IVGCVSW-2371 Add Rsqrt Ref implementation

*Added Unit Tests

Change-Id: I6cceb8e6dcda35ce08415f8e5ca86019a64d26e3

12 files changed, 125 insertions, 1 deletions

diff --git a/src/backends/reference/RefLayerSupport.cpp b/src/backends/reference/RefLayerSupport.cpp
index a64339ec69..56d2e4c659 100644
--- a/src/backends/reference/RefLayerSupport.cpp
+++ b/src/backends/reference/RefLayerSupport.cpp
@@ -495,6 +495,17 @@ bool RefLayerSupport::IsResizeBilinearSupported(const TensorInfo& input,
                                      &TrueFunc<>);
 }
 
+bool RefLayerSupport::IsRsqrtSupported(const TensorInfo& input,
+                                       const TensorInfo& output,
+                                       Optional<std::string&> reasonIfUnsupported) const
+{
+    ignore_unused(output);
+    return IsSupportedForDataTypeRef(reasonIfUnsupported,
+                                     input.GetDataType(),
+                                     &TrueFunc<>,
+                                     &FalseFuncU8<>);
+}
+
 bool RefLayerSupport::IsSoftmaxSupported(const TensorInfo& input,
                                          const TensorInfo& output,
                                          const SoftmaxDescriptor& descriptor,
diff --git a/src/backends/reference/RefLayerSupport.hpp b/src/backends/reference/RefLayerSupport.hpp
index 3941f4bc56..188faa84b6 100644
--- a/src/backends/reference/RefLayerSupport.hpp
+++ b/src/backends/reference/RefLayerSupport.hpp
@@ -185,6 +185,10 @@ public:
     bool IsResizeBilinearSupported(const TensorInfo& input,
                                    Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
 
+    bool IsRsqrtSupported(const TensorInfo& input,
+                          const TensorInfo& output,
+                          Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
+
     bool IsSoftmaxSupported(const TensorInfo& input,
                             const TensorInfo& output,
                             const SoftmaxDescriptor& descriptor,
diff --git a/src/backends/reference/RefWorkloadFactory.cpp b/src/backends/reference/RefWorkloadFactory.cpp
index eb8807eef6..79293635fb 100644
--- a/src/backends/reference/RefWorkloadFactory.cpp
+++ b/src/backends/reference/RefWorkloadFactory.cpp
@@ -312,4 +312,10 @@ std::unique_ptr<IWorkload> RefWorkloadFactory::CreateDebug(const DebugQueueDescr
     return MakeWorkload<RefDebugFloat32Workload, RefDebugUint8Workload>(descriptor, info);
 }
 
-} // namespace armnn
+std::unique_ptr<IWorkload> RefWorkloadFactory::CreateRsqrt(const RsqrtQueueDescriptor& descriptor,
+                                                           const WorkloadInfo& info) const
+{
+    return MakeWorkload<RefRsqrtFloat32Workload, NullWorkload>(descriptor, info);
+}
+
+} // namespace armnn
\ No newline at end of file
diff --git a/src/backends/reference/RefWorkloadFactory.hpp b/src/backends/reference/RefWorkloadFactory.hpp
index f4401ccb6e..f6707f5046 100644
--- a/src/backends/reference/RefWorkloadFactory.hpp
+++ b/src/backends/reference/RefWorkloadFactory.hpp
@@ -164,6 +164,9 @@ public:
 
     virtual std::unique_ptr<IWorkload> CreateDebug(const DebugQueueDescriptor& descriptor,
                                                    const WorkloadInfo& info) const override;
+
+    virtual std::unique_ptr<IWorkload> CreateRsqrt(const RsqrtQueueDescriptor& descriptor,
+                                                   const WorkloadInfo& info) const override;
 private:
 
     template <typename F32Workload, typename U8Workload, typename QueueDescriptorType>
diff --git a/src/backends/reference/backend.mk b/src/backends/reference/backend.mk
index b23c752b89..84f15c9c80 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -57,6 +57,7 @@ BACKEND_SOURCES := \
         workloads/RefReshapeUint8Workload.cpp \
         workloads/RefResizeBilinearFloat32Workload.cpp \
         workloads/RefResizeBilinearUint8Workload.cpp \
+        workloads/RefRsqrtFloat32Workload.cpp \
         workloads/RefSoftmaxFloat32Workload.cpp \
         workloads/RefSoftmaxUint8Workload.cpp \
         workloads/RefSpaceToBatchNdWorkload.cpp \
@@ -64,6 +65,7 @@ BACKEND_SOURCES := \
         workloads/RefSplitterFloat32Workload.cpp \
         workloads/RefSplitterUint8Workload.cpp \
         workloads/ResizeBilinear.cpp \
+        workloads/Rsqrt.cpp \
         workloads/SpaceToBatchNd.cpp \
         workloads/StridedSlice.cpp \
         workloads/StringMapping.cpp \
diff --git a/src/backends/reference/test/RefLayerTests.cpp b/src/backends/reference/test/RefLayerTests.cpp
index 7223f04ea9..50c47aecf9 100644
--- a/src/backends/reference/test/RefLayerTests.cpp
+++ b/src/backends/reference/test/RefLayerTests.cpp
@@ -380,6 +380,12 @@ ARMNN_AUTO_TEST_CASE(SimpleFloor, SimpleFloorTest)
 ARMNN_AUTO_TEST_CASE(SimpleReshapeFloat32, SimpleReshapeFloat32Test)
 ARMNN_AUTO_TEST_CASE(SimpleReshapeUint8, SimpleReshapeUint8Test)
 
+// Rsqrt
+ARMNN_AUTO_TEST_CASE(Rsqrt2d, Rsqrt2dTest)
+ARMNN_AUTO_TEST_CASE(Rsqrt3d, Rsqrt3dTest)
+ARMNN_AUTO_TEST_CASE(RsqrtZero, RsqrtZeroTest)
+ARMNN_AUTO_TEST_CASE(RsqrtNegative, RsqrtNegativeTest)
+
 // Permute
 ARMNN_AUTO_TEST_CASE(SimplePermuteFloat32, SimplePermuteFloat32Test)
 ARMNN_AUTO_TEST_CASE(SimplePermuteUint8, SimplePermuteUint8Test)
diff --git a/src/backends/reference/workloads/CMakeLists.txt b/src/backends/reference/workloads/CMakeLists.txt
index d71e6ea032..d15f77d6e4 100644
--- a/src/backends/reference/workloads/CMakeLists.txt
+++ b/src/backends/reference/workloads/CMakeLists.txt
@@ -94,6 +94,8 @@ list(APPEND armnnRefBackendWorkloads_sources
     RefResizeBilinearFloat32Workload.hpp
     RefResizeBilinearUint8Workload.cpp
     RefResizeBilinearUint8Workload.hpp
+    RefRsqrtFloat32Workload.cpp
+    RefRsqrtFloat32Workload.hpp
     RefSoftmaxFloat32Workload.cpp
     RefSoftmaxFloat32Workload.hpp
     RefSoftmaxUint8Workload.cpp
@@ -110,6 +112,8 @@ list(APPEND armnnRefBackendWorkloads_sources
     RefWorkloadUtils.hpp
     ResizeBilinear.cpp
     ResizeBilinear.hpp
+    Rsqrt.cpp
+    Rsqrt.hpp
     Softmax.cpp
     Softmax.hpp
     SpaceToBatchNd.hpp
diff --git a/src/backends/reference/workloads/RefRsqrtFloat32Workload.cpp b/src/backends/reference/workloads/RefRsqrtFloat32Workload.cpp
new file mode 100644
index 0000000000..c08dbf0cab
--- /dev/null
+++ b/src/backends/reference/workloads/RefRsqrtFloat32Workload.cpp
@@ -0,0 +1,25 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "RefRsqrtFloat32Workload.hpp"
+
+#include "RefWorkloadUtils.hpp"
+#include "Rsqrt.hpp"
+
+#include <Profiling.hpp>
+
+namespace armnn
+{
+
+void RefRsqrtFloat32Workload::Execute() const
+{
+    ARMNN_SCOPED_PROFILING_EVENT(Compute::CpuRef, "RefRsqrtFloat32Workload_Execute");
+
+    Rsqrt(GetInputTensorDataFloat(0, m_Data),
+          GetOutputTensorDataFloat(0, m_Data),
+          GetTensorInfo(m_Data.m_Inputs[0]));
+}
+
+} //namespace armnn
diff --git a/src/backends/reference/workloads/RefRsqrtFloat32Workload.hpp b/src/backends/reference/workloads/RefRsqrtFloat32Workload.hpp
new file mode 100644
index 0000000000..9d1b4505fe
--- /dev/null
+++ b/src/backends/reference/workloads/RefRsqrtFloat32Workload.hpp
@@ -0,0 +1,21 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include <backendsCommon/Workload.hpp>
+#include <backendsCommon/WorkloadData.hpp>
+
+namespace armnn
+{
+
+class RefRsqrtFloat32Workload : public Float32Workload<RsqrtQueueDescriptor>
+{
+public:
+    using Float32Workload<RsqrtQueueDescriptor>::Float32Workload;
+    virtual void Execute() const override;
+};
+
+} //namespace armnn
diff --git a/src/backends/reference/workloads/RefWorkloads.hpp b/src/backends/reference/workloads/RefWorkloads.hpp
index ddce68e60c..8beb03fe32 100644
--- a/src/backends/reference/workloads/RefWorkloads.hpp
+++ b/src/backends/reference/workloads/RefWorkloads.hpp
@@ -59,3 +59,4 @@
 #include "RefBatchToSpaceNdUint8Workload.hpp"
 #include "RefBatchToSpaceNdFloat32Workload.hpp"
 #include "RefDebugWorkload.hpp"
+#include "RefRsqrtFloat32Workload.hpp"
diff --git a/src/backends/reference/workloads/Rsqrt.cpp b/src/backends/reference/workloads/Rsqrt.cpp
new file mode 100644
index 0000000000..cee38fc1f1
--- /dev/null
+++ b/src/backends/reference/workloads/Rsqrt.cpp
@@ -0,0 +1,23 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "Rsqrt.hpp"
+
+#include <cmath>
+
+namespace armnn
+{
+
+void Rsqrt(const float* in,
+           float* out,
+           const TensorInfo& tensorInfo)
+{
+    for (size_t i = 0; i < tensorInfo.GetNumElements(); i++)
+    {
+        out[i] = 1.f / sqrtf(in[i]);
+    }
+}
+
+} //namespace armnn
\ No newline at end of file
diff --git a/src/backends/reference/workloads/Rsqrt.hpp b/src/backends/reference/workloads/Rsqrt.hpp
new file mode 100644
index 0000000000..35cacede66
--- /dev/null
+++ b/src/backends/reference/workloads/Rsqrt.hpp
@@ -0,0 +1,18 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include <armnn/Tensor.hpp>
+#include <armnn/Types.hpp>
+
+namespace armnn
+{
+
+/// Performs the reciprocal squareroot function elementwise
+/// on the inputs to give the outputs.
+void Rsqrt(const float* in,
+           float* out,
+           const TensorInfo& tensorInfo);
+
+} //namespace armnn