Index: llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
===================================================================
--- llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5976,7 +5976,9 @@
       return Error(Operands[3]->getStartLoc(),
                    "writeback operator '!' not allowed when base register "
                    "in register list");
-
+    if (listContainsReg(Inst, 3 + HasWritebackToken, ARM::SP))
+      return Error(Operands[3 + HasWritebackToken]->getStartLoc(),
+                   "SP not allowed in register list");
     break;
   }
   case ARM::LDMIA_UPD:
@@ -5987,7 +5989,19 @@
     // UNPREDICTABLE on v7 upwards. Goodness knows what they did before.
     if (!hasV7Ops())
       break;
-    // Fallthrough
+    if (listContainsReg(Inst, 3, Inst.getOperand(0).getReg()))
+      return Error(Operands.back()->getStartLoc(),
+                   "writeback register not allowed in register list");
+    break;
+  case ARM::t2LDMIA:
+  case ARM::t2LDMDB:
+  case ARM::t2STMIA:
+  case ARM::t2STMDB: {
+    if (listContainsReg(Inst, 3, ARM::SP))
+      return Error(Operands.back()->getStartLoc(),
+                   "SP not allowed in register list");
+    break;
+  }
   case ARM::t2LDMIA_UPD:
   case ARM::t2LDMDB_UPD:
   case ARM::t2STMIA_UPD:
@@ -5995,6 +6009,10 @@
     if (listContainsReg(Inst, 3, Inst.getOperand(0).getReg()))
       return Error(Operands.back()->getStartLoc(),
                    "writeback register not allowed in register list");
+
+    if (listContainsReg(Inst, 4, ARM::SP))
+      return Error(Operands.back()->getStartLoc(),
+                   "SP not allowed in register list");
     break;
   }
   case ARM::sysLDMIA_UPD:
@@ -6063,6 +6081,9 @@
       return Error(Operands[4]->getStartLoc(),
                    "writeback operator '!' not allowed when base register "
                    "in register list");
+    if (listContainsReg(Inst, 4, ARM::SP) && !inITBlock())
+      return Error(Operands.back()->getStartLoc(),
+                   "SP not allowed in register list");
     break;
   }
   case ARM::tADDrSP: {
Index: llvm/test/MC/ARM/thumb-diagnostics.s
===================================================================
--- llvm/test/MC/ARM/thumb-diagnostics.s
+++ llvm/test/MC/ARM/thumb-diagnostics.s
@@ -2,6 +2,8 @@
 @ RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 @ RUN: not llvm-mc -triple=thumbv5-apple-darwin < %s 2> %t
 @ RUN: FileCheck --check-prefix=CHECK-ERRORS-V5 < %t %s
+@ RUN: not llvm-mc -triple=thumbv7m < %s 2> %t
+@ RUN: FileCheck --check-prefix=CHECK-ERRORS-V7M < %t %s
 @ RUN: not llvm-mc -triple=thumbv8 < %s 2> %t
 @ RUN: FileCheck --check-prefix=CHECK-ERRORS-V8 < %t %s
 
@@ -59,6 +61,13 @@
         ldm r2!, {r2, r3, r4}
         ldm r2!, {r2, r3, r4, r10}
         ldmdb r2!, {r2, r3, r4}
+        ldm r0, {r2, sp}
+        ldmia r0, {r2-r3, sp}
+        ldmia r0!, {r2-r3, sp}
+        ldmfd r2, {r1, r3-r6, sp}
+        ldmfd r2!, {r1, r3-r6, sp}
+        ldmdb r1, {r2, r3, sp}
+        ldmdb r1!, {r2, r3, sp} 
 @ CHECK-ERRORS: error: registers must be in range r0-r7
 @ CHECK-ERRORS:         ldm r2!, {r5, r8}
 @ CHECK-ERRORS:                  ^
@@ -74,6 +83,27 @@
 @ CHECK-ERRORS-V8: error: writeback register not allowed in register list
 @ CHECK-ERRORS-V8:         ldmdb r2!, {r2, r3, r4}
 @ CHECK-ERRORS-V8:                 ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldm r0, {r2, sp}
+@ CHECK-ERRORS-V7M:                 ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldmia r0, {r2-r3, sp}
+@ CHECK-ERRORS-V7M:                   ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldmia r0!, {r2-r3, sp}
+@ CHECK-ERRORS-V7M:                    ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldmfd r2, {r1, r3-r6, sp}
+@ CHECK-ERRORS-V7M:                   ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldmfd r2!, {r1, r3-r6, sp}
+@ CHECK-ERRORS-V7M:                    ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldmdb r1, {r2, r3, sp}
+@ CHECK-ERRORS-V7M:                   ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         ldmdb r1!, {r2, r3, sp}
+@ CHECK-ERRORS-V7M:                    ^
 
 @ Invalid writeback and register lists for PUSH/POP
         pop {r1, r2, r10}
@@ -91,6 +121,10 @@
         stm r1!, {r2, r9}
         stm r2!, {r2, r9}
         stmdb r2!, {r0, r2}
+        stm r1!, {r2, sp}
+        stmia r4!, {r0-r3, sp}
+        stmdb r1, {r2, r3, sp}
+        stmdb r1!, {r2, r3, sp}
 @ CHECK-ERRORS: error: instruction requires: thumb2
 @ CHECK-ERRORS:         stm r1, {r2, r6}
 @ CHECK-ERRORS:         ^
@@ -103,6 +137,18 @@
 @ CHECK-ERRORS-V8: error: writeback register not allowed in register list
 @ CHECK-ERRORS-V8:         stmdb r2!, {r0, r2}
 @ CHECK-ERRORS-V8:                  ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         stm r1!, {r2, sp}
+@ CHECK-ERRORS-V7M:                  ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         stmia r4!, {r0-r3, sp}
+@ CHECK-ERRORS-V7M:                    ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         stmdb r1, {r2, r3, sp}
+@ CHECK-ERRORS-V7M:                   ^
+@ CHECK-ERRORS-V7M: error: SP not allowed in register list
+@ CHECK-ERRORS-V7M:         stmdb r1!, {r2, r3, sp}
+@ CHECK-ERRORS-V7M:                    ^
 
 @ Out of range immediates for LSL instruction.
         lsls r4, r5, #-1