[CK]Refactoring threadwise_tensor_slice_transfer_v3r1.hpp (#3263)

Signed-off-by: Michal Kulikowski <Michal.Kulikowski@amd.com>
Co-authored-by: Illia Silin <98187287+illsilin@users.noreply.github.com>
This commit is contained in:
Michał Kulikowski
2026-01-27 19:48:16 +01:00
committed by GitHub
parent b26cb596b0
commit b737f1dee5

View File

@@ -142,66 +142,22 @@ struct ThreadwiseTensorSliceTransfer_v3r1
constexpr auto ordered_src_access_lengths =
container_reorder_given_new2old(src_access_lengths, src_dim_access_order);
// make forward steps
const auto src_forward_steps = generate_tuple(
[&](auto i) {
Index forward_step_idx;
static_for<0, nDim, 1>{}([&](auto j) {
forward_step_idx(j) = (i.value == j.value) ? src_scalar_per_access[i] : 0;
});
return make_tensor_coordinate_step(src_desc, forward_step_idx);
},
Number<nDim>{});
// make backward steps
const auto src_backward_steps = generate_tuple(
[&](auto i) {
Index backward_step_idx;
static_for<0, nDim, 1>{}([&](auto j) {
backward_step_idx(j) = (i.value == j.value) ? -src_scalar_per_access[i] : 0;
});
return make_tensor_coordinate_step(src_desc, backward_step_idx);
},
Number<nDim>{});
// make forward and backward steps
const auto src_forward_steps = ComputeForwardSteps(src_desc, src_scalar_per_access);
const auto src_backward_steps = ComputeBackwardSteps(src_desc, src_scalar_per_access);
// loop over tensor and copy
static_ford<decltype(ordered_src_access_lengths)>{}([&](auto ordered_src_access_idx) {
// judge move forward or move backward
constexpr auto forward_sweep = [&]() {
StaticallyIndexedArray<bool, nDim> forward_sweep_;
forward_sweep_(I0) = true;
static_for<1, nDim, 1>{}([&](auto i) {
index_t tmp = ordered_src_access_idx[I0];
static_for<1, i, 1>{}([&](auto j) {
tmp = tmp * ordered_src_access_lengths[j] + ordered_src_access_idx[j];
});
forward_sweep_(i) = tmp % 2 == 0;
});
return forward_sweep_;
}();
constexpr auto forward_sweep =
ComputeForwardSweep(ordered_src_access_idx, ordered_src_access_lengths);
// calculate src data index
constexpr auto src_data_idx = [&]() {
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i] ? ordered_src_access_idx[i]
: ordered_src_access_lengths[i] - 1 -
ordered_src_access_idx[i];
});
return container_reorder_given_old2new(ordered_idx, src_dim_access_order) *
src_scalar_per_access;
}();
constexpr auto src_data_idx = ComputeDataIndex(ordered_src_access_idx,
ordered_src_access_lengths,
forward_sweep,
src_dim_access_order,
src_scalar_per_access);
constexpr auto src_data_idx_seq = generate_sequence_v2(
[&](auto i) { return Number<src_data_idx[i]>{}; }, Number<src_data_idx.Size()>{});
@@ -308,20 +264,8 @@ struct ThreadwiseTensorSliceTransfer_v3r1
.template SetAsType<dst_vector_t>(src_data_idx_seq,
op_r_v.template AsType<dst_vector_t>()[I0]);
constexpr auto move_on_dim = [&]() constexpr {
StaticallyIndexedArray<bool, nDim> move_on_dim_;
static_for<0, nDim, 1>{}([&](auto i) {
move_on_dim_(i) = ordered_src_access_idx[i] < ordered_src_access_lengths[i] - 1;
static_for<i + 1, nDim, 1>{}([&](auto j) {
move_on_dim_(i) &=
ordered_src_access_idx[j] == ordered_src_access_lengths[j] - 1;
});
});
return move_on_dim_;
}();
constexpr auto move_on_dim =
ComputeMoveOnDim(ordered_src_access_idx, ordered_src_access_lengths);
// move src coord
static_for<0, nDim, 1>{}([&](auto i) {
@@ -382,37 +326,15 @@ struct ThreadwiseTensorSliceTransfer_v3r1
// loop over tensor and copy
static_ford<decltype(ordered_src_access_lengths)>{}([&](auto ordered_src_access_idx) {
// judge move forward or move backward
constexpr auto forward_sweep = [&]() {
StaticallyIndexedArray<bool, nDim> forward_sweep_;
forward_sweep_(I0) = true;
static_for<1, nDim, 1>{}([&](auto i) {
index_t tmp = ordered_src_access_idx[I0];
static_for<1, i, 1>{}([&](auto j) {
tmp = tmp * ordered_src_access_lengths[j] + ordered_src_access_idx[j];
});
forward_sweep_(i) = tmp % 2 == 0;
});
return forward_sweep_;
}();
constexpr auto forward_sweep =
ComputeForwardSweep(ordered_src_access_idx, ordered_src_access_lengths);
// calculate src data index
constexpr auto src_data_idx = [&]() {
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i] ? ordered_src_access_idx[i]
: ordered_src_access_lengths[i] - 1 -
ordered_src_access_idx[i];
});
return container_reorder_given_old2new(ordered_idx, src_dim_access_order) *
src_scalar_per_access;
}();
constexpr auto src_data_idx = ComputeDataIndex(ordered_src_access_idx,
ordered_src_access_lengths,
forward_sweep,
src_dim_access_order,
src_scalar_per_access);
constexpr auto src_data_idx_seq = generate_sequence_v2(
[&](auto i) { return Number<src_data_idx[i]>{}; }, Number<src_data_idx.Size()>{});
@@ -547,66 +469,22 @@ struct ThreadwiseTensorSliceTransfer_v3r1
constexpr auto ordered_dst_access_lengths =
container_reorder_given_new2old(dst_access_lengths, dst_dim_access_order);
// make forward steps
const auto dst_forward_steps = generate_tuple(
[&](auto i) {
Index forward_step_idx;
static_for<0, nDim, 1>{}([&](auto j) {
forward_step_idx(j) = (i.value == j.value) ? dst_scalar_per_access[i] : 0;
});
return make_tensor_coordinate_step(dst_desc, forward_step_idx);
},
Number<nDim>{});
// make backward steps
const auto dst_backward_steps = generate_tuple(
[&](auto i) {
Index backward_step_idx;
static_for<0, nDim, 1>{}([&](auto j) {
backward_step_idx(j) = (i.value == j.value) ? -dst_scalar_per_access[i] : 0;
});
return make_tensor_coordinate_step(dst_desc, backward_step_idx);
},
Number<nDim>{});
// make forward and backward steps
const auto dst_forward_steps = ComputeForwardSteps(dst_desc, dst_scalar_per_access);
const auto dst_backward_steps = ComputeBackwardSteps(dst_desc, dst_scalar_per_access);
// loop over tensor and copy
static_ford<decltype(ordered_dst_access_lengths)>{}([&](auto ordered_dst_access_idx) {
// judge move forward or move backward
constexpr auto forward_sweep = [&]() {
StaticallyIndexedArray<bool, nDim> forward_sweep_;
forward_sweep_(I0) = true;
static_for<1, nDim, 1>{}([&](auto i) {
index_t tmp = ordered_dst_access_idx[I0];
static_for<1, i, 1>{}([&](auto j) {
tmp = tmp * ordered_dst_access_lengths[j] + ordered_dst_access_idx[j];
});
forward_sweep_(i) = tmp % 2 == 0;
});
return forward_sweep_;
}();
constexpr auto forward_sweep =
ComputeForwardSweep(ordered_dst_access_idx, ordered_dst_access_lengths);
// calculate dst data index
constexpr auto dst_data_idx = [&]() {
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i] ? ordered_dst_access_idx[i]
: ordered_dst_access_lengths[i] - 1 -
ordered_dst_access_idx[i];
});
return container_reorder_given_old2new(ordered_idx, dst_dim_access_order) *
dst_scalar_per_access;
}();
constexpr auto dst_data_idx = ComputeDataIndex(ordered_dst_access_idx,
ordered_dst_access_lengths,
forward_sweep,
dst_dim_access_order,
dst_scalar_per_access);
constexpr auto dst_data_idx_seq = generate_sequence_v2(
[&](auto i) { return Number<dst_data_idx[i]>{}; }, Number<dst_data_idx.Size()>{});
@@ -634,20 +512,8 @@ struct ThreadwiseTensorSliceTransfer_v3r1
is_dst_valid,
dst_vector_container.template AsType<dst_vector_t>()[I0]);
constexpr auto move_on_dim = [&]() constexpr {
StaticallyIndexedArray<bool, nDim> move_on_dim_;
static_for<0, nDim, 1>{}([&](auto i) {
move_on_dim_(i) = ordered_dst_access_idx[i] < ordered_dst_access_lengths[i] - 1;
static_for<i + 1, nDim, 1>{}([&](auto j) {
move_on_dim_(i) &=
ordered_dst_access_idx[j] == ordered_dst_access_lengths[j] - 1;
});
});
return move_on_dim_;
}();
constexpr auto move_on_dim =
ComputeMoveOnDim(ordered_dst_access_idx, ordered_dst_access_lengths);
// move dst coord
static_for<0, nDim, 1>{}([&](auto i) {
@@ -679,197 +545,33 @@ struct ThreadwiseTensorSliceTransfer_v3r1
__device__ static constexpr auto GetSrcCoordinateResetStep()
{
// scalar per access on each dim
// TODO: don't use lambda_scalar_per_access
constexpr auto src_scalar_per_access = generate_sequence(
detail::lambda_scalar_per_access<SrcVectorDim, SrcScalarPerVector_>{}, Number<nDim>{});
constexpr auto src_access_lengths = SliceLengths{} / src_scalar_per_access;
constexpr auto src_dim_access_order = SrcDimAccessOrder{};
constexpr auto ordered_src_access_lengths =
container_reorder_given_new2old(src_access_lengths, src_dim_access_order);
// judge move forward or move backward during the last iteration
constexpr auto forward_sweep = [&]() {
StaticallyIndexedArray<bool, nDim> forward_sweep_;
forward_sweep_(I0) = true;
static_for<1, nDim, 1>{}([&](auto i) {
index_t tmp = ordered_src_access_lengths[I0] - 1;
static_for<1, i, 1>{}([&](auto j) {
tmp = tmp * ordered_src_access_lengths[j] + ordered_src_access_lengths[j] - 1;
});
forward_sweep_(i) = tmp % 2 == 0;
});
return forward_sweep_;
}();
// calculate src data index after last iteration in RunRead(), if it has not being reset by
// RunRead()
constexpr auto src_data_idx = [&]() {
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i] ? ordered_src_access_lengths[i] - 1 : 0;
});
return container_reorder_given_old2new(ordered_idx, src_dim_access_order) *
src_scalar_per_access;
}();
//
constexpr auto reset_src_data_step = [&]() {
Index reset_src_data_step_;
static_for<0, nDim, 1>{}([&](auto i) { reset_src_data_step_(i) = -src_data_idx[i]; });
return reset_src_data_step_;
}();
return reset_src_data_step;
return ComputeCoordinateResetStep<SrcVectorDim, SrcScalarPerVector_, SrcDimAccessOrder>();
}
__device__ static constexpr auto GetDstCoordinateResetStep()
{
// scalar per access on each dim
// TODO: don't use lambda_scalar_per_access
constexpr auto dst_scalar_per_access = generate_sequence(
detail::lambda_scalar_per_access<DstVectorDim, DstScalarPerVector_>{}, Number<nDim>{});
constexpr auto dst_access_lengths = SliceLengths{} / dst_scalar_per_access;
constexpr auto dst_dim_access_order = DstDimAccessOrder{};
constexpr auto ordered_dst_access_lengths =
container_reorder_given_new2old(dst_access_lengths, dst_dim_access_order);
// judge move forward or move backward during the last iteration
constexpr auto forward_sweep = [&]() {
StaticallyIndexedArray<bool, nDim> forward_sweep_;
forward_sweep_(I0) = true;
static_for<1, nDim, 1>{}([&](auto i) {
index_t tmp = ordered_dst_access_lengths[I0] - 1;
static_for<1, i, 1>{}([&](auto j) {
tmp = tmp * ordered_dst_access_lengths[j] + ordered_dst_access_lengths[j] - 1;
});
forward_sweep_(i) = tmp % 2 == 0;
});
return forward_sweep_;
}();
// calculate dst data index after last iteration in RunWrite(), if it has not being reset by
// RunWrite()
constexpr auto dst_data_idx = [&]() {
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i] ? ordered_dst_access_lengths[i] - 1 : 0;
});
return container_reorder_given_old2new(ordered_idx, dst_dim_access_order) *
dst_scalar_per_access;
}();
//
constexpr auto reset_dst_data_step = [&]() {
Index reset_dst_data_step_;
static_for<0, nDim, 1>{}([&](auto i) { reset_dst_data_step_(i) = -dst_data_idx[i]; });
return reset_dst_data_step_;
}();
return reset_dst_data_step;
return ComputeCoordinateResetStep<DstVectorDim, DstScalarPerVector_, DstDimAccessOrder>();
}
// src_slice_origin_step_idx need to be known at compile-time, for performance reason
__device__ void MoveSrcSliceWindow(const SrcDesc& src_desc,
const Index& src_slice_origin_step_idx)
{
// if src coord was not reset by RunRead(), then need to adjust the step here
const auto adjusted_step_idx =
SrcResetCoordinateAfterRun ? src_slice_origin_step_idx
: src_slice_origin_step_idx + GetSrcCoordinateResetStep();
// is it OK to construct a new step every time?
const auto adjusted_step = make_tensor_coordinate_step(src_desc, adjusted_step_idx);
move_tensor_coordinate(src_desc, src_coord_, adjusted_step);
MoveSliceWindow<SrcDesc, SrcCoord, SrcResetCoordinateAfterRun>(
src_desc, src_coord_, src_slice_origin_step_idx, GetSrcCoordinateResetStep);
}
// dst_slice_origin_step_idx need to be known at compile-time, for performance reason
__device__ void MoveDstSliceWindow(const DstDesc& dst_desc,
const Index& dst_slice_origin_step_idx)
{
// if dst coord was not reset by RunWrite(), then need to adjust the step here
const auto adjusted_step_idx =
DstResetCoordinateAfterRun ? dst_slice_origin_step_idx
: dst_slice_origin_step_idx + GetDstCoordinateResetStep();
// is it OK to construct a new step every time?
const auto adjusted_step = make_tensor_coordinate_step(dst_desc, adjusted_step_idx);
move_tensor_coordinate(dst_desc, dst_coord_, adjusted_step);
MoveSliceWindow<DstDesc, DstCoord, DstResetCoordinateAfterRun>(
dst_desc, dst_coord_, dst_slice_origin_step_idx, GetDstCoordinateResetStep);
}
__device__ static constexpr auto GetSrcThreadScratchDescriptor()
{
constexpr auto src_scalar_per_access = generate_sequence(
detail::lambda_scalar_per_access<SrcVectorDim, SrcScalarPerVector_>{}, Number<nDim>{});
constexpr auto src_access_lengths = SliceLengths{} / src_scalar_per_access;
constexpr auto src_access_lengths_and_vector_length = container_push_back(
sequence_to_tuple_of_number(src_access_lengths), Number<SrcScalarPerVector>{});
// 1st stage of transforms
constexpr auto desc0 =
make_naive_tensor_descriptor_packed(src_access_lengths_and_vector_length);
// 2nd stage of transforms
constexpr auto transforms = generate_tuple(
[&](auto i) {
if constexpr(i == SrcVectorDim)
{
return make_merge_transform_v3_division_mod(
make_tuple(src_access_lengths_and_vector_length[i],
src_access_lengths_and_vector_length[Number<nDim>{}]));
}
else
{
return make_pass_through_transform(src_access_lengths_and_vector_length[i]);
}
},
Number<nDim>{});
constexpr auto low_dim_idss = generate_tuple(
[&](auto i) {
if constexpr(i == SrcVectorDim)
{
return Sequence<i.value, nDim>{};
}
else
{
return Sequence<i.value>{};
}
},
Number<nDim>{});
constexpr auto up_dim_idss =
generate_tuple([&](auto i) { return Sequence<i.value>{}; }, Number<nDim>{});
return transform_tensor_descriptor(desc0, transforms, low_dim_idss, up_dim_idss);
return ComputeThreadScratchDescriptor<SrcVectorDim, SrcScalarPerVector_>();
}
__device__ static constexpr auto GetSrcOOBThreadScratchDescriptor()
@@ -884,37 +586,149 @@ struct ThreadwiseTensorSliceTransfer_v3r1
__device__ static constexpr auto GetDstThreadScratchDescriptor()
{
return ComputeThreadScratchDescriptor<DstVectorDim, DstScalarPerVector_>();
}
protected:
// Helper function to compute forward sweep pattern
// I.e. if we should move forward or backward in each of tensor's dimensions
template <typename OrderedAccessIdx, typename OrderedAccessLengths>
__device__ static constexpr auto
ComputeForwardSweep(const OrderedAccessIdx& ordered_access_idx,
const OrderedAccessLengths& ordered_access_lengths)
{
StaticallyIndexedArray<bool, nDim> forward_sweep_;
forward_sweep_(I0) = true;
static_for<1, nDim, 1>{}([&](auto i) {
index_t tmp = ordered_access_idx[I0];
static_for<1, i, 1>{}(
[&](auto j) { tmp = tmp * ordered_access_lengths[j] + ordered_access_idx[j]; });
forward_sweep_(i) = tmp % 2 == 0;
});
return forward_sweep_;
}
// Compute which dimensions should have their coordinates updated during iteration
// A dimension moves when it hasn't reached its end and all higher priority dimensions
// have completed their ranges
template <typename OrderedAccessIdx, typename OrderedAccessLengths>
__device__ static constexpr auto
ComputeMoveOnDim(const OrderedAccessIdx& ordered_access_idx,
const OrderedAccessLengths& ordered_access_lengths)
{
StaticallyIndexedArray<bool, nDim> move_on_dim_;
static_for<0, nDim, 1>{}([&](auto i) {
move_on_dim_(i) = ordered_access_idx[i] < ordered_access_lengths[i] - 1;
static_for<i + 1, nDim, 1>{}([&](auto j) {
move_on_dim_(i) &= ordered_access_idx[j] == ordered_access_lengths[j] - 1;
});
});
return move_on_dim_;
}
// Compute data index from ordered access index, converting back to natural order
template <typename OrderedAccessIdx,
typename OrderedAccessLengths,
typename ForwardSweep,
typename DimAccessOrder,
typename ScalarPerAccess>
__device__ static constexpr auto
ComputeDataIndex(const OrderedAccessIdx& ordered_access_idx,
const OrderedAccessLengths& ordered_access_lengths,
const ForwardSweep& forward_sweep,
const DimAccessOrder& dim_access_order,
const ScalarPerAccess& scalar_per_access)
{
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i]
? ordered_access_idx[i]
: ordered_access_lengths[i] - 1 - ordered_access_idx[i];
});
return container_reorder_given_old2new(ordered_idx, dim_access_order) * scalar_per_access;
}
// Compute forward coordinate steps for each dimension
template <typename Desc, typename ScalarPerAccess>
__device__ static constexpr auto ComputeForwardSteps(const Desc& desc,
const ScalarPerAccess& scalar_per_access)
{
return generate_tuple(
[&](auto i) {
Index forward_step_idx;
static_for<0, nDim, 1>{}([&](auto j) {
forward_step_idx(j) = (i.value == j.value) ? scalar_per_access[i] : 0;
});
return make_tensor_coordinate_step(desc, forward_step_idx);
},
Number<nDim>{});
}
// Compute backward coordinate steps for each dimension
template <typename Desc, typename ScalarPerAccess>
__device__ static constexpr auto ComputeBackwardSteps(const Desc& desc,
const ScalarPerAccess& scalar_per_access)
{
return generate_tuple(
[&](auto i) {
Index backward_step_idx;
static_for<0, nDim, 1>{}([&](auto j) {
backward_step_idx(j) = (i.value == j.value) ? -scalar_per_access[i] : 0;
});
return make_tensor_coordinate_step(desc, backward_step_idx);
},
Number<nDim>{});
}
// Generic helper to compute thread scratch descriptor
template <index_t VectorDim, index_t ScalarPerVector_>
__device__ static constexpr auto ComputeThreadScratchDescriptor()
{
constexpr auto scalar_per_access = generate_sequence(
detail::lambda_scalar_per_access<VectorDim, ScalarPerVector_>{}, Number<nDim>{});
constexpr auto access_lengths = SliceLengths{} / scalar_per_access;
constexpr auto access_lengths_and_vector_length = container_push_back(
sequence_to_tuple_of_number(access_lengths), Number<ScalarPerVector_>{});
// 1st stage of transforms
constexpr auto dst_scalar_per_access = generate_sequence(
detail::lambda_scalar_per_access<DstVectorDim, DstScalarPerVector_>{}, Number<nDim>{});
constexpr auto dst_access_lengths = SliceLengths{} / dst_scalar_per_access;
constexpr auto dst_access_lengths_and_vector_length = container_push_back(
sequence_to_tuple_of_number(dst_access_lengths), Number<DstScalarPerVector>{});
constexpr auto desc0 =
make_naive_tensor_descriptor_packed(dst_access_lengths_and_vector_length);
make_naive_tensor_descriptor_packed(access_lengths_and_vector_length);
// 2nd stage of transforms
constexpr auto transforms = generate_tuple(
[&](auto i) {
if constexpr(i == DstVectorDim)
if constexpr(i == VectorDim)
{
return make_merge_transform_v3_division_mod(
make_tuple(dst_access_lengths_and_vector_length[i],
dst_access_lengths_and_vector_length[Number<nDim>{}]));
make_tuple(access_lengths_and_vector_length[i],
access_lengths_and_vector_length[Number<nDim>{}]));
}
else
{
return make_pass_through_transform(dst_access_lengths_and_vector_length[i]);
return make_pass_through_transform(access_lengths_and_vector_length[i]);
}
},
Number<nDim>{});
constexpr auto low_dim_idss = generate_tuple(
[&](auto i) {
if constexpr(i == DstVectorDim)
if constexpr(i == VectorDim)
{
return Sequence<i.value, nDim>{};
}
@@ -931,6 +745,73 @@ struct ThreadwiseTensorSliceTransfer_v3r1
return transform_tensor_descriptor(desc0, transforms, low_dim_idss, up_dim_idss);
}
// Generic helper to move slice window
template <typename Desc,
typename Coord,
bool ResetCoordinateAfterRun,
typename GetCoordinateResetStepFunc>
__device__ static void MoveSliceWindow(const Desc& desc,
Coord& coord,
const Index& slice_origin_step_idx,
GetCoordinateResetStepFunc get_reset_step)
{
// if coord was not reset by RunRead/RunWrite(), then need to adjust the step here
const auto adjusted_step_idx = ResetCoordinateAfterRun
? slice_origin_step_idx
: slice_origin_step_idx + get_reset_step();
// is it OK to construct a new step every time?
const auto adjusted_step = make_tensor_coordinate_step(desc, adjusted_step_idx);
move_tensor_coordinate(desc, coord, adjusted_step);
}
// Generic helper to compute coordinate reset step
template <index_t VectorDim, index_t ScalarPerVector_, typename DimAccessOrder>
__device__ static constexpr auto ComputeCoordinateResetStep()
{
// scalar per access on each dim
// TODO: don't use lambda_scalar_per_access
constexpr auto scalar_per_access = generate_sequence(
detail::lambda_scalar_per_access<VectorDim, ScalarPerVector_>{}, Number<nDim>{});
constexpr auto access_lengths = SliceLengths{} / scalar_per_access;
constexpr auto dim_access_order = DimAccessOrder{};
constexpr auto ordered_access_lengths =
container_reorder_given_new2old(access_lengths, dim_access_order);
// judge move forward or move backward during the last iteration
constexpr auto ordered_access_lengths_minus_1 = generate_tuple(
[&](auto i) { return Number<ordered_access_lengths.At(i) - 1>{}; }, Number<nDim>{});
constexpr auto forward_sweep =
ComputeForwardSweep(ordered_access_lengths_minus_1, ordered_access_lengths);
// calculate data index after last iteration, if it has not being reset
constexpr auto data_idx = [&]() {
Index ordered_idx;
static_for<0, nDim, 1>{}([&](auto i) {
ordered_idx(i) = forward_sweep[i] ? ordered_access_lengths[i] - 1 : 0;
});
return container_reorder_given_old2new(ordered_idx, dim_access_order) *
scalar_per_access;
}();
//
constexpr auto reset_data_step = [&]() {
Index reset_data_step_;
static_for<0, nDim, 1>{}([&](auto i) { reset_data_step_(i) = -data_idx[i]; });
return reset_data_step_;
}();
return reset_data_step;
}
private:
static constexpr auto src_thread_scratch_desc_ = decltype(GetSrcThreadScratchDescriptor()){};
static constexpr auto src_oob_thread_scratch_desc_ =