EVOLUTION-MANAGER

Edit File: reverse_sequence_op.h

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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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,
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==============================================================================*/

#ifndef TENSORFLOW_CORE_KERNELS_REVERSE_SEQUENCE_OP_H_
#define TENSORFLOW_CORE_KERNELS_REVERSE_SEQUENCE_OP_H_
// Generator definition for ReverseSequenceOp, must be compilable by nvcc.

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

namespace tensorflow {

namespace generator {

template <typename T, typename Tlen, size_t Dims>
class ReverseGenerator {
 public:
  EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE
  ReverseGenerator(typename TTypes<T, Dims>::ConstTensor input, int32 batch_dim,
                   int32 seq_dim, typename TTypes<Tlen>::ConstVec seq_lengths)
      : input_(input),
        batch_dim_(batch_dim),
        seq_dim_(seq_dim),
        seq_lengths_(seq_lengths) {}

EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE T
  operator()(const Eigen::array<Eigen::DenseIndex, Dims>& coords) const {
    Eigen::array<Eigen::DenseIndex, Dims> new_coords = coords;
    if (coords[seq_dim_] < seq_lengths_(coords[batch_dim_])) {
      new_coords[seq_dim_] =
          seq_lengths_(coords[batch_dim_]) - coords[seq_dim_] - 1;
    }

return input_(new_coords);
  }

private:
  typename TTypes<T, Dims>::ConstTensor input_;
  int32 batch_dim_;
  int32 seq_dim_;
  typename TTypes<Tlen>::ConstVec seq_lengths_;
};

}  // namespace generator

namespace functor {

template <typename Device, typename T, typename Tlen, size_t Dims>
struct ReverseSequence {
  EIGEN_ALWAYS_INLINE static void Compute(
      const Device& d, typename TTypes<T, Dims>::ConstTensor input,
      int32 batch_dim, int32 seq_dim,
      typename TTypes<Tlen>::ConstVec seq_lengths,
      typename TTypes<T, Dims>::Tensor output) {
    generator::ReverseGenerator<T, Tlen, Dims> generator(input, batch_dim,
                                                         seq_dim, seq_lengths);
    output.device(d) = input.generate(generator);
  }
};

}  // namespace functor

}  // namespace tensorflow

#endif  // TENSORFLOW_CORE_KERNELS_REVERSE_SEQUENCE_OP_H_