diff --git a/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs b/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs
new file mode 100644
index 000000000..261a0e572
--- /dev/null
+++ b/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs
@@ -0,0 +1,29 @@
+using Ryujinx.Graphics.Shader.IntermediateRepresentation;
+using Ryujinx.Graphics.Shader.Translation;
+
+namespace Ryujinx.Graphics.Shader.CodeGen.Msl.Instructions
+{
+    static class IoMap
+    {
+        public static (string, AggregateType) GetMSLBuiltIn(IoVariable ioVariable)
+        {
+            return ioVariable switch
+            {
+                IoVariable.BaseInstance => ("base_instance", AggregateType.S32),
+                IoVariable.BaseVertex => ("base_vertex", AggregateType.S32),
+                IoVariable.ClipDistance => ("clip_distance", AggregateType.Array | AggregateType.FP32),
+                IoVariable.FragmentOutputColor => ("color", AggregateType.Vector2 | AggregateType.Vector3 | AggregateType.Vector4),
+                IoVariable.FragmentOutputDepth => ("depth", AggregateType.FP32),
+                IoVariable.FrontFacing => ("front_facing", AggregateType.Bool),
+                IoVariable.InstanceId => ("instance_id", AggregateType.S32),
+                IoVariable.PointCoord => ("point_coord", AggregateType.Vector2),
+                IoVariable.PointSize => ("point_size", AggregateType.FP32),
+                IoVariable.Position => ("position", AggregateType.Vector4),
+                IoVariable.PrimitiveId => ("primitive_id", AggregateType.S32),
+                IoVariable.VertexId => ("vertex_id", AggregateType.S32),
+                IoVariable.ViewportIndex => ("viewport_array_index", AggregateType.S32),
+                _ => (null, AggregateType.Invalid),
+            };
+        }
+    }
+}