backends/reference: Add ReduceSum operation support

This patch addes ReduceSum operation support for reference backend,
which computes the sum of elements across dimensions of a tensor.

Changelog v1:
- Fix file header descriptions.

Chagelog v2:
- Fix line limit issue.
- Fix type conversion issue.

Changelog v3:
- Remove tabs.
- Modify newly added file headers.

Changelog v4:
- Symbol on header isn't allowed so drop it from newly added file headers.

Changelog v5:
- Remove tabs, fix the use of brackets and align lines correctly.

Changelog v6:
- Add serializer and deserializer support.

Changelog v7:
- Fix build error add missed code.

Changelog v8:
- Rename ReduceSumDecriptor to ReduceDescriptor
    - Update m_KeepDims field data type to bool on ReduceDescriptor
    - Add ReduceOperation field to ReduceDescriptor

- Rename ReduceSumLayer to ReduceLayer
    - Update ReduceLayer to use ReduceDescriptor
    - Update ReduceLayer::ValidateTensorShapesFromInputs() function

- Rename RefReduceSumWokload to RefReduceWorkload
    - Update workload to use ReduceDescriptor
    - Update workload to use Decoders and Encoders

- Remove ReduceSum.hpp and ReduceSum.cpp
- Added Reduce.hpp and Reduce.cpp
     - Move Mean.cpp (which is implementing REDUCE_MEAN) functionality to Reduce.cpp
     - Update RefMeanWorkload to call Reduce function with ReduceOperation::Mean argument

- Remove Mean.hpp and Mean.cpp
- Update the Serializer/Deserializer ArmnnSchema.fbs for ReduceLayer, ReduceDescriptor, and ReduceOperation
- Update Serializer and Deserializer for serializing/parsing ReduceLayer
- Added TfLiter parser Sum test for REDUCE_SUM operator
- Make corresponding changes on front-end and Ref backend to support REDUCE_SUM operator

Changelog v9:
- Fixed build errors.

Change-Id: I8c8e034f3df73f9565b3c18eff51ecca6c542195
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Sadik Armagan <sadik.armagan@arm.com>

8 files changed, 74 insertions, 0 deletions

diff --git a/include/armnn/Descriptors.hpp b/include/armnn/Descriptors.hpp
index f023e00e93..d6e37e535e 100644
--- a/include/armnn/Descriptors.hpp
+++ b/include/armnn/Descriptors.hpp
@@ -1286,4 +1286,36 @@ struct LogicalBinaryDescriptor
     LogicalBinaryOperation m_Operation;
 };
 
+/// A ReduceDescriptor for the REDUCE operators.
+struct ReduceDescriptor
+{
+    ReduceDescriptor()
+        : m_TargetHeight(0)
+        , m_TargetWidth(0)
+        , m_KeepDims(false)
+        , m_vAxis()
+        , m_ReduceOperation(ReduceOperation::Sum)
+    {}
+
+    bool operator ==(const ReduceDescriptor& rhs) const
+    {
+        return m_TargetHeight         == rhs.m_TargetHeight &&
+               m_TargetWidth          == rhs.m_TargetWidth &&
+               m_KeepDims             == rhs.m_KeepDims &&
+               m_vAxis                == rhs.m_vAxis &&
+               m_ReduceOperation      == rhs.m_ReduceOperation;
+    }
+
+    /// Target height value.
+    uint32_t m_TargetHeight;
+    /// Target width value.
+    uint32_t m_TargetWidth;
+    /// if true then output shape has no change.
+    bool m_KeepDims;
+    /// The indices of the dimensions to reduce.
+    std::vector<uint32_t> m_vAxis;
+    /// Specifies the reduction operation to execute
+    ReduceOperation m_ReduceOperation;
+};
+
 } // namespace armnn
diff --git a/include/armnn/DescriptorsFwd.hpp b/include/armnn/DescriptorsFwd.hpp
index dff5ec73ad..054ce51144 100644
--- a/include/armnn/DescriptorsFwd.hpp
+++ b/include/armnn/DescriptorsFwd.hpp
@@ -36,6 +36,7 @@ struct QLstmDescriptor;
 struct ReshapeDescriptor;
 struct ResizeBilinearDescriptor;
 struct ResizeDescriptor;
+struct ReduceDescriptor;
 struct SoftmaxDescriptor;
 struct SpaceToBatchNdDescriptor;
 struct SpaceToDepthDescriptor;
diff --git a/include/armnn/ILayerSupport.hpp b/include/armnn/ILayerSupport.hpp
index 5bcfc7d3cd..602e4e5b57 100644
--- a/include/armnn/ILayerSupport.hpp
+++ b/include/armnn/ILayerSupport.hpp
@@ -324,6 +324,11 @@ public:
                                  const TensorInfo& output,
                                  Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const = 0;
 
+    virtual bool IsReduceSupported(const TensorInfo& input,
+                                   const TensorInfo& output,
+                                   const ReduceDescriptor& descriptor,
+                                   Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const = 0;
+
     virtual bool IsReshapeSupported(const TensorInfo& input,
                                     const TensorInfo& output,
                                     const ReshapeDescriptor& descriptor,
diff --git a/include/armnn/ILayerVisitor.hpp b/include/armnn/ILayerVisitor.hpp
index b8e741d01e..b5112a8f0b 100644
--- a/include/armnn/ILayerVisitor.hpp
+++ b/include/armnn/ILayerVisitor.hpp
@@ -409,6 +409,14 @@ public:
     virtual void VisitRankLayer(const IConnectableLayer* layer,
                                 const char* name = nullptr) = 0;
 
+    /// Function that a reduce layer should call back to when its Accept(ILayerVisitor&) function is invoked.
+    /// @param layer - pointer to the layer which is calling back to this visit function.
+    /// @param ReduceDescriptor - Parameters for the reduce max operation.
+    /// @param name - Optional name for the layer.
+    virtual void VisitReduceLayer(const IConnectableLayer* layer,
+                                  const ReduceDescriptor& reduceDescriptor,
+                                  const char* name = nullptr) = 0;
+
     /// Function a reshape layer should call back to when its Accept(ILayerVisitor&) function is invoked.
     /// @param layer - pointer to the layer which is calling back to this visit function.
     /// @param reshapeDescriptor - Parameters for the reshape operation.
diff --git a/include/armnn/INetwork.hpp b/include/armnn/INetwork.hpp
index b89df63aa4..ca1b725d48 100644
--- a/include/armnn/INetwork.hpp
+++ b/include/armnn/INetwork.hpp
@@ -372,6 +372,13 @@ public:
     virtual IConnectableLayer* AddResizeLayer(const ResizeDescriptor& resizeDescriptor,
                                               const char* name = nullptr) = 0;
 
+    /// Adds a reduce layer to the network.
+    /// @param ReduceDescriptor - Parameters for the reduce operation.
+    /// @param name - Optional name for the layer.
+    /// @return - Interface for configuring the layer.
+    virtual IConnectableLayer* AddReduceLayer(const ReduceDescriptor& reduceDescriptor,
+                                              const char* name = nullptr) = 0;
+
     /// Adds an instance normalization layer to the network.
     /// @param desc - Parameters for the instance normalization operation.
     /// @param name - Optional name for the layer.
diff --git a/include/armnn/LayerSupport.hpp b/include/armnn/LayerSupport.hpp
index 2ec086b185..6f1eb0347b 100644
--- a/include/armnn/LayerSupport.hpp
+++ b/include/armnn/LayerSupport.hpp
@@ -303,6 +303,14 @@ bool IsQuantizedLstmSupported(const BackendId& backend,
                               size_t reasonIfUnsupportedMaxLength = 1024);
 
 /// Deprecated in favor of IBackend and ILayerSupport interfaces
+bool IsReduceSupported(const BackendId& backend,
+                       const TensorInfo& input,
+                       const TensorInfo& output,
+                       const ReduceDescriptor& descriptor,
+                       char* reasonIfUnsupported = nullptr,
+                       size_t reasonIfUnsupportedMaxLength = 1024);
+
+/// Deprecated in favor of IBackend and ILayerSupport interfaces
 bool IsReshapeSupported(const BackendId& backend,
                         const TensorInfo& input,
                         const ReshapeDescriptor& descriptor,
@@ -413,4 +421,5 @@ bool IsTransposeConvolution2dSupported(const BackendId& backend,
                                        const Optional<TensorInfo>& biases,
                                        char* reasonIfUnsupported = nullptr,
                                        size_t reasonIfUnsupportedMaxLength = 1024);
+
 }
diff --git a/include/armnn/LayerVisitorBase.hpp b/include/armnn/LayerVisitorBase.hpp
index a97530ec40..fb88d559bb 100644
--- a/include/armnn/LayerVisitorBase.hpp
+++ b/include/armnn/LayerVisitorBase.hpp
@@ -208,6 +208,10 @@ public:
     void VisitRankLayer(const IConnectableLayer*,
                         const char*) override { DefaultPolicy::Apply(__func__); }
 
+    void VisitReduceLayer(const IConnectableLayer*,
+                          const ReduceDescriptor&,
+                          const char*) override { DefaultPolicy::Apply(__func__); }
+
     void VisitReshapeLayer(const IConnectableLayer*,
                            const ReshapeDescriptor&,
                            const char*) override { DefaultPolicy::Apply(__func__); }
diff --git a/include/armnn/Types.hpp b/include/armnn/Types.hpp
index 46f246f46d..22004bd0a4 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -108,6 +108,14 @@ enum class PoolingAlgorithm
     L2      = 2
 };
 
+enum class ReduceOperation
+{
+    Sum  = 0,
+    Max  = 1,
+    Mean = 2,
+    Min  = 3
+};
+
 enum class ResizeMethod
 {
     Bilinear        = 0,