chore: import upstream snapshot with attribution

paddle/phi/kernels/impl/mv_kernel_impl.h

@@ -0,0 +1,53 @@
+// 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/full_kernel.h"
+#include "paddle/phi/kernels/funcs/blas/blas.h"
+namespace phi {
+
+template <typename T, typename Context>
+void MvKernel(const Context& dev_ctx,
+              const DenseTensor& x,
+              const DenseTensor& vec,
+              DenseTensor* out) {
+  const auto& dim_x = x.dims();
+
+  // get data ptr
+  const T* x_data = x.data<T>();
+  const T* vec_data = vec.data<T>();
+  T* out_data = dev_ctx.template Alloc<T>(out);
+  if (out && out->numel() == 0) {
+    return;
+  }
+  // x.shape [10, 0], vec.shape [0], out.shape [10]
+  if (vec.numel() == 0) {
+    Full<T, Context>(dev_ctx, out->dims(), static_cast<T>(0), out);
+    return;
+  }
+
+  auto blas = funcs::GetBlas<Context, T>(dev_ctx);
+
+  blas.GEMV(false,
+            dim_x[0],
+            dim_x[1],
+            static_cast<T>(1),
+            x_data,
+            vec_data,
+            static_cast<T>(0),
+            out_data);
+}
+
+}  // namespace phi