Files
paddlepaddle--paddle/python/paddle/autograd/backward_utils.py
T
2026-07-13 12:40:42 +08:00

811 lines
24 KiB
Python

# Copyright (c) 2023 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,tes
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import annotations
import collections
import logging
import warnings
from collections.abc import Sequence
from functools import lru_cache
from typing import Any
from paddle import pir
from paddle.base import core
from paddle.base.libpaddle.pir import (
get_used_external_value,
)
from paddle.base.wrapped_decorator import signature_safe_contextmanager
# TODO(CZ): to be removed when we support dynamic shape by default.
ALLOW_DYNAMIC_SHAPE_VJP_OPS = [
"pd_op.abs",
"pd_op.add",
"pd_op.amax",
"pd_op.amin",
"pd_op.angle",
"pd_op.argsort",
"pd_op.assign",
"pd_op.batch_norm_",
"pd_op.cast",
"pd_op.ceil",
"pd_op.concat",
"pd_op.cos",
"pd_op.cumprod",
"pd_op.cumsum",
"pd_op.divide",
"pd_op.dot",
"pd_op.dropout",
"pd_op.elementwise_pow",
"pd_op.erf",
"pd_op.exp",
"pd_op.expand",
"pd_op.floor",
"pd_op.fmax",
"pd_op.fmin",
"pd_op.gather",
"pd_op.gather_nd",
"pd_op.gelu",
"pd_op.group_norm",
"pd_op.hardsigmoid",
"pd_op.hardswish",
"pd_op.kron",
"pd_op.kthvalue",
"pd_op.layer_norm",
"pd_op.leaky_relu",
"pd_op.log",
"pd_op.logcumsumexp",
"pd_op.logsumexp",
"pd_op.linear_v2",
"pd_op.matmul",
"pd_op.max",
"pd_op.maximum",
"pd_op.mean",
"pd_op.minimum",
"pd_op.multiply",
"pd_op.pad",
"pd_op.pow",
"pd_op.prod",
"pd_op.reduce_as",
"pd_op.relu",
"pd_op.relu6",
"pd_op.reshape",
"pd_op.roll",
"pd_op.rsqrt",
"pd_op.scale",
"pd_op.scatter",
"pd_op.scatter_nd_add",
"pd_op.sigmoid",
"pd_op.silu",
"pd_op.sin",
"pd_op.softmax",
"pd_op.softsign",
"pd_op.split",
"pd_op.sqrt",
"pd_op.square",
"pd_op.squeeze",
"pd_op.stack",
"pd_op.subtract",
"pd_op.sum",
"pd_op.swiglu",
"pd_op.swish",
"pd_op.take_along_axis",
"pd_op.tanh",
"pd_op.tile",
"pd_op.topk",
"pd_op.transpose",
"pd_op.trunc",
"pd_op.unsqueeze",
"pd_op.where",
"pd_op.p_norm",
"pd_op.index_put",
"pd_op.index_add",
"pd_op.elu",
"pd_op.masked_fill",
"pd_op.masked_select",
"pd_op.var",
]
class ValueWrapper:
def __init__(self, value) -> None:
if isinstance(value, ValueWrapper):
assert isinstance(value._value, (type(None), pir.Value))
else:
if not isinstance(value, (type(None), pir.Value)):
raise TypeError(
"Value Wrapper is only support None and pir.Value"
)
self._value = value._value if isinstance(value, ValueWrapper) else value
def __hash__(self) -> int:
if isinstance(self._value, pir.Value):
return self._value.hash()
else:
return hash(self._value)
def __eq__(self, other) -> bool:
if not isinstance(other, ValueWrapper):
warnings.warn(
f'In ValueWrapper.__eq__ expected type of `other` is ValueWrapper but received {other.__class__}.'
)
return False
if self._value is None or other._value is None:
return self._value is None and other._value is None
return self._value.is_same(other._value)
class ValueDict:
def __init__(
self,
iter=None,
*,
default_factory=None,
):
self._items: dict[ValueWrapper] = {}
self._default_factory = default_factory
if iter is not None:
for key, val in iter.items():
self[key] = val
def copy(self):
ret = ValueDict()
ret._items = self._items.copy()
ret._default_factory = self._default_factory
return ret
def update(self, other_dict):
for key, val in other_dict.items():
self[key] = val
def keys(self):
for key in self._items.keys():
yield key._value
def values(self):
return self._items.values()
def items(self):
for key, val in self._items.items():
yield key._value, val
def get(self, key, default=None):
if not self.__contains__(key):
return default
return self._items[ValueWrapper(key)]
def pop(self, key):
if not self.__contains__(key):
raise KeyError(f'{key} is not in ValueDict')
return self._items.pop(ValueWrapper(key))
def setdefault(self, key, default=None):
if not self.__contains__(key):
self[key] = default
return self[key]
def __setitem__(self, key, val: Any):
self._items[ValueWrapper(key)] = val
def __getitem__(self, key):
if not self.__contains__(key):
if self._default_factory is not None:
self[key] = self._default_factory()
else:
raise KeyError(f'{key} is not in ValueDict')
return self._items[ValueWrapper(key)]
def __bool__(self):
return bool(self._items)
def __len__(self):
return len(self._items)
def __iter__(self):
return self.keys()
def __contains__(self, key):
return ValueWrapper(key) in self._items
def __repr__(self) -> str:
items_str = ", ".join(f"{key}: {val}" for key, val in self.items())
return f'ValueDict({items_str})'
class ValueSet:
def __init__(
self, iter: Sequence[ValueWrapper] | set[ValueWrapper] | None = None
):
self._set: set[ValueWrapper] = set()
if iter is not None:
for val in iter:
self.add(val)
def copy(self):
ret = ValueSet()
ret._set = self._set.copy()
return ret
def add(self, val):
if not self.__contains__(val):
self._set.add(ValueWrapper(val))
def update(self, other: set):
for val in other:
self.add(val)
def pop(self):
return self._set.pop()._value
def remove(self, val):
self._set.remove(ValueWrapper(val))
def discard(self, val):
self._set.discard(ValueWrapper(val))
def __and__(self, other: ValueSet):
return ValueSet(self._set & other._set)
def __sub__(self, other: ValueSet):
return ValueSet(self._set - other._set)
def __or__(self, other: ValueSet):
return ValueSet(self._set | other._set)
def __bool__(self):
return bool(self._set)
def __len__(self):
return len(self._set)
def __iter__(self):
for val in self._set:
yield val._value
def __contains__(self, val):
return ValueWrapper(val) in self._set
def __repr__(self) -> str:
items_str = ", ".join(repr(item) for item in self)
return f'ValueSet({items_str})'
class State:
"""
record relationship of forward op/value and backward op/value
one state must be binding with a block, if block has parent block,
state will include parent block info.
"""
def __init__(self, block):
self.block = block
# value -> list(list(value))
self.value_to_valuegrad = ValueDict(default_factory=list)
self.value_to_sumvaluegrad = ValueDict(default_factory=list)
# operation -> list(operation)
self.op_to_opgrad = collections.defaultdict(list)
# value -> list(value)
self.valuegrad_to_value = ValueDict(default_factory=list)
self.sumvaluegrad_to_value = ValueDict(default_factory=list)
# operation -> list(operation)
self.opgrad_to_op = collections.defaultdict(list)
# only for controlflow
# inside_value is sub block value, which will yield to parent block,
# parent block value is outside_value
self.inside_value_to_outside_value_map = ValueDict()
def turn_map(self) -> None:
self.valuegrad_to_value = ValueDict(default_factory=list)
self.sumvaluegrad_to_value = ValueDict(default_factory=list)
self.opgrad_to_op = collections.defaultdict(list)
for k, v in self.value_to_valuegrad.items():
if v != []:
for value in v[0]:
self.valuegrad_to_value[value] = [k]
for k, v in self.value_to_sumvaluegrad.items():
if v != []:
for value in v[0]:
self.sumvaluegrad_to_value[value] = [k]
for k, v in self.op_to_opgrad.items():
if v != []:
self.opgrad_to_op[v[0]] = [k]
def copy(self, new_block):
state = State(new_block)
state.value_to_valuegrad = self.value_to_valuegrad.copy()
state.value_to_sumvaluegrad = self.value_to_sumvaluegrad.copy()
# operation -> list(operation)
state.op_to_opgrad = self.op_to_opgrad.copy()
# value -> list(value)
state.valuegrad_to_value = self.valuegrad_to_value.copy()
state.sumvaluegrad_to_value = self.sumvaluegrad_to_value.copy()
# operation -> list(operation)
state.opgrad_to_op = self.opgrad_to_op.copy()
# only for controlflow
state.inside_value_to_outside_value_map = (
self.inside_value_to_outside_value_map.copy()
)
return state
def _check_vjp_dynamic_shape(op, inputs):
for items in inputs:
for item in items:
if (
item.is_dense_tensor_type()
and item.initialized()
and -1 in item.shape
):
return True
# Prim currently does not support dynamic shape, when dynamic shape exits in shape of op inputs, prim will be skipped its vjp op.
@signature_safe_contextmanager
def dynamic_shape_prim_vjp_guard(op, inputs):
origin_prim = core._is_bwd_prim_enabled()
if op.name() == "cf.tuple_push":
skip_prim = True
else:
skip_prim = (
origin_prim
and core._enable_prim_skip_dynamic_shape()
and _check_vjp_dynamic_shape(op, inputs)
and op.name() not in ALLOW_DYNAMIC_SHAPE_VJP_OPS
)
try:
if origin_prim and skip_prim:
core._set_prim_backward_enabled(False)
yield
finally:
if origin_prim:
core._set_prim_backward_enabled(True)
def check_type(input, input_name, expected_type, op_name, extra_message=''):
if not isinstance(input, expected_type):
raise TypeError(
f"The type of '{input_name}' in {op_name} must be {expected_type}, but received {type(input)}. {extra_message}"
)
def _as_list(x):
if x is None:
return []
return list(x) if isinstance(x, Sequence) else [x]
def some_in_set(value_list, value_set):
return any(v in value_set for v in value_list)
def is_control_flow(op):
return op.name() == "pd_op.if" or op.name() == "pd_op.while"
def is_builtin_op(op):
dialect_name, opname = op.name().split(".")
return dialect_name == "builtin"
def update_no_grad_set_by_stopgradient(block, no_grad_set):
for op in block.ops:
if is_control_flow(op):
for sub_block in op.blocks():
update_no_grad_set_by_stopgradient(sub_block, no_grad_set)
for value in op.results():
if value.stop_gradient and value not in no_grad_set:
no_grad_set.add(value)
def get_real_op_inputs(op):
if op.name() == "pd_op.if":
return get_used_external_value(op)
elif op.name() == "pd_op.while":
return op.operands_source() + get_used_external_value(
op.as_while_op().body()
)
elif op.name() == "pd_op.pylayer":
return get_used_external_value(op)
else:
return op.operands_source()
def get_real_op_outputs(op):
outputs = op.results()
if op.name() == "pd_op.array_write_":
for x in op.operands():
outputs.append(x.source())
if op.name() == "pd_op.while":
for internal_op in op.as_while_op().body().ops:
if internal_op.name() == "pd_op.array_write_":
for x in internal_op.operands():
outputs.append(x.source())
return outputs
def inverse_sort_op(old_ops):
'''
if topo graph is op1 -> op2 -> op3
return [op3, op2, op1]
'''
# init pending_count[op] which describes number of
# pending edges for its grad_op
pending_count = collections.defaultdict(int)
ops = []
[ops.append(x) for x in old_ops if x not in ops]
ops_set = set(ops)
sorted_list = []
for op in ops:
for x in get_real_op_inputs(op):
if not pir.is_fake_value(x) and x.get_defining_op() in ops_set:
pending_count[x.get_defining_op()] += 1
queue = collections.deque()
for op in ops:
if pending_count[op] == 0:
queue.append(op)
while queue:
op = queue.popleft()
sorted_list.append(op)
for x in get_real_op_inputs(op):
x_op = x.get_defining_op()
pending_count[x_op] -= 1
if pending_count[x_op] == 0:
queue.append(x_op)
if len(sorted_list) != len(ops):
raise ValueError(
"inverse_sort_op wrong, sorted_list size is not equal to origin_list size"
)
change_list = []
# true %0 = op1, 1% = increment(0%), 3% = op2(0%), tuple_push(%0, 1%, 3%),
# no one use 1% so increment be the first op, actually op2 use 1% ,
# sorted_list = [increment, op2, op1] should be [op2, increment, op1],
# tuple_push(0%) must be forward last op, backward first op, so skip it.
for op in reversed(sorted_list):
if op.name() == 'pd_op.increment_':
idx_1 = sorted_list.index(op)
idx_2 = sorted_list.index(op)
for op_in in reversed(sorted_list[: sorted_list.index(op)]):
if (
some_in_set(
op.operands_source(),
ValueSet(get_real_op_inputs(op_in)),
)
and op_in.name() != "cf.tuple_push"
):
idx_2 = sorted_list.index(op_in)
if idx_1 != idx_2:
change_list.append((idx_1, idx_2))
for idx_1, idx_2 in change_list:
sorted_list[idx_1], sorted_list[idx_2] = (
sorted_list[idx_2],
sorted_list[idx_1],
)
return sorted_list
def is_inplace_net(op_list):
'''
when program has inplace op , it's difficult to find the actual pending_count.
'''
for op in op_list:
if op.name() in ["pd_op.array_write_", "pd_op.assign_out_"]:
return True
if is_control_flow(op):
for block in op.blocks():
if is_inplace_net(block.ops):
return True
return False
def remove_op(block, op, state):
'''
remove op from block
'''
if state.opgrad_to_op[op] != []:
fwd_op = state.opgrad_to_op[op][0]
state.op_to_opgrad[fwd_op].remove(op)
for valuegrad in op.results():
if state.valuegrad_to_value[valuegrad] != []:
value = state.valuegrad_to_value[valuegrad][0]
state.value_to_valuegrad[value] = []
if value in state.sumvaluegrad_to_value:
raise ValueError(
f'input_grad in [%s] is value which need to sum {op.name()}'
)
# NOTE(SigureMo): Ensure access to the op's results before removing it.
# Otherwise, the op will be deconstructed and access the num_results
# will be undefined behavior, it always cause hanging on the macOS.
block.remove_op(op)
def while_prune_check(while_tuple_ops):
if len(while_tuple_ops) != 0:
for opresult in while_tuple_ops[0].results():
if not opresult.use_empty():
return False
return True
return False
def remove_useless_full_like_ops(block, ops, state):
'''
remove ops which are not in use recursively,
'''
remove_ops = []
inverse_ops = inverse_sort_op(list(ops))
# from output to input
for op in inverse_ops:
if op.name() == "pd_op.full_like":
if op.result(0).use_empty():
full_op = op.operand_source(1).get_defining_op()
remove_ops.append(op)
remove_ops.append(full_op)
elif is_control_flow(op):
for sub_block in op.blocks():
remove_useless_full_like_ops(sub_block, sub_block.ops, state)
for op in remove_ops:
remove_op(block, op, state)
def all_stop_gradient_true(block):
for op in block.ops:
for value in op.results():
if value.stop_gradient is False:
return False
return True
def all_input_stop_gradient_true(list_of_list):
for list_ in list_of_list:
for stop_gradient in list_:
if stop_gradient is False:
return False
return True
def all_output_grad_none(list_of_list):
for list_ in list_of_list:
for value in list_:
if value is not None:
return False
return True
def op_has_vjp(op):
# NOTE(MarioLulab): In PIR mode, even though the `PyLayer` op does
# not have a vjp interface, we still need to generate the backward
# block based on its registered backward function. To achieve this,
# we add more handling logic for `PyLayer` Op in the `call_vjp` function
return core.has_vjp(op) or op.name() == "pd_op.pylayer"
def parent_total_ops(block):
'''
when block is sub_block, forward op should include its parent block ops
(sub block nest should Add on demand to avoid block copy)
'''
total_ops = []
if block.parent_block is not None:
if block.parent_block.parent_block:
total_ops += block.parent_block.parent_block.ops
total_ops += block.parent_block.ops
total_ops += block.ops
return total_ops
# only for control_flow to find corresponding value or value_list
def return_map_value(value, map):
output = value
while output in map:
output = map[output]
return output
def return_map_value_list(value, map):
output = []
for i in range(len(value)):
if value[i] in map:
output.append(return_map_value(value[i], map))
else:
output.append(value[i])
return output
def argument_to_value(while_op):
'''
return while op's relationship of (block_argument to input value) and (input value to block_argument).
'''
if while_op.name() != "pd_op.while":
return ValueDict(), ValueDict()
assert len(while_op.as_while_op().block_arguments()) + 1 == len(
while_op.operands_source()
), (
"while op's block_arguments size + 1 should same to while op's operands_source size"
)
arg_to_value_map = ValueDict()
value_to_arg_map = ValueDict()
for arg, value in zip(
while_op.as_while_op().block_arguments(),
while_op.operands_source()[1:],
):
arg_to_value_map[arg] = value
value_to_arg_map[value] = arg
return arg_to_value_map, value_to_arg_map
def get_grad_semantic_info(op):
'''
return whether op's inputs has grad, usually handled from yaml.
some op has uncertain inputs need special handling.
'''
if op.name() in [
"builtin.combine",
"pd_op.if",
"pd_op.while",
"pd_op.pylayer",
"cf.tuple_push",
"dist_op.moe_global_mesh_tensor",
"dist_op.moe_sub_mesh_tensors",
"dist_op.dist_reshape",
]:
grad_semantic_info = [True for _ in range(len(get_real_op_inputs(op)))]
if op.name() == "pd_op.if":
grad_semantic_info[0] = False
else:
grad_semantic_info = op.get_input_grad_semantics()
return grad_semantic_info
def get_split_op(value):
for op in value.all_used_ops():
if op.name() == "builtin.split":
return op
return None
@lru_cache
def warning_once(message: str):
logging.warning(message)
def update_if_output_stopgradient(if_op, true_yield_op, false_yield_op):
"""
Update if_op's stop_gradient based on true_yield_op and false_yield_op.
Args:
true_yield_op: true block of if_op's last op.
false_yield_op: false block of if_op's last op.
if_op: update it's op_results()'s stop_gradient.
"""
if (
true_yield_op.name() != 'cf.yield'
or false_yield_op.name() != 'cf.yield'
):
raise ValueError("param is not yield op")
# Check if operands_source sizes match
if len(true_yield_op.operands_source()) != len(
false_yield_op.operands_source()
):
raise ValueError("Mismatched yield operands_source sizes")
# Check if op_results size matches operands_source
if len(if_op.results()) != len(true_yield_op.operands_source()):
raise ValueError(
"Mismatched if op_results size with yield operands_source"
)
# Update if_op's stop_gradient
for i in range(len(true_yield_op.operands_source())):
stop_grad1 = true_yield_op.operand_source(i).stop_gradient
stop_grad2 = false_yield_op.operand_source(i).stop_gradient
# Set to False if either stop_gradient is False
if not stop_grad1 or not stop_grad2:
if_op.result(i).stop_gradient = False
def update_while_output_stopgradient(while_op, yield_op):
"""
Update while_op's stop_gradient based on yield_op.
Args:
yield_op: The yield operation associated with the while loop.
while_op: The while operation whose op_results()'s stop_gradient needs to be updated.
"""
# Check if yield_op is indeed a yield operation
if yield_op.name() != 'cf.yield':
raise ValueError("yield_op is not a yield operation")
# Check if operands_source size of yield_op matches op_results size of while_op
if len(while_op.results()) + 1 != len(yield_op.operands_source()):
raise ValueError(
f"Mismatched while op_results size %d with yield operands_source %d. {len(while_op.results()) + 1, len(yield_op.operands_source())}"
)
# Update while_op's stop_gradient
for i in range(1, len(yield_op.operands_source())):
stop_grad = yield_op.operand_source(i).stop_gradient
# Set to False if stop_gradient is False
if not stop_grad:
while_op.result(i - 1).stop_gradient = False
def find_index_of_yield(value, yield_op):
for i, v in enumerate(yield_op.operands_source()):
if v.is_same(value):
return i
return -1
def update_tuple_pop_origin_inputs(tuple_pop_outputs):
if tuple_pop_outputs == []:
return tuple_pop_outputs
op = tuple_pop_outputs[0][0].get_defining_op()
assert op.name() == "cf.tuple_pop"
stack_op = op.operand_source(0).get_defining_op()
tuple_push_inputs = stack_op.result(1).first_use().owner().operands_source()
tuple_push_inputs_with_if = []
for input in tuple_push_inputs:
if input.first_use().owner().name() == "cf.yield":
yield_op = input.first_use().owner()
index = find_index_of_yield(input, yield_op)
assert index != -1
tuple_push_inputs_with_if.append(
yield_op.get_parent_block().parent_op.result(index)
)
else:
tuple_push_inputs_with_if.append(input)
# pass inlets
return tuple_push_inputs_with_if[1:]
def value_in_block(value, block):
value_block = value.get_defining_op().get_parent_block()
while block.parent_op.name() != "builtin.module":
if block == value_block:
return True
block = block.parent_block
# now block is module op's block
if block == value_block:
return True
return False