1 files changed, 115 insertions, 0 deletions
diff --git a/src/backends/reference/workloads/Stack.cpp b/src/backends/reference/workloads/Stack.cpp
new file mode 100644
index 0000000000..386c8992eb
--- /dev/null
+++ b/src/backends/reference/workloads/Stack.cpp
@@ -0,0 +1,115 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "Stack.hpp"
+#include "RefWorkloadUtils.hpp"
+
+namespace armnn
+{
+
+void Stack(const StackQueueDescriptor& data,
+           std::vector<std::unique_ptr<Decoder<float>>>& inputs,
+           Encoder<float>& output)
+{
+    const TensorInfo& outputInfo = GetTensorInfo(data.m_Outputs[0]);
+    const TensorInfo& inputInfo = GetTensorInfo(data.m_Inputs[0]);
+
+    unsigned int outputNumDims = outputInfo.GetNumDimensions();
+    unsigned int inputNumDims = inputInfo.GetNumDimensions();
+
+    const armnn::TensorShape& outputDims = outputInfo.GetShape();
+    const armnn::TensorShape& inputDims = inputInfo.GetShape();
+
+    unsigned int axis = data.m_Parameters.m_Axis;
+
+    // Initialise output data
+    unsigned int numOutputElements = 1;
+    for (unsigned int i=0; i<outputNumDims; ++i)
+    {
+        numOutputElements *= outputDims[i];
+    }
+
+    const unsigned int iNumTensors = static_cast<unsigned int>(data.m_Inputs.size());
+    const unsigned int iBatchSize  = inputDims[0];
+    const unsigned int iChannels   = (inputNumDims > 1) ? inputDims[1] : 1;
+    const unsigned int iHeight     = (inputNumDims > 2) ? inputDims[2] : 1;
+    const unsigned int iWidth      = (inputNumDims > 3) ? inputDims[3] : 1;
+
+    const unsigned int oBatchSize  = outputDims[1];
+    const unsigned int oChannels   = (outputNumDims > 2) ? outputDims[2] : 1;
+    const unsigned int oHeight     = (outputNumDims > 3) ? outputDims[3] : 1;
+    const unsigned int oWidth      = (outputNumDims > 4) ? outputDims[4] : 1;
+
+    // Array to store the input coordinates
+    // iCoordinates[0] = i, iCoordinates[1] = bi, iCoordinates[2] = ci
+    // iCoordinates[3] = hi, iCoordinates[4] = wi, iCoordinates[5] = 0
+    // iCoordinates[5] will be always zero and used for not incrementing
+    // the output when the input has less than 4 dimensions
+    std::array<unsigned int, 6> iCoordinates{ 0 };
+
+    // Array of pointers used to map the output coordinates to the input ones, in accordance with the axis
+    // This array is initialized with &iCoordinates[5] since this will be always zero
+    std::array<unsigned int *, 5> oCoordinates = { &iCoordinates[5],
+                                                   &iCoordinates[5],
+                                                   &iCoordinates[5],
+                                                   &iCoordinates[5],
+                                                   &iCoordinates[5] };
+
+    // Set the axis coordinate
+    oCoordinates[axis] = &iCoordinates[0];
+
+    // Map the output coordinates, accounting for the axis
+    unsigned int dim_shift = 0;
+    for(unsigned int dim = 0; dim < inputNumDims; ++dim)
+    {
+        if(dim == axis)
+        {
+            dim_shift++;
+        }
+        oCoordinates[dim + dim_shift] = &iCoordinates[dim + 1];
+    }
+
+    // Alias for the input coordinates
+    unsigned int &i  = iCoordinates[0];
+    unsigned int &bi = iCoordinates[1];
+    unsigned int &ci = iCoordinates[2];
+    unsigned int &hi = iCoordinates[3];
+    unsigned int &wi = iCoordinates[4];
+
+    // Alias for the output coordinates
+    unsigned int &o  = *(oCoordinates[0]);
+    unsigned int &bo = *(oCoordinates[1]);
+    unsigned int &co = *(oCoordinates[2]);
+    unsigned int &ho = *(oCoordinates[3]);
+    unsigned int &wo = *(oCoordinates[4]);
+
+    // Stack tensors
+    for(; i < iNumTensors; ++(i))
+    {
+        for(bi = 0; bi < iBatchSize; ++(bi))
+        {
+            for(ci = 0; ci < iChannels; ++(ci))
+            {
+                for(hi = 0; hi < iHeight; ++(hi))
+                {
+                    for(wi = 0; wi < iWidth; ++(wi))
+                    {
+                        output[o  * oWidth * oHeight * oChannels * oBatchSize +
+                               bo * oWidth * oHeight * oChannels +
+                               co * oWidth * oHeight +
+                               ho * oWidth +
+                               wo];
+
+                        output.Set(inputs[i]->Get());
+
+                        ++(*(inputs[i]));
+                    }
+                }
+            }
+        }
+    }
+}
+
+} // namespace armnn