IVGCVSW-2915 Add Merge Layer and no-op factory method

Change-Id: I54549671e0d3b207904cf9796a843eb2b0a631f7
Signed-off-by: Nattapat Chaimanowong <nattapat.chaimanowong@arm.com>

9 files changed, 185 insertions, 0 deletions

diff --git a/src/armnn/InternalTypes.cpp b/src/armnn/InternalTypes.cpp
index fe1542b162..93a4f94378 100644
--- a/src/armnn/InternalTypes.cpp
+++ b/src/armnn/InternalTypes.cpp
@@ -39,6 +39,7 @@ char const* GetLayerTypeAsCString(LayerType type)
         case LayerType::Maximum: return "Maximum";
         case LayerType::Mean: return "Mean";
         case LayerType::MemCopy: return "MemCopy";
+        case LayerType::Merge: return "Merge";
         case LayerType::Merger: return "Merger";
         case LayerType::Minimum: return "Minimum";
         case LayerType::Multiplication: return "Multiplication";
diff --git a/src/armnn/InternalTypes.hpp b/src/armnn/InternalTypes.hpp
index 1972e9c1b5..7c7c601d95 100644
--- a/src/armnn/InternalTypes.hpp
+++ b/src/armnn/InternalTypes.hpp
@@ -39,6 +39,7 @@ enum class LayerType
     Maximum,
     Mean,
     MemCopy,
+    Merge,
     Merger,
     Minimum,
     Multiplication,
diff --git a/src/armnn/LayerSupport.cpp b/src/armnn/LayerSupport.cpp
index 030973306f..bc6eec891b 100644
--- a/src/armnn/LayerSupport.cpp
+++ b/src/armnn/LayerSupport.cpp
@@ -355,6 +355,16 @@ bool IsMemCopySupported(const BackendId &backend,
     FORWARD_LAYER_SUPPORT_FUNC(backend, IsMemCopySupported, input, output);
 }
 
+bool IsMergeSupported(const BackendId& backend,
+                      const TensorInfo& input0,
+                      const TensorInfo& input1,
+                      const TensorInfo& output,
+                      char* reasonIfUnsupported,
+                      size_t reasonIfUnsupportedMaxLength)
+{
+    FORWARD_LAYER_SUPPORT_FUNC(backend, IsMergeSupported, input0, input1, output);
+}
+
 bool IsMergerSupported(const BackendId& backend,
                        std::vector<const TensorInfo*> inputs,
                        const TensorInfo& output,
diff --git a/src/armnn/LayersFwd.hpp b/src/armnn/LayersFwd.hpp
index 9d87aeeee3..0bd68e04af 100644
--- a/src/armnn/LayersFwd.hpp
+++ b/src/armnn/LayersFwd.hpp
@@ -31,6 +31,7 @@
 #include "layers/MaximumLayer.hpp"
 #include "layers/MeanLayer.hpp"
 #include "layers/MemCopyLayer.hpp"
+#include "layers/MergeLayer.hpp"
 #include "layers/MergerLayer.hpp"
 #include "layers/MinimumLayer.hpp"
 #include "layers/MultiplicationLayer.hpp"
@@ -102,6 +103,7 @@ DECLARE_LAYER(Lstm)
 DECLARE_LAYER(Maximum)
 DECLARE_LAYER(Mean)
 DECLARE_LAYER(MemCopy)
+DECLARE_LAYER(Merge)
 DECLARE_LAYER(Merger)
 DECLARE_LAYER(Minimum)
 DECLARE_LAYER(Multiplication)
diff --git a/src/armnn/Network.cpp b/src/armnn/Network.cpp
index 6dbd4611df..73db2e88d7 100644
--- a/src/armnn/Network.cpp
+++ b/src/armnn/Network.cpp
@@ -966,6 +966,11 @@ IConnectableLayer* Network::AddGatherLayer(const char* name)
     return m_Graph->AddLayer<GatherLayer>(name);
 }
 
+IConnectableLayer* Network::AddMergeLayer(const char* name)
+{
+    return m_Graph->AddLayer<MergeLayer>(name);
+}
+
 void Network::Accept(ILayerVisitor& visitor) const
 {
     for (auto layer : GetGraph())
diff --git a/src/armnn/Network.hpp b/src/armnn/Network.hpp
index 782531acde..bb7b9eb6f4 100644
--- a/src/armnn/Network.hpp
+++ b/src/armnn/Network.hpp
@@ -174,6 +174,8 @@ public:
 
     IConnectableLayer* AddRsqrtLayer(const char* name = nullptr) override;
 
+    IConnectableLayer* AddMergeLayer(const char* name = nullptr) override;
+
     void Accept(ILayerVisitor& visitor) const override;
 
 private:
diff --git a/src/armnn/layers/MergeLayer.cpp b/src/armnn/layers/MergeLayer.cpp
new file mode 100644
index 0000000000..1d4dc49379
--- /dev/null
+++ b/src/armnn/layers/MergeLayer.cpp
@@ -0,0 +1,65 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#include "MergeLayer.hpp"
+
+#include "LayerCloneBase.hpp"
+
+#include <backendsCommon/WorkloadData.hpp>
+#include <backendsCommon/WorkloadFactory.hpp>
+
+namespace armnn
+{
+
+MergeLayer::MergeLayer(const char* name)
+    : Layer(2, 1, LayerType::Merge, name)
+{}
+
+std::unique_ptr<IWorkload> MergeLayer::CreateWorkload(const Graph& graph,
+                                                      const IWorkloadFactory& factory) const
+{
+    return nullptr;
+}
+
+MergeLayer* MergeLayer::Clone(Graph& graph) const
+{
+    return CloneBase<MergeLayer>(graph, GetName());
+}
+
+void MergeLayer::ValidateTensorShapesFromInputs()
+{
+    VerifyLayerConnections(2, CHECK_LOCATION());
+
+    std::vector<TensorShape> inferredShapes = InferOutputShapes({
+        GetInputSlot(0).GetConnection()->GetTensorInfo().GetShape(),
+        GetInputSlot(1).GetConnection()->GetTensorInfo().GetShape(),
+    });
+
+    BOOST_ASSERT(inferredShapes.size() == 1);
+
+    ConditionalThrowIfNotEqual<LayerValidationException>(
+        "MergeLayer: TensorShape set on OutputSlot[0] does not match the inferred shape.",
+        GetOutputSlot(0).GetTensorInfo().GetShape(),
+        inferredShapes[0]);
+}
+
+std::vector<TensorShape> MergeLayer::InferOutputShapes(const std::vector<TensorShape>& inputShapes) const
+{
+    BOOST_ASSERT(inputShapes.size() == 2);
+
+    ConditionalThrowIfNotEqual<LayerValidationException>(
+        "MergeLayer: TensorShapes set on inputs do not match",
+        inputShapes[0],
+        inputShapes[1]
+    );
+
+    return {inputShapes[0]};
+}
+
+void MergeLayer::Accept(ILayerVisitor& visitor) const
+{
+    visitor.VisitMergeLayer(this, GetName());
+}
+
+} // namespace armnn
diff --git a/src/armnn/layers/MergeLayer.hpp b/src/armnn/layers/MergeLayer.hpp
new file mode 100644
index 0000000000..66664ca952
--- /dev/null
+++ b/src/armnn/layers/MergeLayer.hpp
@@ -0,0 +1,47 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#pragma once
+
+#include "Layer.hpp"
+
+namespace armnn
+{
+
+/// This layer dequantizes the input tensor.
+class MergeLayer : public Layer
+{
+public:
+    /// Makes a workload for the Merge type.
+    /// @param [in] graph The graph where this layer can be found.
+    /// @param [in] factory The workload factory which will create the workload.
+    /// @return A pointer to the created workload, or nullptr if not created.
+    virtual std::unique_ptr<IWorkload> CreateWorkload(const Graph& graph,
+                                                      const IWorkloadFactory& factory) const override;
+
+    /// Creates a dynamically-allocated copy of this layer.
+    /// @param [in] graph The graph into which this layer is being cloned.
+    MergeLayer* Clone(Graph& graph) const override;
+
+    /// Check if the input tensor shape(s)
+    /// will lead to a valid configuration of @ref MergeLayer.
+    void ValidateTensorShapesFromInputs() override;
+
+    /// Infers the output shapes from given input shapes.
+    /// @param [in] inputShapes The input shapes layer has.
+    /// @return A vector to the inferred output shape.
+    std::vector<TensorShape> InferOutputShapes(const std::vector<TensorShape>& inputShapes) const override;
+
+    void Accept(ILayerVisitor& visitor) const override;
+
+protected:
+    /// Constructor to create a MergeLayer.
+    /// @param [in] name Optional name for the layer.
+    MergeLayer(const char* name);
+
+    /// Default destructor
+    ~MergeLayer() = default;
+};
+
+} // namespace armnn
diff --git a/src/armnn/test/NetworkTests.cpp b/src/armnn/test/NetworkTests.cpp
index 4de09a2804..dd8eb7773f 100644
--- a/src/armnn/test/NetworkTests.cpp
+++ b/src/armnn/test/NetworkTests.cpp
@@ -417,4 +417,56 @@ BOOST_AUTO_TEST_CASE(Network_AddQuantize)
 
 }
 
+BOOST_AUTO_TEST_CASE(Network_AddMerge)
+{
+    struct Test : public armnn::LayerVisitorBase<armnn::VisitorNoThrowPolicy>
+    {
+        void VisitMergeLayer(const armnn::IConnectableLayer* layer, const char* name) override
+        {
+            m_Visited = true;
+
+            BOOST_TEST(layer);
+
+            std::string expectedName = std::string("merge");
+            BOOST_TEST(std::string(layer->GetName()) == expectedName);
+            BOOST_TEST(std::string(name) == expectedName);
+
+            BOOST_TEST(layer->GetNumInputSlots() == 2);
+            BOOST_TEST(layer->GetNumOutputSlots() == 1);
+
+            const armnn::TensorInfo& infoIn0 = layer->GetInputSlot(0).GetConnection()->GetTensorInfo();
+            BOOST_TEST((infoIn0.GetDataType() == armnn::DataType::Float32));
+
+            const armnn::TensorInfo& infoIn1 = layer->GetInputSlot(1).GetConnection()->GetTensorInfo();
+            BOOST_TEST((infoIn1.GetDataType() == armnn::DataType::Float32));
+
+            const armnn::TensorInfo& infoOut = layer->GetOutputSlot(0).GetTensorInfo();
+            BOOST_TEST((infoOut.GetDataType() == armnn::DataType::Float32));
+        }
+
+        bool m_Visited = false;
+    };
+
+    armnn::INetworkPtr network = armnn::INetwork::Create();
+
+    armnn::IConnectableLayer* input0 = network->AddInputLayer(0);
+    armnn::IConnectableLayer* input1 = network->AddInputLayer(1);
+    armnn::IConnectableLayer* merge = network->AddMergeLayer("merge");
+    armnn::IConnectableLayer* output = network->AddOutputLayer(0);
+
+    input0->GetOutputSlot(0).Connect(merge->GetInputSlot(0));
+    input1->GetOutputSlot(0).Connect(merge->GetInputSlot(1));
+    merge->GetOutputSlot(0).Connect(output->GetInputSlot(0));
+
+    const armnn::TensorInfo info({3,1}, armnn::DataType::Float32);
+    input0->GetOutputSlot(0).SetTensorInfo(info);
+    input1->GetOutputSlot(0).SetTensorInfo(info);
+    merge->GetOutputSlot(0).SetTensorInfo(info);
+
+    Test testMerge;
+    network->Accept(testMerge);
+
+    BOOST_TEST(testMerge.m_Visited == true);
+}
+
 BOOST_AUTO_TEST_SUITE_END()