chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/roll_kernel_impl.h

@@ -0,0 +1,78 @@
+// 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.
+
+#pragma once
+
+#include "glog/logging.h"
+
+#include "paddle/phi/common/int_array.h"
+#include "paddle/phi/core/dense_tensor.h"
+
+namespace phi {
+
+template <typename T>
+inline void ShiftAlongDim(T* data,
+                          const DDim& input_dim,
+                          int64_t dim,
+                          int64_t shift) {
+  if (dim < 0) {
+    dim += input_dim.size();
+  }
+  if (input_dim[dim] == 0) {
+    return;
+  }
+  shift = shift % input_dim[dim];
+  if (shift < 0) {
+    shift += input_dim[dim];
+  }
+
+  auto outer_loops = 1;
+  for (auto i = 0; i < dim; i++) {
+    outer_loops *= input_dim[i];
+  }
+  auto slice_width = 1;
+  for (auto i = dim + 1; i < input_dim.size(); i++) {
+    slice_width *= input_dim[i];
+  }
+
+  VLOG(3) << "shift_along_dim_debug: input_dim: " << input_dim
+          << "; dim: " << dim << "; shift: " << shift
+          << "; outer_loops: " << outer_loops
+          << "; slice_width: " << slice_width;
+  if (shift == 0) {
+    return;
+  }
+
+  std::vector<T> head;
+  auto head_size = slice_width * (input_dim[dim] - shift);
+  head.resize(head_size);
+
+  for (auto i = 0; i < outer_loops; i++) {
+    for (auto j = 0; j < head_size; j++) {
+      head[j] = data[i * input_dim[dim] * slice_width + j];
+    }
+    for (auto j = input_dim[dim] - shift; j < input_dim[dim]; j++) {
+      auto dst_pos = j - input_dim[dim] + shift;
+      for (auto k = 0; k < slice_width; k++) {
+        data[(i * input_dim[dim] + dst_pos) * slice_width + k] =
+            data[(i * input_dim[dim] + j) * slice_width + k];
+      }
+    }
+    for (auto j = 0; j < head_size; j++) {
+      data[(i * input_dim[dim] + shift) * slice_width + j] = head[j];
+    }
+  }
+}
+
+}  // namespace phi