EVOLUTION-MANAGER

Edit File: softsign_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
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==============================================================================*/

#ifndef TENSORFLOW_CORE_KERNELS_SOFTSIGN_OP_H_
#define TENSORFLOW_CORE_KERNELS_SOFTSIGN_OP_H_
// Functor definition for SoftsignOp and SoftsignGradOp, must be compilable by
// nvcc.

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

namespace tensorflow {
namespace functor {

// Functor used by SoftsignOp to do the computations.
template <typename Device, typename T>
struct Softsign {
  // Computes Softsign activation.
  //
  // features: any shape.
  // activations: same shape as "features".
  void operator()(const Device& d, typename TTypes<T>::ConstTensor features,
                  typename TTypes<T>::Tensor activations) {
    activations.device(d) =
        features / (features.abs() + features.constant(T(1)));
  }
};

// Functor used by SoftsignGradOp to do the computations.
template <typename Device, typename T>
struct SoftsignGrad {
  // Computes SoftsignGrad backprops.
  //
  // gradients: gradients backpropagated to the Softsign op.
  // features: inputs that were passed to the Softsign op.
  // backprops: gradients to backpropagate to the Softsign inputs.
  void operator()(const Device& d, typename TTypes<T>::ConstTensor gradients,
                  typename TTypes<T>::ConstTensor features,
                  typename TTypes<T>::Tensor backprops) {
    backprops.device(d) =
        gradients / (features.abs() + features.constant(T(1))).square();
  }
};

}  // namespace functor
}  // namespace tensorflow

#endif  // TENSORFLOW_CORE_KERNELS_SOFTSIGN_OP_H_