IVGCVSW-7830 Remove Reshape where possible

 * Remove reshape on ClBackend
 * Remove unnecessary restriction on NeonBackend remove Reshape

Signed-off-by: Mike Kelly <mike.kelly@arm.com>
Change-Id: I79940c9f8609d19b79f2fbe55225ffc8f0d90c25

3 files changed, 28 insertions, 5 deletions

diff --git a/src/backends/cl/ClBackend.cpp b/src/backends/cl/ClBackend.cpp
index 1d8ae21e5d..6d191a594b 100644
--- a/src/backends/cl/ClBackend.cpp
+++ b/src/backends/cl/ClBackend.cpp
@@ -673,6 +673,19 @@ OptimizationViews ClBackend::OptimizeSubgraphView(const SubgraphView& subgraph,
             }
         }
 
+        // Remove Reshape where possible
+        if (base.GetType() == LayerType::Reshape)
+        {
+            ReshapeLayer* baseLayer = PolymorphicDowncast<ReshapeLayer*>(&base);
+
+            // Cannot remove a Reshape if it's connected to any layer that has an NCHW layout
+            if (ConnectedToLayerWithNCHW(baseLayer))
+            {
+                continue;
+            }
+            RemoveReshapeLayer(baseLayer, untouched, optimizationViews);
+        }
+
         // Special case to fuse padding into average pooling 2d for quantized datatype.
         // Required to be done as a backend specific optimization as Neon does not support this special case.
         if (base.GetType() == LayerType::Pooling2d)
diff --git a/src/backends/cl/test/ClEndToEndTests.cpp b/src/backends/cl/test/ClEndToEndTests.cpp
index 2436a8223f..78d2dea90d 100644
--- a/src/backends/cl/test/ClEndToEndTests.cpp
+++ b/src/backends/cl/test/ClEndToEndTests.cpp
@@ -673,4 +673,19 @@ TEST_CASE("ClForceImportWithMisalignedInputAndOutputBuffersEndToEndTest")
     ForceImportWithMisalignedInputAndOutputBuffersEndToEndTest(clDefaultBackends);
 }
 
+TEST_CASE("ClReshapeRemovalSimpleCaseEndToEnd")
+{
+    ReshapeRemovalEndToEnd<armnn::DataType::Float32>(clDefaultBackends);
+}
+
+TEST_CASE("ClReshapeRemovalNCHWFirstEndToEnd")
+{
+    ReshapeRemovalNCHWEndToEnd<armnn::DataType::Float32>(clDefaultBackends, false, true);
+}
+
+TEST_CASE("ClReshapeRemovalNCHWSecondEndToEnd")
+{
+    ReshapeRemovalNCHWEndToEnd<armnn::DataType::Float32>(clDefaultBackends, false, false);
+}
+
 }
diff --git a/src/backends/neon/NeonBackend.cpp b/src/backends/neon/NeonBackend.cpp
index 7311098631..ebce1a69de 100644
--- a/src/backends/neon/NeonBackend.cpp
+++ b/src/backends/neon/NeonBackend.cpp
@@ -519,11 +519,6 @@ OptimizationViews NeonBackend::OptimizeSubgraphView(const SubgraphView& subgraph
             {
                 continue;
             }
-            // Cannot remove a Reshape if it's connected to a SplitterLayer
-            if (ConnectedToLayerType(baseLayer, LayerType::Splitter))
-            {
-                continue;
-            }
             RemoveReshapeLayer(baseLayer, untouched, optimizationViews);
         }