Dynamo was aggressively specializing on lazy VTs over `set_name_hint` in
`STORE_FAST`, etc., and `isinstance` in `LOAD_FAST_CHECK`. This causes
regional `torch.compile` from optimizing ComfyUI GGUF + LoRA to either
(1). exceed the recompialtion limit of 8, which results in suboptimal
performance, and (2). even if recompilation limit is increased, the
compilation time gets unnecessarily high (180s v.s. 20s for Flux).
This patch fixes the recompilation issue.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/156891
Approved by: https://github.com/williamwen42, https://github.com/mlazos
## The problem
In a typical debugger, `repr()` is used to display variables and not `str()`.
Several classes in Dynamo have a `__str__()` method that returns useful information and a `__repr__()` that does not. Having to call `str(x)` or `[str(i) for i in x]` in the debugger all the time is a chore.
`str()` should be ["informal, nicely printable"](https://docs.python.org/3/library/stdtypes.html#str) and `repr()` should ["attempt to return a string that would yield an object with the same value when passed to eval()](https://docs.python.org/3/library/functions.html#repr)".
## The solution
In the Python object model, if there is no `__str__` method, `__repr__` is used instead (but not the other way around).
So renaming `__str__` to `__repr__` in a few cases where no `__repr__` method exists now should not change observable behavior, and should make debugging easier.
The specific classes changed were all in `torch._dynamo.variables`:
* `builtin.BuiltinVariable`
* `constant.ConstantVariable`
* `constant.EnumVariable`
* `functions.UserMethodVariable`
* `lazy.LazyVariableTracker`
* `lazy.LazySymNodeFormatString`
* `misc.GetAttrVariable`
* `misc.NullVariable`
* `user_defined.UserDefinedObjectVariable`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/136316
Approved by: https://github.com/XuehaiPan, https://github.com/jansel
## `VariableTracker::build()` hides the Builders
### The problem
In the current code, creating a `VariableTracker` involves choosing one of two `Builder` classes and either calling a method, or calling a constructor that creates an object that you immediately call, [like this](083c9149b7/torch/_dynamo/variables/functions.py (L761-L768)).
Variations on this code are repeated in many places.
More, the `Builder` classes have a lot of dependencies, so they have to be loaded late in the whole import process to avoid circular imports, so they end up being repeatedly imported at local scope.
### The solution
In this commit, the import from `builder` and the logic of choosing and calling the Builder class are hidden in a single static factory method, `VariableTracker.build()`, easier to reason about and to import.
This commit net lowers the total lines of code by over 150 lines by removing repetitive logic and unnecessary local imports.
**CHANGES:** Originally the name of the static method was `VariableTracker.create()` but a static method on a derived class, `LazyVariableTracker.create()` now exists with a different signature that's irreconcilable, so the new static method was renamed to `VariableTracker.build()`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135714
Approved by: https://github.com/jansel
Fixes https://github.com/pytorch/pytorch/issues/103602.
This PR implements the idea of "if someone creates a string and then ends up not using it, we would prefer to NOT have specialized." mentioned in above issue. Specifically, we create a lazy variable tracker instead of ConstantVariable when we're in FORMAT_VALUE, and when the lazy variable tracker is realized (i.e. it's going to be used), we create a ConstantVariable and the specialization/guarding happens at the time of realization.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/131529
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
The original motivation for MYPYINDUCTOR was a faster type checking configuration that only checked a subset of files. With the removal of `follow_imports = ignore`, we are now able to use dmypy to do fast incremental typechecking, eliminating the need for this.
Perhaps erroneously, when I tee'ed up this PR I elected to delete the `follow_imports = skip` designations in the mypy-inductor.ini. This lead to a number of extra type error suppressions that I manually edited. You will need to review.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118432
Approved by: https://github.com/Skylion007
ghstack dependencies: #118414, #118418
