IVGCVSW-1952 : add BackendId class to prepare for the replacement of Compute enum

!armnn:152674

Change-Id: I1bcdfdfbfb73e502d58f35717e2558e24651013c

13 files changed, 205 insertions, 71 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 501da806ad..dfda4d1d93 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -147,18 +147,23 @@ endif()
 
 list(APPEND armnn_sources
     include/armnn/ArmNN.hpp
+    include/armnn/BackendId.hpp
     include/armnn/Descriptors.hpp
     include/armnn/DescriptorsFwd.hpp
-    include/armnn/IRuntime.hpp
+    include/armnn/Exceptions.hpp
     include/armnn/ILayerSupport.hpp
     include/armnn/INetwork.hpp
+    include/armnn/IProfiler.hpp
+    include/armnn/IRuntime.hpp
+    include/armnn/LayerSupport.hpp
+    include/armnn/LstmParams.hpp
+    include/armnn/NetworkFwd.hpp
     include/armnn/Optional.hpp
     include/armnn/Tensor.hpp
     include/armnn/TensorFwd.hpp
     include/armnn/Types.hpp
     include/armnn/TypesUtils.hpp
     include/armnn/Utils.hpp
-    include/armnn/LayerSupport.hpp
     include/armnn/Version.hpp
     src/armnn/layers/LayerCloneBase.hpp
     src/armnn/layers/LayerWithParameters.hpp
@@ -378,6 +383,7 @@ if(BUILD_UNIT_TESTS)
         src/armnn/test/InstrumentTests.cpp
         src/armnn/test/ObservableTest.cpp
         src/armnn/test/OptionalTest.cpp
+        src/backends/test/BackendIdTests.cpp
         src/backends/test/BackendRegistryTests.cpp
         src/backends/test/IsLayerSupportedTestImpl.hpp
         src/backends/test/WorkloadDataValidation.cpp
diff --git a/include/armnn/BackendId.hpp b/include/armnn/BackendId.hpp
new file mode 100644
index 0000000000..d1f06beba7
--- /dev/null
+++ b/include/armnn/BackendId.hpp
@@ -0,0 +1,132 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#pragma once
+
+#include <set>
+#include <unordered_set>
+#include <string>
+#include <memory>
+
+namespace armnn
+{
+
+//
+// The Compute enum is now deprecated and it is now
+// replaced by BackendId
+//
+enum class Compute
+{
+    /// CPU Execution: Reference C++ kernels
+    CpuRef      = 0,
+    /// CPU Execution: NEON: ArmCompute
+    CpuAcc      = 1,
+    /// GPU Execution: OpenCL: ArmCompute
+    GpuAcc      = 2,
+    Undefined   = 5
+};
+
+constexpr char const* GetComputeDeviceAsCString(Compute compute)
+{
+    switch (compute)
+    {
+        case armnn::Compute::CpuRef: return "CpuRef";
+        case armnn::Compute::CpuAcc: return "CpuAcc";
+        case armnn::Compute::GpuAcc: return "GpuAcc";
+        default:                     return "Unknown";
+    }
+}
+
+inline std::ostream& operator<<(std::ostream& os, const std::vector<Compute>& compute)
+{
+    for (const Compute& comp : compute) {
+        os << GetComputeDeviceAsCString(comp) << " ";
+    }
+    return os;
+}
+
+inline std::ostream& operator<<(std::ostream& os, const std::set<Compute>& compute)
+{
+    for (const Compute& comp : compute) {
+        os << GetComputeDeviceAsCString(comp) << " ";
+    }
+    return os;
+}
+
+inline std::ostream& operator<<(std::ostream& os, const Compute& compute)
+{
+    os << GetComputeDeviceAsCString(compute);
+    return os;
+}
+
+class BackendId final
+{
+public:
+    BackendId(const std::string& id) : m_Id{id} {}
+    BackendId(const char* id) : m_Id{id} {}
+    BackendId(Compute compute) : m_Id{GetComputeDeviceAsCString(compute)} {}
+
+    operator std::string() const { return m_Id; }
+
+    BackendId& operator=(const std::string& other)
+    {
+        m_Id = other;
+        return *this;
+    }
+
+    BackendId& operator=(Compute compute)
+    {
+        BackendId temp{compute};
+        std::swap(temp.m_Id, m_Id);
+        return *this;
+    }
+
+    bool operator==(const BackendId& other) const
+    {
+        return m_Id == other.m_Id;
+    }
+
+    bool operator<(const BackendId& other) const
+    {
+        return m_Id < other.m_Id;
+    }
+
+    const std::string& Get() const { return m_Id; }
+
+private:
+    // backend Id mustn't be empty:
+    BackendId() = delete;
+    std::string m_Id;
+};
+
+template <template <class...> class TContainer>
+inline std::ostream& operator<<(std::ostream& os,
+                                const TContainer<BackendId>& ids)
+{
+    os << '[';
+    for (const auto& id : ids) { os << id.Get() << " "; }
+    os << ']';
+    return os;
+}
+
+using BackendIdSet = std::unordered_set<BackendId>;
+
+} // namespace armnn
+
+namespace std
+{
+
+// make BackendId compatible with std hashtables by reusing the hash
+// function for strings
+template <>
+struct hash<armnn::BackendId>
+{
+    std::size_t operator()(const armnn::BackendId& id) const
+    {
+        std::hash<std::string> hasher;
+        return hasher(id.Get());
+    }
+};
+
+} // namespace std
diff --git a/include/armnn/Types.hpp b/include/armnn/Types.hpp
index b7ee9472a3..4afc50b1b1 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -7,6 +7,7 @@
 #include <array>
 #include <memory>
 #include "ILayerSupport.hpp"
+#include "BackendId.hpp"
 
 namespace armnn
 {
@@ -94,17 +95,6 @@ enum class OutputShapeRounding
     Ceiling     = 1
 };
 
-enum class Compute
-{
-    /// CPU Execution: Reference C++ kernels
-    CpuRef      = 0,
-    /// CPU Execution: NEON: ArmCompute
-    CpuAcc      = 1,
-    /// GPU Execution: OpenCL: ArmCompute
-    GpuAcc      = 2,
-    Undefined   = 5
-};
-
 /// Each backend should implement an IBackend.
 class IBackend
 {
@@ -113,7 +103,7 @@ protected:
     virtual ~IBackend() {}
 
 public:
-    virtual const std::string& GetId() const = 0;
+    virtual const BackendId& GetId() const = 0;
     virtual const ILayerSupport& GetLayerSupport() const = 0;
 };
 
@@ -189,4 +179,4 @@ private:
 /// Define LayerGuid type.
 using LayerGuid = unsigned int;
 
-}
+} // namespace armnn
diff --git a/include/armnn/TypesUtils.hpp b/include/armnn/TypesUtils.hpp
index c6db905bb9..a9755bd112 100644
--- a/include/armnn/TypesUtils.hpp
+++ b/include/armnn/TypesUtils.hpp
@@ -15,9 +15,9 @@
 namespace armnn
 {
 
-constexpr char const* GetStatusAsCString(Status compute)
+constexpr char const* GetStatusAsCString(Status status)
 {
-    switch (compute)
+    switch (status)
     {
         case armnn::Status::Success: return "Status::Success";
         case armnn::Status::Failure: return "Status::Failure";
@@ -25,17 +25,6 @@ constexpr char const* GetStatusAsCString(Status compute)
     }
 }
 
-constexpr char const* GetComputeDeviceAsCString(Compute compute)
-{
-    switch (compute)
-    {
-        case armnn::Compute::CpuRef: return "CpuRef";
-        case armnn::Compute::CpuAcc: return "CpuAcc";
-        case armnn::Compute::GpuAcc: return "GpuAcc";
-        default:                     return "Unknown";
-    }
-}
-
 constexpr char const* GetActivationFunctionAsCString(ActivationFunction activation)
 {
     switch (activation)
@@ -194,27 +183,6 @@ inline std::ostream& operator<<(std::ostream& os, Status stat)
     return os;
 }
 
-inline std::ostream& operator<<(std::ostream& os, const std::vector<Compute>& compute)
-{
-    for (const Compute& comp : compute) {
-        os << GetComputeDeviceAsCString(comp) << " ";
-    }
-    return os;
-}
-
-inline std::ostream& operator<<(std::ostream& os, const std::set<Compute>& compute)
-{
-    for (const Compute& comp : compute) {
-        os << GetComputeDeviceAsCString(comp) << " ";
-    }
-    return os;
-}
-
-inline std::ostream& operator<<(std::ostream& os, const Compute& compute)
-{
-    os << GetComputeDeviceAsCString(compute);
-    return os;
-}
 
 inline std::ostream & operator<<(std::ostream & os, const armnn::TensorShape & shape)
 {
diff --git a/src/backends/BackendRegistry.cpp b/src/backends/BackendRegistry.cpp
index 68336c45b9..a5e9f0e1d9 100644
--- a/src/backends/BackendRegistry.cpp
+++ b/src/backends/BackendRegistry.cpp
@@ -15,22 +15,22 @@ BackendRegistry& BackendRegistry::Instance()
     return instance;
 }
 
-void BackendRegistry::Register(const std::string& name, FactoryFunction factory)
+void BackendRegistry::Register(const BackendId& id, FactoryFunction factory)
 {
-    if (m_BackendFactories.count(name) > 0)
+    if (m_BackendFactories.count(id) > 0)
     {
-        throw InvalidArgumentException(name + " already registered as backend");
+        throw InvalidArgumentException(std::string(id) + " already registered as backend");
     }
 
-    m_BackendFactories[name] = factory;
+    m_BackendFactories[id] = factory;
 }
 
-BackendRegistry::FactoryFunction BackendRegistry::GetFactory(const std::string& name) const
+BackendRegistry::FactoryFunction BackendRegistry::GetFactory(const BackendId& id) const
 {
-    auto it = m_BackendFactories.find(name);
+    auto it = m_BackendFactories.find(id);
     if (it == m_BackendFactories.end())
     {
-        throw InvalidArgumentException(name + " has no backend factory registered");
+        throw InvalidArgumentException(std::string(id) + " has no backend factory registered");
     }
 
     return it->second;
@@ -42,4 +42,14 @@ void BackendRegistry::Swap(BackendRegistry::FactoryStorage& other)
     std::swap(instance.m_BackendFactories, other);
 }
 
+BackendIdSet BackendRegistry::GetBackendIds() const
+{
+    BackendIdSet result;
+    for (const auto& it : m_BackendFactories)
+    {
+        result.insert(it.first);
+    }
+    return result;
 }
+
+} // namespace armnn
diff --git a/src/backends/BackendRegistry.hpp b/src/backends/BackendRegistry.hpp
index ff01d21715..e2c526d293 100644
--- a/src/backends/BackendRegistry.hpp
+++ b/src/backends/BackendRegistry.hpp
@@ -5,7 +5,6 @@
 #pragma once
 
 #include <armnn/Types.hpp>
-#include <string>
 #include <functional>
 #include <memory>
 #include <unordered_map>
@@ -21,21 +20,23 @@ public:
     using FactoryFunction = std::function<IBackendUniquePtr()>;
 
     static BackendRegistry& Instance();
-    void Register(const std::string& name, FactoryFunction factory);
-    FactoryFunction GetFactory(const std::string& name) const;
+
+    void Register(const BackendId& id, FactoryFunction factory);
+    FactoryFunction GetFactory(const BackendId& id) const;
 
     struct Helper
     {
-        Helper(const std::string& name, FactoryFunction factory)
+        Helper(const BackendId& id, FactoryFunction factory)
         {
-            BackendRegistry::Instance().Register(name, factory);
+            BackendRegistry::Instance().Register(id, factory);
         }
     };
 
     size_t Size() const { return m_BackendFactories.size(); }
+    BackendIdSet GetBackendIds() const;
 
 protected:
-    using FactoryStorage = std::unordered_map<std::string, FactoryFunction>;
+    using FactoryStorage = std::unordered_map<BackendId, FactoryFunction>;
 
     // For testing only
     static void Swap(FactoryStorage& other);
diff --git a/src/backends/cl/ClBackend.cpp b/src/backends/cl/ClBackend.cpp
index d185c15b72..840da8bda3 100644
--- a/src/backends/cl/ClBackend.cpp
+++ b/src/backends/cl/ClBackend.cpp
@@ -12,7 +12,7 @@ namespace armnn
 
 namespace
 {
-static const std::string s_Id = "GpuAcc";
+static const BackendId s_Id{"GpuAcc"};
 
 static BackendRegistry::Helper g_RegisterHelper{
     s_Id,
@@ -24,7 +24,7 @@ static BackendRegistry::Helper g_RegisterHelper{
 
 }
 
-const std::string& ClBackend::GetId() const
+const BackendId& ClBackend::GetId() const
 {
     return s_Id;
 }
diff --git a/src/backends/cl/ClBackend.hpp b/src/backends/cl/ClBackend.hpp
index c43b6a6ce0..b927db4b25 100644
--- a/src/backends/cl/ClBackend.hpp
+++ b/src/backends/cl/ClBackend.hpp
@@ -16,7 +16,7 @@ public:
     ClBackend()  = default;
     ~ClBackend() = default;
 
-    const std::string& GetId() const override;
+    const BackendId& GetId() const override;
 
     const ILayerSupport& GetLayerSupport() const override;
 
diff --git a/src/backends/neon/NeonBackend.cpp b/src/backends/neon/NeonBackend.cpp
index b4f1897704..e35bf7ea45 100644
--- a/src/backends/neon/NeonBackend.cpp
+++ b/src/backends/neon/NeonBackend.cpp
@@ -13,7 +13,7 @@ namespace armnn
 namespace
 {
 
-static const std::string s_Id = "CpuAcc";
+static const BackendId s_Id{"CpuAcc"};
 
 static BackendRegistry::Helper g_RegisterHelper{
     s_Id,
@@ -25,7 +25,7 @@ static BackendRegistry::Helper g_RegisterHelper{
 
 }
 
-const std::string& NeonBackend::GetId() const
+const BackendId& NeonBackend::GetId() const
 {
     return s_Id;
 }
diff --git a/src/backends/neon/NeonBackend.hpp b/src/backends/neon/NeonBackend.hpp
index 5d4bd5dfcc..fa2cad13ee 100644
--- a/src/backends/neon/NeonBackend.hpp
+++ b/src/backends/neon/NeonBackend.hpp
@@ -16,7 +16,7 @@ public:
     NeonBackend()  = default;
     ~NeonBackend() = default;
 
-    const std::string& GetId() const override;
+    const BackendId& GetId() const override;
 
     const ILayerSupport& GetLayerSupport() const override;
 
diff --git a/src/backends/reference/RefBackend.cpp b/src/backends/reference/RefBackend.cpp
index b671e8bca8..63eff52b75 100644
--- a/src/backends/reference/RefBackend.cpp
+++ b/src/backends/reference/RefBackend.cpp
@@ -12,7 +12,7 @@ namespace armnn
 
 namespace
 {
-const std::string s_Id = "CpuRef";
+const BackendId s_Id{"CpuRef"};
 
 static BackendRegistry::Helper s_RegisterHelper{
     s_Id,
@@ -24,7 +24,7 @@ static BackendRegistry::Helper s_RegisterHelper{
 
 }
 
-const std::string& RefBackend::GetId() const
+const BackendId& RefBackend::GetId() const
 {
     return s_Id;
 }
diff --git a/src/backends/reference/RefBackend.hpp b/src/backends/reference/RefBackend.hpp
index e4a11f10c9..dcc974167d 100644
--- a/src/backends/reference/RefBackend.hpp
+++ b/src/backends/reference/RefBackend.hpp
@@ -16,7 +16,7 @@ public:
     RefBackend()  = default;
     ~RefBackend() = default;
 
-    const std::string& GetId() const override;
+    const BackendId& GetId() const override;
 
     const ILayerSupport& GetLayerSupport() const override;
 
diff --git a/src/backends/test/BackendIdTests.cpp b/src/backends/test/BackendIdTests.cpp
new file mode 100644
index 0000000000..0ef0a20d7f
--- /dev/null
+++ b/src/backends/test/BackendIdTests.cpp
@@ -0,0 +1,27 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#include <boost/test/unit_test.hpp>
+
+#include <armnn/BackendId.hpp>
+#include <armnn/Types.hpp>
+
+using namespace armnn;
+
+BOOST_AUTO_TEST_SUITE(BackendIdTests)
+
+BOOST_AUTO_TEST_CASE(CreateBackendIdFromCompute)
+{
+    BackendId fromCompute{Compute::GpuAcc};
+    BOOST_TEST(fromCompute.Get() == GetComputeDeviceAsCString(Compute::GpuAcc));
+}
+
+BOOST_AUTO_TEST_CASE(CreateBackendIdVectorFromCompute)
+{
+    std::vector<BackendId> fromComputes = {Compute::GpuAcc, Compute::CpuRef};
+    BOOST_TEST(fromComputes[0].Get() == GetComputeDeviceAsCString(Compute::GpuAcc));
+    BOOST_TEST(fromComputes[1].Get() == GetComputeDeviceAsCString(Compute::CpuRef));
+}
+
+BOOST_AUTO_TEST_SUITE_END()