pytorch/tools/codegen/api/python.py
Jiakai Liu 79474a1928 [pytorch] simplify tensor options logic in pybinding codegen (#46976)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46976

Technically, it's not semantic preserving, e.g.: emition of
'requires_grad' is no longer gated by 'has_tensor_return' - there is no
guarantee that is_like_or_new_function should all have tensor return.
But the output is identical so there might be some invariant - could
also add assertion to fail loudly when it's broken.

Test Plan: Imported from OSS

Reviewed By: ezyang

Differential Revision: D24589211

Pulled By: ljk53

fbshipit-source-id: 47c7e43b080e4e67a526fde1a8a53aae99df4432
2020-10-28 21:22:59 -07:00

971 lines
41 KiB
Python

from tools.codegen.api.types import *
import tools.codegen.api.cpp as cpp
from tools.codegen.gen import pythonify_default
from tools.codegen.model import *
from dataclasses import dataclass
from typing import Optional, Union, Sequence, Set, List, Tuple
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# Data Models
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# The Python binding codegen produces code that takes the input list of
# PyObjects, finds the matching ATen C++ function using PythonArgParser,
# converts the PyObjects into C++ types and calls the ATen C++ function:
#
# +--------+ parsing +------------------------+ binding +-----------------------+
# | PyObjs | ---------> | PythonArgParser Output | ---------> | Cpp Function Dispatch |
# +--------+ +------------------------+ +-----------------------+
#
# The following examples demonstrate the data models the Python binding
# codegen needs to deal with and the tasks it needs to accomplish. It
# helps understand the purpose of the new data types we introduced below.
#
# - Function Schema (source of truth)
#
# aten::empty.names(int[] size, *, Dimname[]? names,
# ScalarType? dtype=None, Layout? layout=None,
# Device? device=None, bool? pin_memory=None,
# MemoryFormat? memory_format=None) -> Tensor
#
# - Python Signature
#
# It's used to generate input schema string for PythonArgParser.
# Note: TensorOptions fields are reordered and the additional
# 'requires_grad' field is added:
#
# empty(IntArrayRef size, *, DimnameList? names,
# MemoryFormat? memory_format=None, ScalarType dtype=None,
# Layout layout=torch.strided, Device device=None,
# bool pin_memory=False, bool requires_grad=False)
#
# - C++ Signature
#
# It's used to generate C++ lambda formals & dispatch call.
# Note: the scattered TensorOptions fields are packed into 'options'.
#
# auto dispatch_empty =
# [](IntArrayRef size, c10::optional<DimnameList> names,
# const TensorOptions & options,
# c10::optional<MemoryFormat> memory_format) -> Tensor {
# pybind11::gil_scoped_release no_gil;
# return torch::empty(size, names, options, memory_format);
# };
#
# - Binding between Python Arguments and C++ Arguments
#
# Given a set of Python Arguments in scope, we need produce the
# binding expressions that translate the Python API into C++ API:
#
# Python Args Cpp Args Binding Exprs
# -----------------------------------------------------------------
# 0: size size '_r.intlist(0)'
# 1: names names 'names' [special init]
# 2: memory_format -------+
# 3: dtype -----+-|--> options 'options' [special packing]
# 4: layout / |
# 5: device / +--> memory_format '_r.memoryformatOptional(2)'
# 6: pin_memory /
# 7: requires_grad -+
#
# So the full dispatch expression would look like:
#
# dispatch_empty(_r.intlist(0), names, options,
# _r.memoryformatOptional(2))
#
# Where does 'names' come from? It involves special local init:
#
# auto __names = _r.toDimnameListOptional(1);
# c10::optional<DimnameList> names =
# __names ? c10::make_optional(DimnameList(__names.value()))
# : c10::nullopt;
#
# Where does 'options' come from? It involves special local init
# for TensorOptions. Note that Python side has the additional
# 'requires_grad' field:
#
# const auto options = TensorOptions()
# .dtype(_r.scalartype(3))
# .device(_r.device(5))
# .layout(_r.layoutOptional(4))
# .requires_grad(_r.toBool(7))
# .pinned_memory(_r.toBool(6));
#
# In some other cases one Python Argument can map to multiple C++
# Arguments. For example:
#
# aten::max.names_dim(Tensor self, Dimname dim, bool keepdim=False)
# -> (Tensor values, Tensor indices)
#
# Python Args Cpp Args Binding Exprs
# ---------------------------------------------------------------------
# +----> max 'out[0]'
# /-----> max_values 'out[1]
# 0: input / self '_r.tensor(0)'
# 1: dim / dim '_r.dimname(1)'
# 2: keepdim / keepdim '_r.toBool(2)'
# 3: out -----+ [local init] out '_r.tensorlist_n<2>(3)'
#
# As demonstrated above, the binding can involve reordering,
# packing, unpacking and special local inits.
#
#
# Let's look at a concrete example:
#
# static PythonArgParser parser({
# "abs(Tensor input, *, Tensor out=None)",
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ^
# +--- Python Schema, represented by PythonSignature and PythonArgument
#
# }, /*traceable=*/true);
#
# ParsedArgs<2> parsed_args;
# auto _r = parser.parse(nullptr, args, kwargs, parsed_args);
#
# ...
#
# if (_r.isNone(1)) {
# ~~~~~~~~~~~~ <--- Scattered PythonArgParser output (arg name = 'out')
# represented by PythonArgParserOutputExpr
#
# // aten::abs(Tensor self) -> Tensor
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ^
# +--- NativeFunction schema, base version
#
# auto dispatch_abs = [](const Tensor & self) -> Tensor {
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ^
# +--- dispatch_lambda_args / dispatch_lambda_return_str
# generated from NativeFunction / CppSignature
# (deprecated PythonSignature is special)
# arguments are represented by DispatchLambdaArgument
#
# pybind11::gil_scoped_release no_gil;
# return self.abs();
# ~~~~~~~~~~~ <--- cpp_dispatch_target / cpp_dispatch_exprs
# generated from NativeFunction / CppSignature
# };
# return wrap(dispatch_abs(_r.tensor(0)));
# ~~~~~~~~~~~~~
# ^
# +--- dispatch_lambda_exprs
# binding PythonArgParserOutputExpr (python args)
# and DispatchLambdaArgument (c++ args)
#
# } else {
# // aten::abs.out(Tensor self, *, Tensor(a!) out) -> Tensor(a!)
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ^
# +--- NativeFunction schema, out-variant
#
# auto dispatch_abs_out = [](Tensor out, const Tensor & self) -> Tensor {
# pybind11::gil_scoped_release no_gil;
# return at::abs_out(out, self);
# };
# return wrap(dispatch_abs_out(_r.tensor(1), _r.tensor(0)));
# }
#
@dataclass(frozen=True)
class PythonArgument:
name: str
type: Type
# Consistent with 'type' for most cases, except for some TensorOptions fields
# which are hardcoded (see 'signature()' method).
cpp_type_str: str
default: Optional[str]
# Used to generate the default init expr for some PythonArgParser outputs, e.g.:
#
# _r.layoutWithDefault(3, layout_from_backend(self.options().backend())))
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# ^
# +--- default_init str
default_init: Optional[str]
# Compute argument formal for python argument parsing.
# Needs to be consistent with torch/csrc/utils/python_arg_parser.h.
def argument_str(self, *, method: bool = False) -> str:
name = self.name
typename = _simple_type(self.cpp_type_str)
# [old codegen] TODO: remove this and make optional types in simple_type
# to be consistent across tensor and other types after make Tensor? be
# optional instead of undefined
if self.type.is_nullable() and '?' not in typename:
typename = f'{typename}?'
# s/self/input/ outside method bindings
# [old codegen] TODO: remove this? doesn't rename in codegen, it's just
# for the parse string
if name == 'self' and typename == 'Tensor' and not method:
name = 'input'
# add list size annotation
size = self.size
if size is not None:
if typename.endswith('?'):
typename = f'{typename[:-1]}[{size}]?'
else:
typename = f'{typename}[{size}]'
# add default
if self.default is not None:
default = {
'nullptr': 'None',
'c10::nullopt': 'None',
'{}': 'None',
}.get(self.default, self.default)
return f'{typename} {name}={default}'
else:
return f'{typename} {name}'
@property
def size(self) -> Optional[int]:
l = self.type.is_list_like()
return l.size \
if l is not None and l.size is not None and str(l.elem) != 'bool' else None
@dataclass(frozen=True)
class PythonOutArgument(PythonArgument):
# In Python signature multiple output fields are packed into one 'out' argument.
# When binding to C++, it's first binded to a local 'out' variable:
# 'auto out = _r.tensorlist_n<2>(2);',
# then binded to scattered C++ output arguments as 'out[0]', 'out[1]', and etc.
# TODO: maybe don't need keep scattered out fields for python signature?
outputs: Tuple[PythonArgument, ...]
@staticmethod
def from_outputs(outputs: Tuple[PythonArgument, ...]) -> Optional['PythonOutArgument']:
if not outputs:
return None
size = len(outputs)
if size == 1:
return PythonOutArgument(
name=outputs[0].name,
type=outputs[0].type,
cpp_type_str=outputs[0].cpp_type_str,
default='None',
default_init=None,
outputs=outputs,
)
elif size > 1:
if any(map(lambda a: not a.type.is_tensor_like(), outputs)):
raise RuntimeError(f'Unsupported output type: {outputs}')
return PythonOutArgument(
name='out',
type=ListType(BaseType(BaseTy.Tensor), size),
cpp_type_str='TensorList',
default='None',
default_init=None,
outputs=outputs,
)
raise AssertionError(r'Unexpected PythonOutArgument size')
@dataclass(frozen=True)
class PythonSignature:
# Base operator name, without inplace/outplace suffix.
name: str
# Positional arguments.
# TODO: create a dedicated SelfArgument type for 'self'?
input_args: Tuple[PythonArgument, ...]
# Keyword arguments excluding the 'out' argument and scattered kwargs belonging
# to TensorOptions (dtype, layout, device, pin_memory, requires_grad, etc).
input_kwargs: Tuple[PythonArgument, ...]
output_args: Optional[PythonOutArgument]
# These are scattered kwargs arguments belonging to TensorOptions.
# When binding to C++, they are packed into a TensorOptions object 'options'.
# It's possible that the C++ signature doesn't take TensorOptions object (e.g.
# for out variant), in which case they will be used as scattered fields without
# being packed into 'options'.
# TODO: maybe create a PythonTensorOptionsArgument?
tensor_options_args: Tuple[PythonArgument, ...]
# method or function signature?
method: bool
@property
def deprecated(self) -> bool:
return False
def arguments(
self, *, skip_outputs: bool = False, skip_tensor_options: bool = False
) -> Tuple[Union[PythonArgument, PythonOutArgument], ...]:
result: List[Union[PythonArgument, PythonOutArgument]] = []
result.extend(self.input_args)
result.extend(self.input_kwargs)
if self.output_args is not None and not skip_outputs:
result.append(self.output_args)
if not skip_tensor_options:
result.extend(self.tensor_options_args)
return tuple(result)
# [old codegen] Compute the Python function signature for argument parsing,
# as specified in torch/csrc/utils/python_arg_parser.h. WARNING:
# this is NOT the same type signature as specified by PEP 484
# as understood by mypy; our format was independently developed
# and has some quirks to make it more suitable specifically
# for error parsing.
#
# For a translation to mypy-valid type signatures, see
# tools/gen_pyi.py. If you change any logic here, please
# check that file too.
def signature_str(self, *, skip_outputs: bool = False) -> str:
schema_formals: List[str] = \
list(map(lambda a: a.argument_str(method=self.method),
self.arguments(skip_outputs=skip_outputs)))
positional_argc = len(self.input_args)
if len(schema_formals) > positional_argc:
schema_formals.insert(positional_argc, '*')
return f'{self.name}({", ".join(schema_formals)})'
# The deprecated python signature involves some special logic, so create a
# dedicated data model to store these extra properties.
@dataclass(frozen=True)
class PythonSignatureDeprecated(PythonSignature):
# We need keep the order of arguments in deprecated signature.
# Particularly, method signature might have 'self' not at the beginning, e.g.:
# addmm(Scalar beta, Tensor self, Tensor mat1, Tensor mat2)
# When generating lambda function signature we need follow the exact order (even for method=True):
# [](Scalar beta, const Tensor & self, const Tensor & mat1, const Tensor & mat2) -> Tensor
deprecated_args_names: Tuple[str]
# The deprecated signature might miss some arguments that the corresponding
# C++ signature expects. We need store the constant default values to pass in.
# For example:
# [deprecate signature]: addmm(Scalar beta, Tensor self, Tensor mat1, Tensor mat2)
# [func schema]: aten::addmm(Tensor self, Tensor mat1, Tensor mat2, *, Scalar beta=1, Scalar alpha=1) -> Tensor
# [func call]: self.addmm(mat1, mat2, beta, 1)
# We store ['self', 'mat1', 'mat2', 'beta', '1'] in this case.
deprecated_args_exprs: Tuple[str]
@property
def deprecated(self) -> bool:
return True
def signature_str(self, *, skip_outputs: bool = False) -> str:
return PythonSignature.signature_str(self, skip_outputs=skip_outputs) + '|deprecated'
# C++ function dispatch is wrapped in a lambda function. The lambda function
# has almost the same signature as the C++ function, only with some small
# variants - see details below.
# This data model is used to represent arguments of the lambda function
# signature.
@dataclass(frozen=True)
class DispatchLambdaArgument:
name: str
type_str: str
cpp_type_str: str
is_out_arg: bool
# To pass PyObjects arguments to C++ function (via the lambda wrapper),
# we need first convert PyObjects into simple C++ objects. This work
# is done by PythonArgParser.
# This data model is used to represent the output of PythonArgParser.
# It has 1-1 mapping with PythonArgument in PythonSignature.
@dataclass(frozen=True)
class PythonArgParserOutputExpr:
# argument name
name: str
# RHS expression to reference PythonArgParser output.
expr: str
# In some special cases we need create different expr, e.g.:
# '_r.isNone(1)' instead of '_r.tensor(1)'.
index: int
# The python argument it maps to.
argument: PythonArgument
@property
def is_none_expr(self) -> str:
return f'_r.isNone({self.index})'
# To pass PythonArgParser output to the lambda wrapper, we need bind
# PythonArgParserOutputExpr to DispatchLambdaArgument.
# They are not always 1-1 mapped, e.g. scattered TensorOptions fields
# need be packed into a TensorOptions object, which is the argument
# that the lambda function wrapper takes.
@dataclass(frozen=True)
class DispatchLambdaArgumentExprs:
# The exprs that provide the binding for lambda arguments, e.g.:
#
# 'self' -> '_r.tensor(0)'
# 'min' -> 'out[0]' / 'min_indices' -> 'out[1]'
# 'options' -> 'options'
#
# It has 1-1 mapping with DispatchLambdaArgument.
exprs: Sequence[str]
# Special local inits, which might introduce new variables that
# the 'exprs' above reference, e.g.:
#
# 'auto out = _r.tensorlist_n<2>(2);'
#
inits: Sequence[str]
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# Helper Functions
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
# The original simple_type is derived from the 'type' field in Declaration.yaml,
# which is generated from the C++ argument type, following some seemingly
# artificial rules:
#
# Concrete C++ types are preferred in most cases, e.g.:
# 'IntArrayRef' instead of 'int[]'
# 'int64_t' instead of 'int'
#
# Constant/Reference annotation and optional field are handled specially, e.g.:
# 'ScalarType?' instead of 'c10::optional<ScalarType>'
# 'Tensor' instead of 'const Tensor &' / 'Tensor &'
#
# TODO: This needs to be consistent with python_arg_parser - can we simplify it?
def _simple_type(cpp_type_str: str) -> str:
simple_type = cpp_type_str.replace(' &', '').replace('const ', '')
opt_match = re.match(r'c10::optional<(.+)>', simple_type)
if opt_match:
typename = opt_match.group(1)
# HACK: 'Layout?' needs to be hardcoded to 'Layout'!
simple_type = f'{typename}?' if typename != 'Layout' else 'Layout'
return simple_type
def _cpp_signature(f: NativeFunction, *, method: bool = False) -> cpp.CppSignature:
return CppSignatureGroup.from_schema(f.func, method=method).signature
def has_tensor_options(f: NativeFunction) -> bool:
return any(filter(lambda a: isinstance(a, TensorOptionsArguments),
cpp.group_arguments(f.func, method=False)))
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# Python Signature
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
def argument(cpp_arg: CppArgument) -> PythonArgument:
a = cpp_arg.argument
if not isinstance(a, Argument):
# cpp's TensorOptionsArguments is ignored, we will reintroduce the
# scattered fields in tensor_options_args.
raise RuntimeError(f'unsupported cpp argument: \'{cpp_arg}\'')
return PythonArgument(
name=a.name,
type=a.type,
cpp_type_str=cpp_arg.type,
# TODO: directly translate a.default to python default
default=str(pythonify_default(cpp.default_expr(a.default, a.type)))
if a.default is not None else None,
default_init=None,
)
def signature(f: NativeFunction, *, method: bool = False) -> PythonSignature:
# Use cpp api to gather TensorOptions fields from kwargs.
# Always set 'method' to false as ThisArgument is not relevant - 'self'
# is still included as regular Argument type.
# TODO: maybe directly generate from FunctionSchema to avoid slicing back
# into args/kwargs/outputs?
cpp_sig = _cpp_signature(f, method=False)
# Skip ThisArgument if this is method signature.
# Skip TensorOptionsArguments in C++ signature. Python side TensorOptions
# arguments are created based on different rules - see below.
cpp_arguments = tuple(filter(lambda a: not (method and a.name == 'self') and
not isinstance(a.argument, TensorOptionsArguments), cpp_sig.arguments()))
kwarg_only_set = set(a.name for a in f.func.kwarg_only_arguments)
out_arg_set = set(a.name for a in f.func.out_arguments)
input_args = tuple(map(argument,
filter(lambda a: not (a.name in kwarg_only_set or a.name in out_arg_set), cpp_arguments)))
input_kwargs = tuple(map(argument, filter(lambda a: a.name in kwarg_only_set, cpp_arguments)))
outputs = tuple(map(argument, filter(lambda a: a.name in out_arg_set, cpp_arguments)))
# Reintroduce the scattered fields of TensorOptions for Python.
# Compared to the cpp counterpart, the python arguments have new property
# (default_init) and a new argument 'requires_grad', which require some
# special handlings.
# [old codegen] TODO: because these aren't guaranteed to be 100% faithful
# to the original versions in the yaml, this recreation is a potential
# source of drift between eager and JIT. Pull this logic out to a shared place.
has_tensor_input_arg = any(a.type.is_tensor_like()
for a in itertools.chain(f.func.arguments, f.func.kwarg_only_arguments))
if any(a.name == 'requires_grad' for a in f.func.schema_order_arguments()):
raise ValueError('argument named requires_grad is reserved, should not explicitly add it in the schema')
# [old codegen] this probably won't work if one of the returns is not a tensor,
# but it will produce a compile-time error that is obvious.
has_tensor_return = any(r.type.is_tensor_like() for r in f.func.returns)
name: str = cpp.name(f.func)
is_factory_function = f.category_override == 'factory' or (has_tensor_return and not has_tensor_input_arg)
is_like_or_new_function = f.category_override in ('new', 'like') or name.startswith('new_') or name.endswith('_like')
tensor_options_args: List[PythonArgument] = []
if is_factory_function or is_like_or_new_function:
tensor_options_args.append(PythonArgument(
name='dtype',
cpp_type_str='const ScalarType &',
type=BaseType(BaseTy.ScalarType),
default=_dtype_default_type_hack(name),
default_init='self.scalar_type()' if is_like_or_new_function else None,
))
tensor_options_args.append(PythonArgument(
name='layout',
cpp_type_str='c10::optional<Layout>',
type=BaseType(BaseTy.Layout),
default='torch.strided',
default_init='layout_from_backend(self.options().backend())' if is_like_or_new_function else None,
))
tensor_options_args.append(PythonArgument(
name='device',
cpp_type_str='const Device &',
type=BaseType(BaseTy.Device),
default='None',
default_init='self.device()' if is_like_or_new_function else None,
))
tensor_options_args.append(PythonArgument(
name='pin_memory',
cpp_type_str='bool',
type=BaseType(BaseTy.bool),
default='False',
default_init=None,
))
tensor_options_args.append(PythonArgument(
name='requires_grad',
cpp_type_str='bool',
type=BaseType(BaseTy.bool),
default='False',
default_init=None,
))
return PythonSignature(
name=str(f.func.name.name),
input_args=input_args,
input_kwargs=input_kwargs,
output_args=PythonOutArgument.from_outputs(outputs),
tensor_options_args=tuple(tensor_options_args),
method=method,
)
# TODO blowtorch
def _dtype_default_type_hack(name: str) -> str:
if name.startswith('randperm') or name == 'tril_indices' or name == 'triu_indices':
return 'torch.int64'
else:
return 'None'
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# C++ Function Dispatch
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
# This section provides APIs to generate the code that does C++ function
# dispatch. The C++ function call is wrapped by a lambda function.
# For example:
#
# // aten::selu_(Tensor(a!) self) -> Tensor(a!)
# auto dispatch_selu_ = [](Tensor self) -> Tensor {
# pybind11::gil_scoped_release no_gil;
# return at::selu_(self);
# };
#
# The lambda function's signature follows the C++ signature in common
# cases, e.g.:
#
# // aten::add.Tensor(Tensor self, Tensor other, *, Scalar alpha=1) -> Tensor
# [](const Tensor & self, const Tensor & other, Scalar alpha) -> Tensor
#
# For out variant the 'out' argument's type is changed from 'Tensor &'
# to 'Tensor'. It's because when calling the lambda it passes in the
# PythonArgParser output '_r.tensor(3)', which is stack allocated object
# and needs to pass by value. Also see comments in 'dispatch_lambda_return_str()'.
#
# // aten::add.out(Tensor self, Tensor other, *, Scalar alpha=1, Tensor(a!) out) -> Tensor(a!)
# [](Tensor out, const Tensor & self, const Tensor & other, Scalar alpha) -> Tensor
#
# For multi-output case it can keep using reference type because the
# PythonArgParser output has been unpacked to local variables, e.g.:
#
# // aten::max.names_dim_max(Tensor self, Dimname dim, bool keepdim=False, *,
# // Tensor(a!) max, Tensor(b!) max_values) -> (Tensor(a!) values, Tensor(b!) indices)
# [](Tensor & max, Tensor & max_values, const Tensor & self, Dimname dim, bool keepdim) -> std::tuple<Tensor,Tensor>
#
# For deprecated python signature, it should follow deprecated python arg order.
# TODO: This is to keep same byte-for-byte result as the old codegen - maybe unnecessary?
def dispatch_lambda_args(ps: PythonSignature, f: NativeFunction, *, method: bool,
) -> Tuple[DispatchLambdaArgument, ...]:
# Start with cpp arguments - dispatch lambda signature always include 'self'
cpp_args: Sequence[CppArgument] = _cpp_signature(f, method=False).arguments()
# Special reorder logic for deprecated python signature
if isinstance(ps, PythonSignatureDeprecated):
m: Dict[str, CppArgument] = dict((a.name, a) for a in cpp_args)
# reorder according to the deprecated signature
# ignore 'out' argument when binding to non-output function.
ordered_args = filter(lambda n: n != 'out' or f.func.is_out_fn(),
ps.deprecated_args_names)
cpp_args = list(map(lambda n: m[n], ordered_args))
out_args: Set[str] = set(a.name for a in f.func.out_arguments)
# Convert from cpp argument to lambda argument
def dispatch_lambda_arg(cpp_arg: CppArgument) -> DispatchLambdaArgument:
type_str = cpp_arg.type
is_out_arg = cpp_arg.name in out_args
if method and cpp_arg.name == 'self':
# For method's 'self', we can use 'Tensor &' and simply ignore mutability!
type_str = 'Tensor &'
else:
# For other cases we need prevent dangling refs to temps (unless it's
# unpacked scattered output)
# The reason is explained in the comments above and in 'dispatch_lambda_return_str()'.
# TODO: avoid this special handling?
ensure_temp_safe = len(out_args) <= 1 or not is_out_arg
if ensure_temp_safe:
type_str = {
'Tensor &': 'Tensor',
}.get(type_str, type_str)
return DispatchLambdaArgument(
name=cpp_arg.name,
type_str=type_str,
cpp_type_str=cpp_arg.type,
is_out_arg=is_out_arg,
)
return tuple(map(dispatch_lambda_arg, cpp_args))
# [old codegen] XXX: if you got here because of an assertion failure, it doesn't mean
# it's enough to just extend the list here. Before you do this, make sure
# to add an appropriate wrap() overload in torch/csrc/autograd/utils/wrap_outputs.h.
SUPPORTED_RETURN_TYPES = {
'Tensor',
'std::tuple<Tensor,Tensor>',
'std::tuple<Tensor,Tensor,Tensor>',
'std::tuple<Tensor,Tensor,Tensor,Tensor>',
'std::tuple<Tensor,Tensor,Tensor,Tensor,Tensor>',
'std::tuple<Tensor,Tensor,Tensor,int64_t>',
'std::tuple<Tensor,Tensor,double,int64_t>',
'std::tuple<Tensor,Tensor,Tensor,Tensor,int64_t>',
'std::tuple<Tensor,Tensor,double,Tensor,int64_t>',
'std::tuple<double,int64_t>',
'std::vector<Tensor>',
'Scalar', 'bool', 'int64_t', 'void*', 'void',
'QScheme', 'double',
'IntArrayRef',
'ScalarType'
}
def dispatch_lambda_return_str(f: NativeFunction) -> str:
# [old codegen] Remove type annotation (e.g. 'Tensor' rather than 'Tensor &')
# because the dispatch lambdas take mutable arguments *by value*, not
# by reference. If you then return a reference to such an argument, you
# will now have a pointer to a dangling stack entry. Not good.
#
# You want:
#
# auto dispatch_selu_ = [](Tensor self) -> Tensor { ...; return at::selu_(self); };
# ^^^^^^
#
# *not*
#
# auto dispatch_selu_ = [](Tensor self) -> Tensor& { ...; return at::selu_(self); };
# ^^^^^^^
#
# (NB: We can't make dispatch_selu_ take Tensor&, because the enclosing
# codegen looks like dispatch_selu_(_r.tensor(0)), and you can't take a
# mutable reference to temporary. Maybe we could assign it to a
# variable itself.)
returns_without_annotation = tuple(map(lambda r: Return(r.name, r.type, None), f.func.returns))
return_str = cpp.returns_type(returns_without_annotation)
if return_str not in SUPPORTED_RETURN_TYPES:
raise RuntimeError(f'{f.func.name} returns unsupported type {return_str}')
return return_str
def cpp_dispatch_target(f: NativeFunction) -> str:
name = cpp.name(f.func)
if Variant.method in f.variants:
return f'self.{name}'
if Variant.function in f.variants:
if has_tensor_options(f) or f.func.name.name.base.endswith('_like'):
namespace = 'torch'
else:
namespace = 'at'
return f'{namespace}::{name}'
raise RuntimeError(f'could not dispatch, neither function nor method: {f.func}')
def cpp_dispatch_exprs(f: NativeFunction, method: bool, *,
python_signature: Optional[PythonSignature] = None,
) -> Tuple[str, ...]:
cpp_args: Sequence[CppArgument] = _cpp_signature(f, method=False).arguments()
exprs: Tuple[str, ...] = tuple()
if not isinstance(python_signature, PythonSignatureDeprecated):
# By default the exprs are consistent with the C++ signature.
exprs = tuple(map(lambda a: a.name, cpp_args))
else:
# For deprecated python signature we may need fill in some constants.
exprs = tuple(filter(lambda n: n != 'out' or f.func.is_out_fn(),
python_signature.deprecated_args_exprs))
if Variant.method in f.variants:
exprs = tuple(filter('self'.__ne__, exprs))
return exprs
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# Python / C++ Args Binding
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
# TODO: should emit these unpack methods directly from Type to avoid
# indirect translation via cpp_type_str.
UNPACK_METHODS = {
'const Tensor &': 'tensor',
'Tensor &': 'tensor',
'Stream': 'stream',
'c10::optional<Tensor>': 'optionalTensor',
'const c10::optional<Tensor>&': 'optionalTensor',
'c10::optional<Generator>': 'generator',
'Storage': 'storage',
'Storage &': 'storage',
'const ScalarType &': 'scalartype',
'const Device &': 'device',
'c10::optional<DimnameList>': 'toDimnameListOptional',
'c10::optional<ScalarType>': 'scalartypeOptional',
'c10::optional<Layout>': 'layoutOptional',
'c10::optional<MemoryFormat>': 'memoryformatOptional',
'c10::optional<Scalar>': 'scalarOptional',
'c10::optional<IntArrayRef>': 'intlistOptional',
'c10::optional<int64_t>': 'toInt64Optional',
'c10::optional<bool>': 'toBoolOptional',
'c10::optional<double>': 'toDoubleOptional',
'c10::optional<ArrayRef<double>>': 'doublelistOptional',
'ArrayRef<double>': 'doublelist',
'IntArrayRef': 'intlist',
'Scalar': 'scalar',
'ScalarType': 'scalartype',
'Dimname': 'dimname',
'DimnameList': 'dimnamelist',
'TensorList': 'tensorlist',
'int64_t': 'toInt64',
'bool': 'toBool',
'double': 'toDouble',
'std::string': 'string',
'c10::optional<std::string>': 'stringOptional',
}
UNPACK_WITH_SIZE_METHODS = {
'TensorList': 'tensorlist_n<{}>',
'DimnameList': 'dimnamelist',
'IntArrayRef': 'intlist',
'c10::optional<IntArrayRef>': 'intlistOptional',
}
UNPACK_WITH_DEFAULT_METHODS = {
'const ScalarType &': 'scalartypeWithDefault',
'const Device &': 'deviceWithDefault',
'c10::optional<Layout>': 'layoutWithDefault',
}
# Return RHS expression for python argument using PythonArgParser output.
# e.g. for arg name 'foo', arg type 'bool', arg_index = 2, returns '_r.toBool(2)'
def arg_parser_output_expr(
arg_index: int, a: PythonArgument, la: Optional[DispatchLambdaArgument]
) -> PythonArgParserOutputExpr:
# The same python signature (and python schema string) is usually
# associated with two aten C++ functions: the base version and the
# out-place variant. Usually the two functions have the same set of
# arguments - of course, except for the output arguments. But in some
# cases they might have slightly different C++ argument types -
# affected by the 'use_c10_dispatcher' state.
#
# More specially, 'Tensor?' type can be translated into
# either 'const c10::optional<Tensor>&' or 'const Tensor &'.
# Unfortunately, this difference can affect how we should access arg
# parser output. The former expects '_r.optionalTensor(i)' while the
# latter expects '_r.tensor(i)'.
#
# Because of this subtle difference, we cannot solely use the shared
# python signature to determine the RHS expr for both C++ variants.
# We could create and use each C++ variant's own python signature,
# but we have to fix the argument index difference between the two
# python signatures like the old codegen does - and it feels wrong as
# technically there is only one shared python signature!
#
# So here we pass in the lambda wrapper's argument and use it to
# decide what PythonArgParser unpack method to use.
#
# TODO: this seems too complicated - maybe we can simplify after full
# c10 dispatch migration?
typename = la.cpp_type_str \
if a.name != 'out' and la is not None else a.cpp_type_str
if a.default_init is not None:
# Note: only introduced in tensor_options_args
if typename not in UNPACK_WITH_DEFAULT_METHODS:
raise RuntimeError(
f'type \'{typename}\' is not supported in default_init')
unpack_with_default = UNPACK_WITH_DEFAULT_METHODS[typename]
expr = f'_r.{unpack_with_default}({arg_index}, {a.default_init})'
elif a.size is not None:
if typename not in UNPACK_WITH_SIZE_METHODS:
raise RuntimeError(
f'type \'{typename}\' with definite size ({a.size}) is not supported')
unpack_with_size = UNPACK_WITH_SIZE_METHODS[typename].format(a.size)
expr = f'_r.{unpack_with_size}({arg_index})'
else:
unpack = UNPACK_METHODS.get(typename)
if unpack is None:
raise RuntimeError(f'type \'{typename}\' is not supported')
expr = f'_r.{unpack}({arg_index})'
return PythonArgParserOutputExpr(
name=a.name,
expr=expr,
index=arg_index,
argument=a,
)
# Returns a map with key = arg_name and value = PythonArgParserOutputExpr.
def arg_parser_output_exprs(
ps: PythonSignature, f: NativeFunction, *, method: bool
) -> Dict[str, PythonArgParserOutputExpr]:
lambda_args = dispatch_lambda_args(ps, f, method=method)
lambda_args_map = dict(map(lambda a: (a.name, a), lambda_args))
return {e.name: e for i, a in enumerate(ps.arguments())
for e in (arg_parser_output_expr(i, a, lambda_args_map.get(a.name)), )}
# argument name to 'simple_type' for scattered tensor options fields
TENSOR_OPTIONS_FIELDS = {
'dtype': 'ScalarType',
'device': 'Device',
'layout': 'Layout',
'pin_memory': 'bool',
'requires_grad': 'bool',
}
# bind arg parser outputs (python args) with dispatch lambda arguments (c++ args).
def dispatch_lambda_exprs(
ps: PythonSignature, f: NativeFunction, *, method: bool
) -> DispatchLambdaArgumentExprs:
# This method is to bind 'arg_parser_outputs' and 'lambda_args' by producing
# 'inits' and 'lambda_args_exprs' for each lambda argument using arg parser
# outputs.
arg_parser_outputs = arg_parser_output_exprs(ps, f, method=method)
lambda_args = dispatch_lambda_args(ps, f, method=method)
inits: List[str] = []
lambda_args_exprs: Dict[str, str] = dict()
has_toptions = has_tensor_options(f)
# 1. special inits/unpacking to provide binding exprs for lambda arguments.
for a in ps.arguments(skip_tensor_options=True):
name = a.name
arg_parser_expr = arg_parser_outputs[a.name].expr
if has_toptions and name == 'self':
# TODO: why this needs to be special case?
inits.extend([
f'auto self = {arg_parser_expr};',
])
lambda_args_exprs[name] = name
elif isinstance(a, PythonOutArgument) and len(a.outputs) > 1 and f.func.is_out_fn():
inits.extend([
f'auto out = {arg_parser_expr};',
])
for i, out_arg in enumerate(a.outputs):
lambda_args_exprs[out_arg.name] = f'out[{i}]'
elif a.cpp_type_str == 'c10::optional<DimnameList>':
# [old codegen]
# TODO: make this part of something more general, or get rid of it.
# optional<ArrayRef<T>> are special. The PythonArgParser returns an
# optional<vector<T>>, which cannot be implicitly converted to
# optional<ArrayRef<T>>. One needs to unwrap the optional and rewrap.
inits.extend([
f'auto __{name} = {arg_parser_expr};',
f'c10::optional<DimnameList> {name} = __{name} ? c10::make_optional(DimnameList(__{name}.value())) : c10::nullopt;',
])
lambda_args_exprs[name] = name
else:
# default case - directly using PythonArgParser output expr
lambda_args_exprs[name] = arg_parser_expr
# method's self is passed directly to python binding, rather than parsed
if method:
lambda_args_exprs['self'] = 'self'
# 2. special packing/checking for TensorOptions.
tensor_options_args_names = list(map(lambda a: a.name, ps.tensor_options_args))
if has_toptions:
if f.func.is_out_fn():
raise RuntimeError(f'{f.func}: tensor options with output arg')
for a in ps.tensor_options_args:
if a.name not in TENSOR_OPTIONS_FIELDS:
raise RuntimeError(
f'{f.func}: unrecognized tensor options field \'{a.name}\' in python binding arguments')
if _simple_type(a.cpp_type_str) != TENSOR_OPTIONS_FIELDS.get(a.name):
raise RuntimeError(
f'{f.func}: unrecognized type \'{_simple_type(a.cpp_type_str)}\' for tensor options field \'{a.name}\'')
if not all(map(lambda a: a in tensor_options_args_names, TENSOR_OPTIONS_FIELDS.keys())):
raise RuntimeError(
f'{f.func}: incomplete tensor options args: {tensor_options_args_names}')
inits.append(f'''\
const auto options = TensorOptions()
.dtype({arg_parser_outputs['dtype'].expr})
.device({arg_parser_outputs['device'].expr})
.layout({arg_parser_outputs['layout'].expr})
.requires_grad({arg_parser_outputs['requires_grad'].expr})
.pinned_memory({arg_parser_outputs['pin_memory'].expr});
torch::utils::maybe_initialize_cuda(options);
''')
lambda_args_exprs['options'] = 'options'
# 3. special case - access scattered TensorOptions fields without packing
# TODO: maybe move to the generator side as it's not related to binding.
if not has_toptions and tensor_options_args_names:
if 'dtype' in tensor_options_args_names:
# we're an output-arg variant, check these args against output tensor
if not f.func.is_out_fn():
raise RuntimeError(
f'{f.func}: dtype in tensor_options_args without output arg')
if not all(map(lambda a: a in tensor_options_args_names, ('layout', 'device'))):
raise RuntimeError(
f'{f.func}: incomplete tensor options for output check')
inits.append(f"""\
check_out_type_matches({arg_parser_outputs['out'].expr}, {arg_parser_outputs['dtype'].expr},
{arg_parser_outputs['dtype'].is_none_expr}, {arg_parser_outputs['layout'].expr},
{arg_parser_outputs['device'].expr}, {arg_parser_outputs['device'].is_none_expr});
""")
# we'll set requires_grad on outgoing tensor
if 'requires_grad' not in tensor_options_args_names:
raise RuntimeError(
f'{f.func}: expected "requires_grad" in tensor_options_args absent, but found [{tensor_options_args_names}]')
return DispatchLambdaArgumentExprs(
exprs=tuple(map(lambda a: lambda_args_exprs[a.name], lambda_args)),
inits=inits,
)