diff --git a/test/CodeGen/cxx-default-arg.cpp b/test/CodeGen/cxx-default-arg.cpp
new file mode 100644
index 0000000..957b60a
--- /dev/null
+++ b/test/CodeGen/cxx-default-arg.cpp
@@ -0,0 +1,25 @@
+// RUN: clang -emit-llvm %s
+
+// Note: define CLANG_GENERATE_KNOWN_GOOD and compile to generate code
+// that makes all of the defaulted arguments explicit. The resulting
+// byte code should be identical to the compilation without
+// CLANG_GENERATE_KNOWN_GOOD.
+#ifdef CLANG_GENERATE_KNOWN_GOOD
+#  define DEFARG(...) __VA_ARGS__
+#else
+#  define DEFARG(...)
+#endif
+
+extern int x;
+struct S { float x; float y; } s;
+double _Complex c;
+
+void f(int i = 0, int j = 1, int k = x, struct S t = s, double _Complex d = c);
+
+void g() {
+  f(0, 1, x, s DEFARG(, c));
+  f(0, 1, x DEFARG(, s, c));
+  f(0, 1 DEFARG(, x, s, c));
+  f(0 DEFARG(, 1, x, s, c));
+  f(DEFARG(0, 1, x, s, c));
+}