added a mapping from onnx outputs to cntk outputs into the graph's description

Source/CNTKv2LibraryDll/proto/onnx/CNTKToONNX.cpp

@@ -158,6 +158,32 @@ private:
             return description;
         }
 
+        //
+        // ONNX model description (of CNTK exported model) is in this format:
+        // <<<ONNXOutputName, CNTKNodeName>>> pair: <<<onnx_name_0, cntk_name_0>>> <<<onnx_name_0, cntk_name_1>>>
+        //
+        static std::string GetModelOutputNamePairDescription()
+        {
+            std::string description = "<<<ONNXOutputName, CNTKNodeName>>> pair: ";
+            bool first = true;
+            for (auto iter = outputUidNameMap.begin(); iter != outputUidNameMap.end(); ++iter)
+            {
+                std::string cntk_name = iter->second;
+                if (cntk_name == "")
+                    continue;
+                auto uid_iter = uidNodeNameMap.find(iter->first);
+                if (uid_iter != uidNodeNameMap.end())
+                {
+                    if (first)
+                        description += " ";
+                    else
+                        first = false;
+                    description += ("<<<" + uid_iter->second + ", " + cntk_name + ">>>");
+                }
+            }
+            return description;
+        }
+
         //
         // Generate unique name based on nodeName, opName and uid.
         //
@@ -1250,9 +1276,10 @@ void CNTKToONNXHelper::Copy(const FunctionPtr& src, onnxruntime::Graph* dst)
     PostProcessGraph(dst);
 
     //
-    // Save (Uid, ONNXNodeName) pair for all nodes to graph description.
+    // Save (Uid, ONNXNodeName) pair and (ONNXOutputName, CNTKNodeName) pair for all nodes to graph description.
     //
-    dst->SetDescription(UniqueNodeNameStorage::GetUidNodeNamePairDescription());
+    dst->SetDescription(UniqueNodeNameStorage::GetUidNodeNamePairDescription() + "\n" +
+                        UniqueNodeNameStorage::GetModelOutputNamePairDescription());
 }
 
 void CNTKToONNXHelper::HandleRootCombineOp(const FunctionPtr& src, onnxruntime::Graph* dst)
@@ -9147,4 +9174,4 @@ std::unordered_map<std::string, std::string> CNTKToONNXHelper::UniqueNodeNameSto
 std::unordered_set<std::string> CNTKToONNXHelper::UniqueNodeNameStorage::nodeNameSet;
 std::unordered_map<Variable, Variable> CNTKToONNXHelper::UniqueNodeNameStorage::compositeOutputsMap;
 std::unordered_map<Variable, Variable> CNTKToONNXHelper::compositeOutputsMap;
-std::unordered_set<CNTKToONNXHelper::PostProcessFlag, CNTKToONNXHelper::PostProcessFlagHash> CNTKToONNXHelper::postProcessFlags;
+std::unordered_set<CNTKToONNXHelper::PostProcessFlag, CNTKToONNXHelper::PostProcessFlagHash> CNTKToONNXHelper::postProcessFlags;