1 files changed, 43 insertions, 0 deletions
diff --git a/src/System.Private.CoreLib/shared/System/Runtime/Intrinsics/Vector64.cs b/src/System.Private.CoreLib/shared/System/Runtime/Intrinsics/Vector64.cs
new file mode 100644
index 000000000..8ce90b9d0
--- /dev/null
+++ b/src/System.Private.CoreLib/shared/System/Runtime/Intrinsics/Vector64.cs
@@ -0,0 +1,43 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using Internal.Runtime.CompilerServices;
+
+namespace System.Runtime.Intrinsics
+{
+    [Intrinsic]
+    [DebuggerDisplay("{DisplayString,nq}")]
+    [DebuggerTypeProxy(typeof(Vector64DebugView<>))]
+    [StructLayout(LayoutKind.Sequential, Size = 8)]
+    public readonly struct Vector64<T> where T : struct
+    {
+        // These fields exist to ensure the alignment is 8, rather than 1.
+        // This also allows the debug view to work https://github.com/dotnet/coreclr/issues/15694)
+        private readonly ulong _00;
+
+        private unsafe string DisplayString
+        {
+            get
+            {
+                // The IsPrimitive check ends up working for `bool`, `char`, `IntPtr`, and `UIntPtr`
+                // which are not actually supported by any current architecture. This shouldn't be
+                // an issue however and greatly simplifies the check
+
+                if (typeof(T).IsPrimitive)
+                {
+                    var items = new T[8 / Unsafe.SizeOf<T>()];
+                    Unsafe.WriteUnaligned(ref Unsafe.As<T, byte>(ref items[0]), this);
+                    return $"({string.Join(", ", items)})";
+                }
+                else
+                {
+                    return SR.NotSupported_Type;
+                }
+            }
+        }
+    }
+}