Traktor/myenv/Lib/site-packages/torchgen/dest/ufunc.py
2024-05-23 01:57:24 +02:00

546 lines
17 KiB
Python

from dataclasses import dataclass
from typing import Dict, List, Optional, Sequence, Tuple, Union
import torchgen.api.ufunc as ufunc
from torchgen.api.translate import translate
from torchgen.api.types import (
BaseCType,
Binding,
CType,
Expr,
NamedCType,
opmath_t,
scalar_t,
StructuredImplSignature,
VectorizedCType,
)
from torchgen.api.ufunc import UfunctorBindings
from torchgen.context import with_native_function
from torchgen.model import (
Argument,
BaseTy,
BaseType,
DispatchKey,
NativeFunctionsGroup,
ScalarType,
UfuncKey,
)
from torchgen.utils import OrderedSet
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# CUDA STUFF
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
# NB: not bothering to generate dispatch stub forward declaration in header,
# we can just paste it whereever necessary
# TODO: use BackendIndex
# dispatch_key: DispatchKey # only CPU/CUDA right now
# Represents functors for implementing CUDA ufuncs.
# Functors are templated by scalar_t because when USERS instantiate functors
# they are templated. A functor looks something like this:
#
# template <typename scalar_t>
# struct CUDAFunctorOnSelf_add {
# using opmath_t = at::opmath_type<scalar_t>;
# opmath_t other_;
# opmath_t alpha_;
# CUDAFunctorOnSelf_add(opmath_t other, opmath_t alpha)
# : other_(other), alpha_(alpha) {}
# __device__ scalar_t operator()(scalar_t self) {
# return ufunc::add(static_cast<opmath_t>(self), other_, alpha_);
# }
# };
#
@dataclass(frozen=True)
class UfunctorSignature:
g: NativeFunctionsGroup
scalar_tensor_idx: Optional[int]
name: str
def arguments(self) -> UfunctorBindings:
return ufunc.ufunctor_arguments(
self.g, scalar_tensor_idx=self.scalar_tensor_idx, scalar_t=scalar_t
)
def fields(self) -> List[Binding]:
# fields are renamed to have a trailing underscore, as is conventional
return [b.rename(f"{b.name}_") for b in self.arguments().ctor]
def returns_type(self) -> CType:
# TODO: don't hardcode; return type will be inferred based on tags on
# the native function
return BaseCType(scalar_t)
def decl_fields(self) -> str:
return "\n".join(f"{f.type} {f.name};" for f in self.fields())
def inline_defn_ctor(self) -> str:
args_str = ", ".join(a.decl() for a in self.arguments().ctor)
# NB: hypothetically could do this with translate but the
# transition here is very regular
init_str = ", ".join(f"{a.name}_({a.name})" for a in self.arguments().ctor)
return f"{self.name}({args_str}) : {init_str} {{}}"
def decl_apply(self) -> str:
args_str = ", ".join(a.decl() for a in self.arguments().apply)
return f"{self.returns_type().cpp_type()} operator()({args_str}) const"
@dataclass(frozen=True)
class UfuncSignature:
g: NativeFunctionsGroup
name: str
compute_t: CType
def arguments(self) -> List[Binding]:
return ufunc.ufunc_arguments(self.g, compute_t=self.compute_t)
def call(self, ctx: Sequence[Union[Binding, Expr]]) -> str:
return f"{self.name}({', '.join(a.expr for a in translate(ctx, self.arguments()))})"
# steps:
# 1. take the functional signature
# 2. use api.ufunc to convert it to template signature. this establishes
# the type of the template function
# 3. use api.ufunc (II) to generate a split struct / operator() signature.
# this establish context in which we call the template signature
#
# StructuredImplSignature context
# ~> functor constructor sig
#
# Functor constructor context
# ~> functor fields sig
#
# Functor apply context (functor fields + functor apply sig)
# ~> template sig
#
def eligible_for_binary_scalar_specialization(g: NativeFunctionsGroup) -> bool:
num_tensors = sum(
1 for a in g.functional.func.arguments.flat_non_out if a.type.is_tensor_like()
)
return num_tensors == 2
def compute_ufunc_cuda_functors(
g: NativeFunctionsGroup,
) -> Tuple[Dict[ScalarType, Dict[UfuncKey, UfunctorSignature]], str]:
# First, build the functors.
ufunctor_sigs: Dict[ScalarType, Dict[UfuncKey, UfunctorSignature]] = {}
ufunctors: List[str] = []
loops = g.out.ufunc_inner_loop
scalar_tensor_idx_lookup = {
UfuncKey.CUDAFunctorOnSelf: 1,
UfuncKey.CUDAFunctorOnOther: 0,
UfuncKey.CUDAFunctor: None,
}
if eligible_for_binary_scalar_specialization(g):
keys = [
UfuncKey.CUDAFunctorOnSelf,
UfuncKey.CUDAFunctorOnOther,
UfuncKey.CUDAFunctor,
]
else:
keys = [UfuncKey.CUDAFunctor]
for k in [UfuncKey.CUDAFunctorOnSelf, UfuncKey.CUDAFunctorOnOther]:
assert k not in loops, f"cannot use {k} on non-binary function"
for k in keys:
# If the key was directly defined, skip functor codegen; we assume the
# user already done it for us
if k in loops:
ufunctor_sig = UfunctorSignature(
g, scalar_tensor_idx=scalar_tensor_idx_lookup[k], name=loops[k].name
)
for dtype in loops[k].supported_dtypes:
ufunctor_sigs.setdefault(dtype, {})[k] = ufunctor_sig
continue
# Note [ScalarOnly and Generic must match names for CUDA]
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Otherwise, look in ANY of the generic entries. For simplicity of
# codegen, both ScalarOnly and Generic are defined, the ufunc name
# must match (if they didn't match, we'd have to generate distinct
# functors per dtype, which is awful, so we're not going to do it unless
# someone really forces us to)
ufunc_name = None
supported_dtypes: OrderedSet[ScalarType] = OrderedSet()
for lk in [UfuncKey.ScalarOnly, UfuncKey.Generic]:
if lk not in loops:
continue
if ufunc_name is None:
ufunc_name = loops[lk].name
else:
# See Note [ScalarOnly and Generic must match names for CUDA]
assert (
ufunc_name == loops[lk].name
), "ScalarOnly and Generic must have same ufunc name"
supported_dtypes |= loops[lk].supported_dtypes
assert ufunc_name is not None
name = f"{k}_{ufunc_name}"
ufunctor_sig = UfunctorSignature(
g, scalar_tensor_idx=scalar_tensor_idx_lookup[k], name=name
)
for dtype in supported_dtypes:
ufunctor_sigs.setdefault(dtype, {})[k] = ufunctor_sig
ufunc_sig = UfuncSignature(
g, name=f"ufunc::{ufunc_name}", compute_t=BaseCType(opmath_t)
)
apply_ctx = ufunctor_sig.fields() + ufunctor_sig.arguments().apply
ufunctors.append(
f"""
template <typename scalar_t>
struct {ufunctor_sig.name} {{
using opmath_t = at::opmath_type<scalar_t>;
{ufunctor_sig.decl_fields()}
{ufunctor_sig.inline_defn_ctor()}
__device__ {ufunctor_sig.decl_apply()} {{
return {ufunc_sig.call(apply_ctx)};
}}
}};
"""
)
return ufunctor_sigs, "\n".join(ufunctors)
@dataclass(frozen=True)
class BinaryScalarSpecializationConfig:
scalar_idx: int
ctor_tensor: str
ufunc_key: UfuncKey
BinaryScalarSpecializationConfigs = [
BinaryScalarSpecializationConfig(
scalar_idx=0,
ctor_tensor="self",
ufunc_key=UfuncKey.CUDAFunctorOnOther,
),
BinaryScalarSpecializationConfig(
scalar_idx=1,
ctor_tensor="other",
ufunc_key=UfuncKey.CUDAFunctorOnSelf,
),
]
def compute_ufunc_cuda_dtype_body(
g: NativeFunctionsGroup,
dtype: ScalarType,
inner_loops: Dict[UfuncKey, UfunctorSignature],
parent_ctx: Sequence[Binding],
) -> str:
body = "using opmath_t = at::opmath_type<scalar_t>;"
body += "if (false) {}\n" # for ease of codegen
for config in BinaryScalarSpecializationConfigs:
if config.ufunc_key not in inner_loops:
continue
ufunctor_sig = inner_loops[config.ufunc_key]
scalar_idx = config.scalar_idx + 1
# Make a copy and at the same time widen the type (not permissible
# without copy; we don't want to mutate the input argument anyway)
ctx: List[Union[Expr, Binding]] = list(parent_ctx)
ctx.append(
Expr(
expr=f"iter.scalar_value<opmath_t>({scalar_idx})",
type=NamedCType(config.ctor_tensor, BaseCType(opmath_t)),
)
)
ufunctor_ctor_exprs_str = ", ".join(
a.expr for a in translate(ctx, ufunctor_sig.arguments().ctor)
)
# NB: ufunctor must be allocated before iter.remove_operand is called,
# as it relies on iter
body += f"""\
else if (iter.is_cpu_scalar({scalar_idx})) {{
{ufunctor_sig.name}<scalar_t> ufunctor({ufunctor_ctor_exprs_str});
iter.remove_operand({scalar_idx});
gpu_kernel(iter, ufunctor);
}}"""
ufunctor_sig = inner_loops[UfuncKey.CUDAFunctor]
ufunctor_ctor_exprs_str = ", ".join(
a.expr for a in translate(parent_ctx, ufunctor_sig.arguments().ctor)
)
body += f"""
else {{
gpu_kernel(iter, {ufunctor_sig.name}<scalar_t>({ufunctor_ctor_exprs_str}));
}}
"""
return body
@with_native_function
def compute_ufunc_cuda(g: NativeFunctionsGroup) -> str:
# First, build the functors, indexing them by dtype
ufunctor_sigs, ufunctors = compute_ufunc_cuda_functors(g)
# Next, build the conditionals
sig = StructuredImplSignature(g, ufunc.kernel_name(g, DispatchKey.CUDA))
dtype_cases = []
for dtype, inner_ufunc_sigs in ufunctor_sigs.items():
dtype_cases.append(
f"""
AT_DISPATCH_CASE(at::ScalarType::{dtype},
[&]() {{
{compute_ufunc_cuda_dtype_body(g, dtype, inner_ufunc_sigs, sig.arguments())}
}}
)
"""
)
dtype_cases_str = "\n".join(dtype_cases)
stub_sig = StubSignature(g)
return f"""
{ufunctors}
{stub_sig.type_defn()};
{stub_sig.dispatch_decl()};
{stub_sig.kernel_defn()} {{
AT_DISPATCH_SWITCH(iter.common_dtype(), "{sig.name}",
{dtype_cases_str}
);
}}
REGISTER_DISPATCH({stub_sig.name}, &{stub_sig.kernel_name});
{sig.defn()} {{
{stub_sig.direct_call(sig.arguments())};
}}
"""
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
#
# CPU STUFF
#
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
@dataclass(frozen=True)
class StubSignature:
g: NativeFunctionsGroup
@property
def name(self) -> str:
return f"{str(self.g.functional.func.name.name)}_stub"
@property
def kernel_name(self) -> str:
return f"{str(self.g.functional.func.name.name)}_kernel"
@property
def type_name(self) -> str:
return f"{str(self.g.functional.func.name.name)}_fn"
def arguments(self) -> List[Binding]:
return ufunc.stub_arguments(self.g)
def type(self) -> str:
cpp_args = self.arguments()
return f"void(*)(TensorIteratorBase&, {', '.join(a.type for a in cpp_args)})"
def dispatch_decl(self) -> str:
return f"DECLARE_DISPATCH({self.type_name}, {self.name})"
def dispatch_defn(self) -> str:
return f"DEFINE_DISPATCH({self.name})"
def kernel_defn(self) -> str:
return f"void {self.kernel_name}(TensorIteratorBase& iter, {', '.join(a.defn() for a in self.arguments())})"
def type_defn(self) -> str:
return f"using {self.type_name} = {self.type()}"
# must be called from context where this is TensorIteratorBase*
def call(self, ctx: Sequence[Binding]) -> str:
return f"{self.name}(device_type(), *this, {', '.join(a.expr for a in translate(ctx, self.arguments()))})"
# used in CUDA to skip the unnecessary dynamic dispatch
def direct_call(self, ctx: Sequence[Binding]) -> str:
return f"{self.kernel_name}(*this, {', '.join(a.expr for a in translate(ctx, self.arguments()))})"
@with_native_function
def compute_ufunc_cpu(g: NativeFunctionsGroup) -> str:
stub_sig = StubSignature(g)
sig = StructuredImplSignature(g, ufunc.kernel_name(g, DispatchKey.CPU))
return f"""
{stub_sig.type_defn()};
{stub_sig.dispatch_decl()};
{stub_sig.dispatch_defn()};
{sig.defn()} {{
{stub_sig.call(sig.arguments())};
}}
"""
def compute_ufunc_cpu_dtype_body(
g: NativeFunctionsGroup,
dtype: ScalarType,
inner_loops: Dict[UfuncKey, UfuncSignature],
parent_ctx: Sequence[Binding],
) -> str:
assert UfuncKey.CPUScalar in inner_loops, f"{dtype}, {inner_loops.keys()}"
assert inner_loops.keys() <= {UfuncKey.CPUScalar, UfuncKey.CPUVector}
scalar_loop = inner_loops[UfuncKey.CPUScalar]
vec_loop = None
if UfuncKey.CPUVector in inner_loops:
vec_loop = inner_loops[UfuncKey.CPUVector]
# NB: We DON'T use translate here, because translate is
# incapable of CSE'ing the scalar accesses in case it is also
# used by Vectorized; also, the unpacking here is very simple
# and only affects Scalar; everything else is implicitly captured
# by the lambda
# Setup scalar in scope
body = []
ctx = []
for b in parent_ctx:
if isinstance(b.argument, Argument) and b.argument.type != BaseType(
BaseTy.Scalar
):
continue
body.append(f"auto _s_{b.name} = {b.name}.to<scalar_t>();")
ctx.append(Expr(f"_s_{b.name}", NamedCType(b.nctype.name, BaseCType(scalar_t))))
if vec_loop is not None:
for b in parent_ctx:
if isinstance(b.argument, Argument) and b.argument.type != BaseType(
BaseTy.Scalar
):
continue
body.append(
f"auto _v_{b.name} = at::vec::Vectorized<scalar_t>(_s_{b.name});"
)
ctx.append(
Expr(
f"_v_{b.name}",
NamedCType(b.nctype.name, VectorizedCType(BaseCType(scalar_t))),
)
)
# Setup lambda signature
# NB: simplified version of ufunctor_arguments
scalar_bindings = []
vec_bindings = []
for a in g.functional.func.arguments.flat_non_out:
if not a.type.is_tensor_like():
continue
assert a.type == BaseType(BaseTy.Tensor)
scalar_bindings.append(
Binding(
name=a.name,
nctype=NamedCType(a.name, BaseCType(scalar_t)),
argument=a,
)
)
if vec_loop is not None:
vec_bindings.append(
Binding(
name=a.name,
nctype=NamedCType(a.name, VectorizedCType(BaseCType(scalar_t))),
argument=a,
)
)
def with_ctx(b: Sequence[Binding]) -> List[Union[Expr, Binding]]:
r: List[Union[Expr, Binding]] = []
r.extend(ctx)
r.extend(b)
return r
body_str = "\n".join(body)
if vec_loop is not None:
return f"""
{body_str}
cpu_kernel_vec(iter,
[=]({', '.join(b.decl() for b in scalar_bindings)}) {{ return {scalar_loop.call(with_ctx(scalar_bindings))}; }},
[=]({', '.join(b.decl() for b in vec_bindings)}) {{ return {vec_loop.call(with_ctx(vec_bindings))}; }}
);
"""
else:
return f"""
{body_str}
cpu_kernel(iter,
[=]({', '.join(b.decl() for b in scalar_bindings)}) {{ return {scalar_loop.call(with_ctx(scalar_bindings))}; }}
);
"""
@with_native_function
def compute_ufunc_cpu_kernel(g: NativeFunctionsGroup) -> str:
stub_sig = StubSignature(g)
# Reindex the ufunc by dtypes; processing generic/scalaronly as well
loops = g.out.ufunc_inner_loop
ufunc_sigs: Dict[ScalarType, Dict[UfuncKey, UfuncSignature]] = {}
for k in [UfuncKey.CPUScalar, UfuncKey.CPUVector]:
lks = []
# ORDER MATTERS: this specifies overriding precedence
if k in loops: # should happen rarely
lks.append(k)
if UfuncKey.ScalarOnly in loops and k is UfuncKey.CPUScalar:
lks.append(UfuncKey.ScalarOnly)
if UfuncKey.Generic in loops:
lks.append(UfuncKey.Generic)
# TODO: don't hardcode ufunc:: namespace here, should be centralized smh
for lk in lks:
for dtype in loops[lk].supported_dtypes:
compute_t: CType
if k is UfuncKey.CPUScalar:
compute_t = BaseCType(scalar_t)
elif k is UfuncKey.CPUVector:
compute_t = VectorizedCType(BaseCType(scalar_t))
else:
raise AssertionError()
inner_ufunc_sigs = ufunc_sigs.setdefault(dtype, {})
if k not in inner_ufunc_sigs:
inner_ufunc_sigs[k] = UfuncSignature(
g, name=f"ufunc::{loops[lk].name}", compute_t=compute_t
)
# Build the conditionals
dtype_cases = []
for dtype, inner_ufunc_sigs in ufunc_sigs.items():
dtype_cases.append(
f"""
AT_DISPATCH_CASE(at::ScalarType::{dtype},
[&]() {{
{compute_ufunc_cpu_dtype_body(g, dtype, inner_ufunc_sigs, stub_sig.arguments())}
}}
)
"""
)
dtype_cases_str = "\n".join(dtype_cases)
return f"""
namespace {{
{stub_sig.kernel_defn()} {{
AT_DISPATCH_SWITCH(iter.common_dtype(), "{stub_sig.name}",
{dtype_cases_str}
);
}}
}} // anonymous namespace
{stub_sig.type_defn()};
{stub_sig.dispatch_decl()};
REGISTER_DISPATCH({stub_sig.name}, &{stub_sig.kernel_name});
"""