Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/dnn/test/test_misc.cpp

@@ -469,6 +469,42 @@ INSTANTIATE_TEST_CASE_P(/**/, Async, Combine(
   Values(CV_32F, CV_8U),
   testing::ValuesIn(getAvailableTargets(DNN_BACKEND_INFERENCE_ENGINE))
 ));
+
+typedef testing::TestWithParam<Target>  Test_Model_Optimizer;
+TEST_P(Test_Model_Optimizer, forward_two_nets)
+{
+    const int target = GetParam();
+
+    const std::string suffix = (target == DNN_TARGET_OPENCL_FP16 || target == DNN_TARGET_MYRIAD) ? "_fp16" : "";
+    const std::string& model = findDataFile("dnn/layers/layer_convolution" + suffix + ".bin");
+    const std::string& proto = findDataFile("dnn/layers/layer_convolution" + suffix + ".xml");
+
+    Net net0 = readNet(model, proto);
+    net0.setPreferableTarget(target);
+
+    Net net1 = readNet(model, proto);
+    net1.setPreferableTarget(target);
+
+    // Generate inputs.
+    int blobSize[] = {2, 6, 75, 113};
+    Mat input(4, &blobSize[0], CV_32F);
+    randu(input, 0, 255);
+
+    net0.setInput(input);
+    Mat ref0 = net0.forward().clone();
+
+    net1.setInput(input);
+    Mat ref1 = net1.forward();
+
+    net0.setInput(input);
+    Mat ref2 = net0.forward();
+
+    normAssert(ref0, ref2, 0, 0);
+}
+INSTANTIATE_TEST_CASE_P(/**/, Test_Model_Optimizer,
+  testing::ValuesIn(getAvailableTargets(DNN_BACKEND_INFERENCE_ENGINE))
+);
+
 #endif  // HAVE_INF_ENGINE
 
 }} // namespace