The idea is the parent hop's fake tensor mode should ignore the newly allocated unbacked symints in subgraph because the bindings of unbacked symbols in the subgraph should already be done when we trace the subgraph. E.g. if there's an operator in subgraph that produces unbacked symints, the track_tensor_tree logic for that operator will take care of it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/142031
Approved by: https://github.com/zou3519
ghstack dependencies: #142162
* Automatically applies ruff rule 401. Turns loops into equivalent list comprehensions which are faster and do not leak the scope of the loop variables.
* list comprehensions not only often have better typing, but are 50+% faster than for loops on overhead. They also preserve length information etc and are better for the interpreter to optimize.
* Manually went back and made mypy happy after the change.
* Also fixed style lints in files covered by flake8 but not by pyfmt
Pull Request resolved: https://github.com/pytorch/pytorch/pull/140980
Approved by: https://github.com/justinchuby, https://github.com/malfet
There are 4 parts (they are hard to further break into smaller ones cause they're highly coupled) in this PR:
1. **Whenever we call create_graph_input, we try to bind the symbols in the graph input.**
We've enforced the invariant that all create_graph_inputs calls must provide an example value, we could intercept at the create_graph_input calls (This PR only handles free symbols in tensors).
2. **We cache the bound_symbols** to avoid lift the same symbol repeated.
3. For lifted symbols, we re-used **lifted_freevars** i.e. the mapping between symbol proxy in parent graph to the lifted phs in current subgraph, which we handle lifted tensors. In this way, all hops that supports lifted tensors should be able to handle lifted_symints automatically (at least in dynamo part).
4. For **unbacked symbols** created during tracing, we need to also bound these symbols to its proxy. This is to support the tests cases where we want to lift unbacked symbols as input. We need the proxy of the unbacked symbol in parent graph in order to properly create the args to the hop.
5. We change all the tests after free symbols are lifted in subgraphs. And also supports the lifted symbols in existing higher order ops.
**The interaction of nested tracers:**
The previous design for lifting tensor closures is that: suppose we're in nested tracers, whenever we see a new proxy that's not created by create tracer, we recursively look for the proxy in parent tracer until we find the tracer that creates this proxy (either a placeholder or some intermediate results). More detail is in Note [Nested SubgraphTracer and free_variable handling].
Given the above design, the plan for lifting the free symbols is: whenever we lift a free tensor to be the inputs of current subgraph, we'll look at the symbols in it and bind the symbols at the same time.
For example, suppose we have the following function:
```python
def f(x: [s1, s2]):
def true_f():
def true_f_inner():
return x.sin()
```
what will happen in time order:
1. we create a subtracer 1 and start to speculate the outer cond's true_f
2. we create a another subtracer 2 and start to speculate the inner cond's true_f_inner.
3. dynamo realize the tensor input x by calling wrap_tensor in top-level to create graph input x (tracer 0), we bind the symbol s1, s2 after ph for x is created. So the graph now looks like:
```python
def gm(s1, s2, x):
```
4. when seeing TensorVariable.call_method of x, tracer2 wants to create a call_function(sin, proxy_of_x), but it finds that proxy_of_x is not created by current tracer. So it recursively look up its parent tracer1 and find parent tracer1 also doesn't track this proxy_of_x then it finds the root tracer0, who is the creator of it and tracks it as a ph. Then tracer 1 create_graph_input to lift the closure to its input ph1 and add (proxy_of_x: ph1) k-v in **lifted_freevars** of tracer 1.
Now the graph looks like:
```python
def gm(s1, s2, x):
def true_gm(x):
```
5. Since there are free symbols inside this new tensor input, tracer 1 also binds the symbols (maybe_bind_symbol), which calls create_graph_input for s1 and s2. Now the graph looks like
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
```
6. then it goes back to tracer 2, and call create_graph_input for x and get ph2, tracer 2's **lifted_freevars** records (ph1, ph2). and tracer 2 also binds the symbols in this new tensor input. Now the graph looks like:
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
def true_gm_inner(s1, s2, x):
```
7. Finally the sin call_function node is created by tracer 2.
**This PR also handles the following cases:**
- What if we lift two tensors share the same symbol? e.g. x1 [s1, s2], x2 [s2, s3]? Each subtracer maintains bound_symbols as a cache that maps a symbol.expr to its proxy in current tracer. So when we see x1, we'll track s1 and s2 as inputs and bound s1 to ph1, s2 to ph2. So when we try to bind symbols of x2, s2 will already be tracked so no graph input is created.
- what if a subgraph close over a symint? e.g.
```python
def f(x):
def true_f():
c = x.size(0)
def true_fn_inner():
return c
```
When we speculate true_fn_inner, we find proxy_of_c is not tracked by tracer 2, so it recursively looks up its parent. At this point, x and its symbols have been lifted as input of true_f (as a result of lifting x during tracing true_f in tracer 1. Specifically the graph looks like:
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
def true_gm_inner():
```
So tracer 2 is able to find that s1 have been tracked as ph in tracer 1 so it returns back to gm and call create_graph_input on s1. The graph now looks like:
```python
def gm(s1, s2, x):
def true_gm(s1, s2, x):
def true_gm_inner(s1):
return s1
```
- What if subgraph close over an unbacked symint? e.g.
```python
def f(x):
def true_f():
c = x.item()
def true_f_inner():
return c
```
When x.item() is called, proxy_of_c and its symnode variable is created for tracer 1, and we also call track_unbacked_symbols to record this relationship. So when tracer 2 finds proxy_of_c is not created by current tracer, it recursivelly looks up its parent tracer and finds that that expression u0 has been tracked as a result of track_unbacked_symbol in tracer 1. So it will stop the recursion and create_graph_input u0 in tracer 2. Graph looks like:
```python
def f(x):
def true_f(s1, s2, x):
c = x.item()
def true_gm_inner(u0):
return u0
cond(pred, true_gm_inner, false_gm_inner, (c,))
```
- what if subgraph close over a tensor with unbacked symint shape?
```python
def f(x):
def true_f():
c = x.item()
r = torch.randn((c,))
def true_f_inner():
return r + 1
```
This is the same as the case of closing over tensors with backed shapes. where we first lift r, then bind u0 in it, which recursively bind_symint of u0 in its parent and found u0 is tracked in parent tracer as a result of .item() call.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/138363
Approved by: https://github.com/zou3519
TLDR; this PR supports exporting cond x inine_inbuilt nn modules flag by inling into tracing code in proxy_tensor.py _symbolic_trace.py (internally, the pattern is make_fx(record_module_stack)(torch.compile(f))).
We have two special treatments for following cases:
1. _ModuleStackTracer will wrap all the nn modules into _AttrProxy. This _AttrProxy has several subtiles which make it hard to inline in dynamo like overriding _modules with a property method and overrides the `__getattr__`, which mutates captured states when calling `__getattr__`.
Solution to this is that we unwrap the _AttrProxy and get its corresponding nn_module (a 1-1 correspondence). So that dynamo symbolically traces the original nn module instead of tracing _AttrProxy.
2. The tracer applies a bunch of patches the `__getattr__` and `__call__` of nn.Module for tracking reasons. This doesn't work well with dynamo. The immediate error we see is `torch._dynamo.exc.Unsupported: 'inline in skipfiles: WeakKeyDictionary.__contains__ | __contains__ /home/yidi/.conda/envs/pytorch/lib/python3.10/weakref.py` caused by a weakdict in PythonKeyTracer.
Solution to this is that we remove the patches during dynamo symbolic convert temporally. So that dynamo has a clean environment. make_fx will be trace the transformed bytecode of dynamo and patches nn modules there instead.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133731
Approved by: https://github.com/anijain2305
ghstack dependencies: #134775
This is an updated PR to equip cond with the autograd feature and replaces the old [PR](https://github.com/pytorch/pytorch/pull/126007)
@ydwu4 I tried to incorporate your requests already.
Currently there are two problems that I struggle with solving:
1. There seems to be an import issue when trying to import cond in `torch/__init__.py`, see [here](8a704035c9/torch/__init__.py (L1914-L1916)). Therefore, I had to comment those lines, which resolved the import issues, but I believe cond is not proberly exposed as torch.cond.
2. I am not entirely sure how to deal with the opinfo test in `hop_db.py`
Co-authored-by: Yidi Wu <yidi@meta.com>
Co-authored-by: Xuehai Pan <XuehaiPan@outlook.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/126911
Approved by: https://github.com/ydwu4
This is an updated PR to equip cond with the autograd feature and replaces the old [PR](https://github.com/pytorch/pytorch/pull/126007)
@ydwu4 I tried to incorporate your requests already.
Currently there are two problems that I struggle with solving:
1. There seems to be an import issue when trying to import cond in `torch/__init__.py`, see [here](8a704035c9/torch/__init__.py (L1914-L1916)). Therefore, I had to comment those lines, which resolved the import issues, but I believe cond is not proberly exposed as torch.cond.
2. I am not entirely sure how to deal with the opinfo test in `hop_db.py`
Co-authored-by: Yidi Wu <yidi@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/126911
Approved by: https://github.com/ydwu4
Recently we decided to split export IR into two different IRs (training vs inference). In the inference IR, one major change we decided to introduce was we wanted to keep the composite ops that user specified in the IR. This PR does that by overriding the CompositeImplicitAutograd decomp in export inference path.
Differential Revision: [D58701607](https://our.internmc.facebook.com/intern/diff/D58701607)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/128077
Approved by: https://github.com/bdhirsh
Adds trace_subgraph to _MakefxTracer, the motivation is in https://github.com/pytorch/pytorch/pull/122972. Also migrate all existing usage of reenter_make_fx to the new sub-tracer. Previously, the torch function mode for creating torch_fn metadata won't be re-enetered when we're in ProxyTensorMode (since it's inside of __torch_function__). This PR reconstruct the torch function mode based on parent tracer's config and reentered the torch function mode so the metadata is shown in the graph.
**Test Plan:**
Existing tests. We have a bunch of make_fx tests for cond, map and while_loop. Also remove expected failure for torch_fn since reenter_make_fx is able to re-construct torch function modes.
Also fixes https://github.com/pytorch/pytorch/issues/124643
Pull Request resolved: https://github.com/pytorch/pytorch/pull/125363
Approved by: https://github.com/Chillee
ghstack dependencies: #125267
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### <samp>🤖 Generated by Copilot at 08bd685</samp>
Added a utility function `autograd_not_implemented_check` to `torch._higher_order_ops.utils` and used it in `out_dtype_autograd` to simplify and standardize the error handling for higher order operators that do not support autograd.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/106078
Approved by: https://github.com/zou3519
