Merge pull request opencv#19330 from l-bat:lb/onnx_mish_subgraph

Author: alalek

modules/dnn/src/onnx/onnx_graph_simplifier.cpp

@@ -314,6 +314,19 @@ class ExpandSubgraph : public Subgraph
     }
 };
 
+class MishSubgraph : public Subgraph
+{
+public:
+    MishSubgraph()
+    {
+        int input = addNodeToMatch("");
+        int softplus = addNodeToMatch("Softplus", input);
+        int tanh = addNodeToMatch("Tanh", softplus);
+        addNodeToMatch("Mul", input, tanh);
+        setFusedNode("Mish", input);
+    }
+};
+
 class MulCastSubgraph : public Subgraph
 {
 public:
@@ -512,6 +525,7 @@ void simplifySubgraphs(opencv_onnx::GraphProto& net)
     subgraphs.push_back(makePtr<BatchNormalizationSubgraph1>());
     subgraphs.push_back(makePtr<BatchNormalizationSubgraph2>());
     subgraphs.push_back(makePtr<ExpandSubgraph>());
+    subgraphs.push_back(makePtr<MishSubgraph>());
 
     simplifySubgraphs(Ptr<ImportGraphWrapper>(new ONNXGraphWrapper(net)), subgraphs);
 }

modules/dnn/test/test_onnx_importer.cpp

@@ -660,6 +660,11 @@ TEST_P(Test_ONNX_layers, ResizeOpset11_Torch1_6)
     testONNXModels("resize_opset11_torch1.6");
 }
 
+TEST_P(Test_ONNX_layers, Mish)
+{
+    testONNXModels("mish");
+}
+
 TEST_P(Test_ONNX_layers, Conv1d)
 {
     testONNXModels("conv1d");