1 files changed, 36 insertions, 3 deletions

diff --git a/src/armnnUtils/DataLayoutIndexed.hpp b/src/armnnUtils/DataLayoutIndexed.hpp
index 5bb8e0d93f..8bd9701a5e 100644
--- a/src/armnnUtils/DataLayoutIndexed.hpp
+++ b/src/armnnUtils/DataLayoutIndexed.hpp
@@ -8,6 +8,8 @@
 #include <armnn/Types.hpp>
 #include <armnn/Tensor.hpp>
 
+#include <boost/assert.hpp>
+
 namespace armnnUtils
 {
 
@@ -21,9 +23,40 @@ public:
     unsigned int      GetChannelsIndex() const { return m_ChannelsIndex; }
     unsigned int      GetHeightIndex()   const { return m_HeightIndex; }
     unsigned int      GetWidthIndex()    const { return m_WidthIndex; }
-    unsigned int      GetIndex(const armnn::TensorShape& shape,
-                               unsigned int batchIndex, unsigned int channelIndex,
-                               unsigned int heightIndex, unsigned int widthIndex) const;
+
+    inline unsigned int GetIndex(const armnn::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 armnn::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 armnn::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;
+    }
 
 private:
     armnn::DataLayout m_DataLayout;