IVGCVSW-1898 : Ref backend folder structure

* Reference backend is renamed to backends/reference as per
  https://confluence.arm.com/display/MLENG/Pluggable+backends

Change-Id: I27a13c274eb60995dfb459e3c49c0e2f60bcd32c

1 files changed, 82 insertions, 0 deletions

diff --git a/src/backends/reference/workloads/Merger.hpp b/src/backends/reference/workloads/Merger.hpp
new file mode 100644
index 0000000000..867925faa2
--- /dev/null
+++ b/src/backends/reference/workloads/Merger.hpp
@@ -0,0 +1,82 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include "RefWorkloadUtils.hpp"
+
+#include "backends/WorkloadData.hpp"
+
+#include <armnn/Tensor.hpp>
+
+namespace armnn
+{
+
+template <typename DataType>
+void Merger(const MergerQueueDescriptor& data)
+{
+    const TensorInfo& outputInfo0 = GetTensorInfo(data.m_Outputs[0]);
+
+    for (unsigned int index = 0 ; index < outputInfo0.GetNumElements(); ++index)
+    {
+        unsigned int indices[MaxNumOfTensorDimensions] = { 0 };
+
+        unsigned int indexRemainder = index;
+        unsigned int dimensionStride = outputInfo0.GetNumElements();
+
+        for (unsigned int i=0; i<outputInfo0.GetNumDimensions(); i++)
+        {
+            dimensionStride /= outputInfo0.GetShape()[i];
+            indices[i] = indexRemainder / dimensionStride; // Use integer division to round down.
+            indexRemainder -= indices[i] * dimensionStride;
+        }
+
+        for (unsigned int viewIdx = 0; viewIdx < data.m_ViewOrigins.size(); ++viewIdx)
+        {
+            MergerQueueDescriptor::ViewOrigin const& view = data.m_ViewOrigins[viewIdx];
+
+            //Split view extents are defined by the size of (the corresponding) input tensor.
+            const TensorInfo& inputInfo = GetTensorInfo(data.m_Inputs[viewIdx]);
+            BOOST_ASSERT(inputInfo.GetNumDimensions() == outputInfo0.GetNumDimensions());
+
+            // Check all dimensions to see if this element is inside the given input view.
+            bool insideView = true;
+            for (unsigned int i=0; i<inputInfo.GetNumDimensions(); i++)
+            {
+                if (indices[i] < view.m_Origin[i])
+                {
+                    insideView = false;
+                }
+                if (indices[i] >= view.m_Origin[i] + inputInfo.GetShape()[i])
+                {
+                    insideView = false;
+                }
+            }
+
+            if (insideView)
+            {
+                unsigned int inIndex = 0;
+                unsigned int dimensionStride = 1;
+
+                for (unsigned int i = inputInfo.GetNumDimensions(); i-- > 0;)
+                {
+                    inIndex += dimensionStride * (indices[i] - view.m_Origin[i]);
+                    dimensionStride *= inputInfo.GetShape()[i];
+                }
+
+                //We are within the view, copy input data to the output corresponding to this view.
+                (GetOutputTensorData<DataType>(0, data))[index] =
+                    (GetInputTensorData<DataType>(viewIdx, data))[inIndex];
+
+                //What should we do if input views overlap on the output tensor?
+                //We could error, take the average, or shm else...
+                //For now just stop after finding first view (input) that matches.
+                break;
+            }
+        }
+    }
+}
+
+} //namespace armnn