src/armnn/backends/RefWorkloads/Activation.cpp

   1 //
   2 // Copyright © 2017 Arm Ltd. All rights reserved.
   3 // See LICENSE file in the project root for full license information.
   4 //
   5
   6 #include "Activation.hpp"
   7
   8 #include <boost/log/trivial.hpp>
   9
  10 #include <cmath>
  11
  12 namespace armnn
  13 {
  14
  15 void Activation(const float* in,
  16                float* out,
  17                const TensorInfo& tensorInfo,
  18                ActivationFunction function,
  19                float a,
  20                float b)
  21 {
  22     for (size_t i = 0; i<tensorInfo.GetNumElements(); i++)
  23     {
  24         float input = in[i];
  25         float output;
  26
  27         // Compute the result of the activation function.
  28         switch (function)
  29         {
  30             case ActivationFunction::Linear:
  31             {
  32                 output = a * input + b;
  33                 break;
  34             }
  35             case ActivationFunction::Sigmoid:
  36             {
  37                 output = 1.f / (1.f + expf(-input));
  38                 break;
  39             }
  40             case ActivationFunction::ReLu:
  41             {
  42                 output = std::max(0.f, input);
  43                 break;
  44             }
  45             case ActivationFunction::BoundedReLu:
  46             {
  47                 output = std::min(a, std::max(b, input));
  48                 break;
  49             }
  50             case ActivationFunction::SoftReLu:
  51             {
  52                 output = logf(1.0f + expf(input));
  53                 break;
  54             }
  55             case ActivationFunction::LeakyReLu:
  56             {
  57                 output = input > 0.0f ? input : (input * a);
  58                 break;
  59             }
  60             case ActivationFunction::Abs:
  61             {
  62                 output = input < 0 ? -input : input;
  63                 break;
  64             }
  65             case ActivationFunction::Sqrt:
  66             {
  67                 output = sqrtf(input);
  68                 break;
  69             }
  70             case ActivationFunction::Square:
  71             {
  72                 output = input * input;
  73                 break;
  74             }
  75             case ActivationFunction::TanH:
  76             {
  77                 output = a * tanhf(b * input);
  78                 break;
  79             }
  80             default:
  81             {
  82                 BOOST_LOG_TRIVIAL(error) << "Unsupported activation function";
  83                 return;
  84             }
  85         }
  86
  87         out[i] = output;
  88     }
  89 }
  90
  91 } //namespace armnn