chore: import upstream snapshot with attribution

paddle/phi/kernels/impl/decayed_adagrad_kernel_impl.h

@@ -0,0 +1,49 @@
+// Copyright (c) 2023 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/decayed_adagrad_kernel.h"
+#include "paddle/phi/kernels/funcs/eigen/common.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void DecayedAdagradDenseKernel(const Context& dev_ctx,
+                               const DenseTensor& param_t,
+                               const DenseTensor& grad_t,
+                               const DenseTensor& moment_t,
+                               const DenseTensor& learning_rate,
+                               float decay,
+                               float epsilon,
+                               DenseTensor* param_out_t,
+                               DenseTensor* moment_out_t) {
+  dev_ctx.template Alloc<T>(param_out_t);
+  dev_ctx.template Alloc<T>(moment_out_t);
+
+  auto param = EigenVector<T>::Flatten(param_t);
+  auto grad = EigenVector<T>::Flatten(grad_t);
+  auto moment = EigenVector<T>::Flatten(moment_t);
+  auto lr = EigenVector<T>::Flatten(learning_rate);
+
+  auto param_out = EigenVector<T>::Flatten(*param_out_t);
+  auto moment_out = EigenVector<T>::Flatten(*moment_out_t);
+  auto& place = *dev_ctx.eigen_device();
+
+  moment_out.device(place) = decay * moment + (1 - decay) * grad * grad;
+  Eigen::DSizes<int, 1> m_dsize(moment_out_t->numel());
+  param_out.device(place) =
+      param - lr.broadcast(m_dsize) * grad / (moment_out.sqrt() + epsilon);
+}
+}  // namespace phi