diff --git a/llvm/include/llvm/IR/RuntimeLibcalls.td b/llvm/include/llvm/IR/RuntimeLibcalls.td
index 0000000..0000000 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.td
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.td
@@ -3620,6 +3620,15 @@ def MOSSystemLibrary
           __memset,
           abort)>;

+// W65816 (WDC 65816) - integer libcalls only.  Multiply, divide, modulo
+// and shifts go through the standard compiler-rt names (__mulhi3,
+// __divhi3 etc.).  No floating point yet.
+def isW65816 : RuntimeLibcallPredicate<"TT.getArch() == Triple::w65816">;
+
+def W65816SystemLibrary
+    : SystemRuntimeLibrary<isW65816,
+          (add DefaultRuntimeLibcallImpls)>;
+
 //===----------------------------------------------------------------------===//
 // Legacy Default Runtime Libcalls
 //===----------------------------------------------------------------------===//