Index: cfe/trunk/lib/Basic/Targets/AArch64.h
===================================================================
--- cfe/trunk/lib/Basic/Targets/AArch64.h
+++ cfe/trunk/lib/Basic/Targets/AArch64.h
@@ -105,6 +105,8 @@
                         MacroBuilder &Builder) const override;
 
   BuiltinVaListKind getBuiltinVaListKind() const override;
+
+  CallingConvCheckResult checkCallingConvention(CallingConv CC) const override;
 };
 
 class LLVM_LIBRARY_VISIBILITY AArch64beTargetInfo : public AArch64TargetInfo {
Index: cfe/trunk/lib/Basic/Targets/AArch64.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets/AArch64.cpp
+++ cfe/trunk/lib/Basic/Targets/AArch64.cpp
@@ -458,6 +458,23 @@
   return TargetInfo::CharPtrBuiltinVaList;
 }
 
+TargetInfo::CallingConvCheckResult
+MicrosoftARM64TargetInfo::checkCallingConvention(CallingConv CC) const {
+  switch (CC) {
+  case CC_X86StdCall:
+  case CC_X86ThisCall:
+  case CC_X86FastCall:
+  case CC_X86VectorCall:
+    return CCCR_Ignore;
+  case CC_C:
+  case CC_OpenCLKernel:
+  case CC_Win64:
+    return CCCR_OK;
+  default:
+    return CCCR_Warning;
+  }
+}
+
 DarwinAArch64TargetInfo::DarwinAArch64TargetInfo(const llvm::Triple &Triple,
                                                  const TargetOptions &Opts)
     : DarwinTargetInfo<AArch64leTargetInfo>(Triple, Opts) {
Index: cfe/trunk/test/Parser/arm-windows-calling-convention-handling.c
===================================================================
--- cfe/trunk/test/Parser/arm-windows-calling-convention-handling.c
+++ cfe/trunk/test/Parser/arm-windows-calling-convention-handling.c
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -triple thumbv7-windows -fms-compatibility -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple aarch64-windows -fms-compatibility -fsyntax-only -verify %s
 
 int __cdecl cdecl(int a, int b, int c, int d) { // expected-no-diagnostics
   return a + b + c + d;