IVGCVSW-2875 Reference implementation and unit tests for Dequantize

Change-Id: Ie4ade0519cb0bbe35dc36be6c9cd749b9171c74b
Signed-off-by: Nattapat Chaimanowong <nattapat.chaimanowong@arm.com>
diff --git a/src/backends/reference/RefLayerSupport.cpp b/src/backends/reference/RefLayerSupport.cpp
index 820f36b..532c8ea 100644
--- a/src/backends/reference/RefLayerSupport.cpp
+++ b/src/backends/reference/RefLayerSupport.cpp
@@ -380,6 +380,16 @@
                                      &TrueFunc<>);
 }
 
+bool RefLayerSupport::IsDequantizeSupported(const TensorInfo& input,
+                                            const TensorInfo& output,
+                                            Optional<std::string&> reasonIfUnsupported) const
+{
+    return IsSupportedForDataTypeRef(reasonIfUnsupported,
+                                     input.GetDataType(),
+                                     &FalseFunc<>,
+                                     &TrueFunc<>);
+}
+
 bool RefLayerSupport::IsDetectionPostProcessSupported(const armnn::TensorInfo& input0,
                                                       const armnn::TensorInfo& input1,
                                                       const armnn::DetectionPostProcessDescriptor& descriptor,
diff --git a/src/backends/reference/RefLayerSupport.hpp b/src/backends/reference/RefLayerSupport.hpp
index c0d7fcf..42a5a44 100644
--- a/src/backends/reference/RefLayerSupport.hpp
+++ b/src/backends/reference/RefLayerSupport.hpp
@@ -65,6 +65,10 @@
                                          const Optional<TensorInfo>& biases,
                                          Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
 
+    bool IsDequantizeSupported(const TensorInfo& input,
+                               const TensorInfo& output,
+                               Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
+
     bool IsDetectionPostProcessSupported(const TensorInfo& input0,
                                          const TensorInfo& input1,
                                          const DetectionPostProcessDescriptor& descriptor,
diff --git a/src/backends/reference/RefWorkloadFactory.cpp b/src/backends/reference/RefWorkloadFactory.cpp
index 3bf83bd..dda1819 100644
--- a/src/backends/reference/RefWorkloadFactory.cpp
+++ b/src/backends/reference/RefWorkloadFactory.cpp
@@ -348,4 +348,10 @@
     return nullptr;
 }
 
+std::unique_ptr<IWorkload> RefWorkloadFactory::CreateDequantize(const DequantizeQueueDescriptor& descriptor,
+                                                                const WorkloadInfo& info) const
+{
+    return MakeWorkload<NullWorkload, RefDequantizeWorkload>(descriptor, info);
+}
+
 } // namespace armnn
diff --git a/src/backends/reference/RefWorkloadFactory.hpp b/src/backends/reference/RefWorkloadFactory.hpp
index 211f93b..14d3178 100644
--- a/src/backends/reference/RefWorkloadFactory.hpp
+++ b/src/backends/reference/RefWorkloadFactory.hpp
@@ -177,6 +177,9 @@
     std::unique_ptr<IWorkload> CreateGather(const GatherQueueDescriptor& descriptor,
                                             const WorkloadInfo& info) const override;
 
+    std::unique_ptr<IWorkload> CreateDequantize(const DequantizeQueueDescriptor& 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 a75146b..90aa63a 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -39,6 +39,7 @@
         workloads/RefDebugWorkload.cpp \
         workloads/RefDepthwiseConvolution2dFloat32Workload.cpp \
         workloads/RefDepthwiseConvolution2dUint8Workload.cpp \
+        workloads/RefDequantizeWorkload.cpp \
         workloads/RefDetectionPostProcessFloat32Workload.cpp \
         workloads/RefDetectionPostProcessUint8Workload.cpp \
         workloads/RefElementwiseWorkload.cpp \
diff --git a/src/backends/reference/test/RefLayerTests.cpp b/src/backends/reference/test/RefLayerTests.cpp
index 13ea82d..c0e2e78 100644
--- a/src/backends/reference/test/RefLayerTests.cpp
+++ b/src/backends/reference/test/RefLayerTests.cpp
@@ -530,5 +530,7 @@
     DetectionPostProcessFastNmsUint8Test<armnn::RefWorkloadFactory>();
 }
 
+// Dequantize
+ARMNN_AUTO_TEST_CASE(DequantizeUint8, DequantizeUint8Test)
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/backends/reference/workloads/CMakeLists.txt b/src/backends/reference/workloads/CMakeLists.txt
index 89aed91..c4fc202 100644
--- a/src/backends/reference/workloads/CMakeLists.txt
+++ b/src/backends/reference/workloads/CMakeLists.txt
@@ -63,6 +63,8 @@
     RefDepthwiseConvolution2dFloat32Workload.hpp
     RefDepthwiseConvolution2dUint8Workload.cpp
     RefDepthwiseConvolution2dUint8Workload.hpp
+    RefDequantizeWorkload.cpp
+    RefDequantizeWorkload.hpp
     RefDetectionPostProcessUint8Workload.cpp
     RefDetectionPostProcessUint8Workload.hpp
     RefDetectionPostProcessFloat32Workload.cpp
diff --git a/src/backends/reference/workloads/RefDequantizeWorkload.cpp b/src/backends/reference/workloads/RefDequantizeWorkload.cpp
new file mode 100644
index 0000000..d861c50
--- /dev/null
+++ b/src/backends/reference/workloads/RefDequantizeWorkload.cpp
@@ -0,0 +1,34 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "RefDequantizeWorkload.hpp"
+#include "RefWorkloadUtils.hpp"
+
+namespace armnn
+{
+
+void RefDequantizeWorkload::Execute() const
+{
+    ARMNN_SCOPED_PROFILING_EVENT(Compute::CpuRef, "RefDequantizeWorkload_Execute");
+
+    const TensorInfo& inputInfo = GetTensorInfo(m_Data.m_Inputs[0]);
+    const DataType& inputDataType = inputInfo.GetDataType();
+
+    float* outputData = GetOutputTensorData<float>(0, m_Data);
+
+    switch (inputDataType)
+    {
+        case DataType::QuantisedAsymm8:
+            Dequantize<uint8_t>(GetInputTensorData<uint8_t>(0, m_Data), outputData, inputInfo);
+            break;
+        case DataType::QuantisedSymm16:
+            Dequantize<int16_t>(GetInputTensorData<int16_t>(0, m_Data), outputData, inputInfo);
+            break;
+        default:
+            throw InvalidArgumentException("RefDequantizeWorkload: Unsupported input data type");
+    }
+}
+
+} // namespace armnn
diff --git a/src/backends/reference/workloads/RefDequantizeWorkload.hpp b/src/backends/reference/workloads/RefDequantizeWorkload.hpp
new file mode 100644
index 0000000..8d019e3
--- /dev/null
+++ b/src/backends/reference/workloads/RefDequantizeWorkload.hpp
@@ -0,0 +1,22 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include <backendsCommon/Workload.hpp>
+
+namespace armnn
+{
+
+class RefDequantizeWorkload : public BaseWorkload<DequantizeQueueDescriptor>
+{
+public:
+    using BaseWorkload<DequantizeQueueDescriptor>::m_Data;
+    using BaseWorkload<DequantizeQueueDescriptor>::BaseWorkload;
+
+    void Execute() const override;
+};
+
+} // namespace armnn
diff --git a/src/backends/reference/workloads/RefWorkloadUtils.hpp b/src/backends/reference/workloads/RefWorkloadUtils.hpp
index feb4329..ce79616 100644
--- a/src/backends/reference/workloads/RefWorkloadUtils.hpp
+++ b/src/backends/reference/workloads/RefWorkloadUtils.hpp
@@ -127,6 +127,15 @@
     return ret;
 }
 
+template<typename T>
+inline void Dequantize(const T* inputData, float* outputData, const TensorInfo& info)
+{
+    for (unsigned int i = 0; i < info.GetNumElements(); i++)
+    {
+        outputData[i] = Dequantize<T>(inputData[i], info.GetQuantizationScale(), info.GetQuantizationOffset());
+    }
+}
+
 inline void Quantize(uint8_t* quant, const float* dequant, const TensorInfo& info)
 {
     for (size_t i = 0; i < info.GetNumElements(); i++)
diff --git a/src/backends/reference/workloads/RefWorkloads.hpp b/src/backends/reference/workloads/RefWorkloads.hpp
index 2156388..7d2e813 100644
--- a/src/backends/reference/workloads/RefWorkloads.hpp
+++ b/src/backends/reference/workloads/RefWorkloads.hpp
@@ -63,3 +63,4 @@
 #include "RefDebugWorkload.hpp"
 #include "RefRsqrtFloat32Workload.hpp"
 #include "RefComparisonWorkload.hpp"
+#include "RefDequantizeWorkload.hpp"