1 files changed, 111 insertions, 0 deletions
diff --git a/src/armnn/QuantizerVisitor.cpp b/src/armnn/QuantizerVisitor.cpp
new file mode 100644
index 0000000000..7608d0a440
--- /dev/null
+++ b/src/armnn/QuantizerVisitor.cpp
@@ -0,0 +1,111 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "Network.hpp"
+#include "QuantizerVisitor.hpp"
+#include "StaticRangeVisitor.hpp"
+
+#include <cmath>
+#include <stdint.h>
+#include <limits>
+
+namespace armnn
+{
+
+namespace {
+
+std::pair<int, float> ComputeQAsymmParams(int numBits, double min, double max)
+{
+    BOOST_ASSERT_MSG(min < max, "Min >= max will result in invalid quantization.");
+    double highest = (1 << numBits)-1;
+
+    min = std::min(0.0, min); // min <= 0.0
+    max = std::max(0.0, max); // max >= 0.0
+
+    // assumes quantization range [0-highest]
+    double scale = (max-min) / highest;
+    double offset = -min / scale;
+
+    // clamp offset [0-highest]
+    offset = std::max(0.0, std::min(highest, offset));
+
+    return std::make_pair(static_cast<int>(std::round(offset)), static_cast<float>(scale));
+}
+
+} // namespace
+
+QuantizerVisitor::QuantizerVisitor(armnn::StaticRangeVisitor* ranges)
+: m_Ranges(ranges)
+, m_QuantizedNetwork(INetwork::Create())
+{
+}
+
+void QuantizerVisitor::SetQuantizedInputConnections(const IConnectableLayer *srcLayer,
+                                                    IConnectableLayer *quantizedLayer)
+{
+    m_OldToNewGuidMap[srcLayer->GetGuid()] = quantizedLayer->GetGuid();
+
+    for (unsigned int i=0; i < srcLayer->GetNumInputSlots(); i++)
+    {
+        const IInputSlot& srcInputSlot = srcLayer->GetInputSlot(i);
+        const InputSlot* inputSlot = boost::polymorphic_downcast<const InputSlot*>(&srcInputSlot);
+        const OutputSlot* outputSlot = inputSlot->GetConnectedOutputSlot();
+
+        unsigned int slotIdx = outputSlot->CalculateIndexOnOwner();
+        Layer& layerToFind = outputSlot->GetOwningLayer();
+
+        auto found = m_OldToNewGuidMap.find(layerToFind.GetGuid());
+        if (found != m_OldToNewGuidMap.end())
+        {
+            // Connect the slots in the quantized model
+            IConnectableLayer* prevQuantizedLayer = m_GuidToLayerMap[found->second];
+            IInputSlot& newInputSlot = quantizedLayer->GetInputSlot(i);
+            IOutputSlot& newOutputSlot = prevQuantizedLayer->GetOutputSlot(slotIdx);
+            newOutputSlot.Connect(newInputSlot);
+
+            // Fetch the min/max ranges that were computed earlier
+            auto range = m_Ranges->GetRange(layerToFind.GetGuid(), i);
+            auto qParams = ComputeQAsymmParams(8, range.first, range.second);
+
+            // Set the quantization params
+            TensorInfo info(newOutputSlot.GetTensorInfo());
+            info.SetDataType(DataType::QuantisedAsymm8);
+            info.SetQuantizationOffset(qParams.first);
+            info.SetQuantizationScale(qParams.second);
+        }
+        else
+        {
+            // error in graph traversal order
+            BOOST_ASSERT_MSG(false, "Error in graph traversal");
+        }
+    }
+}
+
+void QuantizerVisitor::RecordLayer(IConnectableLayer* layer)
+{
+    m_GuidToLayerMap[layer->GetGuid()] = layer;
+}
+
+void QuantizerVisitor::VisitAdditionLayer(const IConnectableLayer *layer, const char *name)
+{
+    IConnectableLayer* newLayer = m_QuantizedNetwork->AddAdditionLayer(name);
+    RecordLayer(newLayer);
+    SetQuantizedInputConnections(layer, newLayer);
+}
+
+void QuantizerVisitor::VisitInputLayer(const IConnectableLayer *layer, LayerBindingId id, const char *name)
+{
+    IConnectableLayer* newLayer = m_QuantizedNetwork->AddInputLayer(id, name);
+    RecordLayer(newLayer);
+}
+
+void QuantizerVisitor::VisitOutputLayer(const IConnectableLayer *layer, LayerBindingId id, const char *name)
+{
+    IConnectableLayer* newLayer = m_QuantizedNetwork->AddOutputLayer(id, name);
+    RecordLayer(newLayer);
+    SetQuantizedInputConnections(layer, newLayer);
+}
+
+} //namespace armnn
+\ No newline at end of file