Implement JIT Arm64 backend (#4114)

* Implement JIT Arm64 backend

* PPTC version bump

* Address some feedback from Arm64 JIT PR

* Address even more PR feedback

* Remove unused IsPageAligned function

* Sync Qc flag before calls

* Fix comment and remove unused enum

* Address riperiperi PR feedback

* Delete Breakpoint IR instruction that was only implemented for Arm64

2 files changed, 99 insertions, 6 deletions

diff --git a/ARMeilleure/Translation/Cache/JitCache.cs b/ARMeilleure/Translation/Cache/JitCache.cs
index 24affa34..f496a8e9 100644
--- a/ARMeilleure/Translation/Cache/JitCache.cs
+++ b/ARMeilleure/Translation/Cache/JitCache.cs
@@ -1,6 +1,7 @@
 using ARMeilleure.CodeGen;
 using ARMeilleure.CodeGen.Unwinding;
 using ARMeilleure.Memory;
+using ARMeilleure.Native;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -17,6 +18,7 @@ namespace ARMeilleure.Translation.Cache
         private const int CacheSize = 2047 * 1024 * 1024;
 
         private static ReservedRegion _jitRegion;
+        private static JitCacheInvalidation _jitCacheInvalidator;
 
         private static CacheMemoryAllocator _cacheAllocator;
 
@@ -25,8 +27,6 @@ namespace ARMeilleure.Translation.Cache
         private static readonly object _lock = new object();
         private static bool _initialized;
 
-        public static IntPtr Base => _jitRegion.Pointer;
-
         public static void Initialize(IJitMemoryAllocator allocator)
         {
             if (_initialized) return;
@@ -36,6 +36,7 @@ namespace ARMeilleure.Translation.Cache
                 if (_initialized) return;
 
                 _jitRegion = new ReservedRegion(allocator, CacheSize);
+                _jitCacheInvalidator = new JitCacheInvalidation(allocator);
 
                 _cacheAllocator = new CacheMemoryAllocator(CacheSize);
 
@@ -60,11 +61,24 @@ namespace ARMeilleure.Translation.Cache
 
                 IntPtr funcPtr = _jitRegion.Pointer + funcOffset;
 
-                ReprotectAsWritable(funcOffset, code.Length);
-
-                Marshal.Copy(code, 0, funcPtr, code.Length);
+                if (OperatingSystem.IsMacOS() && RuntimeInformation.ProcessArchitecture == Architecture.Arm64)
+                {
+                    unsafe
+                    {
+                        fixed (byte *codePtr = code)
+                        {
+                            JitSupportDarwin.Copy(funcPtr, (IntPtr)codePtr, (ulong)code.Length);
+                        }
+                    }
+                }
+                else
+                {
+                    ReprotectAsWritable(funcOffset, code.Length);
+                    Marshal.Copy(code, 0, funcPtr, code.Length);
+                    ReprotectAsExecutable(funcOffset, code.Length);
 
-                ReprotectAsExecutable(funcOffset, code.Length);
+                    _jitCacheInvalidator.Invalidate(funcPtr, (ulong)code.Length);
+                }
 
                 Add(funcOffset, code.Length, func.UnwindInfo);
 
diff --git a/ARMeilleure/Translation/Cache/JitCacheInvalidation.cs b/ARMeilleure/Translation/Cache/JitCacheInvalidation.cs
new file mode 100644
index 00000000..ec2ae73b
--- /dev/null
+++ b/ARMeilleure/Translation/Cache/JitCacheInvalidation.cs
@@ -0,0 +1,79 @@
+using ARMeilleure.Memory;
+using System;
+using System.Runtime.InteropServices;
+
+namespace ARMeilleure.Translation.Cache
+{
+    class JitCacheInvalidation
+    {
+        private static int[] _invalidationCode = new int[]
+        {
+            unchecked((int)0xd53b0022), // mrs  x2, ctr_el0
+            unchecked((int)0xd3504c44), // ubfx x4, x2, #16, #4
+            unchecked((int)0x52800083), // mov  w3, #0x4
+            unchecked((int)0x12000c45), // and  w5, w2, #0xf
+            unchecked((int)0x1ac42064), // lsl  w4, w3, w4
+            unchecked((int)0x51000482), // sub  w2, w4, #0x1
+            unchecked((int)0x8a220002), // bic  x2, x0, x2
+            unchecked((int)0x1ac52063), // lsl  w3, w3, w5
+            unchecked((int)0xeb01005f), // cmp  x2, x1
+            unchecked((int)0x93407c84), // sxtw x4, w4
+            unchecked((int)0x540000a2), // b.cs 3c <do_ic_clear>
+            unchecked((int)0xd50b7b22), // dc   cvau, x2
+            unchecked((int)0x8b040042), // add  x2, x2, x4
+            unchecked((int)0xeb02003f), // cmp  x1, x2
+            unchecked((int)0x54ffffa8), // b.hi 2c <dc_clear_loop>
+            unchecked((int)0xd5033b9f), // dsb  ish
+            unchecked((int)0x51000462), // sub  w2, w3, #0x1
+            unchecked((int)0x93407c63), // sxtw x3, w3
+            unchecked((int)0x8a220000), // bic  x0, x0, x2
+            unchecked((int)0xeb00003f), // cmp  x1, x0
+            unchecked((int)0x540000a9), // b.ls 64 <exit>
+            unchecked((int)0xd50b7520), // ic   ivau, x0
+            unchecked((int)0x8b030000), // add  x0, x0, x3
+            unchecked((int)0xeb00003f), // cmp  x1, x0
+            unchecked((int)0x54ffffa8), // b.hi 54 <ic_clear_loop>
+            unchecked((int)0xd5033b9f), // dsb  ish
+            unchecked((int)0xd5033fdf), // isb
+            unchecked((int)0xd65f03c0), // ret
+        };
+
+        private delegate void InvalidateCache(ulong start, ulong end);
+
+        private InvalidateCache _invalidateCache;
+        private ReservedRegion _invalidateCacheCodeRegion;
+
+        private readonly bool _needsInvalidation;
+
+        public JitCacheInvalidation(IJitMemoryAllocator allocator)
+        {
+            // On macOS, a different path is used to write to the JIT cache, which does the invalidation.
+            if (!OperatingSystem.IsMacOS() && RuntimeInformation.ProcessArchitecture == Architecture.Arm64)
+            {
+                ulong size = (ulong)_invalidationCode.Length * sizeof(int);
+                ulong mask = (ulong)ReservedRegion.DefaultGranularity - 1;
+
+                size = (size + mask) & ~mask;
+
+                _invalidateCacheCodeRegion = new ReservedRegion(allocator, size);
+                _invalidateCacheCodeRegion.ExpandIfNeeded(size);
+
+                Marshal.Copy(_invalidationCode, 0, _invalidateCacheCodeRegion.Pointer, _invalidationCode.Length);
+
+                _invalidateCacheCodeRegion.Block.MapAsRx(0, size);
+
+                _invalidateCache = Marshal.GetDelegateForFunctionPointer<InvalidateCache>(_invalidateCacheCodeRegion.Pointer);
+
+                _needsInvalidation = true;
+            }
+        }
+
+        public void Invalidate(IntPtr basePointer, ulong size)
+        {
+            if (_needsInvalidation)
+            {
+                _invalidateCache((ulong)basePointer, (ulong)basePointer + size);
+            }
+        }
+    }
+}
\ No newline at end of file