MLCE-530 Add front end support for UnidirectionalSequenceLstm on ArmNN

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: I57bcbdec3eb0155f41af0fe7d6abf9bac2ec86eb

6 files changed, 45 insertions, 4 deletions

diff --git a/include/armnn/BackendHelper.hpp b/include/armnn/BackendHelper.hpp
index 093f822040..dee3b48b81 100644
--- a/include/armnn/BackendHelper.hpp
+++ b/include/armnn/BackendHelper.hpp
@@ -433,6 +433,17 @@ public:
                               const TransposeDescriptor& descriptor,
                               Optional<std::string&> reasonIfUnsupported = EmptyOptional());
 
+    bool IsUnidirectionalSequenceLstmSupported(
+        const TensorInfo& input,
+        const TensorInfo& outputStateIn,
+        const TensorInfo& cellStateIn,
+        const TensorInfo& output,
+        const Optional<TensorInfo>& hiddenStateOutput,
+        const Optional<TensorInfo>& cellStateOutput,
+        const LstmDescriptor& descriptor,
+        const LstmInputParamsInfo& paramsInfo,
+        Optional<std::string&> reasonIfUnsupported = EmptyOptional());
+
 private:
     std::shared_ptr<ILayerSupport> m_LayerSupport;
     const BackendId m_BackendId;
diff --git a/include/armnn/Descriptors.hpp b/include/armnn/Descriptors.hpp
index 683ef7ac98..bcee902d75 100644
--- a/include/armnn/Descriptors.hpp
+++ b/include/armnn/Descriptors.hpp
@@ -926,6 +926,7 @@ struct LstmDescriptor : BaseDescriptor
         , m_PeepholeEnabled(false)
         , m_ProjectionEnabled(false)
         , m_LayerNormEnabled(false)
+        , m_TimeMajor(true)
     {}
 
     bool operator ==(const LstmDescriptor& rhs) const
@@ -935,7 +936,8 @@ struct LstmDescriptor : BaseDescriptor
                m_ClippingThresProj == rhs.m_ClippingThresProj &&
                m_CifgEnabled       == rhs.m_CifgEnabled &&
                m_PeepholeEnabled   == rhs.m_PeepholeEnabled &&
-               m_LayerNormEnabled  == rhs.m_LayerNormEnabled;
+               m_LayerNormEnabled  == rhs.m_LayerNormEnabled &&
+               m_TimeMajor         == rhs.m_TimeMajor;
     }
 
     /// @brief The activation function to use.
@@ -953,8 +955,12 @@ struct LstmDescriptor : BaseDescriptor
     bool m_ProjectionEnabled;
     /// Enable/disable layer normalization
     bool m_LayerNormEnabled;
+    /// Enable/disable time major
+    bool m_TimeMajor;
 };
 
+using UnidirectionalSequenceLstmDescriptor = LstmDescriptor;
+
 /// A MeanDescriptor for the MeanLayer.
 struct MeanDescriptor : BaseDescriptor
 {
diff --git a/include/armnn/DescriptorsFwd.hpp b/include/armnn/DescriptorsFwd.hpp
index 9b22644c7b..3b43c42d23 100644
--- a/include/armnn/DescriptorsFwd.hpp
+++ b/include/armnn/DescriptorsFwd.hpp
@@ -55,5 +55,6 @@ using LogSoftmaxDescriptor   = SoftmaxDescriptor;
 /// MergerDescriptor is deprecated, use ConcatDescriptor instead
 using MergerDescriptor       = OriginsDescriptor;
 using SplitterDescriptor     = ViewsDescriptor;
+using UnidirectionalSequenceLstmDescriptor = LstmDescriptor;
 
 } // namespace armnn
diff --git a/include/armnn/INetwork.hpp b/include/armnn/INetwork.hpp
index b40db62a59..865d1291a9 100644
--- a/include/armnn/INetwork.hpp
+++ b/include/armnn/INetwork.hpp
@@ -691,6 +691,15 @@ public:
     IConnectableLayer* AddLogicalBinaryLayer(const LogicalBinaryDescriptor& descriptor,
                                                      const char* name = nullptr);
 
+    /// Add a UnidirectionalSequenceLstm layer to the network
+    /// @param descriptor - Parameters for the UnidirectionalSequenceLstm operation
+    /// @param params - Weights and biases for the UnidirectionalSequenceLstm
+    /// @param name - Optional name for the layer
+    /// @return - Interface for configuring the layer.
+    IConnectableLayer* AddUnidirectionalSequenceLstmLayer(const UnidirectionalSequenceLstmDescriptor& descriptor,
+                                                          const LstmInputParams& params,
+                                                          const char* name = nullptr);
+
     void Accept(ILayerVisitor& visitor) const;
 
     void ExecuteStrategy(IStrategy& strategy) const;
diff --git a/include/armnn/Types.hpp b/include/armnn/Types.hpp
index e7c17608ca..056aa83d2f 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -333,7 +333,6 @@ using InferenceTimingPair = std::pair<HighResolutionClock, HighResolutionClock>;
     X(ArgMinMax) \
     X(BatchNormalization) \
     X(BatchToSpaceNd)      \
-    X(Cast) \
     X(Comparison) \
     X(Concat) \
     X(Constant) \
@@ -382,7 +381,6 @@ using InferenceTimingPair = std::pair<HighResolutionClock, HighResolutionClock>;
     X(Rank) \
     X(Resize) \
     X(Reduce) \
-    X(Shape) \
     X(Slice) \
     X(Softmax) \
     X(SpaceToBatchNd) \
@@ -396,6 +394,11 @@ using InferenceTimingPair = std::pair<HighResolutionClock, HighResolutionClock>;
     X(Transpose) \
     X(TransposeConvolution2d) \
     X(Unmap) \
+    X(Cast) \
+    X(Shape) \
+    X(UnidirectionalSequenceLstm) \
+
+// New layers should be added at last to minimize instability.
 
 /// When adding a new layer, adapt also the LastLayer enum value in the
 /// enum class LayerType below
@@ -405,7 +408,7 @@ enum class LayerType
     LIST_OF_LAYER_TYPE
 #undef X
     FirstLayer = Activation,
-    LastLayer = Unmap
+    LastLayer = UnidirectionalSequenceLstm
 };
 
 const char* GetLayerTypeAsCString(LayerType type);
diff --git a/include/armnn/backends/ILayerSupport.hpp b/include/armnn/backends/ILayerSupport.hpp
index 462668d738..7ba565a138 100644
--- a/include/armnn/backends/ILayerSupport.hpp
+++ b/include/armnn/backends/ILayerSupport.hpp
@@ -424,6 +424,17 @@ public:
                                       const TransposeDescriptor& descriptor,
                                       Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const = 0;
 
+    virtual bool IsUnidirectionalSequenceLstmSupported(
+        const TensorInfo& input,
+        const TensorInfo& outputStateIn,
+        const TensorInfo& cellStateIn,
+        const TensorInfo& output,
+        const Optional<TensorInfo>& hiddenStateOutput,
+        const Optional<TensorInfo>& cellStateOutput,
+        const LstmDescriptor& descriptor,
+        const LstmInputParamsInfo& paramsInfo,
+        Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const = 0;
+
 }; // class ILayerSupport
 
 using ILayerSupportSharedPtr = std::shared_ptr<ILayerSupport>;