1 files changed, 84 insertions, 0 deletions
diff --git a/src/backends/aclCommon/ArmComputeSubgraphUtils.hpp b/src/backends/aclCommon/ArmComputeSubgraphUtils.hpp
index a0fca46330..521c17cd62 100644
--- a/src/backends/aclCommon/ArmComputeSubgraphUtils.hpp
+++ b/src/backends/aclCommon/ArmComputeSubgraphUtils.hpp
@@ -6,6 +6,9 @@
 #pragma once
 
 #include <armnn/backends/OptimizationViews.hpp>
+#include <armnn/utility/Assert.hpp>
+
+#include <aclCommon/ArmComputeUtils.hpp>
 
 namespace armnn
 {
@@ -147,4 +150,85 @@ LayerType* FuseLayerWithWeightsAndBiases(OptimizationViews& optimizationViews,
     return replacementLayer;
 }
 
+//
+// If reduce layer has multiple axes, add new layer for each axis to simulate the same behaviour
+// as currently only one axis is supported.
+//
+template<typename LayerType>
+std::vector<Layer*> ChainReduceLayers(OptimizationViews& optimizationViews,
+                                      LayerType* baseLayer,
+                                      ReduceDescriptor& desc)
+{
+    // Vector of new chained layers, used for substitution.
+    std::vector<Layer*> layers;
+
+    // Vector of axes so each layer is reshaped correctly.
+    std::vector<uint32_t> axes;
+    unsigned int recalulatedAxis = 0;
+
+    for (unsigned int i = 0; i != desc.m_vAxis.size(); ++i)
+    {
+        // Get TensorInfo from base layer and reduce shape using axis.
+        TensorInfo layerInfo = baseLayer->GetInputSlot(0).GetConnectedOutputSlot()->GetTensorInfo();
+
+        axes.emplace_back(desc.m_vAxis[i]);
+
+        const TensorInfo& reducedTensorInfo = ComputeReductionTensorShape(layerInfo,
+                                                                          axes,
+                                                                          desc.m_KeepDims);
+
+        // Create a vector for the single axis to be assigned to the descriptor.
+        // Update axis if keepDims is set reduce layers correctly.
+        std::vector<uint32_t> singleAxis(1, desc.m_vAxis[i] - recalulatedAxis);
+
+        // Create a descriptor and assign single axis.
+        ReduceDescriptor newReduceDescriptor = baseLayer->GetParameters();
+        newReduceDescriptor.m_vAxis.assign(singleAxis.begin(), singleAxis.end());
+
+        // Add new layer to graph.
+        std::string layerName = "reduce_layer_" + std::to_string(i);
+        Layer* replacementLayer = optimizationViews.GetGraph().AddLayer<LayerType>(newReduceDescriptor,
+                                                                                   layerName.c_str());
+        // Connect previous layer with new layer.
+        // The first and last layer will be connected when the subgraph is replaced.
+        if (!layers.empty())
+        {
+            layers[i - 1]->GetOutputSlot(0).Connect(replacementLayer->GetInputSlot(0));
+        }
+
+        // Set updated tensorInfo for new layer.
+        replacementLayer->GetOutputSlot(0).SetTensorInfo(reducedTensorInfo);
+
+        if (!desc.m_KeepDims)
+        {
+            recalulatedAxis++;
+        }
+
+        layers.emplace_back(replacementLayer);
+    }
+
+    // Check if the TensorInfo from the last layer equals the inferred output from the original layer.
+    ARMNN_ASSERT(baseLayer->GetOutputSlot(0).GetTensorInfo() == layers.back()->GetOutputSlot().GetTensorInfo());
+
+    return layers;
+}
+
+//
+// Substitute baseLayer with new subgraph
+//
+template<typename LayerType>
+void ReplaceLayers(OptimizationViews& optimizationViews,
+                   LayerType* baseLayer,
+                   std::vector<Layer*>& layers)
+{
+    std::list<Layer*> replacementLayers(layers.begin(), layers.end());
+
+    SubgraphView substitutionSubgraph(baseLayer);
+    SubgraphView replacementSubgraph(CreateInputsFrom({replacementLayers.front()}),
+                                     CreateOutputsFrom({replacementLayers.back()}),
+                                     std::move(replacementLayers));
+
+    optimizationViews.AddSubstitution({substitutionSubgraph, replacementSubgraph});
+}
+
 } // namespace armnn