IVGCVSW-2127- Update HAL Policy for mergerbranches/android-nn-driver_18_11

 * Remove permutation when concat axis is inner most
 * Add additional parameter to IsMergerSupported as changed in armnn

!armnn:151

Change-Id: Ie214c9573f242d8f04d58fc61621ad3831991d9a

2 files changed, 38 insertions, 50 deletions

diff --git a/1.0/HalPolicy.cpp b/1.0/HalPolicy.cpp
index d0bd95bb..719d1a24 100644
--- a/1.0/HalPolicy.cpp
+++ b/1.0/HalPolicy.cpp
@@ -241,17 +241,22 @@ bool HalPolicy::ConvertConcatenation(const Operation& operation, const Model& mo
         }
         else if (tensorDimensionsAdded == 2)
         {
-            outputShape = armnn::TensorShape({1, 1, outputShape[0], outputShape[1]});
+            outputShape = armnn::TensorShape({1, 1, outputShape[0]});
         }
     }
 
-    // Get the pair of permutations required for the concatenation
+    // Check if permutations is required and get the pair of permutations required for the concatenation.
+    // Permutation is required when the concat dimension is 2 for a 4D tensor or 1 for a 3D tensor.
     std::pair<armnn::PermutationVector, armnn::PermutationVector> permutationPair =
             std::make_pair(IdentityPermutation4D, IdentityPermutation4D);
 
-    CreatePermutationParameters(inputShapes[0].GetNumDimensions(), concatDim, permutationPair);
+    bool needPermute = CreateConcatPermutationParameters(inputShapes[0].GetNumDimensions(), concatDim, permutationPair);
+
+    if (needPermute)
+    {
+        outputShape = armnnUtils::Permuted(outputShape, permutationPair.first);
+    }
 
-    outputShape = armnnUtils::Permuted(outputShape, permutationPair.first);
     outputInfo.SetShape(outputShape);
 
     // this is no-op for identity swizzles, otherwise it replaces both
@@ -260,10 +265,11 @@ bool HalPolicy::ConvertConcatenation(const Operation& operation, const Model& mo
 
     // Create an armnn merger layer descriptor - this will also perform validation on the input shapes
     armnn::OriginsDescriptor mergerDescriptor;
+
     try
     {
-        // The merger descriptor is always created across the only supported concat
-        // dimension, which is 0 or 1
+        // The merger descriptor is always created across the only supported concat dimension
+        // which is 0, 1 or 3 for a 4-D tensor, or 0 or 2 for a 3-D tensor.
         mergerDescriptor =
             armnn::CreateMergerDescriptorForConcatenation(
                 inputShapes.begin(), inputShapes.end(), concatDim);
@@ -274,7 +280,7 @@ bool HalPolicy::ConvertConcatenation(const Operation& operation, const Model& mo
     }
 
     // Validate the output shape is correct given the input shapes based on the
-    // only valid concat dimension which is 0 or 1
+    // only valid concat dimension which is 0, 1 or 3 for a 4-D tensor, or 0 or 2 for a 3-D tensor.
     if (!ValidateConcatOutputShape(inputShapes, outputShape, concatDim))
     {
         return Fail("%s: Error validating the output shape for concat", __func__);
@@ -287,6 +293,7 @@ bool HalPolicy::ConvertConcatenation(const Operation& operation, const Model& mo
                           armnn::IsMergerSupported,
                           data.m_Compute,
                           inputTensorInfos,
+                          outputInfo,
                           mergerDescriptor))
     {
         return false;
@@ -305,11 +312,14 @@ bool HalPolicy::ConvertConcatenation(const Operation& operation, const Model& mo
         inputHandles[static_cast<unsigned int>(i)].Connect(layer->GetInputSlot(i));
     }
 
-    // Add permutation layer and connect the output to it, the permutation becomes the output layer
-    armnn::IConnectableLayer& deswizzleLayer = AddPermuteLayer(*data.m_Network,
-                                                               layer->GetOutputSlot(0),
-                                                               permutationPair.second);
-    layer = &deswizzleLayer;
+    if (needPermute)
+    {
+        // Add permutation layer and connect the output to it, the permutation becomes the output layer
+        armnn::IConnectableLayer& deswizzleLayer = AddPermuteLayer(*data.m_Network,
+                                                                   layer->GetOutputSlot(0),
+                                                                   permutationPair.second);
+        layer = &deswizzleLayer;
+    }
 
     if (inputsHaveBeenReshaped)
     {
@@ -323,8 +333,7 @@ bool HalPolicy::ConvertConcatenation(const Operation& operation, const Model& mo
         }
         else if (tensorDimensionsAdded == 2)
         {
-            afterConcatInfo.SetShape(armnn::TensorShape({ afterConcatInfo.GetShape()[2],
-                                                          afterConcatInfo.GetShape()[3] }));
+            afterConcatInfo.SetShape(armnn::TensorShape({ afterConcatInfo.GetShape()[2] }));
         }
 
         layer = &AddReshapeLayer(
diff --git a/ConversionUtils.hpp b/ConversionUtils.hpp
index 68ce09d8..c86ad93c 100644
--- a/ConversionUtils.hpp
+++ b/ConversionUtils.hpp
@@ -390,50 +390,29 @@ void SwizzleInputs(armnn::INetwork& network,
     }
 }
 
-void CreatePermutationParameters(const unsigned int numberOfDimensions,
-                                 int32_t & concatDimension,
-                                 std::pair<armnn::PermutationVector, armnn::PermutationVector> & permutationPair)
+bool CreateConcatPermutationParameters(const unsigned int numberOfDimensions,
+                                       int32_t & concatDimension,
+                                       std::pair<armnn::PermutationVector, armnn::PermutationVector> & permutationPair)
 {
+    bool needPermute = false;
     BOOST_ASSERT(numberOfDimensions >= 3);
 
     // ArmNN uses Compute Library subtensors to perform concatenation
-    // This only works when concatenating along dimension 0 or 1 for a 4-D tensor,
-    // or along dimension 0 for a 3-D tensor.
-    if (numberOfDimensions == 4)
+    // This only works when concatenating along dimension 0, 1 or 3 for a 4-D tensor,
+    // or along dimension 0 or 2 for a 3-D tensor.
+    if (numberOfDimensions == 4 && concatDimension == 2)
     {
-        if (concatDimension == 3)
-        {
-            concatDimension = 1;
-            permutationPair = std::make_pair(NHWCToArmNN, ArmNNToNHWC);
-        }
-        else if (concatDimension == 2)
-        {
-            concatDimension = 1;
-            permutationPair = std::make_pair(SwapDim1And2, SwapDim1And2);
-        }
-        else
-        {
-            permutationPair = std::make_pair(IdentityPermutation4D, IdentityPermutation4D);
-        }
-
+        concatDimension = 1;
+        permutationPair = std::make_pair(SwapDim1And2, SwapDim1And2);
+        needPermute = true;
     }
-    else if (numberOfDimensions == 3)
+    else if (numberOfDimensions == 3 && concatDimension == 1)
     {
-        if (concatDimension == 2)
-        {
-            concatDimension = 0;
-            permutationPair = std::make_pair(RotateTensorRight, RotateTensorLeft);
-        }
-        else if (concatDimension == 1)
-        {
-            concatDimension = 0;
-            permutationPair = std::make_pair(RotateTensorLeft, RotateTensorRight);
-        }
-        else
-        {
-            permutationPair = std::make_pair(IdentityPermutation3D, IdentityPermutation3D);
-        }
+        concatDimension = 0;
+        permutationPair = std::make_pair(RotateTensorLeft, RotateTensorRight);
+        needPermute = true;
     }
+    return needPermute;
 }
 
 } // anonymous namespace