diff --git a/test/MC/ARM/thumb2-mclass.s b/test/MC/ARM/thumb2-mclass.s
index b7af7236207..d9c96dfcdd3 100644
--- a/test/MC/ARM/thumb2-mclass.s
+++ b/test/MC/ARM/thumb2-mclass.s
@@ -1,9 +1,10 @@
 @ RUN: llvm-mc -triple=thumbv7m-apple-darwin -show-encoding < %s | FileCheck %s
+@ RUN: llvm-mc -triple=thumbv6m -show-encoding < %s | FileCheck %s
   .syntax unified
   .globl _func
 
 @ Check that the assembler can handle the documented syntax from the ARM ARM.
-@ These tests test instruction encodings specific to v7m & v7m (FeatureMClass).
+@ These tests test instruction encodings specific to v6m & v7m (FeatureMClass).
 
 @------------------------------------------------------------------------------
 @ MRS
@@ -19,9 +20,6 @@
         mrs  r0, msp
         mrs  r0, psp
         mrs  r0, primask
-        mrs  r0, basepri
-        mrs  r0, basepri_max
-        mrs  r0, faultmask
         mrs  r0, control
 
 @ CHECK: mrs	r0, apsr                @ encoding: [0xef,0xf3,0x00,0x80]
@@ -34,9 +32,6 @@
 @ CHECK: mrs	r0, msp                 @ encoding: [0xef,0xf3,0x08,0x80]
 @ CHECK: mrs	r0, psp                 @ encoding: [0xef,0xf3,0x09,0x80]
 @ CHECK: mrs	r0, primask             @ encoding: [0xef,0xf3,0x10,0x80]
-@ CHECK: mrs	r0, basepri             @ encoding: [0xef,0xf3,0x11,0x80]
-@ CHECK: mrs	r0, basepri_max         @ encoding: [0xef,0xf3,0x12,0x80]
-@ CHECK: mrs	r0, faultmask           @ encoding: [0xef,0xf3,0x13,0x80]
 @ CHECK: mrs	r0, control             @ encoding: [0xef,0xf3,0x14,0x80]
 
 @------------------------------------------------------------------------------
@@ -65,9 +60,6 @@
         msr  msp, r0
         msr  psp, r0
         msr  primask, r0
-        msr  basepri, r0
-        msr  basepri_max, r0
-        msr  faultmask, r0
         msr  control, r0
 
 @ CHECK: msr	apsr, r0                @ encoding: [0x80,0xf3,0x00,0x88]
@@ -92,7 +84,4 @@
 @ CHECK: msr	msp, r0                 @ encoding: [0x80,0xf3,0x08,0x88]
 @ CHECK: msr	psp, r0                 @ encoding: [0x80,0xf3,0x09,0x88]
 @ CHECK: msr	primask, r0             @ encoding: [0x80,0xf3,0x10,0x88]
-@ CHECK: msr	basepri, r0             @ encoding: [0x80,0xf3,0x11,0x88]
-@ CHECK: msr	basepri_max, r0         @ encoding: [0x80,0xf3,0x12,0x88]
-@ CHECK: msr	faultmask, r0           @ encoding: [0x80,0xf3,0x13,0x88]
 @ CHECK: msr	control, r0             @ encoding: [0x80,0xf3,0x14,0x88]
diff --git a/test/MC/ARM/thumbv7m.s b/test/MC/ARM/thumbv7m.s
new file mode 100644
index 00000000000..33ed44cd3da
--- /dev/null
+++ b/test/MC/ARM/thumbv7m.s
@@ -0,0 +1,45 @@
+@ RUN: llvm-mc -triple=thumbv7m-apple-darwin -show-encoding < %s | FileCheck %s
+@ RUN: not llvm-mc -triple=thumbv6 -show-encoding 2>&1 < %s | FileCheck %s --check-prefix=CHECK-V6M
+  .syntax unified
+  .globl _func
+
+@ Check that the assembler can handle the documented syntax from the ARM ARM.
+@ These tests test instruction encodings specific to ARMv7m.
+
+@------------------------------------------------------------------------------
+@ MRS
+@------------------------------------------------------------------------------
+
+        mrs  r0, basepri
+        mrs  r0, basepri_max
+        mrs  r0, faultmask
+
+@ CHECK: mrs	r0, basepri             @ encoding: [0xef,0xf3,0x11,0x80]
+@ CHECK: mrs	r0, basepri_max         @ encoding: [0xef,0xf3,0x12,0x80]
+@ CHECK: mrs	r0, faultmask           @ encoding: [0xef,0xf3,0x13,0x80]
+
+@------------------------------------------------------------------------------
+@ MSR
+@------------------------------------------------------------------------------
+
+        msr  basepri, r0
+        msr  basepri_max, r0
+        msr  faultmask, r0
+
+@ CHECK: msr	basepri, r0             @ encoding: [0x80,0xf3,0x11,0x88]
+@ CHECK: msr	basepri_max, r0         @ encoding: [0x80,0xf3,0x12,0x88]
+@ CHECK: msr	faultmask, r0           @ encoding: [0x80,0xf3,0x13,0x88]
+
+@ CHECK-V6M: error: invalid operand for instruction
+@ CHECK-V6M-NEXT: mrs r0, basepri
+@ CHECK-V6M: error: invalid operand for instruction
+@ CHECK-V6M-NEXT: mrs r0, basepri_max
+@ CHECK-V6M: error: invalid operand for instruction
+@ CHECK-V6M-NEXT: mrs r0, faultmask
+@ CHECK-V6M: error: invalid operand for instruction
+@ CHECK-V6M-NEXT: msr basepri, r0
+@ CHECK-V6M: error: invalid operand for instruction
+@ CHECK-V6M-NEXT: msr basepri_max, r0
+@ CHECK-V6M: error: invalid operand for instruction
+@ CHECK-V6M-NEXT: msr faultmask, r0
+