/* Copyright 2015 Google Inc. 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.
==============================================================================*/

#ifndef TENSORFLOW_KERNELS_MATMUL_OP_H_
#define TENSORFLOW_KERNELS_MATMUL_OP_H_

#include "third_party/eigen3/unsupported/Eigen/CXX11/Tensor"
#include "tensorflow/core/framework/tensor_types.h"

namespace tensorflow {
namespace functor {

// Helpers to define tensor<T> needed by MatMul op.
template <typename T>
struct MatMulTypes {
  typedef Eigen::TensorMap<Eigen::Tensor<T, 2, Eigen::RowMajor>, Eigen::Aligned>
      out_type;
  typedef Eigen::TensorMap<Eigen::Tensor<const T, 2, Eigen::RowMajor>,
                           Eigen::Aligned> in_type;
};

template <typename Device, typename In0, typename In1, typename Out,
          typename DimPair>
void MatMul(const Device& d, Out out, In0 in0, In1 in1,
            const DimPair& dim_pair) {
  out.device(d) = in0.contract(in1, dim_pair);
}

template <typename Device, typename T>
struct MatMulFunctor {
  // Computes on device "d": out = in0 * in1, where * is matrix
  // multiplication.
  void operator()(
      const Device& d, typename MatMulTypes<T>::out_type out,
      typename MatMulTypes<T>::in_type in0,
      typename MatMulTypes<T>::in_type in1,
      const Eigen::array<Eigen::IndexPair<Eigen::DenseIndex>, 1>& dim_pair);
};

}  // end namespace functor
}  // end namespace tensorflow

#endif  // TENSORFLOW_KERNELS_MATMUL_OP_H_
