xref: /aosp_15_r20/external/pytorch/aten/src/ATen/native/cpu/SparseFactories.cpp (revision da0073e96a02ea20f0ac840b70461e3646d07c45)
1 #define TORCH_ASSERT_NO_OPERATORS
2 #include <ATen/native/sparse/SparseFactories.h>
3 
4 #include <ATen/Dispatch.h>
5 #include <ATen/TensorIterator.h>
6 #include <ATen/core/TensorBase.h>
7 #include <ATen/native/cpu/Loops.h>
8 #include <c10/core/ScalarType.h>
9 #include <c10/util/Exception.h>
10 
11 namespace at::native {
12 
13 namespace {
_spdiags_kernel_cpu(TensorIterator & iter,const TensorBase & diagonals,TensorBase & values,TensorBase & indices)14 void _spdiags_kernel_cpu(
15     TensorIterator& iter,
16     const TensorBase& diagonals,
17     TensorBase& values,
18     TensorBase& indices) {
19   auto* row_index_write_ptr = indices.data_ptr<int64_t>();
20   auto* col_index_write_ptr = row_index_write_ptr ? row_index_write_ptr + indices.stride(0) : nullptr;
21   const int64_t diagonals_index_stride = diagonals.stride(0);
22   const int64_t diagonals_read_stride = diagonals.stride(1);
23   AT_DISPATCH_ALL_TYPES_AND_COMPLEX_AND4(
24       at::ScalarType::BFloat16,
25       at::ScalarType::Half,
26       at::ScalarType::Bool,
27       at::ScalarType::ComplexHalf,
28       diagonals.scalar_type(),
29       "spdiags_cpu",
30       [&] {
31         auto* const values_write_ptr = values.data_ptr<scalar_t>();
32         const auto* const diagonals_ptr = diagonals.const_data_ptr<scalar_t>();
33 
34         cpu_kernel(
35             iter,
36             [&](int64_t diag_index,
37                 int64_t diag_offset,
38                 int64_t out_offset,
39                 int64_t n_out) -> int64_t {
40               if (n_out > 0) {
41                 auto* rows_start = row_index_write_ptr + out_offset;
42                 auto* cols_start = col_index_write_ptr + out_offset;
43                 auto* vals_start = values_write_ptr + out_offset;
44                 const int64_t first_col = std::max<int64_t>(diag_offset, 0);
45                 const int64_t first_row = first_col - diag_offset;
46                 auto* data_read = (diagonals_ptr +
47                                    diagonals_index_stride * diag_index +
48                                    first_col * diagonals_read_stride);
49                 for (int64_t i = 0; i < n_out; ++i) {
50                   rows_start[i] = first_row + i;
51                   cols_start[i] = first_col + i;
52                   vals_start[i] = data_read[i * diagonals_read_stride];
53                 }
54               }
55               // dummy return
56               return 0;
57             });
58       });
59 }
60 
61 } // namespace
62 
63 REGISTER_DISPATCH(spdiags_kernel_stub, &_spdiags_kernel_cpu);
64 
65 } // namespace at::native
66