IVGCVSW-3030 Refactor code and fix OptimizeSubgraphView

 * Refactored the Optimizer code for readibility, in view of
   upcoming changes
 * Rename one of the ISubgraphViewConverter interface methods to
   give it a more meaningful name
 * Improved the OptimizationViews class, added comments and
   useful funtion overloads
 * Fixed an error in the default implementationof the new
   OptimizeSubgraphView method in IBackendInternal

Change-Id: I683a56d562aa093bac06f0e83fb13e144ed81485
Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/src/backends/backendsCommon/OptimizationViews.hpp b/src/backends/backendsCommon/OptimizationViews.hpp
index 14296f0704..e96c11aaba 100644
--- a/src/backends/backendsCommon/OptimizationViews.hpp
+++ b/src/backends/backendsCommon/OptimizationViews.hpp
@@ -8,6 +8,7 @@
 
 namespace armnn
 {
+
 class OptimizationViews
 {
 public:
@@ -44,18 +45,25 @@ public:
         m_UntouchedSubgraphs.emplace_back(subgraph);
     }
 
-    Substitutions GetSubstitutions() const { return m_SuccesfulOptimizations; }
-    Subgraphs GetFailedSubgraphs() const { return m_FailedOptimizations; }
-    Subgraphs GetUntouchedSubgraphs() const { return m_UntouchedSubgraphs; }
+    const Substitutions& GetSubstitutions() const { return m_SuccesfulOptimizations; }
+    const Subgraphs& GetFailedSubgraphs() const { return m_FailedOptimizations; }
+    const Subgraphs& GetUntouchedSubgraphs() const { return m_UntouchedSubgraphs; }
+
+    Substitutions& GetSubstitutions() { return m_SuccesfulOptimizations; }
+    Subgraphs& GetFailedSubgraphs() { return m_FailedOptimizations; }
+    Subgraphs& GetUntouchedSubgraphs() { return m_UntouchedSubgraphs; }
+
     bool Validate(const SubgraphView& originalSubgraph) const;
 
-    Graph& GetGraph() { return m_Graph; };
+    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 object used only as a container for any layer generated by the optimization process
     Graph m_Graph;
 };
+
 } //namespace armnn