, u0), 1)) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Max(1, u1) < 2) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u1), 1)) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Ne(Max(1, u1), 1)) -> True
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Max(1, u0) < 2) -> False
WARNING:torch.fx.experimental.symbolic_shapes:propagate_real_tensors evaluate_expr(Eq(Max(1, u0), 1)) -> False
```
Potential later follow ups:
* Improve the warning messages (in particular, should provide user frames)
* GC real tensors when they are no longer needed by tracing. Right now, this will use A LOT of memory, equal to as if your GC was broken and every intermediate tensor was kept live
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125115
Approved by: https://github.com/IvanKobzarev
To fix data-dependent errors we want to recommend that people use `torch._check*` APIs. The `constrain_as*` APIs should be fully subsumed by them, and in the future we should kill them entirely.
Differential Revision: D56774333
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125253
Approved by: https://github.com/ezyang
Fix https://github.com/pytorch/pytorch/issues/124900.
When we reconstruct `ContextWrappingVariables`s, we only reconstruct the context class, not the object. Normally, contexts are active (via `with ctx:`) and we initialize the context object in the resume function. But for the case of inactive contexts (contexts declared ahead of time before the `with` block), we do not reconstruct them properly in the optimized bytecode or resume function. So this PR adds initialization for inactive contexts in the resume function.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125203
Approved by: https://github.com/jansel
# Summary
This is part one of adding backwards support to FlexAttention.
This PR focuses on the eager implementation and wiring up enough of the templated_attention_backward(name change soon 😉) to get through aot_eager.
Notably this does not actually wire up the triton template just yet in order to make this PR easier to review. That will be the next follow up PR.
#### Structure
We pass both the forward and backward graph to the backwardsHOP since these are both needed to be inlined into the calculation for backwards:
- the forward graph is needed in order to re-compute the scores
- the joint graph is needed in order to construct the correct gradients post softmax_grad calc
### Attatched AOT Graph
https://gist.github.com/drisspg/ce4c041f8df8a5a7983c5174705cf2b5
Pull Request resolved: https://github.com/pytorch/pytorch/pull/123902
Approved by: https://github.com/Chillee
This PR is to add support for tensor's is_complex method in dynamo. Take the following code as an example:
```python
def test_tensor_is_complex(x):
if x.is_complex():
return x + 1
else:
return x - 1
```
Before this fix, the is_complex() call will cause a graph break "torch.* op returned non-Tensor bool call_method is_complex". After this fix, the graph break can be avoided.
Fixes#122692
Pull Request resolved: https://github.com/pytorch/pytorch/pull/124927
Approved by: https://github.com/ezyang
We guard on key order
1) When a key is a non-constant object
2) When we actually need key order - like .values, .items etc
For dicts/OrderedDicts that do not require key order guarding, we just rely on usual `GuardManger + DictGetItemGuardAccessor`. This is faster than going through the `list(d.keys())` based design for OrderedDicts.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/124779
Approved by: https://github.com/jansel
Update ruff to 0.4.1 .
This version fixes a lot false negatives/false positives, is 20-40% faster, and has various other bug fixes.
Below is a before and after table showing the execution time of ruff lint and ruff format in milliseconds courtesy of https://astral.sh/blog/ruff-v0.4.0
| Repository | Linter (v0.3) | Linter (v0.4) | Formatter (v0.3) | Formatter (v0.4) |
|----------------------------------------------------|---------------|---------------|------------------|------------------|
| [pytorch/pytorch](https://github.com/pytorch/pytorch) | 328.7 | 251.8 | 351.1 | 274.9 |
Pull Request resolved: https://github.com/pytorch/pytorch/pull/124549
Approved by: https://github.com/ezyang
