IVGCVSW-6027 Add IsConstant flag to TensorInfo

Signed-off-by: Jan Eilers <jan.eilers@arm.com>
Change-Id: I7cb0a6a8856d8cd9949bec83c1ddce0a454fdf63

2 files changed, 53 insertions, 12 deletions

diff --git a/include/armnn/Tensor.hpp b/include/armnn/Tensor.hpp
index 95898743bc..6f6abe187b 100644
--- a/include/armnn/Tensor.hpp
+++ b/include/armnn/Tensor.hpp
@@ -158,24 +158,28 @@ public:
     TensorInfo(const TensorShape& shape,
                DataType dataType,
                float quantizationScale = 0.0f,
-               int32_t quantizationOffset = 0);
+               int32_t quantizationOffset = 0,
+               bool isConstant = false);
 
     TensorInfo(unsigned int numDimensions,
                const unsigned int* dimensionSizes,
                DataType dataType,
                float quantizationScale = 0.0f,
-               int32_t quantizationOffset = 0);
+               int32_t quantizationOffset = 0,
+               bool isConstant = false);
 
     TensorInfo(const TensorShape& shape,
                DataType dataType,
                const std::vector<float>& quantizationScales,
-               unsigned int quantizationDim);
+               unsigned int quantizationDim,
+               bool isConstant = false);
 
     TensorInfo(unsigned int numDimensions,
                const unsigned int* dimensionSizes,
                DataType dataType,
                const std::vector<float>& quantizationScales,
-               unsigned int quantizationDim);
+               unsigned int quantizationDim,
+               bool isConstant = false);
 
     TensorInfo(const TensorInfo& other);
 
@@ -212,6 +216,14 @@ public:
 
     bool IsQuantized() const;
 
+    bool IsConstant() const;
+
+    /// Marks the data corresponding to this tensor info as constant.
+    ///
+    /// @details: This can allow further optimization on execution
+    /// @Note: The user has to ensure that the underlying data actually is constant.
+    void SetConstant(const bool IsConstant=true);
+
     /// Check that the types are the same and, if quantize, that the quantization parameters are the same.
     bool IsTypeSpaceMatch(const TensorInfo& other) const;
 
@@ -220,6 +232,7 @@ public:
 private:
     TensorShape m_Shape;
     DataType    m_DataType;
+    bool        m_IsConstant;
 
     /// Vectors of scale and offset are used for per-axis quantization.
     struct Quantization
@@ -316,10 +329,16 @@ class ConstTensor : public BaseTensor<const void*>
 public:
     /// Brings in the constructors and assignment operator.
     using BaseTensor<const void*>::BaseTensor;
-    ConstTensor() : BaseTensor<const void*>() {} // This needs to be redefined explicitly??
+    ConstTensor() : BaseTensor<const void*>()
+    {
+        this->GetInfo().SetConstant();
+    }
 
     /// Can be implicitly constructed from non-const Tensor.
-    ConstTensor(const Tensor& other) : BaseTensor<const void*>(other.GetInfo(), other.GetMemoryArea()) {}
+    ConstTensor(const Tensor& other) : BaseTensor<const void*>(other.GetInfo(), other.GetMemoryArea())
+    {
+        this->GetInfo().SetConstant();
+    }
 
     /// Constructor from a backing container.
     /// @param container - An stl-like container type which implements data() and size() methods.
@@ -330,6 +349,7 @@ public:
     ConstTensor(const TensorInfo& info, const ContainerType<T, ContainerArgs...>& container)
         : BaseTensor<const void*>(info, container.data())
     {
+        this->GetInfo().SetConstant();
         if (container.size() * sizeof(T) != info.GetNumBytes())
         {
             throw InvalidArgumentException("Container size is not correct");
diff --git a/src/armnn/Tensor.cpp b/src/armnn/Tensor.cpp
index 449fdf1f04..6a4dbf8dae 100644
--- a/src/armnn/Tensor.cpp
+++ b/src/armnn/Tensor.cpp
@@ -339,16 +339,18 @@ void TensorShape::CheckSpecifiedNumDimensions() const
 // ---
 
 TensorInfo::TensorInfo()
-: m_DataType(DataType::Float32)
+: m_DataType(DataType::Float32), m_IsConstant(false)
 {
 }
 
 TensorInfo::TensorInfo(const TensorShape& shape,
                        DataType dataType,
                        float quantizationScale,
-                       int32_t quantizationOffset)
+                       int32_t quantizationOffset,
+                       bool isConstant)
     : m_Shape(shape)
     , m_DataType(dataType)
+    , m_IsConstant(isConstant)
 {
     SetQuantizationScale(quantizationScale);
     SetQuantizationOffset(quantizationOffset);
@@ -358,9 +360,11 @@ TensorInfo::TensorInfo(unsigned int numDimensions,
                        const unsigned int* dimensionSizes,
                        DataType dataType,
                        float quantizationScale,
-                       int32_t quantizationOffset)
+                       int32_t quantizationOffset,
+                       bool isConstant)
     : m_Shape(numDimensions, dimensionSizes)
     , m_DataType(dataType)
+        , m_IsConstant(isConstant)
 {
     SetQuantizationScale(quantizationScale);
     SetQuantizationOffset(quantizationOffset);
@@ -369,9 +373,11 @@ TensorInfo::TensorInfo(unsigned int numDimensions,
 TensorInfo::TensorInfo(const TensorShape& shape,
                        DataType dataType,
                        const std::vector<float>& quantizationScales,
-                       unsigned int quantizationDim)
+                       unsigned int quantizationDim,
+                       bool isConstant)
     : m_Shape(shape)
     , m_DataType(dataType)
+    , m_IsConstant(isConstant)
 {
     SetQuantizationScales(quantizationScales);
     SetQuantizationDim(MakeOptional<unsigned int>(quantizationDim));
@@ -381,9 +387,11 @@ TensorInfo::TensorInfo(unsigned int numDimensions,
                        const unsigned int* dimensionSizes,
                        DataType dataType,
                        const std::vector<float>& quantizationScales,
-                       unsigned int quantizationDim)
+                       unsigned int quantizationDim,
+                       bool isConstant)
     : m_Shape(numDimensions, dimensionSizes)
     , m_DataType(dataType)
+    , m_IsConstant(isConstant)
 {
     SetQuantizationScales(quantizationScales);
     SetQuantizationDim(MakeOptional<unsigned int>(quantizationDim));
@@ -392,6 +400,7 @@ TensorInfo::TensorInfo(unsigned int numDimensions,
 TensorInfo::TensorInfo(const TensorInfo& other)
 : m_Shape(other.m_Shape)
 , m_DataType(other.m_DataType)
+, m_IsConstant(other.m_IsConstant)
 , m_Quantization(other.m_Quantization)
 {}
 
@@ -400,6 +409,7 @@ TensorInfo& TensorInfo::operator=(const TensorInfo& other)
     m_Shape = other.m_Shape;
     m_DataType = other.m_DataType;
     m_Quantization = other.m_Quantization;
+    m_IsConstant = other.m_IsConstant;
     return *this;
 }
 
@@ -407,7 +417,8 @@ bool TensorInfo::operator==(const TensorInfo& other) const
 {
     return ((m_Shape == other.m_Shape) &&
             (m_DataType == other.m_DataType) &&
-            (m_Quantization == other.m_Quantization));
+            (m_Quantization == other.m_Quantization) &&
+            (m_IsConstant == other.m_IsConstant));
 }
 
 bool TensorInfo::operator!=(const TensorInfo& other) const
@@ -497,6 +508,16 @@ bool TensorInfo::IsQuantized() const
     return IsQuantizedType(m_DataType);
 }
 
+bool TensorInfo::IsConstant() const
+{
+    return m_IsConstant;
+}
+
+void TensorInfo::SetConstant(const bool IsConstant)
+{
+    m_IsConstant = IsConstant;
+}
+
 // ---
 // --- BaseTensor
 // ---