IVGCVSW-3223 Fix ref convolution performance regression

 * Do not use DataLayoutIndexed::GetIndex for weights and inputs,
   as it causes a large regression in performance
 * It turned out that the calculation of the indexes for the weights
   and inputs was the way it was because of an optimization done
   many months ago
 * Reverted the relevant hunks and added some comments so
   we won't make the same mistake again in the future
 * Made the GetIndex function inline to speed up other usages

Change-Id: I343b2ef0446993086f58b9dea1f0de0ba2d92216
Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>

1 files changed, 0 insertions, 37 deletions

diff --git a/src/armnnUtils/DataLayoutIndexed.cpp b/src/armnnUtils/DataLayoutIndexed.cpp
index b02f07ec85..02f1e816ac 100644
--- a/src/armnnUtils/DataLayoutIndexed.cpp
+++ b/src/armnnUtils/DataLayoutIndexed.cpp
@@ -4,9 +4,6 @@
 //
 
 #include "DataLayoutIndexed.hpp"
-
-#include <boost/assert.hpp>
-
 using namespace armnn;
 
 namespace armnnUtils
@@ -33,40 +30,6 @@ DataLayoutIndexed::DataLayoutIndexed(armnn::DataLayout dataLayout)
     }
 }
 
-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();