1 files changed, 36 insertions, 2 deletions
diff --git a/src/armnnUtils/DataLayoutIndexed.cpp b/src/armnnUtils/DataLayoutIndexed.cpp
index db27de4bdd..b02f07ec85 100644
--- a/src/armnnUtils/DataLayoutIndexed.cpp
+++ b/src/armnnUtils/DataLayoutIndexed.cpp
@@ -5,6 +5,8 @@
 
 #include "DataLayoutIndexed.hpp"
 
+#include <boost/assert.hpp>
+
 using namespace armnn;
 
 namespace armnnUtils
@@ -31,13 +33,45 @@ DataLayoutIndexed::DataLayoutIndexed(armnn::DataLayout dataLayout)
     }
 }
 
-// Definition in include/armnn/Types.hpp
+unsigned int DataLayoutIndexed::GetIndex(const TensorShape& shape,
+                                         unsigned int batchIndex, unsigned int channelIndex,
+                                         unsigned int heightIndex, unsigned int widthIndex) const
+{
+    BOOST_ASSERT( batchIndex < shape[0] || ( shape[0] == 0 && batchIndex == 0 ) );
+    BOOST_ASSERT( channelIndex < shape[m_ChannelsIndex] ||
+                ( shape[m_ChannelsIndex] == 0 && channelIndex == 0) );
+    BOOST_ASSERT( heightIndex < shape[m_HeightIndex] ||
+                ( shape[m_HeightIndex] == 0 && heightIndex == 0) );
+    BOOST_ASSERT( widthIndex < shape[m_WidthIndex] ||
+                ( shape[m_WidthIndex] == 0 && widthIndex == 0) );
+
+    // Offset the given indices appropriately depending on the data layout
+    switch (m_DataLayout)
+    {
+    case DataLayout::NHWC:
+        batchIndex  *= shape[1] * shape[2] * shape[3]; // batchIndex *= heightIndex * widthIndex * channelIndex
+        heightIndex *= shape[m_WidthIndex] * shape[m_ChannelsIndex];
+        widthIndex  *= shape[m_ChannelsIndex];
+        // channelIndex stays unchanged
+        break;
+    case DataLayout::NCHW:
+    default:
+        batchIndex   *= shape[1] * shape[2] * shape[3]; // batchIndex *= heightIndex * widthIndex * channelIndex
+        channelIndex *= shape[m_HeightIndex] * shape[m_WidthIndex];
+        heightIndex  *= shape[m_WidthIndex];
+        // widthIndex stays unchanged
+        break;
+    }
+
+    // Get the value using the correct offset
+    return batchIndex + channelIndex + heightIndex + widthIndex;
+}
+
 bool operator==(const DataLayout& dataLayout, const DataLayoutIndexed& indexed)
 {
     return dataLayout == indexed.GetDataLayout();
 }
 
-// Definition in include/armnn/Types.hpp
 bool operator==(const DataLayoutIndexed& indexed, const DataLayout& dataLayout)
 {
     return indexed.GetDataLayout() == dataLayout;