Release 18.02

Change-Id: Id3c11dc5ee94ef664374a988fcc6901e9a232fa6

1 files changed, 60 insertions, 0 deletions

diff --git a/src/armnn/optimizations/OptimizeConsecutiveReshapes.hpp b/src/armnn/optimizations/OptimizeConsecutiveReshapes.hpp
new file mode 100644
index 0000000000..deb49c6884
--- /dev/null
+++ b/src/armnn/optimizations/OptimizeConsecutiveReshapes.hpp
@@ -0,0 +1,60 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// See LICENSE file in the project root for full license information.
+//
+#pragma once
+
+#include "Optimization.hpp"
+
+namespace armnn
+{
+namespace optimizations
+{
+
+class OptimizeConsecutiveReshapesImpl
+{
+public:
+    /// Run for every connection between a base RashapeLayer and a child ReshapeLayer.
+    /// Inserts an equivalent ReshapeLayer that bypasses both for that connection.
+    void Run(Graph& graph, InputSlot& connection) const
+    {
+        auto& base = connection.GetConnectedOutputSlot()->GetOwningLayer();
+        auto& child = connection.GetOwningLayer();
+
+        BOOST_ASSERT(base.GetType() == LayerType::Reshape);
+        BOOST_ASSERT(child.GetType() == LayerType::Reshape);
+
+        OutputSlot* parentOut = base.GetInputSlot(0).GetConnectedOutputSlot();
+
+        const TensorInfo& inInfo = parentOut->GetTensorInfo();
+        const TensorInfo& outInfo = child.GetOutputHandler().GetTensorInfo();
+
+        if (inInfo.GetShape() != outInfo.GetShape())
+        {
+            // Insert equivalent reshape before base layer
+            const std::string name = std::string("merged-") + base.GetName() + std::string("-with-") + child.GetName();
+            const ReshapeDescriptor descriptor{outInfo.GetShape()};
+            auto& newReshape = *graph.InsertNewLayer<ReshapeLayer>(base.GetInputSlot(0), descriptor, name.c_str());
+            // Set tensor info for new layer
+            newReshape.GetOutputHandler().SetTensorInfo(outInfo);
+            // Reconnect base with original parent
+            newReshape.GetOutputSlot().MoveAllConnections(*parentOut);
+            // Parent is now the new layer
+            parentOut = &newReshape.GetOutputSlot();
+        }
+
+        // Move connections in child output to parent layer.
+        // Child layer will be removed as it's left unconnected.
+        // Base layer will be removed if left unconnected.
+        child.GetOutputSlot().MoveAllConnections(*parentOut);
+    }
+
+protected:
+    OptimizeConsecutiveReshapesImpl() = default;
+    ~OptimizeConsecutiveReshapesImpl() = default;
+};
+
+using OptimizeConsecutiveReshapes = OptimizeForConnection<ReshapeLayer, ReshapeLayer, OptimizeConsecutiveReshapesImpl>;
+
+} // namespace optimizations
+} // namespace armnn