IVGCVSW-2508 Add no-op factory implementations and layer for Gather operator

 * Added GatherQueueDescriptor to WorkloadData
 * Added CreateGather function in WorkloadFactory.hpp
 * Added stub implementation of the CreateGreater function in workload factories
 * Added GatherLayer stub implementation
 * Added AddGatherLayer to Network
 * Added IsGatherSupported to LayerSupportBase

Change-Id: I0408fd54e88a7d4e3d9e1c2811a9323f0da52a04

13 files changed, 76 insertions, 9 deletions

diff --git a/src/backends/backendsCommon/LayerSupportBase.cpp b/src/backends/backendsCommon/LayerSupportBase.cpp
index 187d2f7d38..2e436578b7 100644
--- a/src/backends/backendsCommon/LayerSupportBase.cpp
+++ b/src/backends/backendsCommon/LayerSupportBase.cpp
@@ -156,6 +156,14 @@ bool LayerSupportBase::IsFullyConnectedSupported(const TensorInfo& input,
     return DefaultLayerSupport(__func__, __FILE__, __LINE__, reasonIfUnsupported);
 }
 
+bool LayerSupportBase::IsGatherSupported(const armnn::TensorInfo& input0,
+                                         const armnn::TensorInfo& input1,
+                                         const armnn::TensorInfo& output,
+                                         armnn::Optional<std::string&> reasonIfUnsupported) const
+{
+    return DefaultLayerSupport(__func__, __FILE__, __LINE__, reasonIfUnsupported);
+}
+
 bool LayerSupportBase::IsInputSupported(const TensorInfo& input,
                                         Optional<std::string&> reasonIfUnsupported) const
 {
diff --git a/src/backends/backendsCommon/LayerSupportBase.hpp b/src/backends/backendsCommon/LayerSupportBase.hpp
index c6f943c7e0..77cb302d5e 100644
--- a/src/backends/backendsCommon/LayerSupportBase.hpp
+++ b/src/backends/backendsCommon/LayerSupportBase.hpp
@@ -92,6 +92,11 @@ public:
                                    const FullyConnectedDescriptor& descriptor,
                                    Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
 
+    bool IsGatherSupported(const TensorInfo& input0,
+                           const TensorInfo& input1,
+                           const TensorInfo& output,
+                           Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
+
     bool IsGreaterSupported(const TensorInfo& input0,
                             const TensorInfo& input1,
                             const TensorInfo& output,
diff --git a/src/backends/backendsCommon/WorkloadData.cpp b/src/backends/backendsCommon/WorkloadData.cpp
index 97981e2b8d..072b9a9934 100644
--- a/src/backends/backendsCommon/WorkloadData.cpp
+++ b/src/backends/backendsCommon/WorkloadData.cpp
@@ -1051,6 +1051,12 @@ void RsqrtQueueDescriptor::Validate(const WorkloadInfo& workloadInfo) const
                               "output");
 }
 
+void GatherQueueDescriptor::Validate(const WorkloadInfo& workloadInfo) const
+{
+    ValidateTwoInputs(workloadInfo, "GatherQueueDescriptor");
+    ValidateSingleOutput(workloadInfo, "GatherQueueDescriptor");
+}
+
 void PreCompiledQueueDescriptor::Validate(const WorkloadInfo& workloadInfo) const
 {
     // This is internally generated so it should not need validation.
diff --git a/src/backends/backendsCommon/WorkloadData.hpp b/src/backends/backendsCommon/WorkloadData.hpp
index 453896b912..2d68c9f7ee 100644
--- a/src/backends/backendsCommon/WorkloadData.hpp
+++ b/src/backends/backendsCommon/WorkloadData.hpp
@@ -378,6 +378,11 @@ struct RsqrtQueueDescriptor : QueueDescriptor
     void Validate(const WorkloadInfo& workloadInfo) const;
 };
 
+struct GatherQueueDescriptor : QueueDescriptor
+{
+    void Validate(const WorkloadInfo& workloadInfo) const;
+};
+
 struct PreCompiledQueueDescriptor : QueueDescriptorWithParameters<PreCompiledDescriptor>
 {
     PreCompiledQueueDescriptor()
diff --git a/src/backends/backendsCommon/WorkloadFactory.cpp b/src/backends/backendsCommon/WorkloadFactory.cpp
index 0f015bd540..a70ec7e231 100644
--- a/src/backends/backendsCommon/WorkloadFactory.cpp
+++ b/src/backends/backendsCommon/WorkloadFactory.cpp
@@ -315,6 +315,17 @@ bool IWorkloadFactory::IsLayerSupported(const BackendId& backendId,
                                                reason);
             break;
         }
+        case LayerType::Gather:
+        {
+            const TensorInfo& input0 = layer.GetInputSlot(0).GetConnection()->GetTensorInfo();
+            const TensorInfo& input1 = layer.GetInputSlot(1).GetConnection()->GetTensorInfo();
+            const TensorInfo& output = layer.GetOutputSlot(0).GetTensorInfo();
+            result = layerSupportObject->IsGatherSupported(OverrideDataType(input0, dataType),
+                                                           OverrideDataType(input1, dataType),
+                                                           OverrideDataType(output, dataType),
+                                                           reason);
+            break;
+        }
         case LayerType::Input:
         {
             const TensorInfo& input = layer.GetOutputSlot(0).GetTensorInfo();
@@ -477,16 +488,16 @@ bool IWorkloadFactory::IsLayerSupported(const BackendId& backendId,
                                                             reason);
             break;
         }
-    case LayerType::MemCopy:
-    {
-        const TensorInfo& input  = layer.GetInputSlot(0).GetConnection()->GetTensorInfo();
-        const TensorInfo& output = layer.GetOutputSlot(0).GetTensorInfo();
+        case LayerType::MemCopy:
+        {
+            const TensorInfo& input  = layer.GetInputSlot(0).GetConnection()->GetTensorInfo();
+            const TensorInfo& output = layer.GetOutputSlot(0).GetTensorInfo();
 
-        result = layerSupportObject->IsMemCopySupported(OverrideDataType(input, dataType),
-                                                        OverrideDataType(output, dataType),
-                                                        reason);
-        break;
-    }
+            result = layerSupportObject->IsMemCopySupported(OverrideDataType(input, dataType),
+                                                            OverrideDataType(output, dataType),
+                                                            reason);
+            break;
+        }
         case LayerType::Merger:
         {
             auto cLayer = boost::polymorphic_downcast<const MergerLayer*>(&layer);
diff --git a/src/backends/backendsCommon/WorkloadFactory.hpp b/src/backends/backendsCommon/WorkloadFactory.hpp
index d516698d3f..dd47dd6e05 100644
--- a/src/backends/backendsCommon/WorkloadFactory.hpp
+++ b/src/backends/backendsCommon/WorkloadFactory.hpp
@@ -162,6 +162,9 @@ public:
 
     virtual std::unique_ptr<IWorkload> CreatePreCompiled(const PreCompiledQueueDescriptor& descriptor,
                                                          const WorkloadInfo& info) const = 0;
+
+    virtual std::unique_ptr<IWorkload> CreateGather(const GatherQueueDescriptor& descriptor,
+                                                    const WorkloadInfo& info) const = 0;
 };
 
 } //namespace armnn
diff --git a/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp b/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
index edc58cf514..43c7581b8b 100644
--- a/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
+++ b/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
@@ -344,6 +344,8 @@ DECLARE_LAYER_POLICY_1_PARAM(Floor)
 
 DECLARE_LAYER_POLICY_2_PARAM(FullyConnected)
 
+DECLARE_LAYER_POLICY_1_PARAM(Gather)
+
 DECLARE_LAYER_POLICY_1_PARAM(Greater)
 
 DECLARE_LAYER_POLICY_CUSTOM_PARAM(Input, armnn::LayerBindingId)
diff --git a/src/backends/cl/ClWorkloadFactory.cpp b/src/backends/cl/ClWorkloadFactory.cpp
index 28011cfd7b..71c1b89c09 100644
--- a/src/backends/cl/ClWorkloadFactory.cpp
+++ b/src/backends/cl/ClWorkloadFactory.cpp
@@ -362,4 +362,10 @@ std::unique_ptr<IWorkload> ClWorkloadFactory::CreatePreCompiled(const PreCompile
     return MakeWorkload<NullWorkload, NullWorkload>(descriptor, info);
 }
 
+std::unique_ptr<IWorkload> ClWorkloadFactory::CreateGather(const armnn::GatherQueueDescriptor& descriptor,
+                                                           const armnn::WorkloadInfo& info) const
+{
+    return MakeWorkload<NullWorkload, NullWorkload>(descriptor, info);
+}
+
 } // namespace armnn
diff --git a/src/backends/cl/ClWorkloadFactory.hpp b/src/backends/cl/ClWorkloadFactory.hpp
index 286e897472..ba2f0664dc 100644
--- a/src/backends/cl/ClWorkloadFactory.hpp
+++ b/src/backends/cl/ClWorkloadFactory.hpp
@@ -153,6 +153,9 @@ public:
     virtual std::unique_ptr<IWorkload> CreatePreCompiled(const PreCompiledQueueDescriptor& descriptor,
                                                          const WorkloadInfo& info) const override;
 
+    virtual std::unique_ptr<IWorkload> CreateGather(const GatherQueueDescriptor& descriptor,
+                                                    const WorkloadInfo& info) const override;
+
 private:
     template<typename FloatWorkload, typename Uint8Workload, typename QueueDescriptorType, typename... Args>
     static std::unique_ptr<IWorkload> MakeWorkload(const QueueDescriptorType& descriptor,
diff --git a/src/backends/neon/NeonWorkloadFactory.cpp b/src/backends/neon/NeonWorkloadFactory.cpp
index 3728c86a66..311479a5f7 100644
--- a/src/backends/neon/NeonWorkloadFactory.cpp
+++ b/src/backends/neon/NeonWorkloadFactory.cpp
@@ -330,4 +330,10 @@ std::unique_ptr<IWorkload> NeonWorkloadFactory::CreatePreCompiled(const PreCompi
     return MakeWorkloadHelper<NullWorkload, NullWorkload>(descriptor, info);
 }
 
+std::unique_ptr<IWorkload> NeonWorkloadFactory::CreateGather(const armnn::GatherQueueDescriptor& descriptor,
+                                                             const armnn::WorkloadInfo& info) const
+{
+    return MakeWorkloadHelper<NullWorkload, NullWorkload>(descriptor, info);
+}
+
 } // namespace armnn
diff --git a/src/backends/neon/NeonWorkloadFactory.hpp b/src/backends/neon/NeonWorkloadFactory.hpp
index 68317ed651..fe9f1b08a2 100644
--- a/src/backends/neon/NeonWorkloadFactory.hpp
+++ b/src/backends/neon/NeonWorkloadFactory.hpp
@@ -154,6 +154,9 @@ public:
     virtual std::unique_ptr<IWorkload> CreatePreCompiled(const PreCompiledQueueDescriptor& descriptor,
                                                          const WorkloadInfo& info) const override;
 
+    virtual std::unique_ptr<IWorkload> CreateGather(const GatherQueueDescriptor& descriptor,
+                                                    const WorkloadInfo& info) const override;
+
 private:
     mutable std::shared_ptr<NeonMemoryManager> m_MemoryManager;
 };
diff --git a/src/backends/reference/RefWorkloadFactory.cpp b/src/backends/reference/RefWorkloadFactory.cpp
index 361a3f1f74..cb7d6ea01a 100644
--- a/src/backends/reference/RefWorkloadFactory.cpp
+++ b/src/backends/reference/RefWorkloadFactory.cpp
@@ -324,4 +324,10 @@ std::unique_ptr<IWorkload> RefWorkloadFactory::CreatePreCompiled(const PreCompil
     return nullptr;
 }
 
+std::unique_ptr<IWorkload> RefWorkloadFactory::CreateGather(const armnn::GatherQueueDescriptor& descriptor,
+                                                            const armnn::WorkloadInfo& info) const
+{
+    return MakeWorkload<NullWorkload, NullWorkload>(descriptor, info);
+}
+
 } // namespace armnn
diff --git a/src/backends/reference/RefWorkloadFactory.hpp b/src/backends/reference/RefWorkloadFactory.hpp
index 432ac72c6e..443af76265 100644
--- a/src/backends/reference/RefWorkloadFactory.hpp
+++ b/src/backends/reference/RefWorkloadFactory.hpp
@@ -171,6 +171,9 @@ public:
     virtual std::unique_ptr<IWorkload> CreatePreCompiled(const PreCompiledQueueDescriptor& descriptor,
                                                          const WorkloadInfo& info) const override;
 
+    virtual std::unique_ptr<IWorkload> CreateGather(const GatherQueueDescriptor& descriptor,
+                                                    const WorkloadInfo& info) const override;
+
 private:
 
     template <typename F32Workload, typename U8Workload, typename QueueDescriptorType>