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ReduceOps.cpp
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ReduceOps.cpp
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#include <ATen/native/ReduceOps.h>
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/ExpandUtils.h>
#include <ATen/NativeFunctions.h>
#include <ATen/Parallel.h>
#include <ATen/WrapDimUtils.h>
#include <ATen/WrapDimUtilsMulti.h>
#include <ATen/native/ReduceOpsUtils.h>
#include <ATen/native/Resize.h>
#include <ATen/native/TensorIterator.h>
#include <ATen/NamedTensorUtils.h>
#include <ATen/native/TensorDimApply.h>
#include <ATen/native/SharedReduceOps.h>
#include <ATen/core/grad_mode.h>
#include <c10/util/irange.h>
#include <c10/util/SmallBuffer.h>
#include <algorithm>
#include <functional>
#include <limits>
#include <numeric>
#include <vector>
#include <map>
#include <cmath>
#include <cfloat>
#include <type_traits>
namespace at {
namespace native {
inline ScalarType get_dtype_from_self(
const Tensor& self,
const optional<ScalarType>& dtype,
bool promote_integers) {
if (dtype.has_value()) {
return dtype.value();
}
ScalarType src_type = self.scalar_type();
if (promote_integers && at::isIntegralType(src_type, /*includeBool=*/true)) {
return kLong;
}
return src_type;
}
} // namespace native
namespace meta {
static ScalarType infer_dtype_from_optional(
const Tensor& self,
IntArrayRef dim,
bool keepdim,
const optional<ScalarType>& opt_dtype,
const Tensor& result) {
// 'opt_dtype' has the priority for both cases.
if (result.defined()) {
// Otherwise, get the result type, if defined.
return opt_dtype.value_or(result.scalar_type());
} else {
// Last case is to get the self type.
// If the self type is an integer, we promote it to kLong.
return at::native::get_dtype_from_self(self, opt_dtype, true);
}
}
static IntArrayRef optional_to_arrayref(const c10::optional<int64_t>& opt) {
return opt.has_value() ? opt.value() : IntArrayRef{};
}
static ScalarType get_result_or_bytebool_dtype(const Tensor& self, const Tensor& result) {
// Refer [all, any : uint8 compatibility]
if (result.defined()) {
return result.scalar_type();
} else {
return (self.scalar_type() == kByte) ? kByte : kBool;
}
}
void check_result_is_bytebool(const char* name, const Tensor& self, const Tensor& result) {
if (result.defined()) {
// Refer [all, any : uint8 compatibility]
TORCH_CHECK(
result.scalar_type() == ScalarType::Bool ||
result.scalar_type() == ScalarType::Byte,
name, " only supports bool tensor for result, got: ",
result.scalar_type());
}
}
// Note [all, any : uint8 compatibility]:
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// For NumPy comptability, `all` and `any` return
// Tensor of dtype `bool`. However for compatibility reason,
// for `uint8`, they return Tensor of same dtype `uint8`.
// Reference: https://github.com/pytorch/pytorch/pull/47878#issuecomment-747108561
static void allany_meta(
impl::MetaBase& meta,
const char* name,
const Tensor& self,
IntArrayRef dims,
bool keepdim) {
const auto& result = meta.maybe_get_output();
check_result_is_bytebool(name, self, result);
auto out_dtype = get_result_or_bytebool_dtype(self, result);
resize_reduction(meta, self, dims, keepdim, out_dtype);
}
TORCH_PRECOMPUTE_META_FUNC2(all, dim)(const Tensor& self, int64_t dim, bool keepdim) {
allany_meta(*this, "all", self, dim, keepdim);
return TORCH_PRECOMPUTE_STRUCT2(all, dim)().set_dim(maybe_wrap_dim(dim, self.dim()));
}
TORCH_META_FUNC(all)(const Tensor& self) {
allany_meta(*this, "all", self, {}, false);
}
TORCH_PRECOMPUTE_META_FUNC2(any, dim)(const Tensor& self, int64_t dim, bool keepdim) {
allany_meta(*this, "any", self, dim, keepdim);
return TORCH_PRECOMPUTE_STRUCT2(any, dim)().set_dim(maybe_wrap_dim(dim, self.dim()));
}
TORCH_META_FUNC(any)(const Tensor& self) {
allany_meta(*this, "any", self, {}, false);
}
void check_argmax_argmin(
const char* name,
const Tensor& self,
const c10::optional<int64_t>& dim) {
if (dim.has_value()) {
auto dim_ = maybe_wrap_dim(dim.value(), self.dim());
native::zero_numel_check_dims(self, dim_, name);
} else {
TORCH_CHECK_INDEX(
self.numel() != 0,
name, ": Expected reduction dim to be specified for input.numel() == 0.");
}
}
TORCH_META_FUNC(argmax)
(const Tensor& self, c10::optional<int64_t> dim, bool keepdim) {
check_argmax_argmin("argmax()", self, dim);
resize_reduction(*this, self, optional_to_arrayref(dim), keepdim, kLong);
}
TORCH_META_FUNC(argmin)
(const Tensor& self, c10::optional<int64_t> dim, bool keepdim) {
check_argmax_argmin("argmin()", self, dim);
resize_reduction(*this, self, optional_to_arrayref(dim), keepdim, kLong);
}
void meta_func_cum_ops(
impl::MetaBase& meta,
const char* name,
const Tensor& self,
int64_t dim,
c10::optional<ScalarType> dtype) {
// Checking whether 'dim' is valid.
maybe_wrap_dim(dim, self.dim());
const auto& result = meta.maybe_get_output();
ScalarType out_dtype;
if (result.defined()) {
out_dtype = dtype.value_or(result.scalar_type());
} else {
auto is_integral = at::isIntegralType(self.scalar_type(), /*includeBool=*/true);
out_dtype = dtype.value_or(is_integral ? ScalarType::Long : self.scalar_type());
}
meta.set_output(self.sizes(), self.options().dtype(out_dtype));
namedinference::propagate_names(result, self);
}
TORCH_META_FUNC(cumsum)
(const Tensor& self, int64_t dim, c10::optional<ScalarType> dtype) {
meta_func_cum_ops(*this, "cumsum", self, dim, dtype);
}
TORCH_META_FUNC(cumprod)
(const Tensor& self, int64_t dim, c10::optional<ScalarType> dtype) {
meta_func_cum_ops(*this, "cumprod", self, dim, dtype);
}
TORCH_META_FUNC2(sum, dim_IntList)
(const Tensor& self, IntArrayRef dim, bool keepdim, optional<ScalarType> opt_dtype) {
auto out_dtype = infer_dtype_from_optional(self, dim, keepdim, opt_dtype, maybe_get_output());
resize_reduction(*this, self, dim, keepdim, out_dtype);
}
TORCH_META_FUNC2(prod, dim_int)
(const Tensor& self,
int64_t dim,
bool keepdim,
c10::optional<ScalarType> dtype) {
auto out_dtype = infer_dtype_from_optional(self, dim, keepdim, dtype, maybe_get_output());
resize_reduction(*this, self, dim, keepdim, out_dtype);
}
void check_floating_or_complex_dtype(const char* name, ScalarType dtype) {
TORCH_CHECK(
at::isFloatingType(dtype) || at::isComplexType(dtype),
name, "(): input dtype should be either floating point or complex dtypes. "
"Got ", toString(dtype), " instead.");
}
TORCH_META_FUNC2(mean, dim)
(const Tensor& self, IntArrayRef dim, bool keepdim, optional<ScalarType> opt_dtype) {
check_floating_or_complex_dtype("mean", self.scalar_type());
auto out_dtype = infer_dtype_from_optional(self, dim, keepdim, opt_dtype, maybe_get_output());
resize_reduction(*this, self, dim, keepdim, out_dtype);
}
ScalarType get_result_or_self_value_dtype(
const Tensor& self,
const Tensor& result,
const c10::optional<ScalarType>& dtype) {
if (result.defined()) {
return result.scalar_type();
} else {
return dtype.value_or(toValueType(self.scalar_type()));
}
}
TORCH_META_FUNC2(norm, ScalarOpt_dim)
(const Tensor& self, const OptionalScalarRef p, IntArrayRef dim, bool keepdim) {
check_floating_or_complex_dtype("norm", self.scalar_type());
auto out_dtype = get_result_or_self_value_dtype(self, maybe_get_output(), c10::nullopt);
resize_reduction(*this, self, dim, keepdim, out_dtype);
}
TORCH_META_FUNC2(norm, ScalarOpt_dim_dtype)
(const Tensor& self,
const OptionalScalarRef p,
IntArrayRef dim,
bool keepdim,
ScalarType dtype) {
check_floating_or_complex_dtype("norm", dtype);
auto out_dtype = get_result_or_self_value_dtype(self, maybe_get_output(), dtype);
resize_reduction(*this, self, dim, keepdim, out_dtype);
}
TORCH_META_FUNC(aminmax)
(const Tensor& self, c10::optional<int64_t> dim_opt, bool keepdim) {
DimVector shape;
if (dim_opt.has_value()) {
auto dim = maybe_wrap_dim(dim_opt.value(), self.ndimension());
native::zero_numel_check_dims(self, dim, "aminmax");
shape = get_reduction_shape(self, dim, keepdim);
} else {
TORCH_CHECK(
self.numel() > 0,
"aminmax(): cannot compute aminmax over an empty dimension as the "
"operation has no identity.");
if (keepdim) {
shape = DimVector(self.ndimension(), 1);
}
}
const auto options = self.options();
this->set_output(0, shape, options);
this->set_output(1, shape, options);
}
} // namespace meta
namespace native {
DEFINE_DISPATCH(aminmax_stub);
DEFINE_DISPATCH(aminmax_allreduce_stub);
TORCH_IMPL_FUNC(aminmax_out)
(const Tensor& self,
c10::optional<int64_t> dim_opt,
bool keepdim,
const Tensor& min,
const Tensor& max) {
auto mutable_min = const_cast<Tensor&>(min);
auto mutable_max = const_cast<Tensor&>(max);
if (dim_opt.has_value()) {
aminmax_stub(
self.device().type(),
self,
maybe_wrap_dim(dim_opt.value(), self.ndimension()),
keepdim,
mutable_min,
mutable_max);
} else {
aminmax_allreduce_stub(self.device().type(), self.contiguous(), mutable_min, mutable_max);
}
}
} // namespace native
namespace native {
DEFINE_DISPATCH(sum_stub);
DEFINE_DISPATCH(nansum_stub);
DEFINE_DISPATCH(std_var_stub);
DEFINE_DISPATCH(prod_stub);
DEFINE_DISPATCH(norm_stub);
DEFINE_DISPATCH(mean_stub);
DEFINE_DISPATCH(and_stub);
DEFINE_DISPATCH(or_stub);
DEFINE_DISPATCH(min_values_stub);
DEFINE_DISPATCH(max_values_stub);
DEFINE_DISPATCH(argmax_stub);
DEFINE_DISPATCH(argmin_stub);
DEFINE_DISPATCH(cumsum_stub);
DEFINE_DISPATCH(cumprod_stub);
DEFINE_DISPATCH(logcumsumexp_stub);
Tensor _logcumsumexp_cpu(const Tensor& self, int64_t dim) {
Tensor result = at::empty_like(self, MemoryFormat::Contiguous);
return _logcumsumexp_out_cpu(self, dim, result);
}
Tensor& _logcumsumexp_out_cpu(const Tensor& self, int64_t dim, Tensor& result) {
logcumsumexp_stub(self.device().type(), result, self, dim);
return result;
}
Tensor logcumsumexp(const Tensor& self, int64_t dim) {
auto result = [&]() {
NoNamesGuard guard;
return at::_logcumsumexp(self, dim);
}();
namedinference::propagate_names(result, self);
return result;
}
Tensor& logcumsumexp_out(const Tensor& self, int64_t dim, Tensor& result) {
check_scalar_type_device_layout_equal(result, self);
{
NoNamesGuard guard;
at::_logcumsumexp_out(result, self.toType(result.scalar_type()), dim);
}
namedinference::propagate_names(result, self);
return result;
}
template <class Stub>
void impl_func_cum_ops(
const Tensor& self,
int64_t dim,
c10::optional<ScalarType> dtype,
const Tensor& result,
Stub& stub) {
NoNamesGuard guard;
if (self.dim() == 0) {
result.fill_(self);
} else if (self.numel() == 0) {
result.zero_();
} else {
dim = maybe_wrap_dim(dim, self.dim());
stub(self.device().type(), result, self.to(result.scalar_type()), dim);
}
}
TORCH_IMPL_FUNC(cumsum_out)
(const Tensor& self,
int64_t dim,
c10::optional<ScalarType> dtype,
const Tensor& result) {
impl_func_cum_ops(self, dim, dtype, result, cumsum_stub);
}
TORCH_IMPL_FUNC(cumprod_out)
(const Tensor& self,
int64_t dim,
c10::optional<ScalarType> dtype,
const Tensor& result) {
impl_func_cum_ops(self, dim, dtype, result, cumprod_stub);
}
Tensor reversed_cumsum(const Tensor& w, int64_t dim) {
return w.flip(dim).cumsum(dim).flip(dim);
}
Tensor cumprod_backward(const Tensor& grad, const Tensor& input, int64_t dim, const Tensor& output) {
/*
We show here how to derive an O(n) gradient formula for
abitrary inputs. It follows via a basic application of the
chain rule together with a number of observations for different
cases. We assume that x is an n-dimensional vector and y = cumprod(x).
In the actual implementation we will need to play a bit with masks
to be able to implement the formulas deduced here for tensors.
We will first deduce the formula for the case when
x[i] != 0 for 1 <= i <= n.
For F : R^n -> R the cost function (we will look at the complex case later),
we have
dF / dx_k = sum_j (dF / dy_j) * (dy_j / dx_k) (1)
The term dF / dy_j is just grad_output[j] (assuming again
everything is one-dimensional).
The term (dy_j / dx_k) is easilly seen to be
if j >= k
dy_j / dx_k = prod_{1 <= i <= j, i != k} x_i
else:
dy_j / dx_k = 0
Note that the indicator (j>=k) can be taken out
by replacing the sum in (1) with a sum from
k <= j <= n.
Thus,
dF / dx_k = sum_{k <= j <= n} grad_output[j] * (dy_j / dx_k)
with
dy_j / dx_k = prod_{1 <= i <= j, i != k} x_i (2)
Note that this last term is just the cumulative product
with k omitted. Thus, if x_k (the input) is nonzero, we can
just express this as
dy_j / dx_k = (prod_{1 <= i <= j} x_i) / x_k
= y_j / x_k
So therefore,
dF / dx_k = sum_{k <= j <= n} grad_output[j] * y_j / x_k
This formula just makes sense when input[i] != 0 for every i.
Assume now that there exists at least a zero in the input.
Denote by z1 the first element 1 <= z1 <= n with input[z1] = 0
and z2 the second element z1 < z2 <= n with input[z2] = 0,
(or z2 = n if there is just one zero in input)
We have three cases.
k > z1:
Looking at (2), we see that dy_j / dx_k = 0, for j >= k, as these terms
all include a x_{z1} which is zero. As such, dF / dx_k = 0 in this case
k < z1:
Reasoning as in the previous case, we see that for these elements we have that
dF / dx_k = sum_{k <= j < z1} grad_output[j] * (dy_j / dx_k)
as the terms of the sum for j in z1 <= j <= n are all zero
k = z1:
Similar to the case k < z1, we have that
dF / dx_z1 = sum_{z1 <= j < z2} grad_output[j] * (dy_j / dx_z1)
This case has a subtlety though. To compute (dy_j / dx_z1), we cannot use the formula
dy_j / dx_z1 = y_j / x_z1
as, y_j = x_z1 = 0 for j >= z1. We need to compute it with the formula for its derivative,
that is:
dy_j / dx_z1 = prod(x[:z1]) * (grad_output[z1] + sum(grad_output[z1+1:z2] * cumprod(x[z1+1:z2])))
When the imputs are complex, this is map is holomorphic. As such, to compute
its backwards is just the conjugate of the usual backwards. This simplifies to
conjugating the input. We may also reuse the output as, since the map is holomorphic,
cumprod(input.conj()) = cumprod(input).conj()
*/
if (input.numel() <= 1) {
return grad;
}
dim = at::maybe_wrap_dim(dim, input.dim());
const int64_t dim_size = input.sizes()[dim];
if (dim_size == 1) {
return grad;
}
// To enable complex support.
// From this line on `input_conj` and output_conj`
// are interchangeable with `input` and `output`.
auto input_conj = input.conj();
auto output_conj = output.conj();
const auto w = output_conj * grad;
const auto is_zero = input == 0;
if (!(is_zero.any().item<uint8_t>())) {
return reversed_cumsum(w, dim).div(input_conj);
}
// If we are not computing a second order gradient, we can use an
// O(n) implementation. The derivative of this implementation is _not_
// the second derivative of cumprod. As such, we fallback to a less efficient
// O(n^2) implementation when at::GradMode::is_enabled().
Tensor grad_input = at::zeros(input.sizes(), grad.options());
if (!at::GradMode::is_enabled()) {
// n.b. This could probably be implemented much faster with a kernel
// From here on we need to use some mask gymnastics to
// account for the tensorial dimensions
// We do a cumsum of the zeros along the dimension.
// For a vector is_zero = [False, True, False, True, False]
// we would have cumsum = [0, 1, 1, 2, 2]
// As such we have (in python code for simplicity)
// The mask for the range [0, z1):
// cumsum == 0
// The indices of the first zero z1 and zeros when
// there is no first zero:
// indices = (cumsum == 1).max(dim, keepdim=True).indices
// The mask for the first zero:
// zeros_like(indices).scatter_(dim, indices, 1.) & cumsum == 1
// Note that the logic_and with cumsum == 1 accounts
// for the case when there is no first zero
const auto cumsum = is_zero.cumsum(dim);
// case k < z1
// select everything before the first zero [0, z1)
auto mask = cumsum == 0;
// equiv to grad_input[mask] = deriv[grad]
grad_input.masked_scatter_(mask,
reversed_cumsum(w.masked_fill(~mask, 0.), dim).div_(input_conj).masked_select(mask));
// select everything from the first zero to the second zero [z1, z2)
mask = cumsum == 1;
// case k = z1
// We start by select the first zero [z1]
// We locate the indices of the first zero using the max function
// We then go from the indices to a mask index_fill_
// When there is no zero in the slice, max will return the index 0.
// To account for this, we need to do an intersection with mask,
// which is true in the range [z1, z2)
const auto first_zero_index = std::get<1>(mask.max(dim, /*keepdim*/ true));
const auto first_zero_mask = at::zeros_like(mask)
.scatter_(dim, first_zero_index, /*src*/ 1)
.logical_and_(mask);
// select everything between the first zero and the second zero (z1, z2)
mask &= ~first_zero_mask;
// here we compute
// dy_j / dx_z1 = sum(cumprod(input[z1+1:z2] * grad[z1+1:z2])) * prod(output[z1-1])
// relu_() necessary as gather does not support negative indices
// finally, we do grad_input[z1] = dy_j / dx_z1
grad_input.masked_scatter_(first_zero_mask,
input_conj.masked_fill(~mask, 1.).cumprod(dim)
.mul_(grad.masked_fill(cumsum != 1, 0.))
.sum(dim, /*keepdim*/true)
.mul_(at::gather(output_conj, dim, (first_zero_index - 1).relu_())
.masked_fill_(first_zero_index == 0, 1.))
.masked_select(first_zero_mask));
} else { // GradMode::enabled()
/*
If the input is nonzero, we need to calculate the dy_j / dx_k
by using the formula (2), called in the code omitted_products.
The way the code calculates it is simply by noting that
prod_{1 <= i <= j, i != k} x_i
= (prod_{1 <= i <= k} x_i) * (prod_{k + 1 <= i <= j} x_i)
the first term is calculated as prods_until_k, which since
doesn't depend in j is easy to vectorize.
The second term (indexed by j) is the cumulative product of
x_{k+1}, x_{k+2}, ..., x_n, and it's named in the code
prods_from_k_pkus_1, and it's calculated as a cumprod.
In order to vectorize this properly, we need to add to
omitted_products the dimensions where k > j, and therefore
dy_j / dx_k = 0, which is done right after the assert.
*/
auto ones_size = input.sizes().vec();
ones_size[dim] = 1;
const Tensor ones = at::ones({1}, grad.options()).expand(ones_size);
Tensor prods_from_k_plus_1;
Tensor omitted_products;
for (const auto k : c10::irange(dim_size)) {
if (k == 0) {
prods_from_k_plus_1 = at::cumprod(input_conj.slice(dim, k + 1), dim);
omitted_products = at::cat({ones, prods_from_k_plus_1}, dim);
} else if (k == dim_size - 1) {
const Tensor prods_until_k = at::prod(input_conj.slice(dim, 0, k), dim, true);
omitted_products = prods_until_k;
} else {
const Tensor prods_until_k = at::prod(input_conj.slice(dim, 0, k), dim, true);
prods_from_k_plus_1 = at::cumprod(input_conj.slice(dim, k+1), dim);
omitted_products = prods_until_k.expand_as(prods_from_k_plus_1) * prods_from_k_plus_1;
omitted_products = at::cat({prods_until_k, omitted_products}, dim);
}
// At this point omitted_products is the same size
// as input, except on the dimension dim where it's
// dim_size - k
TORCH_CHECK(omitted_products.size(dim) == dim_size - k);
grad_input.select(dim, k).copy_(
at::sum(grad.slice(dim, k) * omitted_products,dim));
}
}
return grad_input;
}
// Implement std::is_nan<IntegralType> for MSVC.
namespace {
#ifdef _MSC_VER
template<typename T>
inline typename std::enable_if<std::is_integral<T>::value, bool>::type isnan_(T x) {
return false;
}
template<typename T>
inline typename std::enable_if<!std::is_integral<T>::value, bool>::type isnan_(T x) {
return std::isnan(x);
}
#else
template<typename T>
inline bool isnan_(T x) {
return std::isnan(x);
}
#endif
}
template<typename T1, typename T2, typename Operation>
void cummax_cummin_helper(const T1* self_data, T1* values_data, T2* indices_data,
int self_dim_size, int self_stride, int values_stride, int indices_stride) {
Operation op;
T1 out = self_data[0];
int idx = 0;
for (const auto i : c10::irange(self_dim_size)) {
T1 curr_elem = self_data[i*self_stride];
if(isnan_(curr_elem) || (!isnan_(out) && op(curr_elem, out))) {
out = self_data[i*self_stride];
idx = i;
}
values_data[i*values_stride] = out;
indices_data[i*indices_stride] = idx;
}
}
void cummax_helper_cpu(const Tensor& self, Tensor& values, Tensor& indices, int64_t dim) {
AT_DISPATCH_ALL_TYPES_AND2(kBool, kBFloat16,
self.scalar_type(), "cummax_cpu",
[&] {
at::native::tensor_dim_apply3<scalar_t, int64_t>(self, values, indices, dim, cummax_cummin_helper<scalar_t, int64_t, std::greater_equal<scalar_t>>);
});
}
std::tuple<Tensor&, Tensor&> cummax_out(const Tensor& self, int64_t dim, Tensor& values, Tensor& indices) {
check_scalar_type_device_layout_equal(values, self);
check_scalar_type_device_layout_equal(indices, at::empty({0}, self.options().dtype(at::kLong)));
{
NoNamesGuard guard;
at::native::resize_output(values, self.sizes());
at::native::resize_output(indices, self.sizes());
if(self.dim() == 0) {
values.fill_(self);
indices.fill_(0);
} else if(self.numel() != 0) {
dim = maybe_wrap_dim(dim, self.dim());
at::_cummax_helper(self, values, indices, dim);
}
}
namedinference::propagate_names(values, self);
namedinference::propagate_names(indices, self);
return std::forward_as_tuple(values, indices);
}
std::tuple<Tensor, Tensor> cummax(const Tensor& self, int64_t dim) {
auto values = at::empty(self.sizes(), self.options());
auto indices = at::empty(self.sizes(), self.options().dtype(at::kLong));
at::cummax_out(values, indices, self, dim);
return std::make_tuple(values, indices);
}
void cummin_helper_cpu(const Tensor& self, Tensor& values, Tensor& indices, int64_t dim) {
AT_DISPATCH_ALL_TYPES_AND2(kBool, kBFloat16,
self.scalar_type(), "cummin_cpu",
[&] {
at::native::tensor_dim_apply3<scalar_t, int64_t>(self, values, indices, dim, cummax_cummin_helper<scalar_t, int64_t, std::less_equal<scalar_t>>);
});
}
std::tuple<Tensor&, Tensor&> cummin_out(const Tensor& self, int64_t dim, Tensor& values, Tensor& indices) {
check_scalar_type_device_layout_equal(values, self);
check_scalar_type_device_layout_equal(indices, at::empty({0}, self.options().dtype(at::kLong)));
{
NoNamesGuard guard;
at::native::resize_output(values, self.sizes());
at::native::resize_output(indices, self.sizes());
if(self.dim() == 0) {
values.fill_(self);
indices.fill_(0);
} else if(self.numel() != 0) {
dim = maybe_wrap_dim(dim, self.dim());
at::_cummin_helper(self, values, indices, dim);
}
}
namedinference::propagate_names(values, self);
namedinference::propagate_names(indices, self);
return std::forward_as_tuple(values, indices);
}
std::tuple<Tensor, Tensor> cummin(const Tensor& self, int64_t dim) {
auto values = at::empty(self.sizes(), self.options());
auto indices = at::empty(self.sizes(), self.options().dtype(at::kLong));
at::cummin_out(values, indices, self, dim);
return std::make_tuple(values, indices);
}
Tensor cummaxmin_backward(const Tensor& grad, const Tensor& input, const Tensor& indices, int64_t dim) {
if (input.numel() == 0) {
return input;
}
auto result = at::zeros(input.sizes(), input.options());
return result.scatter_add_(dim, indices, grad);
}
static Tensor prepend_append_on_dim(const Tensor& self, const c10::optional<Tensor>& prepend, const c10::optional<Tensor>& append, int64_t dim) {
// Helper for diff that handles prepending and appending when at least one is present
TORCH_INTERNAL_ASSERT(prepend.has_value() || append.has_value(), "either prepend or append must be have value");
if (!prepend.has_value() && append.has_value()) {
return at::cat({self, append.value()}, dim);
} else if (prepend.has_value() && !append.has_value()) {
return at::cat({prepend.value(), self}, dim);
} else {
return at::cat({prepend.value(), self, append.value()}, dim);
}
}
static inline void diff_check_compatible_shape(const Tensor& self, const c10::optional<Tensor>&other, int64_t dim) {
// Helper for diff that checks whether the shape of the tensor to prepend or append
// is compatible with that of input
if (other.has_value()) {
int64_t wrapped_dim = maybe_wrap_dim(dim, self.dim(), false);
TORCH_CHECK(
other.value().dim() == self.dim(),
"diff expects prepend or append to be the same dimension as input");
for (const auto i : c10::irange(other.value().dim())) {
TORCH_CHECK(
other.value().size(i) == self.size(i) || i == wrapped_dim,
"diff expects the shape of tensor to prepend or append to match that of"
" input except along the differencing dimension;"
" input.size(", i, ") = ", self.size(i), ", but got"
" tensor.size(", i, ") = ", other.value().size(i));
}
}
}
static inline void diff_check(const Tensor& self, int64_t n, int64_t dim, const c10::optional<Tensor>&prepend, const c10::optional<Tensor>& append) {
// Helper for diff that checks whether its parameters are valid
TORCH_CHECK(
n == 1,
"diff only supports n = 1 currently. Please file an issue at"
" https://github.com/pytorch/pytorch/issues/new?assignees=&labels=&template=feature-request.md"
" if your use case requires supporting higher-order differences");
TORCH_CHECK(
self.dim() >= 1,
"diff expects input to be at least one-dimensional");
diff_check_compatible_shape(self, prepend, dim);
diff_check_compatible_shape(self, append, dim);
}
static inline Tensor diff_helper(const Tensor& self, int64_t n, int64_t dim) {
auto out_len = self.size(dim) - 1;
if (self.dtype() == at::kBool) {
return at::logical_xor(at::narrow(self, dim, 1, out_len), at::narrow(self, dim, 0, out_len));
}
return at::narrow(self, dim, 1, out_len) - at::narrow(self, dim, 0, out_len);
}
Tensor diff(const Tensor& self, int64_t n, int64_t dim, const c10::optional<Tensor>& prepend, const c10::optional<Tensor>& append) {
diff_check(self, n, dim, prepend, append);
if (!prepend.has_value() && !append.has_value()) {
return diff_helper(self, n, dim);
} else {
auto a = prepend_append_on_dim(self, prepend, append, dim);
return diff_helper(a, n, dim);
}
}
static inline Tensor& diff_out_helper(const Tensor& self, int64_t n, int64_t dim, Tensor& result) {
auto out_len = self.size(dim) - 1;
if (self.dtype() == at::kBool) {
return at::logical_xor_out(result, at::narrow(self, dim, 1, out_len), at::narrow(self, dim, 0, out_len));
}
return at::sub_out(result, at::narrow(self, dim, 1, out_len), at::narrow(self, dim, 0, out_len));
}
Tensor& diff_out(const Tensor& self, int64_t n, int64_t dim, const c10::optional<Tensor>& prepend, const c10::optional<Tensor>& append, Tensor& result) {
diff_check(self, n, dim, prepend, append);
if (!prepend.has_value() && !append.has_value()) {
return diff_out_helper(self, n, dim, result);
} else {
auto a = prepend_append_on_dim(self, prepend, append, dim);
return diff_out_helper(a, n, dim, result);
}
}
void pre_check_gradient(const Tensor& self, c10::optional<int64_t> spacing_size, c10::optional<IntArrayRef> dim, int64_t edge_order) {
// Helper for gradient function to make sure input data satisfies prerequisites
TORCH_CHECK(self.scalar_type() != ScalarType::Byte, "torch.gradient does not support uint8 input.");
if (spacing_size.has_value() && !dim.has_value()) {
TORCH_CHECK(spacing_size.value() == 1 || spacing_size.value() == self.dim(), "torch.gradient expected spacing to be unspecified, a scalar or a list of length ", self.dim(), " but got a list of length ", spacing_size.value());
}
if (spacing_size.has_value() && dim.has_value()) {
TORCH_CHECK(spacing_size.value() == static_cast<int64_t>(dim.value().size()),
"torch.gradient expected spacing to be unspecified, a scalar or it's spacing and dim arguments to have the same length, but got a spacing argument of length ", spacing_size.value(), " and a dim argument of length ", dim.value().size(), "." );
}
TORCH_CHECK(edge_order == 1 || edge_order == 2, "torch.gradient only supports edge_order=1 and edge_order=2.");
for (const auto i : c10::irange(self.dim())) {
TORCH_CHECK(self.size(i) >= edge_order + 1, "torch.gradient expected each dimension size to be at least edge_order+1");
}
if (dim.has_value()) {
// The following function get called to check whether dim argument satisfies prerequisites.
// The output of the function is not used for the computation of gradient.
dim_list_to_bitset(dim.value(), self.dim());
}
}
std::vector<Tensor> gradient_helper(const Tensor& self, TensorList coordinates, IntArrayRef dim, int64_t edge_order) {
for (const auto i : c10::irange(coordinates.size())) {
TORCH_CHECK(self.device() == coordinates[i].device(), "torch.gradient expected each tensor to be on the same device, but got devices ", self.device(), " and ", coordinates[i].device(), "!");
}
std::vector<Tensor> result;
for (const auto i : c10::irange(dim.size())) {
TORCH_CHECK( coordinates[i].dim() == 1, "torch.gradient expected each element of spacing to have one dimension, but got an element with ", coordinates[i].dim(), " dimensions!");
int64_t direction = maybe_wrap_dim(dim[i], self.dim());
Tensor prepend, append;
std::vector<int64_t> shape(self.dim(),1);
shape[ direction ] = -1;
auto ax_dx = coordinates[i].diff(1,0);
auto dx1 = at::slice(ax_dx, 0, 0, -1);
auto dx2 = at::slice(ax_dx, 0, 1);
auto a = ( -dx2 / (dx1*(dx1+dx2)) ).reshape(shape);
auto b = ( (dx2-dx1) / (dx1*dx2) ).reshape(shape);
auto c = ( dx1 / (dx2*(dx1+dx2)) ).reshape(shape);
auto center = a * at::slice(self, direction, 0, -2) + b * at::slice(self, direction , 1, -1) + c * at::slice(self, direction, 2);
if (edge_order == 1) {
prepend = (at::slice(self, direction, 1, 2 ) - at::slice(self, direction, 0, 1 )) / ax_dx[0] ;
append = (at::slice(self, direction, -1 ) - at::slice(self, direction, -2, -1 )) / ax_dx[-1] ;
} else if (edge_order == 2) {
a =-(2.0 * ax_dx[0] + ax_dx[1]) / (ax_dx[0] * (ax_dx[0] + ax_dx[1])) ;
b = ( ax_dx[0] + ax_dx[1]) / (ax_dx[0] * ax_dx[1]) ;
c = ( -ax_dx[0] ) / (ax_dx[1] * (ax_dx[0] + ax_dx[1]));
prepend = a * at::slice(self, direction, 0, 1) + b * at::slice(self, direction, 1, 2) + c * at::slice(self, direction, 2, 3);
a = ( ax_dx[-1] ) / (ax_dx[-2] * (ax_dx[-1] + ax_dx[-2]));
b =-( ax_dx[-1] + ax_dx[-2]) / (ax_dx[-1] * ax_dx[-2]);
c = (2 * ax_dx[-1] + ax_dx[-2]) / (ax_dx[-1] * (ax_dx[-1] + ax_dx[-2]));
append = a * at::slice(self, direction, -3, -2) + b * at::slice(self, direction, -2, -1) + c * at::slice(self, direction, -1);
}
result.emplace_back(prepend_append_on_dim(center, prepend, append, direction));
}
return result;
}
std::vector<Tensor> gradient_helper_float(const Tensor& self, ArrayRef<Scalar> spacing, IntArrayRef dim, int64_t edge_order) {
std::vector<Tensor> result;
for (const auto i : c10::irange(dim.size())) {
int64_t direction = maybe_wrap_dim(dim[i], self.dim());
auto ax_dx = spacing[i];
Tensor prepend, append;
auto center = (at::slice(self,direction, 2 ) - at::slice(self, direction, 0, -2 ) ) / ax_dx;
if (edge_order==1) {
prepend = (at::slice(self,direction, 1, 2) - at::slice(self, direction, 0, 1 ) ) / ax_dx;
append = (at::slice(self,direction, -1 ) - at::slice(self, direction, -2, -1) ) / ax_dx ;
} else if (edge_order==2) {
prepend = (-1.5 * at::slice(self, direction, 0, 1) + 2 * at::slice(self, direction, 1, 2) - 0.5 * at::slice(self, direction, 2, 3))/ ax_dx;
append = (0.5 * at::slice(self, direction, -3, -2) - 2 * at::slice(self, direction, -2, -1) + 1.5 * at::slice(self, direction, -1)) / ax_dx;
}
result.emplace_back(prepend_append_on_dim(center/2, prepend, append, direction));
}
return result;
}
std::vector<int64_t> gradient_dim_preprocess(const Tensor& self, c10::optional<int64_t> dim) {
// if gradient dim is provided as an integer, then we need to compute gradient only on this direction.
// Moreover, if it's not provided at all, then we are interested in gradient for all directions.
// Finally, if dim is provided as vector of ints, then it is not expected to be called by this function.
if (dim.has_value()) {
return std::vector<int64_t>{dim.value()};
}
std::vector<int64_t> axis(self.dim());
std::iota(axis.begin(), axis.end(), 0);
return axis;
}
std::vector<Tensor> gradient(const Tensor& self, TensorList coordinates, IntArrayRef dim, int64_t edge_order) {
pre_check_gradient(self,
c10::optional<int64_t>(coordinates.size()),
c10::optional<IntArrayRef>(dim),
edge_order);
return gradient_helper(self, coordinates, dim, edge_order);
}
std::vector<Tensor> gradient(const Tensor& self, TensorList coordinates, c10::optional<int64_t> dim, int64_t edge_order) {
const auto processed_dim = gradient_dim_preprocess(self, dim);
pre_check_gradient(self,
c10::optional<int64_t>(coordinates.size()),
dim.has_value() ? c10::optional<IntArrayRef>(processed_dim) : c10::nullopt,
edge_order);
return gradient_helper(self, coordinates, processed_dim, edge_order);
}
std::vector<Tensor> gradient(const Tensor& self, c10::ArrayRef<Scalar> spacing, IntArrayRef dim, int64_t edge_order) {
pre_check_gradient(self,
c10::optional<int64_t>(spacing.size()),
c10::optional<IntArrayRef>(dim),
edge_order);
return gradient_helper_float(self, spacing, dim, edge_order);
}
std::vector<Tensor> gradient(const Tensor& self, ArrayRef<Scalar> spacing, c10::optional<int64_t> dim, int64_t edge_order) {
const auto processed_dim = gradient_dim_preprocess(self, dim);
pre_check_gradient(self,
c10::optional<int64_t>(spacing.size()),
dim.has_value() ? c10::optional<IntArrayRef>(processed_dim) : c10::nullopt,
edge_order);
return gradient_helper_float(self, spacing, processed_dim, edge_order);
}
std::vector<Tensor> gradient(const Tensor& self, const Scalar& unit_size, IntArrayRef dim, int64_t edge_order) {
// When spacing is given as scalar, while dim is given as IntArrayRef, scalar value need to
// be taken as unit size at every given dimension element of - dim.
std::vector<Scalar> spacing(dim.size(), unit_size);
pre_check_gradient(self,
c10::optional<int64_t>(spacing.size()),
c10::optional<IntArrayRef>(dim),
edge_order);
return gradient_helper_float(self, spacing, dim, edge_order);
}
std::vector<Tensor> gradient(const Tensor& self, const c10::optional<Scalar>& unit_size, c10::optional<int64_t> dim, int64_t edge_order) {
const auto processed_dim = gradient_dim_preprocess(self, dim);
// When unit_size not provided, it is always assumed to be equal to 1.
// When dim has integer value it implies we are looking for gradient in the specific direction, however when
// it is not provided, it means we are interested to find gradient in all directions.
std::vector<Scalar> spacing(dim.has_value() ? 1 : self.dim(),
unit_size.has_value() ? unit_size.value() : 1.0) ;
pre_check_gradient(self,
unit_size.has_value() ? c10::optional<int64_t>(spacing.size()) : c10::nullopt,
dim.has_value() ? c10::optional<IntArrayRef>(processed_dim) : c10::nullopt,
edge_order);
return gradient_helper_float(self, spacing, processed_dim, edge_order);
}
std::vector<Tensor> gradient(const Tensor& self, IntArrayRef dim, int64_t edge_order) {
std::vector<Scalar> spacing(dim.size(), 1.0) ;
pre_check_gradient(self,
c10::optional<int64_t>(spacing.size()),
c10::optional<IntArrayRef>(dim),
edge_order);
return gradient_helper_float(self, spacing, dim, edge_order);
}
// ALL REDUCE #################################################################
inline ScalarType get_dtype_from_result(Tensor& result, optional<ScalarType> dtype) {
TORCH_CHECK(result.defined(), "Cannot create a new tensor inside a reduction op. You likely tried to call an operator with an out argument but the out argument was an undefined tensor.");
if (dtype.has_value()) {
return dtype.value();
} else {
return result.scalar_type();
}
}
TORCH_IMPL_FUNC(sum_out)
(const Tensor& self,
IntArrayRef dim,
bool keepdim,
optional<ScalarType> opt_dtype,
const Tensor& result) {
auto iter = meta::make_reduction_from_out_ty(self, result, dim, keepdim, result.scalar_type());
if (iter.numel() == 0) {
result.zero_();
} else {
sum_stub(iter.device_type(), iter);
}
}
Tensor sum(const Tensor &self, c10::optional<ScalarType> dtype) {
return at::sum(self, IntArrayRef{}, false, dtype);
}
Tensor sum(const Tensor& self, DimnameList dim, bool keepdim, c10::optional<ScalarType> dtype) {
return at::sum(self, dimnames_to_positions(self, dim), keepdim, dtype);
}
Tensor& sum_out(const Tensor& self, DimnameList dim,