Files
pytorch/torch/csrc/autograd/input_metadata.h
soulitzer 71aefd5595 [reland] Allow setting grad_dtype on leaf tensors (#164751)
ghstack-source-id: e44b3941530be83a630ec93f1478eec741ffca2e
Pull-Request-resolved: https://github.com/pytorch/pytorch/pull/162815

Fixes #ISSUE_NUMBER

Relanding due to internal weirdness. Separate PR to codev w/o ghstack.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/164751
Approved by: https://github.com/albanD
2025-10-08 20:23:13 +00:00

133 lines
3.7 KiB
C++

#pragma once
#include <ATen/ExpandUtils.h>
#include <ATen/NestedTensorImpl.h>
#include <ATen/core/Tensor.h>
#include <c10/core/Device.h>
#include <c10/core/DeviceType.h>
#include <c10/core/Stream.h>
#include <c10/core/SymIntArrayRef.h>
#include <c10/core/TensorImpl.h>
#include <c10/core/impl/DeviceGuardImplInterface.h>
#include <c10/util/DimVector.h>
#include <c10/util/Exception.h>
#include <c10/util/SmallVector.h>
#ifndef AT_PER_OPERATOR_HEADERS
#include <ATen/Functions.h>
#else
#include <ATen/ops/zeros.h>
#endif
namespace torch::autograd {
using SymIntSmallVec = c10::SmallVector<c10::SymInt, c10::kDimVectorStaticSize>;
using MetadataShape = std::variant<SymIntSmallVec, at::Tensor>;
/**
* Records TensorOptions, shape of the tensor, whether or not the Python
* dispatch key is set (tensor subclass), and, where applicable, the stream the
* corresponding operation took place on.
*
* If is_valid() is false, then the corresponding input is not used and may be
* an undefined tensor.
*/
struct TORCH_API InputMetadata {
InputMetadata() = default;
InputMetadata(
const at::TensorOptions& options,
MetadataShape input_shape,
bool is_tensor_subclass,
bool is_nested,
std::optional<at::ScalarType> grad_dtype);
InputMetadata(const at::Tensor& t);
const at::TensorOptions& options() const {
return options_;
}
caffe2::TypeMeta dtype() const {
return options_.dtype();
}
at::Device device() const {
return options_.device();
}
at::Layout layout() const {
return options_.layout();
}
c10::Stream stream() const {
return stream_;
}
bool is_tensor_subclass() const {
return is_tensor_subclass_;
}
at::Tensor zeros_like() const;
bool is_same_shape(const at::Tensor& grad) const;
bool is_expandable_to_shape(const at::Tensor& grad) const;
at::Tensor reduce_grad(at::Tensor& grad) const;
at::Tensor maybe_reduce(
const size_t index,
at::Tensor grad,
const std::function<std::string(const std::string&)>& format_error) const;
std::stringstream incompatible_shape_error_message(
const size_t index,
const at::Tensor& grad) const;
bool was_default_constructed() const {
return was_default_constructed_;
}
bool is_cpp_nested_tensor() const;
bool is_nested_tensor() const {
return is_nested_;
}
c10::SymIntArrayRef shape_as_dim_vector() const;
// Danger: not thread safe, caller must protect with lock
SymIntSmallVec& mutable_shape_as_dim_vector();
std::optional<at::ScalarType> grad_dtype() const {
TORCH_INTERNAL_ASSERT(!was_default_constructed_);
return grad_dtype_;
}
void set_grad_dtype(const std::optional<at::ScalarType>& grad_dtype) {
TORCH_INTERNAL_ASSERT(!was_default_constructed_);
grad_dtype_ = grad_dtype;
}
private:
at::Tensor shape_as_tensor() const;
bool is_nestedness_same(const at::Tensor& grad) const;
bool maybe_expandable_to(const at::Tensor& grad) const;
// NB: The engine does not use the dtype from the options, but rather the
// grad_dtype_ field to validate grad_output dtype.
// NOLINTNEXTLINE(cppcoreguidelines-avoid-const-or-ref-data-members)
const at::TensorOptions options_;
MetadataShape shape_;
c10::Stream stream_ = c10::Stream(c10::Stream::Default::DEFAULT, device());
bool is_tensor_subclass_ = false;
bool is_nested_ = false;
bool was_default_constructed_ = true;
// The grad_dtype_ field is the dtype that the engine expects the grad to be.
// When nullopt, grad_dtype_ is allowed to be any dtype.
// This field is mutated if THPVariable_set_grad_dtype is called
// and the AccumulateGrad has already been created.
std::optional<at::ScalarType> grad_dtype_;
};
} // namespace torch::autograd