1 files changed, 27 insertions, 0 deletions
diff --git a/clang/test/CodeGenCXX/microsoft-abi-byval-vararg.cpp b/clang/test/CodeGenCXX/microsoft-abi-byval-vararg.cpp
new file mode 100644
index 00000000000..33619216e88
--- /dev/null
+++ b/clang/test/CodeGenCXX/microsoft-abi-byval-vararg.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=i686-pc-win32 -mconstructor-aliases -fno-rtti | FileCheck %s
+
+#include <stdarg.h>
+
+struct A {
+  A(int a) : a(a) {}
+  A(const A &o) : a(o.a) {}
+  ~A() {}
+  int a;
+};
+
+int foo(A a, ...) {
+  va_list ap;
+  va_start(ap, a);
+  int sum = 0;
+  for (int i = 0; i < a.a; ++i)
+    sum += va_arg(ap, int);
+  va_end(ap);
+  return sum;
+}
+
+int main() {
+  return foo(A(3), 1, 2, 3);
+}
+// CHECK-LABEL: define i32 @main()
+// CHECK: %[[argmem_cast:[^ ]*]] = bitcast <{ %struct.A, i32, i32, i32 }>* %argmem to <{ %struct.A }>*
+// CHECK: call i32 (<{ %struct.A }>*, ...)* @"\01?foo@@YAHUA@@ZZ"(<{ %struct.A }>* inalloca %[[argmem_cast]])