1 /*
2 * Copyright (c) Meta Platforms, Inc. and affiliates.
3 * All rights reserved.
4 *
5 * This source code is licensed under the BSD-style license found in the
6 * LICENSE file in the root directory of this source tree.
7 */
8
9 #include <executorch/runtime/kernel/kernel_includes.h>
10 #include <cstddef>
11
12 namespace torch {
13 namespace executor {
14 namespace native {
15 namespace {
16
check_roll_args(const Tensor & in,IntArrayRef shifts,IntArrayRef dims,const Tensor & out)17 bool check_roll_args(
18 const Tensor& in,
19 IntArrayRef shifts,
20 IntArrayRef dims,
21 const Tensor& out) {
22 ET_LOG_AND_RETURN_IF_FALSE(tensor_has_rank_greater_or_equal_to(in, 1));
23 if (in.numel() > 0) {
24 for (const auto& d : dims) {
25 ET_LOG_AND_RETURN_IF_FALSE(dim_is_valid(d, in.dim()));
26 }
27 }
28 ET_LOG_AND_RETURN_IF_FALSE(!shifts.empty());
29 ET_LOG_AND_RETURN_IF_FALSE(shifts.size() == dims.size());
30 ET_LOG_AND_RETURN_IF_FALSE(tensors_have_same_dtype(in, out));
31 return true;
32 }
33
unshift_flat_ix(size_t ix,const Tensor & in,IntArrayRef dim_shifts)34 size_t unshift_flat_ix(size_t ix, const Tensor& in, IntArrayRef dim_shifts) {
35 size_t ix_coord[kTensorDimensionLimit];
36 indexToCoordinate(in, ix, ix_coord);
37
38 size_t shifted_coord[kTensorDimensionLimit];
39 for (size_t d = 0; d < in.dim(); d++) {
40 shifted_coord[d] =
41 (ix_coord[d] + in.size(d) - dim_shifts[d] % in.size(d)) % in.size(d);
42 }
43
44 return coordinateToIndex(in, shifted_coord);
45 }
46
47 } // namespace
48
roll_out(KernelRuntimeContext & ctx,const Tensor & in,IntArrayRef shifts,IntArrayRef dims,Tensor & out)49 Tensor& roll_out(
50 KernelRuntimeContext& ctx,
51 const Tensor& in,
52 IntArrayRef shifts,
53 IntArrayRef dims,
54 Tensor& out) {
55 (void)ctx;
56
57 ET_KERNEL_CHECK(
58 ctx, resize_tensor(out, in.sizes()) == Error::Ok, InvalidArgument, out);
59
60 ET_KERNEL_CHECK(
61 ctx, check_roll_args(in, shifts, dims, out), InvalidArgument, out);
62
63 ET_KERNEL_CHECK(
64 ctx, tensors_have_same_dim_order(in, out), InvalidArgument, out);
65
66 if (in.numel() == 0) {
67 return out;
68 }
69
70 int64_t dim_shift_array[kTensorDimensionLimit];
71 for (size_t i = 0; i < in.dim(); i++) {
72 dim_shift_array[i] = 0;
73 }
74 for (size_t i = 0; i < dims.size(); i++) {
75 const auto d = dims[i] < 0 ? dims[i] + in.dim() : dims[i];
76 dim_shift_array[d] += shifts[i];
77 }
78
79 size_t dim_shift_array_length = static_cast<size_t>(in.dim()); // NOLINT
80 IntArrayRef dim_shifts(dim_shift_array, dim_shift_array_length);
81
82 constexpr auto name = "roll.out";
83
84 ET_SWITCH_REALHB_TYPES(in.scalar_type(), ctx, name, CTYPE, [&] {
85 const CTYPE* in_data = in.const_data_ptr<CTYPE>();
86 CTYPE* out_data = out.mutable_data_ptr<CTYPE>();
87
88 for (size_t ix = 0; ix < out.numel(); ++ix) {
89 out_data[ix] = in_data[unshift_flat_ix(ix, in, dim_shifts)];
90 }
91 });
92
93 return out;
94 }
95
96 } // namespace native
97 } // namespace executor
98 } // namespace torch
99