chore: import upstream snapshot with attribution

paddle/phi/kernels/matmul_kernel.h

@@ -0,0 +1,61 @@
+// Copyright (c) 2021 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/infermeta/binary.h"
+#include "paddle/phi/kernels/empty_kernel.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void MatmulKernel(const Context& dev_ctx,
+                  const DenseTensor& x,
+                  const DenseTensor& y,
+                  bool transpose_x,
+                  bool transpose_y,
+                  DenseTensor* out);
+
+template <typename T, typename Context>
+void MmOutDtypeKernel(const Context& dev_ctx,
+                      const DenseTensor& x,
+                      const DenseTensor& y,
+                      DataType out_dtype,
+                      DenseTensor* out);
+
+// In order to be compatible with `mul` op in fluid,
+// it is no longer used in 2.x API
+template <typename T, typename Context>
+void MatmulWithFlattenKernel(const Context& dev_ctx,
+                             const DenseTensor& x,
+                             const DenseTensor& y,
+                             int x_num_col_dims,
+                             int y_num_col_dims,
+                             DenseTensor* out);
+
+template <typename T, typename Context>
+DenseTensor Matmul(const Context& dev_ctx,
+                   const DenseTensor& x,
+                   const DenseTensor& y,
+                   bool transpose_x = false,
+                   bool transpose_y = false) {
+  DenseTensor dense_out;
+  MetaTensor meta_out(&dense_out);
+  MatmulInferMeta(x, y, transpose_x, transpose_y, &meta_out);
+  MatmulKernel<T, Context>(dev_ctx, x, y, transpose_x, transpose_y, &dense_out);
+  return dense_out;
+}
+
+}  // namespace phi