src/armnn/NetworkUtils.cpp

//
// Copyright © 2017 Arm Ltd. All rights reserved.
// SPDX-License-Identifier: MIT
//

#include "NetworkUtils.hpp"

#include "SubgraphViewSelector.hpp"

#include <armnn/Exceptions.hpp>
#include <armnn/BackendRegistry.hpp>

namespace armnn
{

std::vector<ConvertFp16ToFp32Layer*> InsertConvertFp16ToFp32LayersBefore(Graph& graph, Layer& layer)
{
    std::vector<ConvertFp16ToFp32Layer*> convertLayers;
    convertLayers.reserve(layer.GetNumInputSlots());

    for (auto&& inputSlot = layer.BeginInputSlots(); inputSlot != layer.EndInputSlots(); ++inputSlot)
    {
        // Insert FP16 to FP32 converter layer before the layer
        const std::string name =
            std::string("convert_fp16_to_fp32-" + std::to_string(inputSlot->GetSlotIndex()) + "-") + layer.GetName();
        ConvertFp16ToFp32Layer* convertLayer =
            graph.InsertNewLayer<ConvertFp16ToFp32Layer>(*inputSlot, name.c_str());

        // Sets output tensor info for the convert layer
        TensorInfo convertInfo = convertLayer->GetInputSlot(0).GetConnectedOutputSlot()->GetTensorInfo();
        convertInfo.SetDataType(DataType::Float32);

        convertLayer->GetOutputSlot().SetTensorInfo(convertInfo);

        convertLayers.emplace_back(convertLayer);
    }

    // Sets the output tensor info for the unsupported layer
    auto UpdateTensorInfo = [](auto& outputSlot)
    {
        // Copy original tensor info and change data type to FP32
        TensorInfo newTensorInfo = outputSlot.GetTensorInfo();
        newTensorInfo.SetDataType(DataType::Float32);

        outputSlot.SetTensorInfo(newTensorInfo);
    };

    std::for_each(layer.BeginOutputSlots(), layer.EndOutputSlots(), UpdateTensorInfo);

    return convertLayers;
}

std::vector<ConvertFp32ToFp16Layer*> InsertConvertFp32ToFp16LayersAfter(Graph& graph, Layer& layer)
{
    std::vector<ConvertFp32ToFp16Layer*> convertLayers;
    convertLayers.reserve(layer.GetNumOutputSlots());

    int index = 0;
    // Change outputs to DataType::Float16
    for (auto&& outputSlot = layer.BeginOutputSlots(); outputSlot != layer.EndOutputSlots(); ++outputSlot)
    {
        BOOST_ASSERT(outputSlot->GetTensorInfo().GetDataType() == DataType::Float32);

        // Insert FP32 to FP16 converter layer after the layer
        const std::string name =
            std::string("convert_fp32_to_fp16-" + std::to_string(index++) + "-") + layer.GetName();
        ConvertFp32ToFp16Layer* convertLayer =
            graph.InsertNewLayer<ConvertFp32ToFp16Layer>(*outputSlot, name.c_str());

        // Sets output tensor info for the convert layer.
        TensorInfo convertInfo = convertLayer->GetInputSlot(0).GetConnectedOutputSlot()->GetTensorInfo();
        convertInfo.SetDataType(DataType::Float16);

        convertLayer->GetOutputSlot().SetTensorInfo(convertInfo);

        convertLayers.emplace_back(convertLayer);
    }

    return convertLayers;
}

std::vector<DebugLayer*> InsertDebugLayerAfter(Graph& graph, Layer& layer)
{
    std::vector<DebugLayer*> debugLayers;
    debugLayers.reserve(layer.GetNumOutputSlots());

    // Connect a DebugLayer to each output slot of the layer
    for (auto outputSlot = layer.BeginOutputSlots(); outputSlot != layer.EndOutputSlots(); ++outputSlot)
    {
        const std::string debugName = std::string("DebugLayerAfter") + layer.GetNameStr();

        DebugLayer* debugLayer =
            graph.InsertNewLayer<DebugLayer>(*outputSlot, debugName.c_str());

        // Sets output tensor info for the debug layer.
        BOOST_ASSERT(debugLayer->GetInputSlot(0).GetConnectedOutputSlot() == &(*outputSlot));
        TensorInfo debugInfo = debugLayer->GetInputSlot(0).GetConnectedOutputSlot()->GetTensorInfo();

        debugLayer->GetOutputSlot().SetTensorInfo(debugInfo);

        // NOTE: It is OK to do this because DebugLayer is only supported on CpuRef
        debugLayer->SetBackendId(Compute::CpuRef);

        debugLayers.emplace_back(debugLayer);
    }

    return debugLayers;
}

} // namespace armnn