It generally recommended to use `is/is not` to compare types. Therefore this series of changes apply this suggestion in the code base, and it aims to finally enabling related linter checks.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165037
Approved by: https://github.com/mlazos
Summary: This PR introduces shape guards to export. Previously only value ranges, equalities, and specializations would be tracked for symbolic expressions, and we had a forward hook to check them. Instead now we create a function to check shape guards and call it in the exported program.
Test Plan:
updated several tests
Rollback Plan:
Differential Revision: D80713603
Pull Request resolved: https://github.com/pytorch/pytorch/pull/161178
Approved by: https://github.com/tugsbayasgalan
Preview: https://docs-preview.pytorch.org/pytorch/pytorch/157750/export.html
Changes:
* Rename draft_export.md -> export.draft_export.md for consistency.
* Removed non-strict section in export, instead pointed to programming model doc.
* Extended "Expressing Dynamism" section to include Dim hints, ShapeCollection, and AdditionalInputs.
* Removed Specialization section in favor of programming model doc
* Added pt2 archive doc
* Cleaned up sidebar
Pull Request resolved: https://github.com/pytorch/pytorch/pull/157750
Approved by: https://github.com/pianpwk
With `AdditionalInputs`, the behavior is the same as with tensors:
```python
class M(torch.nn.Module):
def forward(self, x, y):
return x + y
additional_inputs = torch.export.AdditionalInputs()
additional_inputs.add((5, 5))
additional_inputs.add((3, 5))
additional_inputs.add((5, 4))
ep = torch.export.export(
M(), (6, 7), dynamic_shapes=additional_inputs, strict=False
)
```
With `ShapesCollection`, we now need to wrap integer inputs as `_IntWrapper` so that we can have a unique identifier for each integer input.
```python
class M(torch.nn.Module):
def forward(self, x, y):
return x + y
from torch.export.dynamic_shapes import _IntWrapper
args = (_IntWrapper(5), _IntWrapper(5))
# Or we can do `args = pytree.tree_map_only(int, lambda a: _IntWrapper(a), orig_args)`
shapes_collection = torch.export.ShapesCollection()
shapes_collection[args[0]] = Dim.DYNAMIC
shapes_collection[args[1]] = Dim.DYNAMIC
ep = torch.export.export(
M(), args, dynamic_shapes=shapes_collection, strict=False
)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/151842
Approved by: https://github.com/pianpwk
Summary:
Instead of explicitly specifying dynamic shapes, it is possible to infer them from additional example inputs. Together with the example inputs provided to export, we can basically make any varying dim dynamic and keep any fixed dim static. This should be useful for prod scenarios that have access to tests and/or profiling data, yet are somewhat removed from the model authoring process.
However this alone is not satisfactory: the exported program by design has only one graph, representing one path through the model, and we cannot necessarily guarantee that this graph works for the additional example inputs because different guards might have been created if we had exported with them instead (corresponding to different traced paths). However, checking that the additional example inputs satisfy the guards created by the original export should be sufficient for generalization.
Now, while we don't preserve all guards in the exported program, we do check a subset of them as part of input matching. So we add a verification step at the end of export when such additional example inputs are provided. This should be enough for now.
Test Plan: added test (positive and negative cases)
Differential Revision: D72001771
Pull Request resolved: https://github.com/pytorch/pytorch/pull/150144
Approved by: https://github.com/bobrenjc93
Over time, a large number of the existing type ignores have become irrelevant/unused/dead as a result of improvements in annotations and type checking.
Having these `# type: ignore` linger around is not ideal for two reasons:
- They are verbose/ugly syntatically.
- They could hide genuine bugs in the future, if a refactoring would actually introduce a bug but it gets hidden by the ignore.
I'm counting over 1500 unused ignores already. This is a first PR that removes some of them. Note that I haven't touched type ignores that looked "conditional" like the import challenge mentioned in https://github.com/pytorch/pytorch/pull/60006#issuecomment-2480604728. I will address these at a later point, and eventually would enable `warn_unused_ignores = True` in the mypy configuration as discussed in that comment to prevent accumulating more dead ignores going forward.
This PR should have no effect on runtime at all.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/142325
Approved by: https://github.com/Skylion007, https://github.com/janeyx99
Previously we'd been raising UserErrors when `Dim()` and DimHints (`Dim.AUTO/Dim.DYNAMIC`) were both specified in `dynamic_shapes`, this PR stops that, and uses `Dim()` objects to guide DimHints.
The key to this was making the `EqualityConstraint` class happy when it checks that inferred equivalence relations were specified in the original `dynamic_shapes` spec, and this introduces a `RelaxedConstraint` object to mark the hinted dimensions, so equality checks between `RelaxedConstraints` and other constraints are treated as valid.
Current behavior is that:
```
class Foo(torch.nn.Module):
def forward(self, x, y):
return x - y
inputs = (torch.randn(4, 4), torch.randn(4, 4))
shapes = {
"x": (Dim.AUTO, Dim("d1", min=3)),
"y": (Dim("d0", max=8), Dim.DYNAMIC),
}
ep = export(Foo(), inputs, dynamic_shapes=shapes)
```
The dimensions marked `AUTO` and `DYNAMIC` will have max & min ranges of 8 & 3 respectively. Note that inferred equality between `Dim()` objects & `Dim.STATIC` will still raise errors - `Dim()` suggests not specializing to a constant.
Differential Revision: D64636101
Pull Request resolved: https://github.com/pytorch/pytorch/pull/138490
Approved by: https://github.com/avikchaudhuri
Summary:
When we handle dynamic shapes markers like `Dim.AUTO, Dim.DYNAMIC`, we use dynamo decorators, attaching set attributes to the export input tensors, e.g. `x._dynamo_dynamic_indices = set()`.
I thought this was fine, since it's done all the time with torch.compile, but it breaks some PT2Inference tests, specifically because unpickling a set attribute isn't possible with the C++ torch::jit::pickle_load call.
We've agreed that the PT2Inference side will clone sample inputs & pickle the original inputs to be safe, but this still establishes a nice invariant that user-facing decorators are both ignored & cleaned out in the lifecycle of an export call.
Test Plan: test_export
Differential Revision: D63773534
Pull Request resolved: https://github.com/pytorch/pytorch/pull/137230
Approved by: https://github.com/avikchaudhuri
Removing `_transform_shapes_for_default_dynamic` and `assume_static_by_default=False` as added in https://github.com/pytorch/pytorch/pull/133620.
This reverts back to `assume_static_by_default=True` with the use of dynamo decorators (e.g. `maybe_mark_dynamic, mark_static`, instead) for handling Dim.AUTO & Dim.STATIC instead. This is easier to maintain, as it doesn't requiring reasoning about "inverting" the dynamic_shapes specs, and also opens up usage of other decorators (`mark_dynamic, mark_unbacked`).
On the user side this change has no effect, but internally this means dynamic behavior is determined only by the `dynamic_shapes` specs (ignoring user-side input decorators following https://github.com/pytorch/pytorch/pull/135536), but transferring this information for _DimHints via decorators, for Dynamo/non-strict to create symbolic_contexts accordingly, e.g. 7c6d543a5b/torch/_dynamo/variables/builder.py (L2646-L2666)
One caveat is we don't raise errors for dynamic decorators on the user side, since we don't know if they're from user markings, or from re-exporting with inputs we've previously marked.
Differential Revision: D63358628
Pull Request resolved: https://github.com/pytorch/pytorch/pull/136591
Approved by: https://github.com/avikchaudhuri
Previously we were accomodating `torch._dynamo.mark_dynamic()` for export's dynamic shapes. Here we clean things up and ignore it, requiring users to specify an export input for `dynamic_shapes`.
Note: there's 4 decorators relevant to export, `mark_dynamic, maybe_mark_dynamic, mark_static, mark_unbacked`. User calls that involve export have only been `mark_dynamic()`, and we use `maybe_mark_dynamic` under the hood for `Dim.AUTO`, but we could start using others. One reason I decided to not warn and just silently ignore is these decorators cause the tensors to carry dynamic info, and it'll be hard to tell whether the markers are from export or user calls when re-exporting with the same inputs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135536
Approved by: https://github.com/avikchaudhuri
Summary:
A bit of refactoring to prepare to remove `None` as a way to specify static dimensions in dynamic shapes, given we already have `Dim.STATIC` for the same purpose. We will now warn whenever this happens. However no tests were modified because problematic uses of `None` still need to behave as they do today, until we are ready to remove support. It should be easy to port tests by replacing the warning function to raise instead.
Note that other uses of `None`, such as for entire values (tensor or non-tensor) remain as is. Moving forward this should be the only purpose of `None` (at least externally).
Finally, there's a bit of confusion in our representation now because `AUTO` also internally transforms to `None`. Renamed dynamic_shapes to transformed_dynamic_shapes where this happens. Overall the two forms (pre and post transformation) have different properties so should probably not be represented in the same format in the future.
Test Plan: existing
Differential Revision: D62040729
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134877
Approved by: https://github.com/pianpwk
Summary: Recently https://github.com/pytorch/pytorch/pull/133620 added support for automatic dynamic shapes, where a new enum, `DIM`, was introduced to provide hints like `AUTO` and `STATIC`. This PR is a nominal change where we expose the hints via the existing public `Dim` API, and remove `DIM` from the public API. The main motivation is to avoid having users need to import too many things.
Test Plan: existing
Differential Revision: D61807361
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134484
Approved by: https://github.com/angelayi
Summary: apparently DIM.AUTO leads to duck sizing, I didn't catch this. Doing the least intrusive fix possible by using `torch._dynamo.maybe_mark_dynamic()` under the hood.
Test Plan: added test
Differential Revision: D61809344
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134486
Approved by: https://github.com/avikchaudhuri
Starter version of automatic dynamic shapes for export.
Creates enums `DIM.AUTO`, `DIM.STATIC`, allowing user to specify `AUTO` for dims in dynamic_shapes specs, meaning that corresponding dims are treated as dynamic, and relevant guards will do what's necessary (e.g. refine ValueRanges, set replacements based on equality, or even set static) without raising ConstraintViolationErrors. Basically allows the user to say, "a bunch of these dims can be dynamic, let export do model analysis and return the program with maximum possible dynamism, without complaining".
The usage for specifying `dynamic_shapes` is now:
```
AUTO -> dynamic by default, return whatever produce_guards() says, even if it's static
None/int/STATIC -> static
Dim/DerivedDim -> same as before - will complain if the min/max range is invalid, or if dims related to this are unspecified.
```
Caveat 1: specifying `AUTO` for a dim won't guarantee it'll be dynamic:
- specifying `AUTO` for a dim will return the maximum possible dynamism given your program and other specified constraints, but this can still mean you'll get a static program. For example, with the program below, x is specified dynamic, but it's equal to y, which is specified static, and with how we currently do things we won't promote y to dynamic, but will demote(?) x to static. So this can be surprising if you don't fully know your model, and/or missed one of your other inputs when specifying auto-dynamic shapes.
```
class Foo(torch.nn.Module):
def forward(self, x, y):
return x + y
inputs = (torch.randn(6), torch.randn(6))
export(Foo(), inputs, dynamic_shapes={"x": (DIM.AUTO,), "y": None})
```
Caveat 2: specifying `AUTO` and Dims in the same spec is still problematic:
- The way Dims/DerivedDims are currently handled is very strict. A Dim represents a symbol, and we require a user to specify the symbol for all dims governed by the symbol - that's why we've seen errors in the past like `The values of x must always be related to y by ...`, asking the user to specify the exact relation as in the program. We also require the specified min/max range to be a subset of the valid range from model analysis. All this doesn't compose well with specifying `AUTO` just yet - for example in the program below, ideal behavior could be to return a dynamic program, where `dx = x.size(0) = y.size(0)` has range (3,6). Unfortunately this crashes, and correct behavior is to specify `dx` for both inputs. So currently we raise a UserError and crash if both Dims + `AUTO` are present in the spec.
```
class Foo(torch.nn.Module):
def forward(self, x, y):
return x + y
inputs = (torch.randn(6), torch.randn(6))
export(Foo(), inputs, dynamic_shapes={"x": (DIM.AUTO,), "y": {0: Dim("dx", min=3, max=6)}}) # this doesn't work, because x & y and related
```
Implementation details:
This is done by setting `assume_static_by_default=False`, and doing a transform on the `dynamic_shapes` spec to preserve semantics. `assume_static_by_default=False` will treat unspecified dims or Nones as dynamic. This is the opposite of what `export.export()` currently does - unspecified Dims/Nones are treated as static. Historically this static-by-default behavior, where the user deals with fewer guards, has been desirable, and we would like to respect that in this implementation. So this internal spec transformation is added, `_transform_shapes_for_default_dynamic()`, does the spec conversion necessary to be compatbile with dynamic by default. Specifically, AUTOs are converted into Nones, and Nones/unspecified dims are filled in with explicitly static constraints.
For example, this would look like, for a 3-d tensor: `{0: DIM.AUTO, 1: None, 2: Dim("dx")} -> {0: None, 1: 32, 2: Dim("dx")}`
This does seem overly complicated, but it's done to preserve dynamic shapes semantics for `torch._dynamo.export()`, which already uses `assume_static_by_default=False`, and follows the same process for generating shape constraints , via `_process_dynamic_shapes`. There the semantics are:
```
None/unspecified: dynamic by default
Dim/DerivedDim: also a strict assertion
```
If we don't care about BC for `_dynamo.export(dynamic_shapes)`, then we can just modify semantics for `_process_dynamic_shapes()` and change all the relevant tests in `test/dynamo/test_export.py`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133620
Approved by: https://github.com/avikchaudhuri
Summary:
Previously, reuse of the same `Dim` was encoded by "sharing" internal constraints among constraint targets. This kind of sharing, implemented using `shared` fields between `_Constraint`s, was originally motivated by `dynamic_dim`, specifically to support `==` between `dynamic_dim`s, but we no longer need to maintain this overcomplicated structure: we can simply use names of `Dims` to directly encode sharing information.
Thus this PR vastly simplifies the structure of `_Constraint` by removing `shared` fields. As a result, both `_Constraint` and its moral subclass, `_DerivedConstraint`, are 1-1 with `Dim` and its moral subclass, `DerivedDim`.
Note that this will break `==` over `dynamic_dim`, so an immediate follow-up will be to remove `dynamic_dim` entirely from our public API. (It's been more than 6 months since the deprecation warning anyway.) I just didn't want to deal with that process in the same PR.
Test Plan: existing
Differential Revision: D61559413
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134045
Approved by: https://github.com/pianpwk
Summary: `_ConstraintTarget` is an internal data structure that has some redundancy: tensors are identified by their id but also carry a weak reference. The weak reference was probably useful a year back but everything is done with ids right now, and the lifetime of these tensors ensures that using their ids is OK.
Test Plan: existing tests
Differential Revision: D61488816
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133890
Approved by: https://github.com/tugsbayasgalan
Sorryyyyy for another refactor. This splits `_process_dynamic_shapes` into 3 parts:
1. `_combine_args` - mostly the same thing
2. `_check_dynamic_shapes`, which is responsible for raising 99% of UserErrors if the dynamic shapes spec is invalid (minus 1 UserError with DerivedDims)
3. `_process_dynamic_shapes`, which for now, is the same thing, minus the stuff in 2.
This refactor is helpful for incoming automatic dynamic shapes work, because, we're switching to `assume_static_by_default=False`, which is what `_dynamo.export` currently does. This means any unspecified dims are allocated a symbol, in contrast to export today which keeps unspecified dims static. Historically this has been desirable - export users don't want too much dynamism. So we want to change how the spec is translated into constraints.
This means when we switch over to automatic dynamic shapes, we want to plug in something in between steps 2. and 3. which patches up the spec for `assume_static_by_default=False`, filling in static shapes for any unspecified dims, and potentially clearing out the auto-dynamic dims (since they're no-ops). We would do this in-between 2. and 3. to keep `_process_dynamic_shapes` semantically the same, since it's used with `_dynamo.export`.
We could do this without a refactor, plugging in this transform before `_process_dynamic_shapes`, but since that function's responsible for both spec checking + constraint production, moving spec checking to before we transform the specs helps guarantee we're raising errors on what the user's specified, and not an internal export bug.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133391
Approved by: https://github.com/avikchaudhuri
Summary: When PyTree detects a structural mismatch between inputs and dynamic shapes, the error messages are quite horrible. This PR fixes these error messages by adding, for each kind of error, the path to the point where the error happens and an actionable reason for the error.
Test Plan: added test with several cases
Differential Revision: D60956976
Pull Request resolved: https://github.com/pytorch/pytorch/pull/132982
Approved by: https://github.com/yushangdi
In a previous life, we used sympy.oo to represent the lower/upper bounds of integer ranges. Later, we changed this to be sys.maxsize - 1 for a few reasons: (1) sometimes we do tests on a value being exactly sys.maxsize, and we wanted to avoid a data dependent guard in this case, (2) sympy.oo corresponds to floating point infinity, so you get incorrect types for value ranges with oo, and (3) you can do slightly better reasoning if you assume that input sizes fall within representable 64-bit integer range.
After working in the sys.maxsize regime for a bit, I've concluded that this was actually a bad idea. Specifically, the problem is that you end up with sys.maxsize in your upper bound, and then whenever you do any sort of size-increasing computation like size * 2, you end up with 2 * sys.maxsize, and you end up doing a ton of arbitrary precision int computation that is totally unnecessary. A symbolic bound is better.
But especially after #126905, we can't go back to using sympy.oo, because that advertises that it's not an integer, and now your ValueRanges is typed incorrectly. So what do we do? We define a new numeric constant `int_oo`, which is like `sympy.oo` but it advertises `is_integer`. **test/test_sympy_utils.py** describes some basic properties of the number, and **torch/utils/_sympy/numbers.py** has the actual implementation.
The rest of the changes of the PR are working out the implications of this change. I'll give more commentary as inline comments.
Fixes https://github.com/pytorch/pytorch/issues/127396
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/127693
Approved by: https://github.com/lezcano
ghstack dependencies: #126905
In a previous life, we used sympy.oo to represent the lower/upper bounds of integer ranges. Later, we changed this to be sys.maxsize - 1 for a few reasons: (1) sometimes we do tests on a value being exactly sys.maxsize, and we wanted to avoid a data dependent guard in this case, (2) sympy.oo corresponds to floating point infinity, so you get incorrect types for value ranges with oo, and (3) you can do slightly better reasoning if you assume that input sizes fall within representable 64-bit integer range.
After working in the sys.maxsize regime for a bit, I've concluded that this was actually a bad idea. Specifically, the problem is that you end up with sys.maxsize in your upper bound, and then whenever you do any sort of size-increasing computation like size * 2, you end up with 2 * sys.maxsize, and you end up doing a ton of arbitrary precision int computation that is totally unnecessary. A symbolic bound is better.
But especially after #126905, we can't go back to using sympy.oo, because that advertises that it's not an integer, and now your ValueRanges is typed incorrectly. So what do we do? We define a new numeric constant `int_oo`, which is like `sympy.oo` but it advertises `is_integer`. **test/test_sympy_utils.py** describes some basic properties of the number, and **torch/utils/_sympy/numbers.py** has the actual implementation.
The rest of the changes of the PR are working out the implications of this change. I'll give more commentary as inline comments.
Fixes https://github.com/pytorch/pytorch/issues/127396
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/127693
Approved by: https://github.com/lezcano
ghstack dependencies: #126905
At a high level, the idea behind this PR is:
* Make it clearer what the promotion and int/float rules for various Sympy operations are. Operators that previously were polymorphic over int/float are now split into separate operators for clarity. We never do mixed int/float addition/multiplication etc in sympy, instead, we always promote to the appropriate operator. (However, equality is currently not done correctly.)
* Enforce strict typing on ValueRanges: if you have a ValueRange for a float, the lower and upper MUST be floats, and so forth for integers.
The story begins in **torch/utils/_sympy/functions.py**. Here, I make some changes to how we represent certain operations in sympy expressions:
* FloorDiv now only supports integer inputs; to do float floor division, do a truediv and then a trunc. Additionally, we remove the divide out addition by gcd optimization, because sympy gcd is over fields and is willing to generate rationals (but rationals are bad for ValueRange strict typing).
* ModularIndexing, LShift, RShift now assert they are given integer inputs.
* Mod only supports integer inputs; eventually we will support FloatMod (left for later work, when we build out Sympy support for floating operations). Unfortunately, I couldn't assert integer inputs here, because of a bad interaction with sympy's inequality solver that is used by the offline solver
* TrueDiv is split into FloatTrueDiv and IntTrueDiv. This allows for us to eventually generate accurate code for Python semantics IntTrueDiv, which is written in a special way to preserve precision when the inputs are >= 2**53 beyond what first coercing the integer to floats and then doing true division.
* Trunc is split to TruncToFloat and TruncToInt.
* Round is updated to return a float, not an int, making it consistent with the round op handler in Inductor. To get Python-style conversion to int, we call TruncToInt on the result.
* RoundDecimal updated to consistently only ever return a float
* Add ToFloat for explicit coercion to float (required so we can enforce strict ValueRanges typing)
In **torch/__init__.py**, we modify SymInt and SymFloat to appropriately call into new bindings that route to these refined sympy operations. Also, we modify `torch.sym_min` and `torch.sym_max` to have promotion semantics (if one argument is a float, the return result is always a float), making them inconsistent with builtins.min/max, but possible to do type analysis without runtime information.
We also need to introduce some new op handlers in **torch/_inductor/ops_handler.py**:
* `to_int` for truncation to int64, directly corresponding to TruncToInt; this can be implemented by trunc and dtype, but with a dedicated handler it is more convenient for roundtripping in Sympy
* `int_truediv` for Python-style integer true division, which has higher precision than casting to floats and then running `truediv`
These changes have consequences. First, we need to make some administrative changes:
* Actually wire up these Sympy functions from SymInt/SymFloat in **torch/fx/experimental/sym_node.py**, including the new promotion rules (promote2)
* Add support for new Sympy functions in **torch/utils/_sympy/interp.py**, **torch/utils/_sympy/reference.py**
* In particular, in torch.utils._sympy.reference, we have a strong preference to NOT do nontrivial compute, instead, everything in ops handler should map to a singular sympy function
* TODO: I chose to roundtrip mod back to our Mod function, but I think I'm going to have to deal with the C/Python inconsistency this to fix tests here
* Add printer support for the Sympy functions in **torch/_inductor/codegen/common.py**, **torch/_inductor/codegen/cpp_utils.py**, **torch/_inductor/codegen/triton.py**. `int_truediv` and mixed precision equality is currently not implemented soundly, so we will lose precision in codegen for large values. TODO: The additions here are not exhaustive yet
* Update ValueRanges logic to use new sympy functions in **torch/utils/_sympy/value_ranges.py**. In general, we prefer to use the new Sympy function rather than try to roll things by hand, which is what was done previously for many VR analysis functions.
In **torch/fx/experimental/symbolic_shapes.py** we need to make some symbolic reasoning adjustments:
* Avoid generation of rational subexpressions by removing simplification of `x // y` into `floor(x / y)`. This simplification then triggers an addition simplification rule `(x + y) / c --> x / c + y / c` which is bad because x / c is a rational number now
* `_assert_bound_is_rational` is no more, we no longer generate rational bounds
* Don't intersect non-int value ranges with the `int_range`
* Support more sympy Functions for guard SYMPY_INTERP
* Assert the type of value range is consistent with the variable type
The new asserts uncovered necessary bug fixes:
* **torch/_inductor/codegen/cpp.py**, **torch/_inductor/select_algorithm.py**, **torch/_inductor/sizevars.py** - Ensure Wild/Symbol manually allocated in Inductor is marked `is_integer` so it's accepted to build expressions
* **torch/_inductor/utils.py** - make sure you actually pass in sympy.Expr to these functions
* **torch/_inductor/ir.py** - make_contiguous_strides_for takes int/SymInt, not sympy.Expr!
* **torch/export/dynamic_shapes.py** - don't use infinity to represent int ranges, instead use sys.maxsize - 1
Because of the removal of some symbolic reasoning that produced rationals, some of our symbolic reasoning has gotten worse and we are unable to simplify some guards. Check the TODO at **test/test_proxy_tensor.py**
**Reland notes.** This requires this internal fbcode diff https://www.internalfb.com/phabricator/paste/view/P1403322587 but I cannot prepare the diff codev due to https://fb.workplace.com/groups/osssupport/posts/26343544518600814/
It also requires this Executorch PR https://github.com/pytorch/executorch/pull/3911 but the ET PR can be landed prior to this landing.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/126905
Approved by: https://github.com/xadupre, https://github.com/lezcano
Summary:
Part of the work helping export's automatic dynamic shapes / dynamic shapes refining based on suggested fixes.
Introduces a util function refine_dynamic_shapes_from_suggested_fixes() that takes the error message from a ConstraintViolationError message containing suggested dynamic shapes fixes, along with the original dynamic shapes spec, and returns the new spec. Written so that the suggested fixes from export can be directly parsed and used.
Example usage for the automatic dynamic shapes workflow:
```
# export, fail, parse & refine suggested fixes, re-export
try:
export(model, inps, dynamic_shapes=dynamic_shapes)
except torch._dynamo.exc.UserError as exc:
new_shapes = refine_dynamic_shapes_from_suggested_fixes(exc.msg, dynamic_shapes)
export(model, inps, dynamic_shapes=new_shapes)
```
For examples of behavior, see the added test and docstring. Will take suggestions for renaming the function to something else 😅
Test Plan: test_export tests
Differential Revision: D57409142
Pull Request resolved: https://github.com/pytorch/pytorch/pull/127436
Approved by: https://github.com/avikchaudhuri
