dnn/Vulkan: support log softmax

Signed-off-by: Wu Zhiwen <zhiwen.wu@intel.com>

modules/dnn/src/vkcom/shader/softmax.comp

@@ -18,6 +18,7 @@ layout(push_constant) uniform pushBlock {
     int channel_size;
     int outer_size;
     int channels;
+    int logsoftmax;
 } p;
 layout(local_size_x = LOCAL_SZ_X, local_size_y = 1, local_size_z = 1) in;
 
@@ -68,9 +69,8 @@ void main()
         for (int i = 0; i < p.channel_size; ++i)
         {
             float v = output_buffer[index] / sum_buffer[reduced_buffer_off + i];
-#ifdef LOG_SOFTMAX
-            v = log(v);
-#endif
+            if (p.logsoftmax == 1)
+                v = log(v);
             output_buffer[index] = v;
             index++;
         }

modules/dnn/src/vkcom/shader/spv_shader.hpp

@@ -16,7 +16,7 @@ extern const unsigned int permute_spv[765];
 extern const unsigned int lrn_spv[1845];
 extern const unsigned int concat_spv[541];
 extern const unsigned int avg_pool_spv[1538];
-extern const unsigned int softmax_spv[1440];
+extern const unsigned int softmax_spv[1496];
 extern const unsigned int prior_box_spv[1480];
 extern const unsigned int max_pool_spv[1449];
 extern const unsigned int relu_spv[502];

modules/dnn/src/vkcom/src/op_softmax.cpp

@@ -22,6 +22,7 @@ struct SoftmaxParam {
     int channel_size;
     int outer_size;
     int channels;
+    int logsoftmax;
 };
 
 OpSoftmax::OpSoftmax(const int axis, const bool log_softmax)
@@ -90,7 +91,7 @@ bool OpSoftmax::forward(Tensor& in, Tensor& out)
     bindTensor(device_, *max_tensor_,  1, descriptor_set_);
     bindTensor(device_, *sum_tensor_,  2, descriptor_set_);
     bindTensor(device_, out, 3, descriptor_set_);
-    SoftmaxParam param = {channel_size_, outer_size_, channels_};
+    SoftmaxParam param = {channel_size_, outer_size_, channels_, log_softmax_ == true ? 1 : 0};
     recordCommandBuffer((void *)&param, sizeof(SoftmaxParam));
     runCommandBuffer();
     return true;