Add LogSoftmax and LogSigmoid support

src/CMakeLists.txt

@@ -162,6 +162,8 @@ ncnn_add_layer(Unfold)
 ncnn_add_layer(GridSample)
 ncnn_add_layer(CumulativeSum)
 ncnn_add_layer(CopyTo)
+ncnn_add_layer(LogSoftmax)
+ncnn_add_layer(LogSigmoid)
 
 if(NCNN_VULKAN)
     ncnn_add_shader(${CMAKE_CURRENT_SOURCE_DIR}/convert_ycbcr.comp)

src/layer/logsigmoid.cpp

@@ -0,0 +1,52 @@
+// Tencent is pleased to support the open source community by making ncnn available.
+//
+// Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
+//
+// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
+// in compliance with the License. You may obtain a copy of the License at
+//
+// https://opensource.org/licenses/BSD-3-Clause
+//
+// 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.
+
+#include "logsigmoid.h"
+
+#include <math.h>
+
+namespace ncnn {
+
+LogSigmoid::LogSigmoid()
+{
+    one_blob_only = true;
+    support_inplace = true;
+}
+
+int LogSigmoid::forward_inplace(Mat& bottom_top_blob, const Option& opt) const
+{
+    int w = bottom_top_blob.w;
+    int h = bottom_top_blob.h;
+    int d = bottom_top_blob.d;
+    int channels = bottom_top_blob.c;
+    int size = w * h * d;
+
+    #pragma omp parallel for num_threads(opt.num_threads)
+    for (int q = 0; q < channels; q++)
+    {
+        float* ptr = bottom_top_blob.channel(q);
+
+        for (int i = 0; i < size; i++)
+        {
+            float v = ptr[i];
+            v = std::min(v, 88.3762626647949f);
+            v = std::max(v, -88.3762626647949f);
+            ptr[i] = -logf(1.f + expf(-v));
+        }
+    }
+
+    return 0;
+}
+
+} // namespace ncnn

src/layer/logsigmoid.h

@@ -0,0 +1,32 @@
+// Tencent is pleased to support the open source community by making ncnn available.
+//
+// Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
+//
+// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
+// in compliance with the License. You may obtain a copy of the License at
+//
+// https://opensource.org/licenses/BSD-3-Clause
+//
+// 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 LAYER_LOGSIGMOID_H
+#define LAYER_LOGSIGMOID_H
+
+#include "layer.h"
+
+namespace ncnn {
+
+class LogSigmoid : public Layer
+{
+public:
+    LogSigmoid();
+
+    virtual int forward_inplace(Mat& bottom_top_blob, const Option& opt) const;
+};
+
+} // namespace ncnn
+
+#endif // LAYER_LOGSIGMOID_H