DynamicSample.cpp

This is simple example that shows how to use a dynamic backend. Dynamic Backends can be compiled as standalone against Arm NN and can be loaded by Arm NN dynamically at runtime. This way you can quickly integrate new backends without having to worry or recompile Arm NN.

This example makes use of a very simplistic dynamic backend called 'SampleDynamic'. There is a guide that tells you more about dynamic backends and how this particular backend was created so you can create a dynamic backend yourself Dynamically loadable Backend.

//
// Copyright © 2020 Arm Ltd. All rights reserved.
// SPDX-License-Identifier: MIT
//
#include <armnn/INetwork.hpp>
#include <armnn/IRuntime.hpp>
#include <armnn/Utils.hpp>
#include <armnn/Descriptors.hpp>

#include <iostream>

/// A simple example of using the ArmNN SDK API with the standalone sample dynamic backend.
/// In this example, an addition layer is used to add 2 input tensors to produce a result output tensor.
int main()
{
    using namespace armnn;

    // Construct ArmNN network
    armnn::NetworkId networkIdentifier;
    INetworkPtr myNetwork = INetwork::Create();

    IConnectableLayer* input0 = myNetwork->AddInputLayer(0);
    IConnectableLayer* input1 = myNetwork->AddInputLayer(1);
    IConnectableLayer* add    = myNetwork->AddAdditionLayer();
    IConnectableLayer* output = myNetwork->AddOutputLayer(0);

    input0->GetOutputSlot(0).Connect(add->GetInputSlot(0));
    input1->GetOutputSlot(0).Connect(add->GetInputSlot(1));
    add->GetOutputSlot(0).Connect(output->GetInputSlot(0));

    TensorInfo tensorInfo(TensorShape({2, 1}), DataType::Float32);
    input0->GetOutputSlot(0).SetTensorInfo(tensorInfo);
    input1->GetOutputSlot(0).SetTensorInfo(tensorInfo);
    add->GetOutputSlot(0).SetTensorInfo(tensorInfo);

    // Create ArmNN runtime
    IRuntime::CreationOptions options; // default options
    armnn::IRuntimePtr run(armnn::IRuntime::Create(options));

    // Optimise ArmNN network
    armnn::IOptimizedNetworkPtr optNet = Optimize(*myNetwork, {"SampleDynamic"}, run->GetDeviceSpec());
    if (!optNet)
    {
        // This shouldn't happen for this simple sample, with reference backend.
        // But in general usage Optimize could fail if the hardware at runtime cannot
        // support the model that has been provided.
        std::cerr << "Error: Failed to optimise the input network." << std::endl;
        return 1;
    }

    // Load graph into runtime
    run->LoadNetwork(networkIdentifier, std::move(optNet));

    // input data
    std::vector<float> input0Data
        {
            5.0f, 3.0f
        };
    std::vector<float> input1Data
        {
            10.0f, 8.0f
        };
    std::vector<float> outputData(2);

    TensorInfo inputTensorInfo = run->GetInputTensorInfo(networkIdentifier, 0);
    inputTensorInfo.SetConstant(true);
    InputTensors inputTensors
        {
            {0,armnn::ConstTensor(inputTensorInfo, input0Data.data())},
            {1,armnn::ConstTensor(inputTensorInfo, input1Data.data())}
        };
    OutputTensors outputTensors
        {
            {0,armnn::Tensor(run->GetOutputTensorInfo(networkIdentifier, 0), outputData.data())}
        };

    // Execute network
    run->EnqueueWorkload(networkIdentifier, inputTensors, outputTensors);

    std::cout << "Addition operator result is {" << outputData[0] << "," << outputData[1] << "}" << std::endl;
    return 0;
}