chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/roll_grad_kernel.cc

@@ -0,0 +1,68 @@
+// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "paddle/phi/kernels/roll_grad_kernel.h"
+
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/core/tensor_utils.h"
+#include "paddle/phi/kernels/cpu/roll_kernel_impl.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void RollGradKernel(const Context& dev_ctx,
+                    const DenseTensor& x UNUSED,
+                    const DenseTensor& out_grad,
+                    const IntArray& shifts,
+                    const std::vector<int64_t>& axis,
+                    DenseTensor* x_grad) {
+  if (x_grad && x_grad->numel() == 0) {
+    dev_ctx.template Alloc<T>(x_grad);
+    return;
+  }
+  std::vector<T> out_vec;
+  TensorToVector(out_grad, dev_ctx, &out_vec);
+
+  auto shifts_data = shifts.GetData();
+  size_t nums = shifts_data.size();
+  DDim input_dim = out_grad.dims();
+  auto dims = axis;
+
+  // axis = none, reshape to 1-D tensor
+  if (dims.empty()) {
+    dims.push_back(0l);
+    input_dim = Dim<1>(out_vec.size());
+  }
+
+  for (size_t i = 0; i < nums; i++) {
+    ShiftAlongDim(out_vec.data(), input_dim, dims[i], 0 - shifts_data[i]);
+  }
+
+  dev_ctx.template Alloc<T>(x_grad);
+  TensorFromVector(out_vec, dev_ctx, x_grad);
+  x_grad->Resize(out_grad.dims());
+}
+
+}  // namespace phi
+
+PD_REGISTER_KERNEL(roll_grad,
+                   CPU,
+                   ALL_LAYOUT,
+                   phi::RollGradKernel,
+                   float,
+                   double,
+                   int,
+                   int64_t,
+                   phi::complex64,
+                   phi::complex128) {}