chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/mp_allreduce_sum_kernel.cc

@@ -0,0 +1,35 @@
+// Copyright (c) 2024 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/core/kernel_registry.h"
+#include "paddle/phi/kernels/all_reduce_kernel.h"
+
+namespace phi {
+template <typename T, typename Context>
+void MpAllReduceSumKernel(const Context& dev_ctx,
+                          const DenseTensor& x,
+                          DenseTensor* out) {
+  AllReduceKernel<T, Context>(
+      dev_ctx, x, static_cast<int>(ReduceType::kRedSum), out);
+}
+}  // namespace phi
+PD_REGISTER_KERNEL(mp_allreduce_sum,
+                   CPU,
+                   ALL_LAYOUT,
+                   phi::MpAllReduceSumKernel,
+                   float,
+                   double,
+                   int,
+                   int64_t,
+                   phi::float16) {}