IVGCVSW-3031 Reparent layer to new graph

Change-Id: Ic4423b8d21d794f44ddae291853e0e3b89d11bc0
Signed-off-by: Derek Lamberti <derek.lamberti@arm.com>

4 files changed, 36 insertions, 9 deletions

diff --git a/src/armnn/Graph.hpp b/src/armnn/Graph.hpp
index 88d2002112..062d727fd1 100644
--- a/src/armnn/Graph.hpp
+++ b/src/armnn/Graph.hpp
@@ -235,18 +235,40 @@ class Graph::LayerInGraphBase : public LayerT
 protected:
     template <typename... Args>
     LayerInGraphBase(Graph& graph, Iterator insertBefore, Args&&... args)
-        : LayerT(std::forward<Args>(args)...), m_Graph(graph)
+        : LayerT(std::forward<Args>(args)...), m_Graph(&graph)
     {
-        m_Graph.m_PosInGraphMap.emplace(this, m_Graph.m_Layers.emplace(insertBefore, this));
+        Insert(*m_Graph, insertBefore);
     }
     ~LayerInGraphBase()
     {
-        const size_t numErased = m_Graph.m_PosInGraphMap.erase(this);
+        Remove(*m_Graph);
+    }
+
+    void Reparent(Graph& destGraph, Iterator insertBefore) override
+    {
+        Insert(destGraph, insertBefore);
+        Remove(*m_Graph);
+        m_Graph->m_Layers.erase(m_Graph->GetPosInGraph(*this));
+
+        m_Graph = &destGraph;
+    }
+
+private:
+    void Insert(Graph& graph, Iterator insertBefore)
+    {
+        graph.m_PosInGraphMap.emplace(this, graph.m_Layers.emplace(insertBefore, this));
+    }
+
+    void Remove(Graph& graph)
+    {
+        const size_t numErased = graph.m_PosInGraphMap.erase(this);
         boost::ignore_unused(numErased);
         BOOST_ASSERT(numErased == 1);
     }
 
-    Graph& m_Graph;
+protected:
+    Graph* m_Graph;
+
 };
 
 /// Input/Output layers specialize this template.
@@ -284,7 +306,7 @@ public:
                                        std::next(graph.begin(), IteratorDifference(graph.GetNumInputs())),
                                        std::forward<Args>(args)...)
     {
-        const bool isNewId = m_Graph.m_InputIds.emplace(GetBindingId()).second;
+        const bool isNewId = m_Graph->m_InputIds.emplace(GetBindingId()).second;
         if (!isNewId)
         {
             throw InvalidArgumentException("A layer already exists with the specified id");
@@ -298,7 +320,7 @@ public:
     }
     ~LayerInGraph() override
     {
-        const size_t numErased = m_Graph.m_InputIds.erase(GetBindingId());
+        const size_t numErased = m_Graph->m_InputIds.erase(GetBindingId());
         boost::ignore_unused(numErased);
         BOOST_ASSERT(numErased == 1);
     }
@@ -316,7 +338,7 @@ public:
                                         graph.end(),
                                         std::forward<Args>(args)...)
     {
-        const bool isNewId = m_Graph.m_OutputIds.emplace(GetBindingId()).second;
+        const bool isNewId = m_Graph->m_OutputIds.emplace(GetBindingId()).second;
         if (!isNewId)
         {
             throw InvalidArgumentException("A layer already exists with the specified id");
@@ -324,7 +346,7 @@ public:
     }
     ~LayerInGraph() override
     {
-        const size_t numErased = m_Graph.m_OutputIds.erase(GetBindingId());
+        const size_t numErased = m_Graph->m_OutputIds.erase(GetBindingId());
         boost::ignore_unused(numErased);
         BOOST_ASSERT(numErased == 1);
     }
diff --git a/src/armnn/Layer.hpp b/src/armnn/Layer.hpp
index 507b37bf95..cbb1771668 100644
--- a/src/armnn/Layer.hpp
+++ b/src/armnn/Layer.hpp
@@ -298,6 +298,7 @@ public:
 
     const std::list<std::string>& GetRelatedLayerNames() { return m_RelatedLayerNames; }
 
+    virtual void Reparent(Graph& dest, std::list<Layer*>::const_iterator iterator) = 0;
 protected:
     // Graph needs access to the virtual destructor.
     friend class Graph;
diff --git a/src/backends/backendsCommon/IBackendInternal.hpp b/src/backends/backendsCommon/IBackendInternal.hpp
index f49a210988..5316f68009 100644
--- a/src/backends/backendsCommon/IBackendInternal.hpp
+++ b/src/backends/backendsCommon/IBackendInternal.hpp
@@ -65,7 +65,7 @@ public:
 
     // Default implementation of OptimizeSubgraphView for backward compatibility with old API.
     // Override this method with a custom optimization implementation.
-    virtual OptimizationViews OptimizeSubgraphView(const SubgraphView& subgraph)
+    virtual OptimizationViews OptimizeSubgraphView(const SubgraphView& subgraph) const
     {
         bool attempted=false;
         SubgraphViewUniquePtr optSubgraph = OptimizeSubgraphView(subgraph, attempted);
diff --git a/src/backends/backendsCommon/OptimizationViews.hpp b/src/backends/backendsCommon/OptimizationViews.hpp
index cf7051d887..e1b59ed633 100644
--- a/src/backends/backendsCommon/OptimizationViews.hpp
+++ b/src/backends/backendsCommon/OptimizationViews.hpp
@@ -45,9 +45,13 @@ public:
     Subgraphs GetUntouchedSubgraphs() const { return m_UntouchedSubgraphs; }
     bool Validate(const SubgraphView& originalSubgraph) const;
 
+    Graph& GetGraph() { return m_Graph; };
+
 private:
     Substitutions m_SuccesfulOptimizations;     ///< Proposed substitutions from successful optimizations
     Subgraphs m_FailedOptimizations;            ///< Subgraphs from the original subgraph which cannot be supported
     Subgraphs m_UntouchedSubgraphs;             ///< Subgraphs from the original subgraph which remain unmodified
+
+    Graph m_Graph;
 };
 } //namespace armnn
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