1 files changed, 159 insertions, 0 deletions
diff --git a/ARMeilleure/CodeGen/X86/CallingConvention.cs b/ARMeilleure/CodeGen/X86/CallingConvention.cs
new file mode 100644
index 00000000..2769fd93
--- /dev/null
+++ b/ARMeilleure/CodeGen/X86/CallingConvention.cs
@@ -0,0 +1,159 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace ARMeilleure.CodeGen.X86
+{
+    static class CallingConvention
+    {
+        private const int RegistersMask = 0xffff;
+
+        public static int GetIntAvailableRegisters()
+        {
+            return RegistersMask & ~(1 << (int)X86Register.Rsp);
+        }
+
+        public static int GetVecAvailableRegisters()
+        {
+            return RegistersMask;
+        }
+
+        public static int GetIntCallerSavedRegisters()
+        {
+            if (GetCurrentCallConv() == CallConvName.Windows)
+            {
+                return (1 << (int)X86Register.Rax) |
+                       (1 << (int)X86Register.Rcx) |
+                       (1 << (int)X86Register.Rdx) |
+                       (1 << (int)X86Register.R8)  |
+                       (1 << (int)X86Register.R9)  |
+                       (1 << (int)X86Register.R10) |
+                       (1 << (int)X86Register.R11);
+            }
+            else /* if (GetCurrentCallConv() == CallConvName.SystemV) */
+            {
+                return (1 << (int)X86Register.Rax) |
+                       (1 << (int)X86Register.Rcx) |
+                       (1 << (int)X86Register.Rdx) |
+                       (1 << (int)X86Register.Rsi) |
+                       (1 << (int)X86Register.Rdi) |
+                       (1 << (int)X86Register.R8)  |
+                       (1 << (int)X86Register.R9)  |
+                       (1 << (int)X86Register.R10) |
+                       (1 << (int)X86Register.R11);
+            }
+        }
+
+        public static int GetVecCallerSavedRegisters()
+        {
+            if (GetCurrentCallConv() == CallConvName.Windows)
+            {
+                return (1 << (int)X86Register.Xmm0) |
+                       (1 << (int)X86Register.Xmm1) |
+                       (1 << (int)X86Register.Xmm2) |
+                       (1 << (int)X86Register.Xmm3) |
+                       (1 << (int)X86Register.Xmm4) |
+                       (1 << (int)X86Register.Xmm5);
+            }
+            else /* if (GetCurrentCallConv() == CallConvName.SystemV) */
+            {
+                return RegistersMask;
+            }
+        }
+
+        public static int GetIntCalleeSavedRegisters()
+        {
+            return GetIntCallerSavedRegisters() ^ RegistersMask;
+        }
+
+        public static int GetVecCalleeSavedRegisters()
+        {
+            return GetVecCallerSavedRegisters() ^ RegistersMask;
+        }
+
+        public static int GetArgumentsOnRegsCount()
+        {
+            return 4;
+        }
+
+        public static int GetIntArgumentsOnRegsCount()
+        {
+            return 6;
+        }
+
+        public static int GetVecArgumentsOnRegsCount()
+        {
+            return 8;
+        }
+
+        public static X86Register GetIntArgumentRegister(int index)
+        {
+            if (GetCurrentCallConv() == CallConvName.Windows)
+            {
+                switch (index)
+                {
+                    case 0: return X86Register.Rcx;
+                    case 1: return X86Register.Rdx;
+                    case 2: return X86Register.R8;
+                    case 3: return X86Register.R9;
+                }
+            }
+            else /* if (GetCurrentCallConv() == CallConvName.SystemV) */
+            {
+                switch (index)
+                {
+                    case 0: return X86Register.Rdi;
+                    case 1: return X86Register.Rsi;
+                    case 2: return X86Register.Rdx;
+                    case 3: return X86Register.Rcx;
+                    case 4: return X86Register.R8;
+                    case 5: return X86Register.R9;
+                }
+            }
+
+            throw new ArgumentOutOfRangeException(nameof(index));
+        }
+
+        public static X86Register GetVecArgumentRegister(int index)
+        {
+            int count;
+
+            if (GetCurrentCallConv() == CallConvName.Windows)
+            {
+                count = 4;
+            }
+            else /* if (GetCurrentCallConv() == CallConvName.SystemV) */
+            {
+                count = 8;
+            }
+
+            if ((uint)index < count)
+            {
+                return X86Register.Xmm0 + index;
+            }
+
+            throw new ArgumentOutOfRangeException(nameof(index));
+        }
+
+        public static X86Register GetIntReturnRegister()
+        {
+            return X86Register.Rax;
+        }
+
+        public static X86Register GetIntReturnRegisterHigh()
+        {
+            return X86Register.Rdx;
+        }
+
+        public static X86Register GetVecReturnRegister()
+        {
+            return X86Register.Xmm0;
+        }
+
+        public static CallConvName GetCurrentCallConv()
+        {
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
+                ? CallConvName.Windows
+                : CallConvName.SystemV;
+        }
+    }
+}
+\ No newline at end of file