IVGCVSW-6119 ConstTensorsAsInput: FullyConnected Bug Fix

 * Updated FullyConnected layer member variables when cloning as
   some backends still require them.
 * Added SetConstant call when using deprecated AddFullyConnectedLayer
   method to ensure backwards compatibility.
 * Added SetConstant to SimpleSample to ensure it runs on all backends.

Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: Ie7b4e4b868f23f8fcf9c41ffd12e2ea9ea53afca

4 files changed, 23 insertions, 3 deletions

diff --git a/samples/SimpleSample.cpp b/samples/SimpleSample.cpp
index 6bdc2983bb..3f94b53ca1 100644
--- a/samples/SimpleSample.cpp
+++ b/samples/SimpleSample.cpp
@@ -29,6 +29,7 @@ int main()
 
     float weightsData[] = {1.0f}; // Identity
     TensorInfo weightsInfo(TensorShape({1, 1}), DataType::Float32);
+    weightsInfo.SetConstant();
     ConstTensor weights(weightsInfo, weightsData);
 
     // Constant layer that now holds weights data for FullyConnected
@@ -54,7 +55,7 @@ int main()
 
     TensorInfo outputTensorInfo(TensorShape({1, 1}), DataType::Float32);
     fullyConnectedLayer->GetOutputSlot(0).SetTensorInfo(outputTensorInfo);
-    constantWeightsLayer->GetOutputSlot(0).SetTensorInfo(outputTensorInfo);
+    constantWeightsLayer->GetOutputSlot(0).SetTensorInfo(weightsInfo);
 
     // Optimise ArmNN network
     IOptimizedNetworkPtr optNet = Optimize(*myNetwork, {Compute::CpuRef}, run->GetDeviceSpec());
diff --git a/src/armnn/BackendHelper.cpp b/src/armnn/BackendHelper.cpp
index 9ab30f8fb2..594d76916c 100644
--- a/src/armnn/BackendHelper.cpp
+++ b/src/armnn/BackendHelper.cpp
@@ -407,12 +407,18 @@ bool LayerSupportHandle::IsFullyConnectedSupported(const TensorInfo& input,
         {
             if(!weights.IsConstant())
             {
+                reasonIfUnsupported.value() =
+                        "This backend might not support non constant weights. "
+                        "If weights are constant make sure to set IsConstant when creating TensorInfo";
                 return false;
             }
             if(descriptor.m_BiasEnabled)
             {
                 if(!biases.IsConstant())
                 {
+                    reasonIfUnsupported.value() =
+                            "This backend might not support non constant bias. "
+                            "If bias are constant make sure to set IsConstant when creating TensorInfo";
                     return false;
                 }
             }
diff --git a/src/armnn/Network.cpp b/src/armnn/Network.cpp
index 22a71c4923..365f1bdfa1 100644
--- a/src/armnn/Network.cpp
+++ b/src/armnn/Network.cpp
@@ -1805,7 +1805,11 @@ IConnectableLayer* NetworkImpl::AddFullyConnectedLayer(const FullyConnectedDescr
     {
         weightsLayer = m_Graph->AddLayer<ConstantLayer>("Weights");
         weightsLayer->m_LayerOutput = std::make_shared<ScopedTensorHandle>(weights.value());
-        weightsLayer->GetOutputSlot(0).SetTensorInfo(weightsLayer->m_LayerOutput->GetTensorInfo());
+
+        TensorInfo weightsInfo = weightsLayer->m_LayerOutput->GetTensorInfo();
+        weightsInfo.SetConstant();
+
+        weightsLayer->GetOutputSlot(0).SetTensorInfo(weightsInfo);
     }
     else if (fullyConnectedDescriptor.m_ConstantWeights)
     {
@@ -1817,7 +1821,11 @@ IConnectableLayer* NetworkImpl::AddFullyConnectedLayer(const FullyConnectedDescr
     {
         biasLayer = m_Graph->AddLayer<ConstantLayer>("Biases");
         biasLayer->m_LayerOutput = std::make_shared<ScopedTensorHandle>(biases.value());
-        biasLayer->GetOutputSlot(0).SetTensorInfo(biasLayer->m_LayerOutput->GetTensorInfo());
+
+        TensorInfo biasInfo = biasLayer->m_LayerOutput->GetTensorInfo();
+        biasInfo.SetConstant();
+
+        biasLayer->GetOutputSlot(0).SetTensorInfo(biasInfo);
     }
 
     if (numInputs < 2)
diff --git a/src/armnn/layers/FullyConnectedLayer.cpp b/src/armnn/layers/FullyConnectedLayer.cpp
index 8dfb011730..259d4149c8 100644
--- a/src/armnn/layers/FullyConnectedLayer.cpp
+++ b/src/armnn/layers/FullyConnectedLayer.cpp
@@ -38,6 +38,11 @@ std::unique_ptr<IWorkload> FullyConnectedLayer::CreateWorkload(const IWorkloadFa
 FullyConnectedLayer* FullyConnectedLayer::Clone(Graph& graph) const
 {
     auto layer = CloneBase<FullyConnectedLayer>(graph, m_Param, GetName());
+    layer->m_Weight = m_Weight ? m_Weight : nullptr;
+    if (layer->m_Param.m_BiasEnabled)
+    {
+        layer->m_Bias = m_Bias ? m_Bias : nullptr;
+    }
     return std::move(layer);
 }