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pytorch/torch/_functorch/compile_utils.py

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4.0 KiB
Python

# mypy: ignore-errors
from typing import Callable
import torch
import torch.fx as fx
from torch.utils import _pytree as pytree
from torch.utils._pytree import tree_flatten
aten = torch.ops.aten
def get_aten_target(node: fx.Node) -> Callable:
if hasattr(node.target, "overloadpacket"):
return node.target.overloadpacket
return node.target
rand_ops = [
aten.dropout,
aten._fused_dropout,
aten._standard_gamma,
aten.bernoulli,
aten.multinomial,
aten.native_dropout,
aten.normal,
aten.poisson,
aten.binomial,
aten.rrelu,
aten.rand_like,
aten.rand,
aten.randint,
aten.randn,
aten.randperm,
]
# return a new copy of torch.fx.graph.Graph with CSE applied to the input graph
def fx_graph_cse(fx_g: torch.fx.graph.Graph):
new_graph = fx.Graph()
env = {} # map from node in the old graph to node in the new graph
hash_env = {} # map from hash to a node in the new graph
token_map = {} # map from hash to token
for n in fx_g.nodes:
# The placeholder, output, and get_attr nodes are copied to the new graph without change
# do not CSE away random operations
if (
n.op == "placeholder"
or n.op == "output"
or n.op == "get_attr"
or get_aten_target(n) in rand_ops
):
new_node = new_graph.node_copy(n, lambda x: env[x])
env[n] = new_node
else: # n.op == 'call_function', should never see n.op == 'call_module' or 'call_method'
# substitute args and kwargs members to their mapping in env if exists
# specs can be used to reconstruct nested list/dictionaries
def substitute(arg_list):
arg_list, spec = tree_flatten(arg_list)
for i in range(len(arg_list)):
v = arg_list[i]
if isinstance(v, torch.fx.node.Node) and v in env:
arg_list[i] = env[v]
if isinstance(v, (torch.SymBool, torch.SymInt, torch.SymFloat)):
arg_list[i] = v.node
return tuple(arg_list), spec
args, args_spec = substitute(n.args)
kwargs, kwargs_spec = substitute(n.kwargs)
# each token corresponds to a unique node
# nodes with the same token can be substituted
token = {
"target": n.target,
"args": args,
"args_spec": args_spec,
"kwargs": kwargs,
"kwargs_spec": kwargs_spec,
}
# hash substituted args to a number, do not hash specs because specs are not hashable
# We need to add type into hash to avoid situations like:
# hash((primals_2, 1.0)) == hash((primals_2, 1))
hash_arg = hash(
(tuple((a, type(a)) for a in args), tuple((a, type(a)) for a in kwargs))
)
hash_val = (n.target, hash_arg)
# check if a node has a substitute and can be eliminated
hash_val_in_hash_env = hash_val in hash_env
if hash_val_in_hash_env and token_map[hash_val] == token:
env[n] = hash_env[hash_val]
continue
new_node = new_graph.node_copy(n, lambda x: env[x])
env[n] = new_node
if not hash_val_in_hash_env:
hash_env[hash_val] = new_node
token_map[hash_val] = token
return new_graph
def strip_overloads(gm):
"""
Modifies the target of graph nodes in :attr:`gm` to strip overloads.
Args:
gm(fx.GraphModule): The input Fx graph module to be modified
"""
for node in gm.graph.nodes:
if isinstance(node.target, torch._ops.OpOverload):
node.target = node.target.overloadpacket
gm.recompile()
def get_placeholders(graph):
return graph.find_nodes(op="placeholder")
def get_outputs(graph):
for node in graph.find_nodes(op="output"):
return pytree.tree_leaves(node.args[0])
raise AssertionError("No output node found")