Index: cfe/trunk/include/clang/Basic/Attr.td
===================================================================
--- cfe/trunk/include/clang/Basic/Attr.td
+++ cfe/trunk/include/clang/Basic/Attr.td
@@ -268,10 +268,10 @@
 def TargetMSP430 : TargetArch<["msp430"]>;
 def TargetX86 : TargetArch<["x86"]>;
 def TargetAnyX86 : TargetArch<["x86", "x86_64"]>;
-def TargetWindows : TargetArch<["x86", "x86_64", "arm", "thumb"]> {
+def TargetWindows : TargetArch<["x86", "x86_64", "arm", "thumb", "aarch64"]> {
   let OSes = ["Win32"];
 }
-def TargetMicrosoftCXXABI : TargetArch<["x86", "x86_64", "arm", "thumb"]> {
+def TargetMicrosoftCXXABI : TargetArch<["x86", "x86_64", "arm", "thumb", "aarch64"]> {
   let CXXABIs = ["Microsoft"];
 }
 
Index: cfe/trunk/test/Sema/dllimport.c
===================================================================
--- cfe/trunk/test/Sema/dllimport.c
+++ cfe/trunk/test/Sema/dllimport.c
@@ -2,6 +2,7 @@
 // RUN: %clang_cc1 -triple x86_64-win32   -fsyntax-only -fms-extensions -verify -std=c11 -DMS %s
 // RUN: %clang_cc1 -triple i686-mingw32   -fsyntax-only -fms-extensions -verify -std=c11 -DGNU %s
 // RUN: %clang_cc1 -triple x86_64-mingw32 -fsyntax-only -fms-extensions -verify -std=c99 -DGNU %s
+// RUN: %clang_cc1 -triple aarch64-win32  -fsyntax-only -fms-extensions -verify -std=c99 -DMS %s
 
 // Invalid usage.
 __declspec(dllimport) typedef int typedef1;