Files
pytorch/torch/export/dynamic_shapes.py
Avik Chaudhuri e7846447e0 dynamic shapes builder API (#124898)
This PR introduces a new way of building `dynamic_shapes` for export. The idea is to build up a mapping from input tensors to the dynamic shapes that should be assigned to their corresponding fake tensors.

This mapping is automatically converted to the current form of `dynamic_shapes`, which must exactly match the structure of inputs. We do this by using pytree utils.

With the current `dynamic_shapes`, we had to be careful about user-defined classes that are registered with pytree, since  such classes are not necessarily polymorphic containers; they may be fine containing tensors, but not dynamic shapes. Thus we had decided to allow input instances of such classes to be associated with dynamic shapes in flattened form. This decision needs to be mirrored in this PR as well. To make it easier to keep these code paths in sync, we refactor the current recursive procedure for associating inputs with dynamic shapes to use the same pytree utils. This needs minor fixes to a few tests where `dynamic_shapes` were not exactly matching the structure of inputs.

Differential Revision: D56551992

Pull Request resolved: https://github.com/pytorch/pytorch/pull/124898
Approved by: https://github.com/zhxchen17
2024-04-30 03:59:49 +00:00

894 lines
34 KiB
Python

import builtins
import dataclasses
import inspect
import math
import sys
import weakref
from collections import defaultdict
from typing import Any, Callable, Dict, List, Optional, Tuple, TYPE_CHECKING, Union
import torch
from torch.utils._pytree import _get_node_type, BUILTIN_TYPES, SUPPORTED_NODES, tree_map
from .exported_program import ExportedProgram
if TYPE_CHECKING:
from sympy import Symbol
from torch._guards import Source
from ..fx.experimental.symbolic_shapes import ShapeEnv, StrictMinMaxConstraint
__all__ = ["Constraint", "Dim", "dims", "dynamic_dim"]
class _Dim(type):
"""
Metaclass for :func:`Dim` types.
"""
@staticmethod
def readable(name, min_, max_):
if min_ == 2:
min_ = None
if max_ == sys.maxsize - 1:
max_ = None
if min_ is None and max_ is None:
return f"Dim('{name}')"
if min_ is None:
return f"Dim('{name}', max={max_})"
if max_ is None:
return f"Dim('{name}', min={min_})"
return f"Dim('{name}', min={min_}, max={max_})"
def __add__(cls, other):
# e.g., dim + 1
if type(other) is not int:
raise NotImplementedError(
f"Attempted to add {other} to {cls.__name__}, where an integer was expected. "
"(Only increasing linear operations with integer coefficients are supported.)"
)
return cls._derive(lambda x: x + other)
def __radd__(cls, other):
return cls + other
def __sub__(cls, other):
# e.g., dim - 1
if type(other) is not int:
raise NotImplementedError(
f"Attempted to subtract {other} from {cls.__name__}, where an integer was expected. "
"(Only increasing linear operations with integer coefficients are supported.)"
)
return cls._derive(lambda x: x - other)
def __rsub__(cls, other):
raise NotImplementedError(
f"Attempted to negate {cls.__name__}. "
"(Only increasing linear operations with integer coefficients are supported.)"
)
def __mul__(cls, other):
# e.g., dim * 2
if type(other) is not int or other <= 0:
raise NotImplementedError(
f"Attempted to multiply {other} with {cls.__name__}, where a positive integer was expected. "
"(Only increasing linear operations with integer coefficients are supported.)"
)
return cls._derive(lambda x: x * other)
def __rmul__(cls, other):
return cls * other
def _derived_name(cls, fn):
from sympy import sympify
return str(fn(sympify(cls.__name__)))
def _derive(cls, fn):
return _DerivedDim(cls._derived_name(fn), (int,), {"root": cls, "fn": fn})
class _StaticDim(_Dim):
"""
Meta class for static :func:`Dim` types.
This class is only for setting and checking static dim constraints,
and the user should never interact with it.
"""
@property
def min(self):
return self.value # type: ignore[attr-defined]
@property
def max(self):
return self.value # type: ignore[attr-defined]
class _DerivedDim(_Dim):
"""
Metaclass for derived :func:`Dim` types.
Currently we only support increasing linear expressions with integer coefficients.
In other words, a derived Dim can always be written in the form Ax + B, where
x is a regular Dim (i.e., non-derived Dim), A and B are integers, and A is positive.
(In particular, the latter ensures that x < y => Ax + B < Ay + B.)
These restrictions on the form of derived Dims makes the metatheory simpler: e.g.,
it simplifies computing ranges for derived Dims, solving for underlying regular Dims,
deciding equalities between derived Dims, and so on.
The function lambda x: Ax + B is expressed by `fn`, where x is a normal Dim, `root`.
The range of a derived Dim is computed by mapping `fn` over the range of its `root`.
"""
@property
def min(self):
# assume that self.fn is an increasing function
# TODO(avik): use sympy value range analysis instead?
from sympy import Integer
_min_symint = self.fn(Integer(self.root.min)) # type: ignore[attr-defined]
root = self.root # type: ignore[attr-defined]
assert _min_symint >= 0, (
f"Expected derived min value of {self.__name__} to be >= 0. "
f"Please specify an appropriate min value for {root.__name__} "
f"(currently {root.min})."
)
return int(_min_symint)
@property
def max(self):
# assume that self.fn is an increasing function
# TODO(avik): use sympy value range analysis instead?
from sympy import Integer
_max_symint = self.fn(Integer(self.root.max)) # type: ignore[attr-defined]
root = self.root # type: ignore[attr-defined]
assert _max_symint <= sys.maxsize - 1, (
f"Expected derived max value of {self.__name__} to be <= {sys.maxsize - 1}. "
f"Please specify an appropriate max value for {root.__name__} "
f"(currently {root.max})."
)
return int(_max_symint)
def _derive(self, fn):
# We support nesting, e.g., 2*dim + 1.
# This is implemented by composing operations on the same root.
# As a consequence, roots are always regular Dims (i.e., not derived Dims).
return _DerivedDim(
self._derived_name(fn),
(int,),
{"root": self.root, "fn": lambda x: fn(self.fn(x))}, # type: ignore[attr-defined]
)
def Dim(name: str, *, min: Optional[int] = None, max: Optional[int] = None):
"""
:func:`Dim` constructs a type analogous to a named symbolic integer with a range.
It can be used to describe multiple possible values of a dynamic tensor dimension.
Note that different dynamic dimensions of the same tensor, or of different tensors,
can be described by the same type.
Args:
name (str): Human-readable name for debugging.
min (Optional[int]): Minimum possible value of given symbol (inclusive)
max (Optional[int]): Maximum possible value of given symbol (inclusive)
Returns:
A type that can be used in dynamic shape specifications for tensors.
"""
_min = 0 if min is None else min
_max = sys.maxsize - 1 if max is None else builtins.min(max, sys.maxsize - 1)
assert _max > _min, f"Cannot create Dim with inconsistent min={min}, max={max}"
dim = _Dim(name, (int,), {"min": _min, "max": _max})
dim.__module__ = getattr(
inspect.getmodule(inspect.stack()[1][0]), "__name__", "__main__"
)
return dim
def dims(*names: str, min: Optional[int] = None, max: Optional[int] = None):
"""
Util to create multiple :func:`Dim` types.
"""
return tuple(Dim(name, min=min, max=max) for name in names)
@dataclasses.dataclass
class _ConstraintTarget:
"""
This represents input tensor dimensions. Don't create this
class directly; instead, use :func:`dynamic_dim`.
"""
w_tensor: Any # weakref to torch.Tensor
# TODO: We don't need t_id; we can get it off of w_tensor
t_id: int
dim: int
class _ConstraintFactory(type):
"""
Metaclass that ensures a private constructor for :class:`_Constraint`
"""
def __call__(cls, *args, **kwargs):
raise TypeError(
f"{cls.__module__}.{cls.__qualname__} has no public constructor. "
f"Please use torch.export.dynamic_dim() to create one"
)
def _create(
cls, w_tensor, t_id, dim, constraint_range, shared=None, debug_name=None
):
return super().__call__(
w_tensor, t_id, dim, constraint_range, shared, debug_name
)
def _create_constraint(
w_tensor, t_id, dim, constraint_range, shared=None, debug_name=None
):
return _Constraint._create(
w_tensor, t_id, dim, constraint_range, shared, debug_name
)
@dataclasses.dataclass
class _Constraint(_ConstraintTarget, metaclass=_ConstraintFactory):
"""
.. warning::
Do not construct :class:`_Constraint` directly, use :func:`dynamic_dim` instead.
This represents constraints on input tensor dimensions, e.g., requiring
them to be fully polymorphic or within some range.
"""
# NOTE(avik): In the future, this could be Union[StrictMinMaxConstraint, <other kinds>]
constraint_range: "StrictMinMaxConstraint"
# Represent that `constraint_range` is shared with another _ConstraintTarget, which
# typically arises because of a specified equality with another dynamic dimension.
shared: Optional[_ConstraintTarget] = None
debug_name: Optional[str] = None
def _clone_with_range(self, lower=0, upper=math.inf):
# Import sympy locally
from torch.fx.experimental.symbolic_shapes import StrictMinMaxConstraint
from torch.utils._sympy.value_ranges import ValueRanges
constraint_range = StrictMinMaxConstraint(
vr=self.constraint_range.vr & ValueRanges(lower=lower, upper=upper),
warn_only=False,
)
return _create_constraint(
self.w_tensor,
self.t_id,
self.dim,
constraint_range,
self.shared,
self.debug_name,
)
def __ge__(self, lower):
return self._clone_with_range(lower=lower)
def __gt__(self, lower):
return self._clone_with_range(lower=lower + 1)
def __le__(self, upper):
return self._clone_with_range(upper=upper)
def __lt__(self, upper):
return self._clone_with_range(upper=upper - 1)
def __bool__(self):
# NOTE(avik): We do not support compound expressions like a <= x <= b.
# This is because Python implicitly desugars them into bool(a <= x) and bool(x <= b),
# and moreover, enforces that any overload of __bool__ must return True or False.
# FWIW, sympy also raises TypeError in this case.
raise TypeError(
"Cannot determine truth value of _Constraint. "
"If you are trying to combine _Constraint's with logical connectives, "
"you can specify them separately instead."
)
@property
def serializable_spec(self):
# We need a serialization compatible format of the constraint so that it
# can be savedin the graph module w/o breaking the module serialization.
# The saved constraints will be used directly for the post-exporting pass
# that converts constraints to runtime assertion. The saved constraints
# will not be saved in the serialized module.
# TODO: A better way is needed. Currently we use 't_id' to map the constraint,
# which is not reliable
return {
"t_id": self.t_id,
"dim": self.dim,
"min": self.constraint_range.vr.lower,
"max": self.constraint_range.vr.upper,
}
def __eq__(self, other):
if not isinstance(other, _Constraint):
raise TypeError(
"A dynamic dim can be specified equal only to another dynamic dim. "
f"Equality with {type(other)} is not supported."
)
# import sympy locally
from torch.fx.experimental.symbolic_shapes import StrictMinMaxConstraint
constraint_range = StrictMinMaxConstraint(
vr=self.constraint_range.vr & other.constraint_range.vr,
warn_only=False,
)
if self.debug_name is None:
debug_name = other.debug_name
else:
assert other.debug_name is None or self.debug_name == other.debug_name
debug_name = self.debug_name
return _create_constraint(
self.w_tensor,
self.t_id,
self.dim,
constraint_range,
shared=_ConstraintTarget(other.w_tensor, other.t_id, other.dim),
debug_name=debug_name,
)
@dataclasses.dataclass
class _PhantomRoot:
"""
This represents the root of a derived Dim where the root does not directly
specify the shape of any input dimension, but the derived Dim does.
e.g., the input shapes 2*dim and dim + 1 are related via a "phantom" dim.
The fields `name`, `constraint_range`, and `val` carried by a phantom root
help create a symbol for it. Any derived dims with this phantom root are
backed by expressions over this symbol.
"""
name: str
constraint_range: "StrictMinMaxConstraint"
val: int
@dataclasses.dataclass
class _DerivedConstraint(_ConstraintTarget):
"""
This represents a derived Dim, whose root is either a regular constraint target
(which directly specifies the shape of some input dimension) or a phantom root
(which does so indirectly).
"""
# NOTE: This is not currently a subclass of _Constraint because we do not support
# `shared` for derived `Dim`s. Indeed, sharing is a necessary concept only for
# legacy constraints based on `dynamic_dim`: equality can be expressed simply by
# reusing the same (derived or normal) `Dim`.
root: Union[_ConstraintTarget, _PhantomRoot]
fn: Callable
constraint_range: "StrictMinMaxConstraint"
debug_name: Optional[str] = None
@property
def shared(self):
# Some code paths expect a union of _Constraint and _DerivedConstraint.
# Thus we expose a `shared` field that is always None.
# TODO(avik): clean this up
return None
@property
def serializable_spec(self):
# same as _Constraint.serializable_spec
return {
"t_id": self.t_id,
"dim": self.dim,
"min": self.constraint_range.vr.lower,
"max": self.constraint_range.vr.upper,
}
Constraint = Union[_Constraint, _DerivedConstraint]
def dynamic_dim(t: torch.Tensor, index: int, debug_name: Optional[str] = None):
"""
.. warning::
(This feature is DEPRECATED. See :func:`Dim` instead.)
:func:`dynamic_dim` constructs a :class:`_Constraint` object that describes the dynamism of
a dimension ``index`` of tensor ``t``. :class:`_Constraint` objects should be passed to
``constraints`` argument of :func:`export`.
Args:
t (torch.Tensor): Example input tensor that have dynamic dimension size(s)
index (int): Index of dynamic dimension
Returns:
A :class:`_Constraint` object that describes shape dynamism. It can be passed to :func:`export` so
that :func:`export` does not assume static size of specified tensor, i.e. keeping it dynamic
as a symbolic size rather than specializing according to size of example tracing input.
Specifically :func:`dynamic_dim` can be used to express following types of dynamism.
- Size of a dimension is dynamic and unbounded::
t0 = torch.rand(2, 3)
t1 = torch.rand(3, 4)
# First dimension of t0 can be dynamic size rather than always being static size 2
constraints = [dynamic_dim(t0, 0)]
ep = export(fn, (t0, t1), constraints=constraints)
- Size of a dimension is dynamic with a lower bound::
t0 = torch.rand(10, 3)
t1 = torch.rand(3, 4)
# First dimension of t0 can be dynamic size with a lower bound of 5 (inclusive)
# Second dimension of t1 can be dynamic size with a lower bound of 2 (exclusive)
constraints = [
dynamic_dim(t0, 0) >= 5,
dynamic_dim(t1, 1) > 2,
]
ep = export(fn, (t0, t1), constraints=constraints)
- Size of a dimension is dynamic with an upper bound::
t0 = torch.rand(10, 3)
t1 = torch.rand(3, 4)
# First dimension of t0 can be dynamic size with a upper bound of 16 (inclusive)
# Second dimension of t1 can be dynamic size with a upper bound of 8 (exclusive)
constraints = [
dynamic_dim(t0, 0) <= 16,
dynamic_dim(t1, 1) < 8,
]
ep = export(fn, (t0, t1), constraints=constraints)
- Size of a dimension is dynamic and it is always equal to size of another dynamic dimension::
t0 = torch.rand(10, 3)
t1 = torch.rand(3, 4)
# Sizes of second dimension of t0 and first dimension are always equal
constraints = [
dynamic_dim(t0, 1) == dynamic_dim(t1, 0),
]
ep = export(fn, (t0, t1), constraints=constraints)
- Mix and match all types above as long as they do not express conflicting requirements
"""
from torch._dynamo.exc import UserError, UserErrorType
if not isinstance(t, torch.Tensor):
raise UserError(
UserErrorType.DYNAMIC_DIM,
f"Expected tensor as input to dynamic_dim but got {type(t)}",
)
if t.dim() < 1:
raise UserError(
UserErrorType.DYNAMIC_DIM, "Cannot mark 0-dimension tensors to be dynamic"
)
if index >= t.dim():
raise UserError(
UserErrorType.DYNAMIC_DIM,
f"Expected the dimension passed to dynamic_dim to be in the range [0:{t.dim()-1}]"
f" but got {index}, which is out of bounds for the given tensor.",
)
# Import sympy locally
import sympy
from torch.fx.experimental.symbolic_shapes import StrictMinMaxConstraint
from torch.utils._sympy.value_ranges import ValueRanges
return _create_constraint(
weakref.ref(t),
id(t),
index,
StrictMinMaxConstraint(
vr=ValueRanges(lower=0, upper=sympy.oo), warn_only=False
),
debug_name=debug_name,
)
def _process_equalities(
constraint: Constraint,
get_sources: Callable[[int, int], List["Source"]],
shape_env: "ShapeEnv",
source_pairs: List[Tuple["Source", "Source"]],
derived_equalities: List[Tuple["Source", Union["Source", "Symbol"], Callable]],
phantom_symbols: Dict[str, "Symbol"],
):
"""
Updates `source_pairs`, `derived_equalities`, and `phantom_symbols` (which become
fields of `EqualityConstraint`) based on a given input `constraint`.
"""
source, *other_sources = get_sources(constraint.t_id, constraint.dim)
# When t.size()[dim] maps to src0, src1, ..., srcN, we add
# constraints that make src0 "equal" to src1, ..., srcN.
source_pairs.extend((source, other_source) for other_source in other_sources)
if not isinstance(constraint, _DerivedConstraint):
if constraint.shared is not None:
# Moreover, when t.size()[dim] is specified equal to t'.size()[dim']
# and t'.size()[dim'] maps to src1', ..., srcN', we add
# constraints that also make src0 "equal" to src1', ..., srcN'.
other_sources = get_sources(constraint.shared.t_id, constraint.shared.dim)
source_pairs.extend(
(source, other_source) for other_source in other_sources
)
else:
# branch based on the root of the _DerivedConstraint
if not isinstance(constraint.root, _PhantomRoot):
# either root points to an input source
root = get_sources(constraint.root.t_id, constraint.root.dim)[0] # type: ignore[assignment]
else:
# or root points to a phantom symbol
if constraint.root.name in phantom_symbols:
root = phantom_symbols[constraint.root.name] # type: ignore[assignment]
else:
# create a phantom symbol in the shape env based on the _PhantomRoot
root = shape_env.create_symbol(
val=constraint.root.val,
source=torch._dynamo.source.ConstantSource(constraint.root.name),
dynamic_dim=torch.fx.experimental.symbolic_shapes.DimDynamic.DYNAMIC,
constraint_dim=constraint.root.constraint_range,
)
phantom_symbols[constraint.root.name] = root # type: ignore[assignment]
fn = constraint.fn
# A derived equality (source, root, fn) informally corresponds to source = fn(root).
# Here source describes an input and root might describe another input or a phantom symbol.
derived_equalities.append((source, root, fn))
def _tree_map(
func: Callable[..., Any],
tree: Any,
*dynamic_shapes: Any,
) -> Any:
"""
Customized tree_map for mapping pytrees to dynamic_shapes.
For built-in types (e.g., standard collections) this behaves exactly like tree_map.
OTOH for a user-defined class C registered with pytree, we cannot assume that a C
containing tensors can be mapped to a C containing dynamic shapes (i.e., C may not
be a polymorphic container). In that case we use the flattened form of C instead.
Thus a C(**tensors) that flattens to (**tensors) will map to (**dynamic_shapes).
Args:
func: function to apply to each (int, float, str, bool, None, torch.Tensor)
tree: input pytree
dynamic_shapes: zero or more (typically one) dynamic_shapes to match
Returns:
output pytree mapping func to each (int, float, str, bool, None, torch.Tensor)
"""
def is_leaf(t):
# BUILTIN_TYPES is a subset of SUPPORTED_NODES, the latter being all types
# registered with pytree. Types *not* in BUILTIN_TYPES include primitive types
# (int, float, str, bool, None, torch.Tensor), which are not in SUPPORTED_NODES,
# as well as user-defined classes registered with pytree, which are.
return _get_node_type(t) not in BUILTIN_TYPES
def f(t, *dynamic_shapes):
typ = _get_node_type(t)
# typ is not in BUILTIN_TYPES
if typ in SUPPORTED_NODES:
# thus typ is a user-defined class registered with pytree,
# in which case flatten and recurse
return tree_map(
f,
SUPPORTED_NODES[typ].flatten_fn(t)[0],
*dynamic_shapes,
is_leaf=is_leaf,
)
else:
return func(t, *dynamic_shapes)
return tree_map(f, tree, *dynamic_shapes, is_leaf=is_leaf)
def _combine_args(f, args, kwargs):
# combine args and kwargs following the signature of f, as it happens
# in the body of f when called with *args, **kwargs
if isinstance(f, ExportedProgram):
f = f.module()
signature = (
inspect.signature(f.forward)
if isinstance(f, torch.nn.Module)
else inspect.signature(f)
)
kwargs = kwargs if kwargs is not None else {}
return signature.bind(*args, **kwargs).arguments
class ShapesCollection:
"""
Builder for dynamic_shapes.
Used to assign dynamic shape specifications to tensors that appear in inputs.
Example::
args = ({"x": tensor_x, "others": [tensor_y, tensor_z]})
dim = torch.export.Dim(...)
dynamic_shapes = torch.export.ShapesCollection()
dynamic_shapes[tensor_x] = (dim, dim + 1, 8)
dynamic_shapes[tensor_y] = {0: dim * 2}
# This is equivalent to the following (now auto-generated):
# dynamic_shapes = {"x": (dim, dim + 1, 8), "others": [{0: dim * 2}, None]}
torch.export(..., args, dynamic_shapes=dynamic_shapes)
"""
def __init__(self):
self._shapes = {}
def __setitem__(self, t, shape):
assert isinstance(
t, torch.Tensor
), f"Cannot assign shape to non-tensor type {type(t)}"
# TODO(avik): check that shape is indeed a Shape
t_id = id(t)
if t_id in self._shapes:
_shape = self._shapes[t_id]
assert (
shape == _shape
), f"Shapes assigned to tensor do not match: expected {_shape}, got {shape}"
else:
self._shapes[id(t)] = shape
def __getitem__(self, t):
t_id = id(t)
if t_id in self._shapes:
return self._shapes[t_id]
else:
return None
def __len__(self):
return len(self._shapes)
def dynamic_shapes(self, m, args, kwargs=None):
"""
Generate dynamic_shapes.
"""
t_ids = set()
def find_shape(t):
t_id = id(t)
if t_id in self._shapes:
t_ids.add(t_id)
return self._shapes[t_id]
else:
return None
combined_args = _combine_args(m, args, kwargs)
dynamic_shapes = _tree_map(find_shape, combined_args)
if any(t_id not in t_ids for t_id in self._shapes):
raise ValueError(
"Some tensors that were assigned shapes were not found in args. "
"Maybe such tensors were copied when passing them as args? "
"Maybe such tensors are contained in classes that were not registered with pytree?"
)
return dynamic_shapes
def _process_dynamic_shapes(
f: Callable,
args: Tuple[Any, ...],
kwargs: Optional[Dict[str, Any]] = None,
dynamic_shapes: Optional[Union[Dict[str, Any], Tuple[Any], List[Any]]] = None,
) -> Optional[List[Constraint]]:
from torch._dynamo.exc import UserError, UserErrorType
if dynamic_shapes is None or len(dynamic_shapes) == 0:
return None
# map of Dim names representing input shape dimensions to constraints on them
symbols: Dict[str, List[Constraint]] = defaultdict(list)
# track roots that do not directly represent input shape dimensions
phantom_roots: Dict[str, _PhantomRoot] = {}
derived_constraints_with_phantom_root: List[_DerivedConstraint] = []
def to_constraint(dim, tensor, i):
import sympy
from torch.fx.experimental.symbolic_shapes import StrictMinMaxConstraint
from torch.utils._sympy.solve import try_solve
from torch.utils._sympy.value_ranges import ValueRanges
def root_value():
# given tensor.shape[i] is the value of dim = fn(root),
# find the value of root
symbol = sympy.Symbol(dim.root.__name__, integer=True)
expr = dim.fn(symbol)
solution = try_solve(sympy.Eq(expr, tensor.shape[i]), symbol)
if solution is not None:
return int(solution[1]) # type: ignore[call-overload]
else:
raise UserError( # noqa: TRY200
UserErrorType.CONSTRAINT_VIOLATION,
f"Expected shape[{i}] = {tensor.shape[i]} of input Tensor to be "
f"of the form {expr}, where {symbol} is an integer",
)
if isinstance(dim, _DerivedDim):
# generate a _DerivedConstraint where the root is:
# - either a _ConstraintTarget (if dim.root directly describes an input shape)
# - or a _PhantomRoot (otherwise)
dim_root = dim.root # type: ignore[attr-defined]
if dim_root.__name__ in symbols:
# root represents an input shape dimension
root_constraint = symbols[dim_root.__name__][0]
root = _ConstraintTarget(
root_constraint.w_tensor,
root_constraint.t_id,
root_constraint.dim,
)
elif dim_root.__name__ not in phantom_roots:
# create a phantom root
root = _PhantomRoot( # type: ignore[assignment]
name=dim_root.__name__,
constraint_range=StrictMinMaxConstraint(
vr=ValueRanges(lower=dim_root.min, upper=dim_root.max),
warn_only=False,
),
val=root_value(),
)
phantom_roots[dim_root.__name__] = root # type: ignore[assignment]
else:
root = phantom_roots[dim_root.__name__] # type: ignore[assignment]
constraint = _DerivedConstraint(
weakref.ref(tensor),
id(tensor),
i,
root,
dim.fn, # type: ignore[attr-defined]
StrictMinMaxConstraint(
vr=ValueRanges(lower=dim.min, upper=dim.max),
warn_only=False,
),
debug_name=dim.__name__,
)
if isinstance(root, _PhantomRoot):
# NOTE(avik): since we have not processed all inputs yet, we may replace this
# with a root that does represent an input shape dimension later (see below)
derived_constraints_with_phantom_root.append(constraint)
elif isinstance(dim, _StaticDim):
constraint = _create_constraint(
weakref.ref(tensor),
id(tensor),
i,
StrictMinMaxConstraint(
vr=ValueRanges(lower=dim.value, upper=dim.value), warn_only=False # type: ignore[attr-defined]
),
debug_name=dim.__name__,
)
else:
constraint = dynamic_dim(tensor, i, debug_name=dim.__name__)
if dim.min != 0:
constraint = constraint >= dim.min
if dim.max != sys.maxsize - 1:
constraint = constraint <= dim.max
return constraint
bounds: Dict[str, Tuple[int, int]] = {}
def check_same_bounds(dim):
if dim.__name__ in symbols:
min_, max_ = bounds[dim.__name__]
if dim.min != min_ or dim.max != max_:
this_ = _Dim.readable(dim.__name__, min_, max_)
that_ = _Dim.readable(dim.__name__, dim.min, dim.max)
raise UserError(
UserErrorType.INVALID_INPUT,
f"Found different definitions {this_} and {that_} "
f"for the same symbolic dimension {dim}!",
)
else:
bounds[dim.__name__] = (dim.min, dim.max)
def update_symbols(tensor, shape):
def _create_static_dim(tensor, i, value):
return _StaticDim(str(value), (int,), {"value": value})
if isinstance(shape, dict):
for i, dim in shape.items():
if isinstance(dim, (int, _Dim)):
if isinstance(dim, int):
dim = _create_static_dim(tensor, i, dim)
check_same_bounds(dim)
constraint = to_constraint(dim, tensor, i)
symbols[dim.__name__].append(constraint)
else:
if dim is not None:
raise UserError(
UserErrorType.INVALID_INPUT,
f"Unexpected item #{i} ({dim}) in dynamic_shape {shape} of Tensor, "
"try None instead",
)
elif isinstance(shape, (tuple, list)):
for i, dim in enumerate(shape):
if isinstance(dim, (int, _Dim)):
if isinstance(dim, int):
dim = _create_static_dim(tensor, i, dim)
check_same_bounds(dim)
constraint = to_constraint(dim, tensor, i)
symbols[dim.__name__].append(constraint)
else:
if dim is not None:
raise UserError(
UserErrorType.INVALID_INPUT,
f"Unexpected item #{i} ({dim}) in dynamic_shape {shape} of Tensor, "
"try None instead",
)
else:
if shape is not None:
raise UserError(
UserErrorType.INVALID_INPUT,
f"Unexpected dynamic_shape {shape} of Tensor, " "try None instead",
)
def assoc_shapes(combined_args, dynamic_shapes):
def assoc_shape(t, dynamic_shape):
if isinstance(t, torch.Tensor):
update_symbols(t, dynamic_shape)
else:
if dynamic_shape is not None:
raise UserError(
UserErrorType.INVALID_INPUT,
f"Cannot associate shape {dynamic_shape} to non-tensor type {type(t)}, "
f"expected None",
)
_tree_map(assoc_shape, combined_args, dynamic_shapes)
combined_args = _combine_args(f, args, kwargs)
if not isinstance(dynamic_shapes, dict):
assert isinstance(dynamic_shapes, (tuple, list))
combined_args = type(dynamic_shapes)(combined_args.values()) # type: ignore[assignment, misc]
assoc_shapes(combined_args, dynamic_shapes)
constraints = []
for derived_constraint_with_phantom_root in derived_constraints_with_phantom_root:
phantom_root_name = derived_constraint_with_phantom_root.root.name # type: ignore[union-attr]
if phantom_root_name in symbols:
# We found an input shape dimension corresponding to this name, so we
# do not need a phantom symbol for it after all.
# NOTE(avik): Overall we want to maintain the invariant that roots that
# are phantom symbols are really "phantom," i.e., they cannot be represented
# by any input source. This is important when we are deciding derived equalities,
# since we can focus our attention exclusively on input sources: deciding
# derived equalities involving phantom symbols are, in comparison, trivial.
derived_constraint_with_phantom_root.root = symbols[phantom_root_name][0]
for dynamic_dims in symbols.values():
if all(
isinstance(dynamic_dim, _DerivedConstraint) for dynamic_dim in dynamic_dims
):
constraints.extend(dynamic_dims)
else:
primary, *others = dynamic_dims
if others:
for other in others:
constraints.append(primary == other) # type: ignore[arg-type]
else:
constraints.append(primary)
return constraints # type: ignore[return-value]