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Source code for torch.export.graph_signature

import dataclasses
from enum import auto, Enum
from typing import Collection, Dict, List, Mapping, Optional, Set, Tuple, Union


__all__ = [
    "ConstantArgument",
    "CustomObjArgument",
    "ExportBackwardSignature",
    "ExportGraphSignature",
    "InputKind",
    "InputSpec",
    "OutputKind",
    "OutputSpec",
    "SymIntArgument",
    "TensorArgument",
]


@dataclasses.dataclass
class TensorArgument:
    name: str


@dataclasses.dataclass
class TokenArgument:
    name: str


@dataclasses.dataclass
class SymIntArgument:
    name: str


[docs]@dataclasses.dataclass class CustomObjArgument: name: str class_fqn: str
@dataclasses.dataclass class ConstantArgument: name: str value: Union[int, float, bool, str, None] ArgumentSpec = Union[ TensorArgument, SymIntArgument, ConstantArgument, CustomObjArgument, TokenArgument, ]
[docs]class InputKind(Enum): USER_INPUT = auto() PARAMETER = auto() BUFFER = auto() CONSTANT_TENSOR = auto() CUSTOM_OBJ = auto() TOKEN = auto()
[docs]@dataclasses.dataclass class InputSpec: kind: InputKind arg: ArgumentSpec target: Optional[str] persistent: Optional[bool] = None def __post_init__(self): if self.kind == InputKind.BUFFER: assert ( self.persistent is not None ), "Failed to specify persistent flag on BUFFER." assert isinstance( self.arg, ( TensorArgument, SymIntArgument, ConstantArgument, CustomObjArgument, TokenArgument, ), ), f"got {type(self.arg)}"
[docs]class OutputKind(Enum): USER_OUTPUT = auto() LOSS_OUTPUT = auto() BUFFER_MUTATION = auto() GRADIENT_TO_PARAMETER = auto() GRADIENT_TO_USER_INPUT = auto() USER_INPUT_MUTATION = auto() TOKEN = auto()
[docs]@dataclasses.dataclass class OutputSpec: kind: OutputKind arg: ArgumentSpec target: Optional[str] def __post_init__(self): assert isinstance( self.arg, (TensorArgument, SymIntArgument, ConstantArgument, TokenArgument) )
def _sig_to_specs( *, user_inputs: Set[str], inputs_to_parameters: Mapping[str, str], inputs_to_buffers: Mapping[str, str], user_outputs: Set[str], buffer_mutations: Mapping[str, str], user_input_mutations: Mapping[str, str], grad_params: Mapping[str, str], grad_user_inputs: Mapping[str, str], loss_output: Optional[str], inputs: List[ArgumentSpec], outputs: List[ArgumentSpec], input_tokens: List[str], output_tokens: List[str], ) -> Tuple[List[InputSpec], List[OutputSpec]]: def to_input_spec(inp: ArgumentSpec) -> InputSpec: if isinstance(inp, TokenArgument): return InputSpec(kind=InputKind.TOKEN, arg=inp, target=None) if not isinstance(inp, TensorArgument): return InputSpec(kind=InputKind.USER_INPUT, arg=inp, target=None) name = inp.name if name in user_inputs: return InputSpec(kind=InputKind.USER_INPUT, arg=inp, target=None) elif name in inputs_to_parameters: return InputSpec( kind=InputKind.PARAMETER, arg=inp, target=inputs_to_parameters[name], ) elif name in inputs_to_buffers: return InputSpec( kind=InputKind.BUFFER, arg=inp, target=inputs_to_buffers[name], # Mark as True for now; we will fix this up to distinguish # persistent from non-persistent later in tracing. # See: rewrite_non_persistent_buffers() # TODO(suo): this is horrible. persistent=True, ) else: raise AssertionError(f"Unknown tensor input kind: {name}") def to_output_spec(idx: int, o: ArgumentSpec) -> OutputSpec: if isinstance(o, TokenArgument): return OutputSpec(kind=OutputKind.TOKEN, arg=o, target=None) if not isinstance(o, TensorArgument): return OutputSpec(kind=OutputKind.USER_OUTPUT, arg=o, target=None) name = o.name if idx < len(buffer_mutations) + len(user_input_mutations) + len(output_tokens): if name in buffer_mutations: return OutputSpec( kind=OutputKind.BUFFER_MUTATION, arg=o, target=buffer_mutations[name], ) elif name in user_input_mutations: return OutputSpec( kind=OutputKind.USER_INPUT_MUTATION, arg=o, target=user_input_mutations[name], ) else: raise AssertionError(f"Unknown tensor mutation kind: {name}") else: if name in user_outputs: return OutputSpec(kind=OutputKind.USER_OUTPUT, arg=o, target=None) elif name in grad_params: return OutputSpec( kind=OutputKind.GRADIENT_TO_PARAMETER, arg=o, target=grad_params[name], ) elif name in grad_user_inputs: return OutputSpec( kind=OutputKind.GRADIENT_TO_USER_INPUT, arg=o, target=grad_user_inputs[name], ) elif name == loss_output: return OutputSpec(kind=OutputKind.LOSS_OUTPUT, arg=o, target=None) else: raise AssertionError(f"Unknown tensor output kind: {name}") input_specs = [to_input_spec(inp) for inp in inputs] output_specs = [to_output_spec(idx, o) for idx, o in enumerate(outputs)] return input_specs, output_specs
[docs]@dataclasses.dataclass class ExportBackwardSignature: gradients_to_parameters: Dict[str, str] gradients_to_user_inputs: Dict[str, str] loss_output: str
[docs]@dataclasses.dataclass class ExportGraphSignature: """ :class:`ExportGraphSignature` models the input/output signature of Export Graph, which is a fx.Graph with stronger invariants gurantees. Export Graph is functional and does not access "states" like parameters or buffers within the graph via ``getattr`` nodes. Instead, :func:`export` gurantees that parameters, buffers, and constant tensors are lifted out of the graph as inputs. Similarly, any mutations to buffers are not included in the graph either, instead the updated values of mutated buffers are modeled as additional outputs of Export Graph. The ordering of all inputs and outputs are:: Inputs = [*parameters_buffers_constant_tensors, *flattened_user_inputs] Outputs = [*mutated_inputs, *flattened_user_outputs] e.g. If following module is exported:: class CustomModule(nn.Module): def __init__(self): super(CustomModule, self).__init__() # Define a parameter self.my_parameter = nn.Parameter(torch.tensor(2.0)) # Define two buffers self.register_buffer('my_buffer1', torch.tensor(3.0)) self.register_buffer('my_buffer2', torch.tensor(4.0)) def forward(self, x1, x2): # Use the parameter, buffers, and both inputs in the forward method output = (x1 + self.my_parameter) * self.my_buffer1 + x2 * self.my_buffer2 # Mutate one of the buffers (e.g., increment it by 1) self.my_buffer2.add_(1.0) # In-place addition return output Resulting Graph would be:: graph(): %arg0_1 := placeholder[target=arg0_1] %arg1_1 := placeholder[target=arg1_1] %arg2_1 := placeholder[target=arg2_1] %arg3_1 := placeholder[target=arg3_1] %arg4_1 := placeholder[target=arg4_1] %add_tensor := call_function[target=torch.ops.aten.add.Tensor](args = (%arg3_1, %arg0_1), kwargs = {}) %mul_tensor := call_function[target=torch.ops.aten.mul.Tensor](args = (%add_tensor, %arg1_1), kwargs = {}) %mul_tensor_1 := call_function[target=torch.ops.aten.mul.Tensor](args = (%arg4_1, %arg2_1), kwargs = {}) %add_tensor_1 := call_function[target=torch.ops.aten.add.Tensor](args = (%mul_tensor, %mul_tensor_1), kwargs = {}) %add_tensor_2 := call_function[target=torch.ops.aten.add.Tensor](args = (%arg2_1, 1.0), kwargs = {}) return (add_tensor_2, add_tensor_1) Resulting ExportGraphSignature would be:: ExportGraphSignature( input_specs=[ InputSpec(kind=<InputKind.PARAMETER: 2>, arg=TensorArgument(name='arg0_1'), target='my_parameter'), InputSpec(kind=<InputKind.BUFFER: 3>, arg=TensorArgument(name='arg1_1'), target='my_buffer1'), InputSpec(kind=<InputKind.BUFFER: 3>, arg=TensorArgument(name='arg2_1'), target='my_buffer2'), InputSpec(kind=<InputKind.USER_INPUT: 1>, arg=TensorArgument(name='arg3_1'), target=None), InputSpec(kind=<InputKind.USER_INPUT: 1>, arg=TensorArgument(name='arg4_1'), target=None) ], output_specs=[ OutputSpec(kind=<OutputKind.BUFFER_MUTATION: 3>, arg=TensorArgument(name='add_2'), target='my_buffer2'), OutputSpec(kind=<OutputKind.USER_OUTPUT: 1>, arg=TensorArgument(name='add_1'), target=None) ] ) """ input_specs: List[InputSpec] output_specs: List[OutputSpec] # A list of parameters uniquely identified by mangled fully qualified name @property def parameters(self) -> Collection[str]: # TODO Make this tuple. return [ s.target for s in self.input_specs if s.kind == InputKind.PARAMETER if isinstance(s.target, str) ] # A list of buffers uniquely identified by mangled fully qualified name @property def buffers(self) -> Collection[str]: # TODO Make this tuple. return [ s.target for s in self.input_specs if s.kind == InputKind.BUFFER if isinstance(s.target, str) ] @property def non_persistent_buffers(self) -> Collection[str]: return [ s.target for s in self.input_specs if s.kind == InputKind.BUFFER if s.persistent is False if isinstance(s.target, str) ] # A list of lifted constant tensors @property def lifted_tensor_constants(self) -> Collection[str]: # TODO Make this tuple. return [ s.target for s in self.input_specs if s.kind == InputKind.CONSTANT_TENSOR if isinstance(s.target, str) ] @property def lifted_custom_objs(self) -> Collection[str]: # TODO Make this tuple. return [ s.target for s in self.input_specs if s.kind == InputKind.CUSTOM_OBJ if isinstance(s.target, str) ] # Graph node names of pytree-flattened inputs of original program @property def user_inputs(self) -> Collection[Union[int, float, bool, None, str]]: user_inputs: List[Union[int, float, bool, None, str]] = [] for s in self.input_specs: if s.kind != InputKind.USER_INPUT: continue if isinstance(s.arg, (TensorArgument, SymIntArgument, CustomObjArgument)): user_inputs.append(s.arg.name) elif isinstance(s.arg, ConstantArgument): user_inputs.append(s.arg.value) else: raise RuntimeError(f"{s.arg} is not a valid user inputs") return tuple(user_inputs) # Graph node names of pytree-flattened outputs of original program @property def user_outputs(self) -> Collection[Union[int, float, bool, None, str]]: user_outputs: List[Union[int, float, bool, None, str]] = [] for s in self.output_specs: if s.kind != OutputKind.USER_OUTPUT: continue if isinstance(s.arg, (TensorArgument, SymIntArgument)): user_outputs.append(s.arg.name) elif isinstance(s.arg, ConstantArgument): user_outputs.append(s.arg.value) else: raise RuntimeError(f"{s.arg} is not a valid user output") return tuple(user_outputs) # A dictionary mapping graph input node names to parameters. If a graph input # name is found in this dictionary, it is guranteed to be a lifted parameter. @property def inputs_to_parameters(self) -> Mapping[str, str]: return { s.arg.name: s.target for s in self.input_specs if s.kind == InputKind.PARAMETER and isinstance(s.arg, TensorArgument) and isinstance(s.target, str) } # A dictionary mapping graph input node names to buffers. If a graph input # name is found in this dictionary, it is guranteed to be a lifted buffer. @property def inputs_to_buffers(self) -> Mapping[str, str]: return { s.arg.name: s.target # type: ignore[union-attr, misc] for s in self.input_specs if s.kind == InputKind.BUFFER and isinstance(s.arg, TensorArgument) and isinstance(s.target, str) } # A dictionary mapping graph output node names to buffers that are mutated in the # original program. Buffers that are not mutated will not be found in this dictionary. @property def buffers_to_mutate(self) -> Mapping[str, str]: return { s.arg.name: s.target for s in self.output_specs if s.kind == OutputKind.BUFFER_MUTATION and isinstance(s.arg, TensorArgument) and isinstance(s.target, str) } @property def user_inputs_to_mutate(self) -> Mapping[str, str]: return { s.arg.name: s.target for s in self.output_specs if s.kind == OutputKind.USER_INPUT_MUTATION and isinstance(s.arg, TensorArgument) and isinstance(s.target, str) } # A dictionary mapping graph input node names to lifted tensor constants. @property def inputs_to_lifted_tensor_constants(self) -> Mapping[str, str]: return { s.arg.name: s.target for s in self.input_specs if s.kind == InputKind.CONSTANT_TENSOR and isinstance(s.arg, TensorArgument) and isinstance(s.target, str) } @property def inputs_to_lifted_custom_objs(self) -> Mapping[str, str]: return { s.arg.name: s.target for s in self.input_specs if s.kind == InputKind.CUSTOM_OBJ and isinstance(s.arg, CustomObjArgument) and isinstance(s.target, str) } @property def backward_signature(self) -> Optional[ExportBackwardSignature]: loss_output = None gradients_to_parameters: Dict[str, str] = {} gradients_to_user_inputs: Dict[str, str] = {} for spec in self.output_specs: if spec.kind == OutputKind.LOSS_OUTPUT: assert loss_output is None assert isinstance(spec.arg, TensorArgument) loss_output = spec.arg.name elif spec.kind == OutputKind.GRADIENT_TO_PARAMETER: assert isinstance(spec.target, str) assert isinstance(spec.arg, TensorArgument) gradients_to_parameters[spec.arg.name] = spec.target elif spec.kind == OutputKind.GRADIENT_TO_USER_INPUT: assert isinstance(spec.target, str) assert isinstance(spec.arg, TensorArgument) gradients_to_user_inputs[spec.arg.name] = spec.target if loss_output is None: return None return ExportBackwardSignature( loss_output=loss_output, gradients_to_parameters=gradients_to_parameters, gradients_to_user_inputs=gradients_to_user_inputs, ) # Map from assertion dependency token index to assertion dep token output # name in output. The shape of output after aot_autograd will be like: # (updated_inputs, user_outputs, dep_token). @property def assertion_dep_token(self) -> Optional[Mapping[int, str]]: return None @property def input_tokens(self) -> List[str]: input_tokens = [] for s in self.input_specs: if s.kind == InputKind.TOKEN: assert isinstance(s.arg, TokenArgument) input_tokens.append(s.arg.name) return input_tokens @property def output_tokens(self) -> List[str]: output_tokens = [] for s in self.output_specs: if s.kind == OutputKind.TOKEN: assert isinstance(s.arg, TokenArgument) output_tokens.append(s.arg.name) return output_tokens def __post_init__(self) -> None: assertion_dep_token = self.assertion_dep_token if assertion_dep_token is None: return assert len(assertion_dep_token) == 1 assertion_dep_token_index = next(iter(assertion_dep_token.keys())) assert ( len(self.user_outputs) + len(self.buffers_to_mutate) == assertion_dep_token_index )
[docs] def replace_all_uses(self, old: str, new: str): """ Replace all uses of the old name with new name in the signature. """ assert isinstance(old, str) assert isinstance(new, str) arg_types = (TensorArgument, SymIntArgument, CustomObjArgument) for o in self.output_specs: if isinstance(o.arg, arg_types): if o.arg.name == old: o.arg.name = new for i in self.input_specs: if isinstance(i.arg, arg_types): if i.arg.name == old: i.arg.name = new
[docs] def get_replace_hook(self): def _(old, new, user): if user.op in ("output", "input"): self.replace_all_uses(old.name, new) return _

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