IVGCVSW-3739 Add Arm NN front end support for Abs Layer

	* Add Abs Layer
	* Add no-op factory implementations for CpuRef, CpuAcc, GpuAcc
	* Add Queue Descriptor in WorkloadData
	* Add IsAbsLayerSupported to LayerSupport
	* Add LayerVisitor tests

Signed-off-by: Kevin May <kevin.may@arm.com>
Change-Id: Ib0992571d1c80de851cea466291be904e9bdb430

2 files changed, 95 insertions, 0 deletions

diff --git a/src/armnn/layers/AbsLayer.cpp b/src/armnn/layers/AbsLayer.cpp
new file mode 100644
index 0000000000..f87706aec2
--- /dev/null
+++ b/src/armnn/layers/AbsLayer.cpp
@@ -0,0 +1,53 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "AbsLayer.hpp"
+
+#include "LayerCloneBase.hpp"
+
+#include <armnn/TypesUtils.hpp>
+#include <backendsCommon/WorkloadData.hpp>
+#include <backendsCommon/WorkloadFactory.hpp>
+
+namespace armnn
+{
+
+AbsLayer::AbsLayer(const char* name)
+    : Layer(1, 1, LayerType::Abs, name)
+{
+}
+
+std::unique_ptr<IWorkload> AbsLayer::CreateWorkload(const Graph& graph,
+                                                    const IWorkloadFactory& factory) const
+{
+    AbsQueueDescriptor descriptor;
+    return factory.CreateAbs(descriptor, PrepInfoAndDesc(descriptor, graph));
+}
+
+AbsLayer* AbsLayer::Clone(Graph& graph) const
+{
+    return CloneBase<AbsLayer>(graph, GetName());
+}
+
+void AbsLayer::ValidateTensorShapesFromInputs()
+{
+    VerifyLayerConnections(1, CHECK_LOCATION());
+
+    auto inferredShapes = InferOutputShapes({ GetInputSlot(0).GetConnection()->GetTensorInfo().GetShape() });
+
+    BOOST_ASSERT(inferredShapes.size() == 1);
+
+    ConditionalThrowIfNotEqual<LayerValidationException>(
+            "AbsLayer: TensorShape set on OutputSlot[0] does not match the inferred shape.",
+            GetOutputSlot(0).GetTensorInfo().GetShape(),
+            inferredShapes[0]);
+}
+
+void AbsLayer::Accept(ILayerVisitor& visitor) const
+{
+    visitor.VisitAbsLayer(this, GetName());
+}
+
+} // namespace armnn
\ No newline at end of file
diff --git a/src/armnn/layers/AbsLayer.hpp b/src/armnn/layers/AbsLayer.hpp
new file mode 100644
index 0000000000..643cf4b629
--- /dev/null
+++ b/src/armnn/layers/AbsLayer.hpp
@@ -0,0 +1,42 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include <Layer.hpp>
+
+namespace armnn
+{
+
+class AbsLayer : public Layer
+{
+public:
+    /// Makes a workload for the Abs 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.
+    AbsLayer* Clone(Graph& graph) const override;
+
+    /// Check if the input tensor shape(s)
+    /// will lead to a valid configuration of @ref AbsLayer.
+    void ValidateTensorShapesFromInputs() override;
+
+    void Accept(ILayerVisitor& visitor) const override;
+
+protected:
+    /// Constructor to create an AbsLayer.
+    /// @param [in] name Optional name for the layer.
+    AbsLayer(const char* name);
+
+    /// Default destructor
+    ~AbsLayer() = default;
+};
+
+} // namespace
\ No newline at end of file