pytorch/torch/_dynamo/side_effects.py
Will Feng 386884e553 [Traceable FSDP2] Ignore FSDP2 forward hook side-effects in AC; Support FSDP2 + AC (#134997)
> Ignore FSDP2 forward hook side-effects in AC

Under AC, FSDP2 does not rely on forward hook to all-gather weights to do recomputation, instead it relies on pre-backward hook to do this job:
451eaf0ff2/torch/distributed/_composable/fsdp/_fsdp_state.py (L219-L220)

So when we use `speculate_subgraph` to trace the utils.checkpoint AC region, we don't actually need to worry about FSDP2 forward hook's side effects and can safely ignore it, because we are not and we don't expect to re-run the FSDP2 forward hook during backward recomputation.

----

Test commands:
- `pytest -rA test/distributed/_composable/fsdp/test_fully_shard_compile.py::TestFullyShardCompile::test_nested_fully_shard_backend_inductor`
- `pytest -rA test/distributed/_composable/fsdp/test_fully_shard_compile.py::TestFullyShardCompile::test_transformer_backend_inductor`

Pull Request resolved: https://github.com/pytorch/pytorch/pull/134997
Approved by: https://github.com/zou3519
ghstack dependencies: #135727
2024-09-15 02:00:17 +00:00

754 lines
31 KiB
Python

# mypy: allow-untyped-defs
import contextlib
import functools
import inspect
import warnings
import weakref
from collections.abc import MutableMapping
from typing import Any, Dict, List, Optional, Type, Union
import torch.nn
from . import utils, variables
from .bytecode_transformation import (
bytecode_from_template,
create_call_function,
create_call_method,
create_instruction,
)
from .codegen import PyCodegen
from .exc import unimplemented
from .source import GlobalSource, LocalSource, Source
from .utils import is_frozen_dataclass, nn_module_new, object_new
from .variables.base import (
is_side_effect_safe,
MutableLocalBase,
MutableLocalSource,
VariableTracker,
)
from .variables.user_defined import FrozenDataClassVariable
class MutableSideEffects(MutableLocalBase):
"""
VariableTracker.mutable_local marker to indicate a list passed as
an input that if we mutate we need to re-apply those mutations after
the graph runs.
"""
def __init__(self, source: Source, is_modified: bool = False):
super().__init__(MutableLocalSource.Existing)
self.source = source
self.is_modified = is_modified
class AttributeMutation(MutableLocalBase):
"""
VariableTracker.mutable_local marker to track changes to attributes
"""
def __init__(self, typ: MutableLocalSource, source: Optional[Source]):
super().__init__(typ)
self.source = source
class AttributeMutationExisting(AttributeMutation):
def __init__(self, source: Source):
super().__init__(MutableLocalSource.Existing, source)
self.source = source
class AttributeMutationNew(AttributeMutation):
def __init__(self, source: Optional[Source], cls_source: Optional[Source]):
super().__init__(MutableLocalSource.Local, source)
self.cls_source = cls_source
def _manual_update_dict(dict_from, dict_to):
for k, v in dict_from.items():
dict_to[k] = v
class SideEffects:
"""
Track side effects (list mutation, setattr, etc) that need to be
applied after an FX graph is run.
"""
id_to_variable: Dict[int, VariableTracker]
store_attr_mutations: Dict[MutableLocalBase, Dict[str, VariableTracker]]
keepalive: List[Any]
def __init__(
self,
output_graph,
id_to_variable=None,
store_attr_mutations=None,
keepalive=None,
save_for_backward=None,
tensor_hooks=None,
):
super().__init__()
self.output_graph_weakref = weakref.ref(output_graph)
self.id_to_variable = id_to_variable or {}
self.store_attr_mutations = store_attr_mutations or {}
self.keepalive = keepalive or []
self.save_for_backward = save_for_backward or []
self.tensor_hooks = tensor_hooks or {}
# Track Compiled Autograd final callbacks that must be called at the end of Compiled Autograd backward graph.
# Only applicable if this graph is created from Dynamo tracing in Compiled Autograd.
self.ca_final_callbacks_var = None
def __eq__(self, other: object) -> bool:
assert isinstance(other, SideEffects)
# NB: do NOT test keepalive
return (
self.id_to_variable == other.id_to_variable
and self.store_attr_mutations == other.store_attr_mutations
and self.save_for_backward == other.save_for_backward
and self.tensor_hooks == other.tensor_hooks
)
def diff(self, other: "SideEffects") -> Optional[str]:
if self.id_to_variable != other.id_to_variable:
sk_itv = self.id_to_variable.keys()
ok_itv = other.id_to_variable.keys()
if sk_itv != ok_itv:
return f"id_to_variable keys: {sk_itv} != {ok_itv}"
# Feel free to augment this with more fancy diffing logic
# if needed for debugging
return "id_to_variable: unknown diff"
elif self.store_attr_mutations != other.store_attr_mutations:
sk_sam = self.store_attr_mutations.keys()
ok_sam = other.store_attr_mutations.keys()
if sk_sam != ok_sam:
return f"store_attr_mutations keys: {sk_sam} != {ok_sam}"
return "store_attr_mutations: unknown diff"
elif self.save_for_backward != other.save_for_backward:
return "save_for_backward"
elif self.tensor_hooks != other.tensor_hooks:
return "tensor_hooks"
else:
return None
def clone(self):
"""Create a shallow copy"""
return self.__class__(
output_graph=self.output_graph_weakref(),
id_to_variable=dict(self.id_to_variable),
store_attr_mutations={
k: dict(v) for k, v in self.store_attr_mutations.items()
},
keepalive=list(self.keepalive),
save_for_backward=self.save_for_backward,
tensor_hooks=self.tensor_hooks,
)
def __contains__(self, item):
return id(item) in self.id_to_variable
def __getitem__(self, item):
return self.id_to_variable[id(item)]
def should_allow_side_effects_under_checkpoint(self):
output_graph = self.output_graph_weakref()
return (
output_graph
and output_graph.current_tx.output.current_tracer.under_activation_checkpoint
and output_graph.current_tx.output.current_tracer.allow_side_effects_under_checkpoint
)
def check_allowed_side_effect(self, item):
from torch._dynamo.variables.misc import AutogradFunctionContextVariable
# People do things like self.dim = dim inside autograd.Function.
# These are benign.
if isinstance(item, AutogradFunctionContextVariable):
return True
if self.should_allow_side_effects_under_checkpoint():
return True
if not is_side_effect_safe(item.mutable_local):
unimplemented(
"HigherOrderOperator: Mutating a variable not in the current scope (SideEffects)"
)
def store_attr(self, item: VariableTracker, name: str, value: VariableTracker):
assert self.is_attribute_mutation(item)
self.check_allowed_side_effect(item)
if item.mutable_local not in self.store_attr_mutations:
self.store_attr_mutations[item.mutable_local] = {}
self.store_attr_mutations[item.mutable_local][name] = value
def load_attr(self, item, name, deleted_ok=False):
assert self.is_attribute_mutation(item)
result = self.store_attr_mutations[item.mutable_local][name]
if not deleted_ok and isinstance(result, variables.DeletedVariable):
unimplemented("read deleted attribute")
return result
def store_cell(self, cellvar, value):
assert isinstance(cellvar, variables.NewCellVariable)
assert isinstance(value, variables.VariableTracker)
self.store_attr(cellvar, "cell_contents", value)
def load_cell(self, cellvar):
assert isinstance(cellvar, variables.NewCellVariable)
return self.load_attr(cellvar, "cell_contents")
def load_global(self, gvar: VariableTracker, name: str):
assert isinstance(gvar, variables.VariableTracker)
return self.load_attr(gvar, name)
def store_global(self, gvar: VariableTracker, name: str, value: VariableTracker):
assert isinstance(gvar, variables.VariableTracker)
assert isinstance(value, variables.VariableTracker)
self.store_attr(gvar, name, value)
@staticmethod
def cls_supports_mutation_side_effects(cls):
return (
inspect.getattr_static(cls, "__getattribute__", None)
is object.__getattribute__
)
def is_attribute_mutation(self, item):
return isinstance(item.mutable_local, AttributeMutation)
def has_pending_mutation(self, item):
return self.is_attribute_mutation(item) and bool(
self.store_attr_mutations.get(item.mutable_local)
)
def has_pending_mutation_of_attr(self, item, name):
return self.is_attribute_mutation(
item
) and name in self.store_attr_mutations.get(item.mutable_local, ())
def is_modified(self, item):
if isinstance(item.mutable_local, AttributeMutationNew):
return True
if self.is_attribute_mutation(item):
return item.mutable_local in self.store_attr_mutations
return item.mutable_local.is_modified
def _track_obj(
self,
item: Any,
variable: VariableTracker,
mutable_cls=MutableSideEffects,
):
"""Start tracking a new variable for mutation"""
assert variable.source is not None
if id(item) in self.id_to_variable:
raise AssertionError(
f"{variable} is already tracked for mutation. This could be "
"because you are not using VariableBuilder to construct "
"the variable tracker. "
f"Source of new object: {variable.source}. "
f"Source of previously tracked object: {self.id_to_variable[id(item)].source}."
)
variable.mutable_local = mutable_cls(variable.source)
self.id_to_variable[id(item)] = variable
self.keepalive.append(item)
return variable
track_mutable = _track_obj
def track_object_existing(
self,
item: Any,
variable: VariableTracker,
):
return self._track_obj(item, variable, mutable_cls=AttributeMutationExisting)
def track_object_new(
self,
cls_source: Source,
user_cls: Any,
variable_cls: Any,
options,
):
if user_cls is torch.autograd.function.FunctionCtx:
with warnings.catch_warnings(record=True):
obj = torch.autograd.Function()
elif issubclass(user_cls, torch.nn.Module):
obj = nn_module_new(user_cls)
else:
obj = object_new(user_cls)
variable = variable_cls(
obj,
mutable_local=AttributeMutationNew(None, cls_source),
**options,
)
self.id_to_variable[id(obj)] = variable
self.keepalive.append(obj)
return variable
def track_object_new_from_user_defined_class(
self,
cls_variable: "variables.UserDefinedClassVariable",
):
cls_source = cls_variable.source
user_cls = cls_variable.value
# Find the variable class
variable_cls: Type[
variables.UserDefinedObjectVariable
] = variables.UserDefinedObjectVariable
if issubclass(user_cls, torch.nn.Module):
variable_cls = variables.UnspecializedNNModuleVariable
elif issubclass(user_cls, MutableMapping):
variable_cls = variables.MutableMappingVariable
elif is_frozen_dataclass(user_cls):
variable_cls = FrozenDataClassVariable
else:
variable_cls = variables.UserDefinedObjectVariable
assert issubclass(variable_cls, variables.UserDefinedObjectVariable)
variable_cls = functools.partial(variable_cls, cls_source=cls_source)
return self.track_object_new(cls_source, user_cls, variable_cls, {})
def track_cell_new(
self,
):
obj = object()
variable = variables.NewCellVariable(
mutable_local=AttributeMutationNew(None, None),
)
self.id_to_variable[id(obj)] = variable
self.keepalive.append(obj)
return variable
def track_cell_existing(self, source: Source, item: Any):
variable = variables.NewCellVariable(
mutable_local=AttributeMutationExisting(source),
)
self.id_to_variable[id(item)] = variable
self.keepalive.append(item)
return variable
def track_global_existing(self, source: Source, item: Any):
variable = variables.NewGlobalVariable(
mutable_local=AttributeMutationExisting(source),
)
self.id_to_variable[id(item)] = variable
self.keepalive.append(item)
return variable
def track_save_for_backward(self, ctx, args):
assert isinstance(ctx, variables.AutogradFunctionContextVariable)
self.save_for_backward.append((ctx, args))
def track_tensor_variables_from_runahead_side_effects(self, other):
# In higher order ops we want to keep track of tensors seen in the
# speculate_subgraph so that we don't lift them again as a new input in
# other speculate_subgraph or in the root tracer.
for other_item in other.keepalive:
other_id = id(other_item)
other_variable = other.id_to_variable[other_id]
if other_id not in self.id_to_variable and isinstance(
other_variable, variables.TensorVariable
):
self.track_object_existing(other_item, other_variable)
def prune_dead_object_new(self, tx):
live_new_objects = set()
# use this to avoid cycles in mutable_local (though I'm not sure if that
# can actually happen).
visited: Any = set({})
def visit(var: VariableTracker):
mutable_local = var.mutable_local
if mutable_local is None:
return
if mutable_local in visited:
return
visited.add(mutable_local)
# Object may have been mutated, store this mutation.
if isinstance(mutable_local, AttributeMutationNew):
live_new_objects.add(mutable_local)
# It's possible that we have mutated the value of this variable
# to be another one. The new value is in store_attr_mutations.
# Also recurse through the new value to detect alive AttributeMutationNew.
if var.mutable_local in self.store_attr_mutations:
VariableTracker.visit(
visit, self.store_attr_mutations[var.mutable_local]
)
def is_live(var: Union[MutableLocalBase, VariableTracker]):
if isinstance(var, AttributeMutationNew):
return var in live_new_objects
if isinstance(var, VariableTracker):
return is_live(var.mutable_local)
return True
pre_existing_vars = [
var
for var in self.id_to_variable.values()
if not isinstance(var.mutable_local, AttributeMutationNew)
]
# The only live side effects come from returns (tx.stack), any intermediates
# during a graph break (tx.symbolic_locals), and mutation on pre-existing variables.
# Recursively visit Variables and see if any of them have been mutated.
VariableTracker.visit(visit, (tx.stack, tx.symbolic_locals, pre_existing_vars))
# NB: cell variable handling.is tricky.
# cell variables must stay alive if any NestedUserFunctionVariable
# are live. "visit"-ing the NestedUserFunctionVariable visits
# the .closures field, from which we will see if we need to keep
# any mutations to cell variables alive.
self.id_to_variable = {
k: v for k, v in self.id_to_variable.items() if is_live(v)
}
self.store_attr_mutations = {
k: v for k, v in self.store_attr_mutations.items() if is_live(k)
}
def mutation(self, var):
self.check_allowed_side_effect(var)
if isinstance(var.mutable_local, MutableSideEffects):
var.mutable_local = MutableSideEffects(var.mutable_local.source, True)
def _get_modified_vars(self):
return [var for var in self.id_to_variable.values() if self.is_modified(var)]
def codegen_save_tempvars(self, cg: PyCodegen):
for var in self._get_modified_vars():
if isinstance(
var.mutable_local, (AttributeMutationExisting, AttributeMutationNew)
) and isinstance(var, variables.NewCellVariable):
cg.add_push_null(
lambda: cg.load_import_from(utils.__name__, "make_cell")
)
cg.extend_output(create_call_function(0, False))
cg.add_cache(var)
if isinstance(var.mutable_local, AttributeMutationNew):
var.mutable_local.source = LocalSource(cg.tempvars[var]) # type: ignore[attr-defined]
elif isinstance(var.mutable_local, AttributeMutationNew):
if isinstance(var, variables.AutogradFunctionContextVariable):
unimplemented("AutogradFunctionContextVariable escaped")
cg.add_push_null(
lambda: cg.load_import_from(utils.__name__, "object_new")
)
cg(var.mutable_local.cls_source)
cg.extend_output(create_call_function(1, False))
cg.add_cache(var)
var.mutable_local.source = LocalSource(cg.tempvars[var])
elif var in cg.tempvars:
assert cg.tempvars.get(var) is None
# subsequent usage should point to the original variable
cg(var.mutable_local.source)
cg.add_cache(var)
for ctx, args in self.save_for_backward:
cg(ctx.source)
cg.load_method("save_for_backward")
for arg in args:
cg(arg)
cg.extend_output(
[
*create_call_method(len(args)),
create_instruction("POP_TOP"),
]
)
def register_hook(self, tensor, hook, handle, name):
assert isinstance(tensor, variables.TensorVariable)
assert isinstance(hook, variables.VariableTracker)
assert (
isinstance(handle, variables.RemovableHandleVariable)
and handle.mutable_local
)
assert hasattr(torch.Tensor, name)
idx = len(self.tensor_hooks.keys())
# duplicate index possible because of self.remove_hook()
while idx in self.tensor_hooks:
idx += 1
self.tensor_hooks[idx] = (tensor, hook, handle, name)
assert not handle.idx
handle.idx = idx
def remove_hook(self, idx):
del self.tensor_hooks[idx]
def codegen_hooks(self, cg):
for (
tensor,
hook,
handle,
name,
) in self.tensor_hooks.values():
# Note: [On tensor.register_hook]
#
# register_hook on a tensor, AKA backward hooks, have slightly nuanced differences in how they are implemented
# when it comes to hooks on objects with sources (inputs, params) vs objects without sources (intermediaries).
#
# For tensors with a source, we bypass direct inclusion of register_hook calls in the graph.
# Instead, these are tracked and stashed as a global variable, enabling their association with tensors in
# the residuals. During dynamo's frame creation, these hooks are invoked seamlessly on known reconstructible/fetch-able
# tensors. Because a source indicates knowledge of this object outside the torch compile region, and
# because we are running residuals firmly before .backward() can be run, it is sound to invoke
# `register_hook` on a known tensor.
#
# For tensors without a source, we support a limited subset of hooks. Global functions only, and
# compiled_autograd must be enabled or we will graph break.
#
# Handling the Handle: When a user retains the register_hook result in a handle, we intercept the
# STORE_FAST operation to record the user-designated local variable name. This ensures the reconstructed
# bytecode retains this name. If no handle is defined, we simply pop the generated value to keep the
# stack intact.
#
# Dynamo Tensor Hooks Workflow:
# - Functions passed to register_hook are lifted globally.
# - For tensors with sources:
# - In the "side_effects" phase of codegen, we iterate over tensors with hooks to:
# - Generate the tensor.
# - Issue a register_hook call on the tensor, linking to the globally stored function.
# - Incorporate a handle if one was established in the eager phase.
# - For tensors without sources:
# - We don't generate any instructions for registering a hook.
# - Handles from intermediary hooks are NYI.
# - We produce a call function that utilizes the trace_wrapped higher order op, closing over it.
# - We then manually insert the call function above into the graph.
# - The handle's exact user-specified name, "user_code_variable_name", is discerned and associated during STORE_FAST.
assert tensor.source, "Hooks on non input tensors NYI - should not get here"
def gen_fn():
cg(tensor)
cg.extend_output([cg.create_load_attr(name)])
cg.add_push_null(gen_fn)
cg(hook)
cg.extend_output(create_call_function(1, False))
# Adding the handle to the cache means RemovableHandleVariable().reconstruct() will
# be associated with the return value of register_hook(). This consumes the top of stack.
cg.add_cache(handle)
def get_ca_final_callbacks_var(self):
from .variables.base import MutableLocal
if self.ca_final_callbacks_var is None:
self.ca_final_callbacks_var = variables.ListVariable(
[], mutable_local=MutableLocal()
)
return self.ca_final_callbacks_var
def codegen_update_mutated(self, cg: PyCodegen):
suffixes = []
for var in self._get_modified_vars():
if isinstance(var, variables.ListVariable):
# old[:] = new
cg(var, allow_cache=False)
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.extend_output(
[
cg.create_load_const(None),
cg.create_load_const(None),
create_instruction("BUILD_SLICE", arg=2),
]
)
suffixes.append([create_instruction("STORE_SUBSCR")])
elif isinstance(var, variables.CustomizedDictVariable):
# need to update the dict manually since update method may be invalid
varname_map = {}
for name in _manual_update_dict.__code__.co_varnames:
varname_map[name] = cg.tx.output.new_var()
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.extend_output(
[create_instruction("STORE_FAST", argval=varname_map["dict_to"])]
)
cg(var, allow_cache=False)
cg.extend_output(
[create_instruction("STORE_FAST", argval=varname_map["dict_from"])]
)
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.load_method("clear")
# unfortunately can't just use DICT_MERGE due to possible custom behaviors
dict_update_insts = bytecode_from_template(
_manual_update_dict, varname_map=varname_map
)
suffixes.append(
[
*create_call_method(0), # clear
create_instruction("POP_TOP"),
*dict_update_insts,
create_instruction("POP_TOP"),
]
)
elif isinstance(var, variables.ConstDictVariable):
# Reconstruct works as follow:
# (1) codegen(...) each pair of key/value
# (2) create a new dictionary with the pairs of key/values above
# (3) clear the original dictionary
# + only if a key was removed from the input dict
# (4) update the original dictionary with the dict created in (2)
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.load_method("update")
cg(var, allow_cache=False)
if var.should_reconstruct_all:
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.load_method("clear")
suffixes.append(
[
*create_call_method(1), # update
create_instruction("POP_TOP"),
]
)
if var.should_reconstruct_all:
suffixes.append(
[
*create_call_method(0), # clear
create_instruction("POP_TOP"),
]
)
elif isinstance(
var, variables.torch_function.TorchFunctionModeStackVariable
):
# Needed in the finally block for stack restoration
cg.add_push_null(
lambda: cg.load_import_from(
utils.__name__, "get_torch_function_mode_stack"
)
)
cg.call_function(0, False)
name = variables.torch_function.get_prev_stack_var_name()
cg.code_options["co_varnames"] += (name,)
cg.append_output(create_instruction("STORE_FAST", argval=name))
cg.add_push_null(
lambda: cg.load_import_from(
utils.__name__, "set_torch_function_mode_stack"
)
)
cg.foreach(var.symbolic_stack)
cg.append_output(
create_instruction("BUILD_LIST", arg=len(var.symbolic_stack))
)
cg.call_function(1, False)
cg.append_output(create_instruction("POP_TOP"))
elif self.is_attribute_mutation(var):
# Applying mutations involves two steps: 1) Push all
# reconstructed objects onto the stack. 2) Call STORE_ATTR to
# apply the mutations.
#
# Dynamo must ensure that mutations are applied in the same
# order as in the original program. Therefore, two reverse
# operations occur below.
#
# The first reverse operation concerns `suffixes`. We apply
# suffixes in reverse order due to the way Python handles the
# stack. In Step 1, we push all reconstructed objects onto the
# stack, but the item at the top of the stack refers to the last
# attribute in the mutation order. If not fixed, this will apply
# the mutations of attributes in the reverse order. To account
# for this reversal, we iterate through the mutable attributes
# in reverse order.
for name, value in reversed(
self.store_attr_mutations.get(var.mutable_local, {}).items()
):
if isinstance(var, variables.NewGlobalVariable):
cg.tx.output.update_co_names(name)
cg(value)
assert isinstance(var.mutable_local.source, GlobalSource) # type: ignore[attr-defined]
suffixes.append(
[create_instruction("STORE_GLOBAL", argval=name)]
)
elif isinstance(value, variables.DeletedVariable):
if isinstance(
var.mutable_local, AttributeMutationExisting
) and hasattr(getattr(var, "value", None), name):
cg.tx.output.update_co_names(name)
cg(var.mutable_local.source)
suffixes.append(
[create_instruction("DELETE_ATTR", argval=name)]
)
elif (
isinstance(var, variables.UserDefinedObjectVariable)
and var.needs_slow_setattr()
):
# __setattr__ is defined on this object, so call object.__setattr__ directly
cg.load_import_from("builtins", "object")
cg.load_method("__setattr__")
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg(variables.ConstantVariable(name))
cg(value)
suffixes.append(
[*create_call_method(3), create_instruction("POP_TOP")]
)
else:
cg.tx.output.update_co_names(name)
cg(value)
cg(var.mutable_local.source)
suffixes.append([create_instruction("STORE_ATTR", argval=name)])
elif isinstance(var, variables.TupleIteratorVariable):
for _ in range(var.index):
cg.add_push_null(
lambda: cg.load_import_from(utils.__name__, "iter_next")
)
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.call_function(1, False)
cg.pop_top()
elif isinstance(var, variables.RandomVariable):
# set correct random seed state
def gen_fn():
cg(var.mutable_local.source) # type: ignore[attr-defined]
cg.load_attr("setstate")
cg.add_push_null(gen_fn)
cg(var.wrap_state(var.random.getstate()))
suffixes.append(
[
*create_call_function(1, False), # setstate
create_instruction("POP_TOP"),
]
)
else:
raise AssertionError(type(var))
# do all the actual mutations at the very end to handle dependencies
for suffix in reversed(suffixes):
cg.extend_output(suffix)
def is_empty(self):
return not (
any(map(self.is_modified, self.id_to_variable.values()))
or self.tensor_hooks
or self.save_for_backward
or self.tensor_hooks
)
def clear(self):
self.keepalive.clear()
self.id_to_variable.clear()
@contextlib.contextmanager
def allow_side_effects_under_checkpoint(tx: "InstructionTranslator"): # type: ignore[name-defined] # noqa: F821
assert tx.output.current_tracer.under_activation_checkpoint
orig_val = tx.output.current_tracer.allow_side_effects_under_checkpoint
try:
tx.output.current_tracer.allow_side_effects_under_checkpoint = True
yield
finally:
tx.output.current_tracer.allow_side_effects_under_checkpoint = orig_val