ai-content-maker/.venv/Lib/site-packages/torch/include/ATen/TensorIndexing.h

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2024-05-03 04:18:51 +03:00
#pragma once
#include <ATen/ExpandUtils.h>
#include <ATen/ScalarOps.h>
#include <ATen/core/Tensor.h>
#include <ATen/core/TensorBody.h>
#include <c10/core/SymInt.h>
#include <c10/util/Optional.h>
#include <c10/util/irange.h>
#ifndef AT_PER_OPERATOR_HEADERS
#include <ATen/Functions.h>
#include <ATen/NativeFunctions.h>
#else
#include <ATen/ops/alias.h>
#include <ATen/ops/empty.h>
#include <ATen/ops/scalar_tensor.h>
#include <ATen/ops/zeros.h>
#endif
#include <ATen/core/List.h>
#include <utility>
namespace at::indexing {
constexpr int64_t INDEX_MIN = c10::SymInt::min_representable_int();
constexpr int64_t INDEX_MAX = -(INDEX_MIN + 1);
enum class TensorIndexType { None, Ellipsis, SymInt, Boolean, Slice, Tensor };
constexpr c10::nullopt_t None = c10::nullopt;
struct TORCH_API EllipsisIndexType final {
EllipsisIndexType() = default;
};
TORCH_API extern const EllipsisIndexType Ellipsis;
struct TORCH_API Slice final {
public:
Slice(
c10::optional<c10::SymInt> start_index = c10::nullopt,
c10::optional<c10::SymInt> stop_index = c10::nullopt,
c10::optional<c10::SymInt> step_index = c10::nullopt) {
if (!step_index.has_value()) {
step_ = c10::SymInt(1);
} else {
step_ = std::move(step_index).value();
}
TORCH_CHECK_VALUE(step_ != 0, "slice step cannot be zero");
if (!start_index.has_value()) {
start_ = c10::SymInt(step_ < 0 ? INDEX_MAX : 0);
} else {
start_ = std::move(start_index).value();
}
if (!stop_index.has_value()) {
stop_ = c10::SymInt(step_ < 0 ? INDEX_MIN : INDEX_MAX);
} else {
stop_ = std::move(stop_index).value();
}
}
inline c10::SymInt start() const {
return start_;
}
inline c10::SymInt stop() const {
return stop_;
}
inline c10::SymInt step() const {
return step_;
}
private:
c10::SymInt start_;
c10::SymInt stop_;
c10::SymInt step_;
};
TORCH_API std::ostream& operator<<(std::ostream& stream, const Slice& slice);
// `at::indexing::TensorIndex` is used for converting C++ tensor indices such as
// `{None, "...", Ellipsis, 0, true, Slice(1, None, 2), torch::tensor({1, 2})}`
// into its equivalent `std::vector<TensorIndex>`, so that further tensor
// indexing operations can be performed using the supplied indices.
//
// There is one-to-one correspondence between Python and C++ tensor index types:
// Python | C++
// -----------------------------------------------------
// `None` | `at::indexing::None`
// `Ellipsis` | `at::indexing::Ellipsis`
// `...` | `"..."`
// `123` | `123`
// `True` / `False` | `true` / `false`
// `:` | `Slice()` / `Slice(None, None)`
// `::` | `Slice()` / `Slice(None, None, None)`
// `1:` | `Slice(1, None)`
// `1::` | `Slice(1, None, None)`
// `:3` | `Slice(None, 3)`
// `:3:` | `Slice(None, 3, None)`
// `::2` | `Slice(None, None, 2)`
// `1:3` | `Slice(1, 3)`
// `1::2` | `Slice(1, None, 2)`
// `:3:2` | `Slice(None, 3, 2)`
// `1:3:2` | `Slice(1, 3, 2)`
// `torch.tensor([1, 2])`) | `torch::tensor({1, 2})`
struct TORCH_API TensorIndex final {
// Case 1: `at::indexing::None`
TensorIndex(c10::nullopt_t) : type_(TensorIndexType::None) {}
// Case 2: "..." / `at::indexing::Ellipsis`
TensorIndex(at::indexing::EllipsisIndexType)
: type_(TensorIndexType::Ellipsis) {}
TensorIndex(const char* str) : TensorIndex(at::indexing::Ellipsis) {
TORCH_CHECK_VALUE(
strcmp(str, "...") == 0,
"Expected \"...\" to represent an ellipsis index, but got \"",
str,
"\"");
}
// Case 3: (Sym) Integer value
TensorIndex(SymInt integer)
: integer_(std::move(integer)), type_(TensorIndexType::SymInt) {}
TensorIndex(int64_t integer) : TensorIndex(SymInt(integer)) {}
TensorIndex(int integer) : TensorIndex(SymInt(integer)) {}
// Case 4: Boolean value
template <class T, class = std::enable_if_t<std::is_same_v<bool, T>>>
TensorIndex(T boolean) : boolean_(boolean), type_(TensorIndexType::Boolean) {}
// Case 5: Slice represented in `at::indexing::Slice` form
TensorIndex(Slice slice)
: slice_(std::move(slice)), type_(TensorIndexType::Slice) {}
// Case 6: Tensor value
TensorIndex(Tensor tensor)
: tensor_(std::move(tensor)), type_(TensorIndexType::Tensor) {}
inline bool is_none() const {
return type_ == TensorIndexType::None;
}
inline bool is_ellipsis() const {
return type_ == TensorIndexType::Ellipsis;
}
inline bool is_integer() const {
return type_ == TensorIndexType::SymInt;
}
inline SymInt integer() const {
return integer_;
}
inline bool is_boolean() const {
return type_ == TensorIndexType::Boolean;
}
inline bool boolean() const {
return boolean_;
}
inline bool is_slice() const {
return type_ == TensorIndexType::Slice;
}
inline const Slice& slice() const {
return slice_;
}
inline bool is_tensor() const {
return type_ == TensorIndexType::Tensor;
}
inline const Tensor& tensor() const {
return tensor_;
}
private:
SymInt integer_ = 0;
bool boolean_ = false;
Slice slice_;
Tensor tensor_;
TensorIndexType type_;
};
TORCH_API std::ostream& operator<<(
std::ostream& stream,
const TensorIndex& tensor_index);
TORCH_API std::ostream& operator<<(
std::ostream& stream,
const std::vector<TensorIndex>& tensor_indices);
namespace impl {
static inline Tensor applySlice(
const Tensor& self,
int64_t dim,
c10::SymInt start,
c10::SymInt stop,
c10::SymInt step,
bool disable_slice_optimization,
const at::Device& self_device,
const c10::optional<SymIntArrayRef>& self_sizes) {
// TODO: implement negative step
TORCH_CHECK_VALUE(step > 0, "step must be greater than zero");
// See NOTE [nested tensor size for indexing]
if (self_sizes.has_value()) {
// Skip this optimization if we are tracing, as the trace may be polymorphic
// over the shape of the `self` tensor, and we still want to record
// the slice.
SymInt length = (self_device == at::kCPU || self_device == at::kCUDA)
? (*self_sizes)[dim]
: self.sym_size(dim);
if (!disable_slice_optimization &&
TORCH_GUARD_SIZE_OBLIVIOUS(start.sym_eq(0)) && length == stop &&
step == 1) {
return self;
}
}
return self.slice_symint(
dim, std::move(start), std::move(stop), std::move(step));
}
static inline Tensor applySelect(
const Tensor& self,
int64_t dim,
SymInt index,
int64_t real_dim,
const at::Device& /*self_device*/,
const c10::optional<SymIntArrayRef>& self_sizes) {
// See NOTE [nested tensor size for indexing]
if (self_sizes.has_value()) {
auto maybe_index = index.maybe_as_int();
if (maybe_index.has_value()) {
TORCH_CHECK_INDEX(
!(maybe_index.value() == 0 && dim == 0 && self_sizes->empty()),
"invalid index of a 0-dim tensor. ",
"Use `tensor.item()` in Python or `tensor.item<T>()` in C++ to convert a 0-dim tensor to a number");
}
auto size = (*self_sizes)[dim];
// Note: `size >= -index` is not equivalent to `size > -1 - index` if index
// is INT64_MIN For std::numeric_limits<int64_t>::min() result of unary
// minus is undefined by the standard but in practice is equal to self. On
// the other hand, indexing wraping is valid for all negative int64_t
// values, as x[INT64_MIN] is the same as x[INT64_MAX]
TORCH_CHECK_INDEX(
size > -1 - index && size > index,
"index ",
index,
" is out of bounds for dimension ",
real_dim,
" with size ",
size);
}
// if the index is negative, do not normalize it because that would fix the
// index on the current tensor size in the tracer. aten::select also works on
// negative indices
return self.select_symint(dim, std::move(index));
}
static inline Tensor boolToIndexingTensorCPUOrCUDA(
const Tensor& self,
bool value) {
// booleans add a dimension of size 1. true indexes this dimension as if 0:,
// false as empty.
if (value) {
return at::empty({1}, self.options().dtype(kLong)).fill_(0.);
} else {
return at::empty({0}, self.options().dtype(kLong));
}
}
static inline Tensor boolToIndexingTensorNonNativeDeviceType(
const Tensor& self,
bool value) {
// booleans add a dimension of size 1. true indexes this dimension as if 0:,
// false as empty.
if (value) {
return at::zeros({1}, self.options().dtype(kLong));
} else {
return at::empty({0}, self.options().dtype(kLong));
}
}
static inline Tensor boolToIndexingTensor(
const Tensor& self,
bool value,
const at::Device& self_device) {
if (self_device == at::kCPU || self_device == at::kCUDA) {
return boolToIndexingTensorCPUOrCUDA(self, value);
} else {
return boolToIndexingTensorNonNativeDeviceType(self, value);
}
}
static inline Tensor scalarToTensorNonNativeDeviceType(
const Scalar& v,
const TensorOptions& options) {
return at::scalar_tensor(v, options);
}
static inline void recordTensorIndex(
const Tensor& tensor,
std::vector<Tensor>& outIndices,
int64_t* dim_ptr) {
// TODO: check scalarType
outIndices.resize(*dim_ptr + 1);
outIndices[*dim_ptr] = tensor;
(*dim_ptr)++;
};
static inline c10::List<c10::optional<Tensor>> typeConvertIndices(
const Tensor& /*self*/,
std::vector<Tensor>&& indices) {
c10::List<c10::optional<Tensor>> converted_inds;
converted_inds.reserve(indices.size());
for (auto&& i : std::move(indices)) {
converted_inds.push_back(std::move(i));
}
return converted_inds;
}
// NOTE: Why do we mirror instead of replace the `count_specified_dimensions`
// function in torch/csrc/autograd/python_variable_indexing.cpp? It's because
// `count_specified_dimensions` is on the hot path of Python tensor multi-dim
// indexing (i.e. it's called by `applySlicing` which is called by
// `THPVariable_getitem` / `THPVariable_setitem` when handling indexing of more
// than one dimension). If we were to merge the Python/C++
// `count_specified_dimensions` function, on the Python side we would have to
// construct a `std::vector` container to be consumed by the C++
// `count_specified_dimensions` function, which adds 100s of nanoseconds
// overhead and is undesirable.
static inline int64_t count_specified_dimensions(
const ArrayRef<TensorIndex>& indices) {
// Count the number of indexed dimensions (everything but ellipsis and None)
int64_t count = 0;
for (auto& obj : indices) {
if (obj.is_tensor()) {
auto& tensor = obj.tensor();
if (tensor.scalar_type() == kByte || tensor.scalar_type() == kBool) {
count += tensor.dim();
} else {
count++;
}
} else if (!obj.is_none() && !obj.is_ellipsis() && !obj.is_boolean()) {
count++;
}
}
return count;
}
} // namespace impl
// NOTE: Many functions below are only for consumption from Python indexing
// implementation, they include:
//
// - `Tensor scalarToTensor(...)`
// - `IntArrayRef slicePrefix1sSize(...)`
// - `void copy_to(...)`
// - `Tensor handleDimInMultiDimIndexing(...)`
// - `Tensor dispatch_index(...)`
// - `Tensor dispatch_index_put_(...)`
// - `Tensor get_item(...)`
// - `void set_item(...)`
//
// The rest of the functions are in `at::indexing::impl` namespace, signifying
// that they shouldn't be used from Python indexing implementation.
static inline Tensor scalarToTensor(
const Scalar& v,
const TensorOptions& options,
const at::Device& self_device) {
if (self_device == at::kCPU && !v.isSymbolic()) {
return at::detail::scalar_tensor_static(
v, options.dtype_opt()->toScalarType(), self_device);
} else {
return impl::scalarToTensorNonNativeDeviceType(v, options);
}
}
// To match numpy semantics:
// As a special case for backwards compatibility,
// strip away unit dimensions from the left of 'src'
static inline SymIntArrayRef slicePrefix1sSize(const SymIntArrayRef& sizes) {
size_t first_non1_src = sizes.size();
for (const auto i : c10::irange(sizes.size())) {
// Unbacked SymInt has different behavior, but this is sound because
// failing to slice will only ever cause an error, not divergent
// behavior
if (!sizes[i].has_hint() || sizes[i] != 1) {
first_non1_src = i;
break;
}
}
return sizes.slice(first_non1_src);
}
static inline void copy_to(const Tensor& dst, const Tensor& src) {
if (dst.sym_sizes().equals(src.sym_sizes())) {
// A shortcut to avoid generating hard-coded constant sizes during tracing.
// This is not a perfect solution: when src & dst have different shapes,
// constants will still appear. Users can workaround that case by
// dst[index..] = src.reshape(..)
dst.copy_(src);
return;
} else if (src.dim() == 0 && src.device().type() == at::kCPU) {
dst.fill_(src);
return;
}
auto src_view = src.view_symint(slicePrefix1sSize(src.sym_sizes()));
c10::MaybeOwned<Tensor> b_src = expand_inplace(dst, src_view, "setitem");
dst.copy_(*b_src);
}
// See NOTE [ Setting `disable_slice_optimization` when calling C++ tensor
// indexing functions from Python ]
static inline Tensor handleDimInMultiDimIndexing(
const Tensor& prev_dim_result,
const Tensor& original_tensor,
const TensorIndex& index,
int64_t* dim_ptr,
int64_t* specified_dims_ptr,
int64_t real_dim,
std::vector<Tensor>& outIndices,
bool disable_slice_optimization,
const at::Device& original_tensor_device,
const c10::optional<SymIntArrayRef>& prev_dim_result_sizes) {
if (index.is_integer()) {
return impl::applySelect(
prev_dim_result,
*dim_ptr,
index.integer(),
real_dim,
original_tensor_device,
prev_dim_result_sizes);
} else if (index.is_slice()) {
Tensor result = impl::applySlice(
prev_dim_result,
*dim_ptr,
index.slice().start(),
index.slice().stop(),
index.slice().step(),
/*disable_slice_optimization=*/disable_slice_optimization,
original_tensor_device,
prev_dim_result_sizes);
(*dim_ptr)++;
return result;
} else if (index.is_ellipsis()) {
(*dim_ptr) += original_tensor.dim() - (*specified_dims_ptr);
return prev_dim_result;
} else if (index.is_none()) {
Tensor result = prev_dim_result.unsqueeze(*dim_ptr);
(*dim_ptr)++;
return result;
} else if (index.is_boolean()) {
Tensor result = prev_dim_result.unsqueeze(*dim_ptr);
impl::recordTensorIndex(
impl::boolToIndexingTensor(
result, index.boolean(), original_tensor_device),
outIndices,
dim_ptr);
return result;
} else if (index.is_tensor()) {
Tensor result = prev_dim_result;
const Tensor& tensor = index.tensor();
auto scalar_type = tensor.scalar_type();
if (tensor.dim() == 0 &&
at::isIntegralType(scalar_type, /*includeBool=*/true)) {
if (scalar_type != at::kByte && scalar_type != at::kBool) {
result = impl::applySelect(
result,
*dim_ptr,
tensor.item<int64_t>(),
real_dim,
original_tensor_device,
prev_dim_result_sizes);
} else {
result = result.unsqueeze(*dim_ptr);
if (scalar_type == at::kBool) {
impl::recordTensorIndex(
impl::boolToIndexingTensor(
result, tensor.item<bool>() != 0, original_tensor_device),
outIndices,
dim_ptr);
} else {
impl::recordTensorIndex(
impl::boolToIndexingTensor(
result, tensor.item<uint8_t>() != 0, original_tensor_device),
outIndices,
dim_ptr);
}
}
} else {
impl::recordTensorIndex(tensor, outIndices, dim_ptr);
}
return result;
} else {
TORCH_INTERNAL_ASSERT(false, "Invalid TensorIndex type");
}
}
namespace impl {
// This mirrors `applySlicing` in
// torch/csrc/autograd/python_variable_indexing.cpp
static inline Tensor applySlicing(
const Tensor& self,
const ArrayRef<TensorIndex>& indices,
std::vector<Tensor>& outIndices,
bool disable_slice_optimization,
const at::Device& self_device,
const c10::optional<SymIntArrayRef>& self_sizes) {
int64_t dim = 0;
int64_t specified_dims = impl::count_specified_dimensions(indices);
// See NOTE [nested tensor size for indexing]
if (self_sizes.has_value()) {
TORCH_CHECK_INDEX(
specified_dims <= (int64_t)self_sizes->size(),
"too many indices for tensor of dimension ",
(int)self_sizes->size());
}
Tensor result = self;
for (const auto i : c10::irange(indices.size())) {
auto& obj = indices[i];
// See NOTE [nested tensor size for indexing]
c10::optional<SymIntArrayRef> result_sizes = result.is_nested()
? c10::optional<SymIntArrayRef>(c10::nullopt)
: c10::optional<SymIntArrayRef>(result.sym_sizes());
result = handleDimInMultiDimIndexing(
/*prev_dim_result=*/result,
/*original_tensor=*/self,
/*index=*/obj,
/*dim_ptr=*/&dim,
/*specified_dims_ptr=*/&specified_dims,
/*real_dim=*/static_cast<int64_t>(i),
/*outIndices=*/outIndices,
/*disable_slice_optimization=*/disable_slice_optimization,
/*original_tensor_device=*/self_device,
/*prev_dim_result_sizes=*/result_sizes);
}
return result;
}
} // namespace impl
static inline Tensor dispatch_index(
const Tensor& self,
std::vector<Tensor>&& indices) {
return self.index(impl::typeConvertIndices(self, std::move(indices)));
}
static inline Tensor dispatch_index_put_(
Tensor& self,
std::vector<Tensor>&& indices,
const Tensor& value) {
return self.index_put_(
impl::typeConvertIndices(self, std::move(indices)), value);
}
// NOTE [ Setting `disable_slice_optimization` when calling C++ tensor indexing
// functions from Python ]
//
// Question: When should we set `disable_slice_optimization` to `true` when
// calling C++ tensor indexing functions from Python indexing code?
//
// Answer: What "slice optimization" means: when we have a slicing expression
// like `x[0:5, 0]`, where the sliced tensor was of size 5 in dimension 0, we
// would skip dispatching the actual slice call as an optimization. However,
// here are the cases where we DON'T want this optimization:
//
// 1. When we are doing 1-D slicing (e.g. `tensor[:]`).
// Reason: we always return a shallow copy for expressions such as
// `tensor[:]` / `tensor[...]` / `tensor[:, :]`. (Note that for `tensor[:,
// :]`, we return an alias of `tensor` by doing the following:
// ```
// Tensor sliced = impl::applySlicing(self, indices, tensorIndices,
// disable_slice_optimization, self_device, self_sizes); if
// (tensorIndices.empty()) {
// if (sliced.is_same(self)) {
// // ensure we return a shallow copy for things like x[...]
// sliced = at::alias(sliced);
// }
// return sliced;
// }
// ```)
// 2. When we are doing JIT tracing.
// Reason: JIT tracing needs the `self.slice(...)` call to properly trace the
// slice operation.
// This mirrors `THPVariable_getitem` in
// torch/csrc/autograd/python_variable_indexing.cpp See NOTE [ Setting
// `disable_slice_optimization` when calling C++ tensor indexing functions from
// Python ]
static inline Tensor get_item(
const Tensor& self,
const ArrayRef<TensorIndex>& indices,
bool disable_slice_optimization = false) {
at::Device self_device = self.device();
// NOTE [nested tensor size for indexing]
// nested tensor does not have a size (yet) so for now we represent its size
// as null may need to be changed after we reach a better solution for nested
// tensor size
c10::optional<SymIntArrayRef> self_sizes = self.is_nested()
? c10::optional<SymIntArrayRef>(c10::nullopt)
: c10::optional<SymIntArrayRef>(self.sym_sizes());
// handle simple types: integers, slices, none, ellipsis, bool
if (indices.size() == 1) {
const TensorIndex& index = indices[0];
if (index.is_integer()) {
return impl::applySelect(
self, 0, index.integer(), 0, self_device, self_sizes);
} else if (index.is_slice()) {
return impl::applySlice(
self,
0,
index.slice().start(),
index.slice().stop(),
index.slice().step(),
/*disable_slice_optimization=*/true,
self_device,
self_sizes);
} else if (index.is_none()) {
return self.unsqueeze(0);
} else if (index.is_ellipsis()) {
return at::alias(self);
} else if (index.is_boolean()) {
Tensor result = self.unsqueeze(0);
return dispatch_index(
result,
std::vector<Tensor>{impl::boolToIndexingTensor(
result, index.boolean(), self_device)});
}
}
std::vector<Tensor> tensorIndices;
Tensor sliced = impl::applySlicing(
self,
indices,
tensorIndices,
disable_slice_optimization,
self_device,
self_sizes);
if (tensorIndices.empty()) {
if (sliced.is_same(self)) {
// ensure we return a shallow copy for things like x[...]
sliced = at::alias(sliced);
}
return sliced;
}
// indexing by tensors ("advanced" indexing)
return dispatch_index(sliced, std::move(tensorIndices));
}
// This mirrors `THPVariable_setitem` in
// torch/csrc/autograd/python_variable_indexing.cpp for "the assigned value is a
// Tensor" case See NOTE [ Setting `disable_slice_optimization` when calling C++
// tensor indexing functions from Python ]
static inline void set_item(
const Tensor& self,
const ArrayRef<TensorIndex>& indices,
const Tensor& value,
bool disable_slice_optimization = false) {
at::Device self_device = self.device();
SymIntArrayRef self_sizes = self.sym_sizes();
// handle simple types: integers, slices, ellipsis, bool
if (indices.size() == 1) {
const TensorIndex& index = indices[0];
if (index.is_boolean() && !index.boolean()) {
// do nothing for false (technically we should check the size, but we
// don't have real 0-sized shapes.
return;
} else if (index.is_ellipsis()) {
copy_to(self, value);
return;
} else if (index.is_none() || (index.is_boolean() && index.boolean())) {
copy_to(self.unsqueeze(0), value);
return;
} else if (index.is_integer()) {
copy_to(
impl::applySelect(
self, 0, index.integer(), 0, self_device, self_sizes),
value);
return;
} else if (index.is_slice()) {
copy_to(
impl::applySlice(
self,
0,
index.slice().start(),
index.slice().stop(),
index.slice().step(),
/*disable_slice_optimization=*/disable_slice_optimization,
self_device,
self_sizes),
value);
return;
}
}
std::vector<Tensor> tensorIndices;
Tensor sliced = impl::applySlicing(
self,
indices,
tensorIndices,
disable_slice_optimization,
self_device,
self_sizes);
if (tensorIndices.empty()) {
copy_to(sliced, value);
return;
}
SymIntArrayRef valueSizes = value.sym_sizes();
SymIntArrayRef slicedValueSizes = slicePrefix1sSize(valueSizes);
Tensor valuesSliced;
if (!valueSizes.equals(slicedValueSizes)) {
valuesSliced = value.view_symint(slicedValueSizes);
} else {
valuesSliced = value;
}
dispatch_index_put_(sliced, std::move(tensorIndices), valuesSliced);
return;
}
} // namespace at::indexing