From 48f0271c22b12a15847ba92b134cecea2a1dead0 Mon Sep 17 00:00:00 2001
From: imhameed <imhameed@microsoft.com>
Date: Sat, 31 Jul 2021 20:29:41 -0700
Subject: [PATCH] [mono] Unconditionally enable NEON/AdvSimd for arm64 with
 LLVM (#56323)

* [mono] Unconditionally enable NEON/AdvSimd for arm64 with LLVM

* Remove `mattr=neon` from the Mono AOT command line arguments for LLVM AOT tests

This is now enabled by default when using LLVM.
---
 src/mono/mono/mini/mini.c | 7 ++++++-
 src/tests/run.proj        | 1 -
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/mono/mono/mini/mini.c b/src/mono/mono/mini/mini.c
index 7d24fe6..28ce38a 100644
--- a/src/mono/mono/mini/mini.c
+++ b/src/mono/mono/mini/mini.c
@@ -4450,7 +4450,12 @@ mini_get_cpu_features (MonoCompile* cfg)
 
 #if defined(TARGET_ARM64)
 	// All Arm64 devices have this set
-	features |= MONO_CPU_ARM64_BASE; 
+	features |= MONO_CPU_ARM64_BASE;
+
+	// This is a standard part of ARMv8-A; see A1.5 in "ARM
+	// Architecture Reference Manual ARMv8, for ARMv8-A
+	// architecture profile"
+	features |= MONO_CPU_ARM64_NEON; 
 #endif
 
 	// apply parameters passed via -mattr
diff --git a/src/tests/run.proj b/src/tests/run.proj
index 3289e9c..4f17417 100644
--- a/src/tests/run.proj
+++ b/src/tests/run.proj
@@ -601,7 +601,6 @@ namespace $([System.String]::Copy($(Category)).Replace(".","_").Replace("\","").
     <ItemGroup Condition="'$(TargetArchitecture)' == 'arm64'">
       <MonoAotOption Include="mattr=crc" />
       <MonoAotOption Include="mattr=crypto" />
-      <MonoAotOption Include="mattr=neon" />
     </ItemGroup>
     <ItemGroup Condition="'$(TargetArchitecture)' == 'x64'">
       <MonoAotOption Include="mattr=sse4.2" />
-- 
2.7.4