// 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"

namespace phi {

// Using dimensional constraints on matrix multiplication, it is
// straight-forward to check the following table for when X and Y
// are both matrices.
//
// dX = | dOut vec^T
// dVec = | X^T dOut
template <typename T, typename Context>
void MvGradKernel(const Context& ctx,
                  const DenseTensor& x,
                  const DenseTensor& vec,
                  const DenseTensor& out_grad,
                  DenseTensor* x_grad,
                  DenseTensor* vec_grad);

}  // namespace phi
