Splitting source files between CUDA and CPU code.

1 files changed, 48 insertions, 0 deletions

diff --git a/src/caffe/layers/tanh_layer.cpp b/src/caffe/layers/tanh_layer.cpp
new file mode 100644
index 00000000..d6f99560
--- /dev/null
+++ b/src/caffe/layers/tanh_layer.cpp
@@ -0,0 +1,48 @@
+// Copyright 2014 Aravindh Mahendran
+// TanH neuron activation function layer.
+// Adapted from ReLU layer code written by Yangqing Jia
+
+#include <algorithm>
+#include <vector>
+
+#include "caffe/layer.hpp"
+#include "caffe/vision_layers.hpp"
+
+namespace caffe {
+
+template <typename Dtype>
+void TanHLayer<Dtype>::Forward_cpu(const vector<Blob<Dtype>*>& bottom,
+    vector<Blob<Dtype>*>* top) {
+  const Dtype* bottom_data = bottom[0]->cpu_data();
+  Dtype* top_data = (*top)[0]->mutable_cpu_data();
+  Dtype exp2x;
+  const int count = bottom[0]->count();
+  for (int i = 0; i < count; ++i) {
+    exp2x = exp(2*bottom_data[i]);
+    top_data[i] = (exp2x - Dtype(1))/(exp2x + Dtype(1));
+  }
+}
+
+template <typename Dtype>
+Dtype TanHLayer<Dtype>::Backward_cpu(const vector<Blob<Dtype>*>& top,
+    const bool propagate_down,
+    vector<Blob<Dtype>*>* bottom) {
+  if (propagate_down) {
+    const Dtype* bottom_data = (*bottom)[0]->cpu_data();
+    const Dtype* top_diff = top[0]->cpu_diff();
+    Dtype* bottom_diff = (*bottom)[0]->mutable_cpu_diff();
+    const int count = (*bottom)[0]->count();
+    Dtype exp2x;
+    Dtype tanhx;
+    for (int i = 0; i < count; ++i) {
+      exp2x = exp(2*bottom_data[i]);
+      tanhx = (exp2x - Dtype(1))/(exp2x + Dtype(1));
+      bottom_diff[i] = top_diff[i] * (1 - tanhx*tanhx);
+    }
+  }
+  return Dtype(0);
+}
+
+INSTANTIATE_CLASS(TanHLayer);
+
+}  // namespace caffe