chore: import upstream snapshot with attribution

paddle/phi/kernels/impl/meshgrid_kernel_impl.h

@@ -0,0 +1,112 @@
+// 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/core/dense_tensor.h"
+#include "paddle/phi/core/tensor_utils.h"
+#include "paddle/phi/kernels/funcs/eigen/common.h"
+#include "paddle/phi/kernels/funcs/eigen/eigen_function.h"
+#include "paddle/phi/kernels/meshgrid_kernel.h"
+
+namespace phi {
+
+template <typename T, typename Context, int Rank>
+void MeshgridForward(const Context& dev_ctx,
+                     const std::vector<const DenseTensor*>& ins,
+                     std::vector<DenseTensor*> outs) {
+  PADDLE_ENFORCE_GT(
+      ins.size(),
+      0,
+      common::errors::InvalidArgument(
+          "Expected at least 1 input tensors, but only received %d.",
+          ins.size()));
+
+  int64_t size = ins.size();
+  std::vector<int64_t> shape(size);
+
+  for (int64_t i = 0; i < size; i++) {
+    switch (ins[i]->dims().size()) {
+      case 0:
+        shape[i] = 1;
+        break;
+      case 1:
+        shape[i] = ins[i]->dims()[0];
+        break;
+      default:
+        PADDLE_THROW(common::errors::InvalidArgument(
+            "Expected scalar or 1D tensor in the tensor list but got tensor "
+            "%d: ",
+            i));
+    }
+  }
+
+  for (int64_t i = 0; i < size; i++) {
+    std::vector<int64_t> view_shape(size, 1);
+    view_shape[i] = shape[i];
+
+    DenseTensor reshape_ins_tensor;
+    Copy(dev_ctx, *ins[i], dev_ctx.GetPlace(), false, &reshape_ins_tensor);
+    DDim out_dims_reshape = make_ddim(view_shape);
+    reshape_ins_tensor.Resize(out_dims_reshape);
+    DDim out_dims = make_ddim(shape);
+
+    Eigen::DSizes<int64_t, Rank> bcast_dims;
+    for (int64_t j = 0; j < size; j++) {
+      bcast_dims[j] = shape[j];
+    }
+    bcast_dims[i] = 1;
+
+    outs[i]->Resize(out_dims);
+    auto x = EigenTensor<T, Rank>::From(
+        static_cast<const DenseTensor>(reshape_ins_tensor));
+    dev_ctx.template Alloc<T>(outs[i]);
+    auto y = EigenTensor<T, Rank>::From(*outs[i]);
+    auto& place = *dev_ctx.eigen_device();
+    funcs::EigenBroadcast<std::decay_t<decltype(place)>, T, Rank>::Eval(
+        place, y, x, bcast_dims);
+  }
+}
+
+template <typename T, typename Context>
+void MeshgridKernel(const Context& dev_ctx,
+                    const std::vector<const DenseTensor*>& inputs,
+                    std::vector<DenseTensor*> outputs) {
+  int rank = inputs.size();
+  switch (rank) {
+    case 1:
+      MeshgridForward<T, Context, 1>(dev_ctx, inputs, outputs);
+      break;
+    case 2:
+      MeshgridForward<T, Context, 2>(dev_ctx, inputs, outputs);
+      break;
+    case 3:
+      MeshgridForward<T, Context, 3>(dev_ctx, inputs, outputs);
+      break;
+    case 4:
+      MeshgridForward<T, Context, 4>(dev_ctx, inputs, outputs);
+      break;
+    case 5:
+      MeshgridForward<T, Context, 5>(dev_ctx, inputs, outputs);
+      break;
+    case 6:
+      MeshgridForward<T, Context, 6>(dev_ctx, inputs, outputs);
+      break;
+    default:
+      PADDLE_THROW(common::errors::InvalidArgument(
+          "Excepted Tensor numbers between 1 and 6, but only received %d .",
+          rank));
+  }
+}
+}  // namespace phi