IVGCVSW-5525 Handle Neon optionality on 32 bit linux platforms

 * Add neon detection for linux using HWCAPs
 * Add test to check for backend throwing BackendUnavailable exception

Signed-off-by: Francis Murtagh <francis.murtagh@arm.com>
Change-Id: Ib74aeb06abe5f88f21ecdd1edb2a1cd20ee2019d

1 files changed, 11 insertions, 1 deletions

diff --git a/src/backends/neon/NeonRegistryInitializer.cpp b/src/backends/neon/NeonRegistryInitializer.cpp
index fd2e84dd5f..fc981ab270 100644
--- a/src/backends/neon/NeonRegistryInitializer.cpp
+++ b/src/backends/neon/NeonRegistryInitializer.cpp
@@ -6,6 +6,7 @@
 #include "NeonBackend.hpp"
 
 #include <armnn/BackendRegistry.hpp>
+#include <armnn/Utils.hpp>
 
 namespace
 {
@@ -18,7 +19,16 @@ static BackendRegistry::StaticRegistryInitializer g_RegisterHelper
     NeonBackend::GetIdStatic(),
     []()
     {
-        return IBackendInternalUniquePtr(new NeonBackend);
+        // Check if device supports Neon.
+        if (NeonDetected())
+        {
+            return IBackendInternalUniquePtr(new NeonBackend);
+        }
+
+        // If device does not support Neon throw exception so the Backend is not added to supportedBackends
+        ARMNN_LOG(info) << "Neon support not found on device, could not register CpuAcc Backend.";
+        throw armnn::BackendUnavailableException(
+                "Neon support not found on device, could not register CpuAcc Backend.\n");
     }
 };