IVGCVSW-3418 Add Arm NN front end support for the new Stack layer

 * Added new StackLayer class
 * Made necessary changes to Descriptors, ILayerSupport, ILayerVisitor, etc.
 * Added unit tests

Signed-off-by: Matthew Jackson <matthew.jackson@arm.com>
Change-Id: Ieb97a928a342ffe1901c6058eb895711c358fd3d

1 files changed, 49 insertions, 0 deletions

diff --git a/src/armnn/layers/StackLayer.hpp b/src/armnn/layers/StackLayer.hpp
new file mode 100644
index 0000000000..6c845972d0
--- /dev/null
+++ b/src/armnn/layers/StackLayer.hpp
@@ -0,0 +1,49 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#pragma once
+
+#include "LayerWithParameters.hpp"
+
+namespace armnn
+{
+
+/// This layer represents a stack operation.
+class StackLayer : public LayerWithParameters<StackDescriptor>
+{
+public:
+    /// Makes a workload for the Stack 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.
+    StackLayer* Clone(Graph& graph) const override;
+
+    /// Check if the input tensor shape(s)
+    /// will lead to a valid configuration of @ref StackLayer.
+    void ValidateTensorShapesFromInputs() override;
+
+    /// By default returns inputShapes if the number of inputs are equal to number of outputs,
+    /// otherwise infers the output shapes from given input shapes and layer properties.
+    /// @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 StackLayer.
+    /// @param [in] param StackDescriptor to configure the stack operation.
+    /// @param [in] name Optional name for the layer.
+    StackLayer(const StackDescriptor& param, const char* name);
+
+    /// Default destructor
+    ~StackLayer() = default;
+};
+
+} // namespace