chore: import upstream snapshot with attribution

paddle/phi/kernels/impl/channel_shuffle_kernel_impl.h

@@ -0,0 +1,60 @@
+// 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 <string>
+#include <vector>
+
+#include "paddle/phi/core/dense_tensor.h"
+#include "paddle/phi/kernels/funcs/math_function.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void ChannelShuffleKernel(const Context& dev_ctx,
+                          const DenseTensor& x,
+                          int groups,
+                          const std::string& data_format,
+                          DenseTensor* out) {
+  auto* in = &x;
+  dev_ctx.template Alloc<T>(out);
+  if (out && out->numel() == 0) {
+    return;
+  }
+  bool channel_last = (data_format == "NHWC");
+  const auto& in_dims = in->dims();
+  const auto& o_dims = out->dims();
+
+  DenseTensor t(*in);
+  if (!channel_last) {
+    t.Resize({in_dims[0], groups, in_dims[1] / groups, in_dims[2], in_dims[3]});
+  } else {
+    t.Resize({in_dims[0], in_dims[1], in_dims[2], groups, in_dims[3] / groups});
+  }
+  auto axis = !channel_last ? std::vector<int>{0, 2, 1, 3, 4}
+                            : std::vector<int>{0, 1, 2, 4, 3};
+
+  DenseTensor o(*out);
+  if (!channel_last) {
+    o.Resize({in_dims[0], in_dims[1] / groups, groups, in_dims[2], in_dims[3]});
+  } else {
+    o.Resize({in_dims[0], in_dims[1], in_dims[2], in_dims[3] / groups, groups});
+  }
+  funcs::Transpose<Context, T, 5> trans;
+  trans(dev_ctx, t, &o, axis);
+  out->Resize(o_dims);
+}
+
+}  // namespace phi