IVGCVSW-1978: Support NHWC for ResizeBilinear CpuRef

* Adds implementation to plumb DataLayout parameter
  for ResizeBilinear on CpuRef.
* Adds unit tests to execute ResizeBilinear on CpuRef
  using the NHWC data layout.
* Adds DataLayoutIndexed API, allowing easy access to
  the Channels, Height and Width of a tensor based on
  its data layout. This reduces code duplication.
* Refactors original ResizeBilinear implementation and
  tests to use the DataLayoutIndexed API when required.

Change-Id: Ic2b8916cdd2e370d070175547079d774daf6d7bf

2 files changed, 47 insertions, 3 deletions

diff --git a/include/armnn/Descriptors.hpp b/include/armnn/Descriptors.hpp
index c2efa211a6..c0510055f2 100644
--- a/include/armnn/Descriptors.hpp
+++ b/include/armnn/Descriptors.hpp
@@ -313,9 +313,9 @@ struct ResizeBilinearDescriptor
     , m_DataLayout(DataLayout::NCHW)
     {}
 
-    uint32_t   m_TargetWidth;
-    uint32_t   m_TargetHeight;
-    DataLayout m_DataLayout;
+    uint32_t          m_TargetWidth;
+    uint32_t          m_TargetHeight;
+    DataLayoutIndexed m_DataLayout;
 };
 
 struct ReshapeDescriptor
diff --git a/include/armnn/Types.hpp b/include/armnn/Types.hpp
index 4afc50b1b1..bb0b1e6ca7 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -31,12 +31,56 @@ enum class DataType
     Signed32  = 3
 };
 
+// Begin: DataLayout
+
 enum class DataLayout
 {
     NCHW = 1,
     NHWC = 2
 };
 
+// Provides access to the appropriate indexes for Channels, Height and Width based on DataLayout
+class DataLayoutIndexed
+{
+public:
+    DataLayoutIndexed(DataLayout dataLayout) : m_DataLayout(dataLayout)
+    {
+        switch (dataLayout)
+        {
+            case DataLayout::NHWC:
+                m_ChannelsIndex = 3;
+                m_HeightIndex   = 1;
+                m_WidthIndex    = 2;
+                break;
+            case DataLayout::NCHW:
+                m_ChannelsIndex = 1;
+                m_HeightIndex   = 2;
+                m_WidthIndex    = 3;
+                break;
+            default:
+                throw InvalidArgumentException("Unknown DataLayout value: " +
+                                               std::to_string(static_cast<int>(dataLayout)));
+        }
+    }
+
+    DataLayout   GetDataLayout()    const { return m_DataLayout; }
+    unsigned int GetChannelsIndex() const { return m_ChannelsIndex; }
+    unsigned int GetHeightIndex()   const { return m_HeightIndex; }
+    unsigned int GetWidthIndex()    const { return m_WidthIndex; }
+
+private:
+    DataLayout   m_DataLayout;
+    unsigned int m_ChannelsIndex;
+    unsigned int m_HeightIndex;
+    unsigned int m_WidthIndex;
+};
+
+// Conversion methods - implementations in src/armnn/InternalTypes.cpp
+bool operator==(const DataLayout& dataLayout, const DataLayoutIndexed& indexed);
+bool operator==(const DataLayoutIndexed& indexed, const DataLayout& dataLayout);
+
+// End: DataLayout
+
 enum class ActivationFunction
 {
     Sigmoid     = 0,