chore: import upstream snapshot with attribution

paddle/phi/kernels/impl/add_n_kernel_impl.h

@@ -0,0 +1,80 @@
+// 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 "paddle/phi/kernels/add_n_kernel.h"
+
+#include "paddle/phi/core/kernel_registry.h"
+#include "paddle/phi/core/tensor_utils.h"
+#include "paddle/phi/kernels/funcs/eigen/common.h"
+#include "paddle/phi/kernels/funcs/math_function.h"
+
+#include "paddle/phi/kernels/funcs/selected_rows_functor.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void AddNArrayKernel(const Context& dev_ctx,
+                     const std::vector<const TensorArray*>& x,
+                     TensorArray* out) {
+  for (auto& ele : *out) {
+    dev_ctx.template Alloc<T>(&ele);
+  }
+  bool in_place = true;
+  if (x.size() > 0 && x[0]->size() == out->size()) {
+    for (size_t i = 0; i < out->size(); i++) {
+      if (x[0]->at(i).IsInitialized() &&
+          out->at(i).data() != x[0]->at(i).data()) {
+        in_place = false;
+        break;
+      }
+    }
+  } else {
+    in_place = false;
+  }
+  for (size_t i = in_place ? 1 : 0; i < x.size(); ++i) {
+    auto* in_array = x.at(i);
+
+    for (size_t j = 0; j < in_array->size(); ++j) {
+      if (in_array->at(j).IsInitialized() && (in_array->at(j).numel() != 0)) {
+        if (j >= out->size()) {
+          out->resize(j + 1);
+        }
+        if (!out->at(j).IsInitialized() || (out->at(j).numel() == 0)) {
+          Copy<Context>(dev_ctx,
+                        in_array->at(j),
+                        in_array->at(j).place(),
+                        false,
+                        &out->at(j));
+          out->at(j).set_lod(in_array->at(j).lod());
+        } else {
+          PADDLE_ENFORCE_EQ(
+              out->at(j).lod(),
+              in_array->at(j).lod(),
+              common::errors::InvalidArgument(
+                  "The lod message between inputs[%d] and"
+                  " outputs[%d] must be same, but now is not same.",
+                  j,
+                  j));
+          auto in = EigenVector<T>::Flatten(in_array->at(j));
+          auto result = EigenVector<T>::Flatten(out->at(j));
+          result.device(*dev_ctx.eigen_device()) = result + in;
+        }
+      }
+    }
+  }
+}
+
+}  // namespace phi