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

7 files changed, 60 insertions, 0 deletions

diff --git a/src/backends/backendsCommon/LayerSupportBase.cpp b/src/backends/backendsCommon/LayerSupportBase.cpp
index ee8dc5f7e9..464ec4e108 100644
--- a/src/backends/backendsCommon/LayerSupportBase.cpp
+++ b/src/backends/backendsCommon/LayerSupportBase.cpp
@@ -34,6 +34,13 @@ bool DefaultLayerSupport(const char* func,
 namespace armnn
 {
 
+bool LayerSupportBase::IsAbsSupported(const TensorInfo &input,
+                                      const TensorInfo &output,
+                                      Optional<std::string &> reasonIfUnsupported) const
+{
+    return DefaultLayerSupport(__func__, __FILE__, __LINE__, reasonIfUnsupported);
+}
+
 bool LayerSupportBase::IsActivationSupported(const TensorInfo& input,
                                              const TensorInfo& output,
                                              const ActivationDescriptor& descriptor,
diff --git a/src/backends/backendsCommon/LayerSupportBase.hpp b/src/backends/backendsCommon/LayerSupportBase.hpp
index 0d5a2af16e..3cf3d4e672 100644
--- a/src/backends/backendsCommon/LayerSupportBase.hpp
+++ b/src/backends/backendsCommon/LayerSupportBase.hpp
@@ -13,6 +13,10 @@ namespace armnn
 class LayerSupportBase : public ILayerSupport
 {
 public:
+    bool IsAbsSupported(const TensorInfo& input,
+                        const TensorInfo& output,
+                        Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
+
     bool IsActivationSupported(const TensorInfo& input,
                                const TensorInfo& output,
                                const ActivationDescriptor& descriptor,
diff --git a/src/backends/backendsCommon/WorkloadData.cpp b/src/backends/backendsCommon/WorkloadData.cpp
index b590da1552..fed159bd60 100644
--- a/src/backends/backendsCommon/WorkloadData.cpp
+++ b/src/backends/backendsCommon/WorkloadData.cpp
@@ -2534,4 +2534,28 @@ void QuantizedLstmQueueDescriptor::Validate(const WorkloadInfo& workloadInfo) co
     ValidateBiasTensorQuantization(outputGateBiasInfo, inputInfo, inputToInputWeightsInfo, descriptorName);
 }
 
+void AbsQueueDescriptor::Validate(const WorkloadInfo& workloadInfo) const
+{
+    const std::string descriptorName{"AbsQueueDescriptor"};
+
+    ValidateNumInputs(workloadInfo,  descriptorName, 1);
+    ValidateNumOutputs(workloadInfo, descriptorName, 1);
+
+    const TensorInfo& inputTensorInfo  = workloadInfo.m_InputTensorInfos[0];
+    const TensorInfo& outputTensorInfo = workloadInfo.m_OutputTensorInfos[0];
+
+    ValidateTensorShapesMatch(inputTensorInfo, outputTensorInfo, descriptorName, "input", "output");
+
+    std::vector<DataType> supportedTypes =
+        {
+            DataType::Float16,
+            DataType::Float32,
+            DataType::QuantisedAsymm8,
+            DataType::QuantisedSymm16
+        };
+
+    ValidateDataTypes(inputTensorInfo, supportedTypes, descriptorName);
+    ValidateTensorDataTypesMatch(inputTensorInfo, outputTensorInfo, descriptorName, "input", "output");
+}
+
 } // namespace armnn
diff --git a/src/backends/backendsCommon/WorkloadData.hpp b/src/backends/backendsCommon/WorkloadData.hpp
index c055beb88d..a43c7cccdb 100644
--- a/src/backends/backendsCommon/WorkloadData.hpp
+++ b/src/backends/backendsCommon/WorkloadData.hpp
@@ -524,4 +524,9 @@ struct QuantizedLstmQueueDescriptor : QueueDescriptor
     void Validate(const WorkloadInfo& workloadInfo) const;
 };
 
+struct AbsQueueDescriptor : QueueDescriptor
+{
+    void Validate(const WorkloadInfo& workloadInfo) const;
+};
+
 } //namespace armnn
diff --git a/src/backends/backendsCommon/WorkloadFactory.cpp b/src/backends/backendsCommon/WorkloadFactory.cpp
index ffef5b4eb7..9d081af8e9 100644
--- a/src/backends/backendsCommon/WorkloadFactory.cpp
+++ b/src/backends/backendsCommon/WorkloadFactory.cpp
@@ -69,6 +69,15 @@ bool IWorkloadFactory::IsLayerSupported(const BackendId& backendId,
 
     switch(layer.GetType())
     {
+        case LayerType::Abs:
+        {
+            const TensorInfo& input = layer.GetInputSlot(0).GetConnection()->GetTensorInfo();
+            const TensorInfo& output = layer.GetOutputSlot(0).GetTensorInfo();
+            result = layerSupportObject->IsAbsSupported(OverrideDataType(input, dataType),
+                                                        OverrideDataType(output, dataType),
+                                                        reason);
+            break;
+        }
         case LayerType::Activation:
         {
             auto cLayer = boost::polymorphic_downcast<const ActivationLayer*>(&layer);
@@ -952,6 +961,12 @@ bool IWorkloadFactory::IsLayerSupported(const IConnectableLayer& connectableLaye
 }
 
 // Default Implementations
+std::unique_ptr<IWorkload> IWorkloadFactory::CreateAbs(const AbsQueueDescriptor& descriptor,
+                                                       const WorkloadInfo& info) const
+{
+    return std::unique_ptr<IWorkload>();
+}
+
 std::unique_ptr<IWorkload> IWorkloadFactory::CreateActivation(const ActivationQueueDescriptor& descriptor,
                                                               const WorkloadInfo& info) const
 {
diff --git a/src/backends/backendsCommon/WorkloadFactory.hpp b/src/backends/backendsCommon/WorkloadFactory.hpp
index a9c6049c37..d0164b202d 100644
--- a/src/backends/backendsCommon/WorkloadFactory.hpp
+++ b/src/backends/backendsCommon/WorkloadFactory.hpp
@@ -49,6 +49,9 @@ public:
     virtual std::unique_ptr<ITensorHandle> CreateTensorHandle(const TensorInfo& tensorInfo,
                                                               DataLayout dataLayout) const = 0;
 
+    virtual std::unique_ptr<IWorkload> CreateAbs(const AbsQueueDescriptor& descriptor,
+                                                 const WorkloadInfo& info) const;
+
     virtual std::unique_ptr<IWorkload> CreateActivation(const ActivationQueueDescriptor& descriptor,
                                                         const WorkloadInfo&              info) const;
 
diff --git a/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp b/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
index 1f43c989d6..caf5e588f7 100644
--- a/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
+++ b/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
@@ -385,6 +385,8 @@ template<armnn::LayerType Type, armnn::DataType DataType>
 struct LayerTypePolicy;
 
 // Every entry in the armnn::LayerType enum must be accounted for below.
+DECLARE_LAYER_POLICY_1_PARAM(Abs)
+
 DECLARE_LAYER_POLICY_2_PARAM(Activation)
 
 DECLARE_LAYER_POLICY_1_PARAM(Addition)