1 files changed, 96 insertions, 0 deletions
diff --git a/ARMeilleure/CodeGen/Arm64/CallingConvention.cs b/ARMeilleure/CodeGen/Arm64/CallingConvention.cs
new file mode 100644
index 00000000..fda8d786
--- /dev/null
+++ b/ARMeilleure/CodeGen/Arm64/CallingConvention.cs
@@ -0,0 +1,96 @@
+using System;
+
+namespace ARMeilleure.CodeGen.Arm64
+{
+    static class CallingConvention
+    {
+        private const int RegistersMask = unchecked((int)0xffffffff);
+
+        // Some of those register have specific roles and can't be used as general purpose registers.
+        // X18 - Reserved for platform specific usage.
+        // X29 - Frame pointer.
+        // X30 - Return address.
+        // X31 - Not an actual register, in some cases maps to SP, and in others to ZR.
+        private const int ReservedRegsMask = (1 << CodeGenCommon.ReservedRegister) | (1 << 18) | (1 << 29) | (1 << 30) | (1 << 31);
+
+        public static int GetIntAvailableRegisters()
+        {
+            return RegistersMask & ~ReservedRegsMask;
+        }
+
+        public static int GetVecAvailableRegisters()
+        {
+            return RegistersMask;
+        }
+
+        public static int GetIntCallerSavedRegisters()
+        {
+            return (GetIntCalleeSavedRegisters() ^ RegistersMask) & ~ReservedRegsMask;
+        }
+
+        public static int GetFpCallerSavedRegisters()
+        {
+            return GetFpCalleeSavedRegisters() ^ RegistersMask;
+        }
+
+        public static int GetVecCallerSavedRegisters()
+        {
+            return GetVecCalleeSavedRegisters() ^ RegistersMask;
+        }
+
+        public static int GetIntCalleeSavedRegisters()
+        {
+            return 0x1ff80000; // X19 to X28
+        }
+
+        public static int GetFpCalleeSavedRegisters()
+        {
+            return 0xff00; // D8 to D15
+        }
+
+        public static int GetVecCalleeSavedRegisters()
+        {
+            return 0;
+        }
+
+        public static int GetArgumentsOnRegsCount()
+        {
+            return 8;
+        }
+
+        public static int GetIntArgumentRegister(int index)
+        {
+            if ((uint)index < (uint)GetArgumentsOnRegsCount())
+            {
+                return index;
+            }
+
+            throw new ArgumentOutOfRangeException(nameof(index));
+        }
+
+        public static int GetVecArgumentRegister(int index)
+        {
+            if ((uint)index < (uint)GetArgumentsOnRegsCount())
+            {
+                return index;
+            }
+
+            throw new ArgumentOutOfRangeException(nameof(index));
+        }
+
+        public static int GetIntReturnRegister()
+        {
+            return 0;
+        }
+
+        public static int GetIntReturnRegisterHigh()
+        {
+            return 1;
+        }
+
+        public static int GetVecReturnRegister()
+        {
+            return 0;
+        }
+    }
+}
+\ No newline at end of file