Index: include/clang/Basic/BuiltinsARM.def
===================================================================
--- include/clang/Basic/BuiltinsARM.def
+++ include/clang/Basic/BuiltinsARM.def
@@ -94,7 +94,7 @@
 LANGBUILTIN(__dmb, "vUi", "nc", ALL_MS_LANGUAGES)
 LANGBUILTIN(__dsb, "vUi", "nc", ALL_MS_LANGUAGES)
 LANGBUILTIN(__isb, "vUi", "nc", ALL_MS_LANGUAGES)
-LANGBUILTIN(__ldrexd, "WiCDWi*", "", ALL_MS_LANGUAGES)
+LANGBUILTIN(__ldrexd, "WiWiCD*", "", ALL_MS_LANGUAGES)
 LANGBUILTIN(_MoveFromCoprocessor, "UiUiUiUiUiUi", "", ALL_MS_LANGUAGES)
 LANGBUILTIN(_MoveFromCoprocessor2, "UiUiUiUiUiUi", "", ALL_MS_LANGUAGES)
 LANGBUILTIN(_MoveToCoprocessor, "vUiUiUiUiUiUi", "", ALL_MS_LANGUAGES)
Index: test/CodeGen/builtins-arm-ms.c
===================================================================
--- test/CodeGen/builtins-arm-ms.c
+++ test/CodeGen/builtins-arm-ms.c
@@ -0,0 +1,7 @@
+// REQUIRES: arm-registered-target
+// RUN: %clang_cc1 -Wall -Werror -triple thumbv7-eabi -target-cpu cortex-a8 -O3 -emit-llvm -fms-extensions -o - %s | FileCheck %s
+
+void ldrexd()
+{
+	__ldrexd(0); // CHECK: call {{.*}} @llvm.arm.ldrexd(i8* null)
+}
Index: test/Sema/builtins-arm-ms.c
===================================================================
--- test/Sema/builtins-arm-ms.c
+++ test/Sema/builtins-arm-ms.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -triple armv7 -fsyntax-only -fms-extensions -verify %s
+// RUN: %clang_cc1 -triple armv7 -target-abi apcs-gnu -fms-extensions -fsyntax-only -verify %s
+
+void test1() {
+  const long long * ptr;
+  __ldrexd(); // expected-error {{too few arguments to function call, expected 1, have 0}} 
+  __ldrexd(1); // expected-warning {{incompatible integer to pointer conversion passing 'int' to parameter of type 'const volatile long long *'}}
+  __ldrexd(ptr);
+}