Index: lib/Driver/ToolChain.cpp
===================================================================
--- lib/Driver/ToolChain.cpp
+++ lib/Driver/ToolChain.cpp
@@ -279,7 +279,8 @@
     // FIXME: Thumb should just be another -target-feaure, not in the triple.
     StringRef Suffix =
       getLLVMArchSuffixForARM(getARMTargetCPU(Args, Triple));
-    bool ThumbDefault = Suffix.startswith("v6m") ||
+    bool ThumbDefault = Suffix.startswith("v6m") || Suffix.startswith("v7m") ||
+      Suffix.startswith("v7em") ||
       (Suffix.startswith("v7") && getTriple().isOSDarwin());
     std::string ArchName = "arm";
 
Index: test/Driver/arm-cortex-cpus.c
===================================================================
--- test/Driver/arm-cortex-cpus.c
+++ test/Driver/arm-cortex-cpus.c
@@ -71,10 +71,12 @@
 // RUN: %clang -target arm -march=armv6m -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V6M %s
 // CHECK-V6M: "-cc1"{{.*}} "-triple" "thumbv6m-{{.*}} "-target-cpu" "cortex-m0"
 
-// RUN: %clang -target armv7m-apple-darwin -arch armv7m -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7M %s
+// RUN: %clang -target armv7m -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7M %s
+// RUN: %clang -target arm -march=armv7-m -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7M %s
 // CHECK-V7M: "-cc1"{{.*}} "-triple" "thumbv7m-{{.*}} "-target-cpu" "cortex-m3"
 
-// RUN: %clang -target armv7em-apple-darwin -arch armv7em -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7EM %s
+// RUN: %clang -target armv7em -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7EM %s
+// RUN: %clang -target arm -march=armv7e-m -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V7EM %s
 // CHECK-V7EM: "-cc1"{{.*}} "-triple" "thumbv7em-{{.*}} "-target-cpu" "cortex-m4"
 
 // RUN: %clang -target armv6m-apple-darwin -arch armv6m -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V6M-DARWIN %s
@@ -136,10 +138,10 @@
 // CHECK-CPUV6M: "-cc1"{{.*}} "-triple" "thumbv6m-{{.*}}
 
 // RUN: %clang -target arm-linux-gnueabi -mcpu=cortex-m3 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV7M %s
-// CHECK-CPUV7M: "-cc1"{{.*}} "-triple" "armv7m-{{.*}}
+// CHECK-CPUV7M: "-cc1"{{.*}} "-triple" "thumbv7m-{{.*}}
 
 // RUN: %clang -target arm-linux-gnueabi -mcpu=cortex-m4 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV7EM %s
-// CHECK-CPUV7EM: "-cc1"{{.*}} "-triple" "armv7em-{{.*}}
+// CHECK-CPUV7EM: "-cc1"{{.*}} "-triple" "thumbv7em-{{.*}}
 
 // RUN: %clang -target arm-linux-gnueabi -mcpu=cortex-r4 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV7R %s
 // RUN: %clang -target arm-linux-gnueabi -mcpu=cortex-r5 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV7R %s