Index: cfe/trunk/lib/CodeGen/TargetInfo.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/TargetInfo.cpp
+++ cfe/trunk/lib/CodeGen/TargetInfo.cpp
@@ -4860,6 +4860,22 @@
 
   bool doesReturnSlotInterfereWithArgs() const override { return false; }
 };
+
+class WindowsAArch64TargetCodeGenInfo : public AArch64TargetCodeGenInfo {
+public:
+  WindowsAArch64TargetCodeGenInfo(CodeGenTypes &CGT, AArch64ABIInfo::ABIKind K)
+      : AArch64TargetCodeGenInfo(CGT, K) {}
+
+  void getDependentLibraryOption(llvm::StringRef Lib,
+                                 llvm::SmallString<24> &Opt) const override {
+    Opt = "/DEFAULTLIB:" + qualifyWindowsLibrary(Lib);
+  }
+
+  void getDetectMismatchOption(llvm::StringRef Name, llvm::StringRef Value,
+                               llvm::SmallString<32> &Opt) const override {
+    Opt = "/FAILIFMISMATCH:\"" + Name.str() + "=" + Value.str() + "\"";
+  }
+};
 }
 
 ABIArgInfo AArch64ABIInfo::classifyArgumentType(QualType Ty) const {
@@ -8508,7 +8524,8 @@
     if (getTarget().getABI() == "darwinpcs")
       Kind = AArch64ABIInfo::DarwinPCS;
     else if (Triple.isOSWindows())
-      Kind = AArch64ABIInfo::Win64;
+      return SetCGInfo(
+          new WindowsAArch64TargetCodeGenInfo(Types, AArch64ABIInfo::Win64));
 
     return SetCGInfo(new AArch64TargetCodeGenInfo(Types, Kind));
   }
Index: cfe/trunk/test/CodeGen/pragma-comment.c
===================================================================
--- cfe/trunk/test/CodeGen/pragma-comment.c
+++ cfe/trunk/test/CodeGen/pragma-comment.c
@@ -4,6 +4,7 @@
 // RUN: %clang_cc1 %s -triple thumbv7-linux-gnueabihf -fms-extensions -emit-llvm -o - | FileCheck -check-prefix LINUX %s
 // RUN: %clang_cc1 %s -triple i686-pc-linux -fms-extensions -emit-llvm -o - | FileCheck -check-prefix LINUX %s
 // RUN: %clang_cc1 %s -triple x86_64-scei-ps4 -fms-extensions -emit-llvm -o - | FileCheck -check-prefix PS4 %s
+// RUN: %clang_cc1 %s -triple aarch64-windows-msvc -fms-extensions -emit-llvm -o - | FileCheck %s
 
 #pragma comment(lib, "msvcrt.lib")
 #pragma comment(lib, "kernel32")