Index: lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp
===================================================================
--- lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp
+++ lib/Target/MSP430/AsmParser/MSP430AsmParser.cpp
@@ -497,7 +497,11 @@
         getLexer().Lex(); // Eat '+'
         return false;
       }
-      Operands.push_back(MSP430Operand::CreateIndReg(RegNo, StartLoc, EndLoc));
+      if (Operands.size() > 1) // Emulate @rd in destination position as 0(rd)
+        Operands.push_back(MSP430Operand::CreateMem(RegNo,
+            MCConstantExpr::create(0, getContext()), StartLoc, EndLoc));
+      else
+        Operands.push_back(MSP430Operand::CreateIndReg(RegNo, StartLoc, EndLoc));
       return false;
     }
     case AsmToken::Hash:
Index: lib/Target/MSP430/Disassembler/MSP430Disassembler.cpp
===================================================================
--- lib/Target/MSP430/Disassembler/MSP430Disassembler.cpp
+++ lib/Target/MSP430/Disassembler/MSP430Disassembler.cpp
@@ -249,6 +249,10 @@
   case amSymbolic:
   case amImmediate:
   case amAbsolute:
+    if (Bytes.size() < (Words + 1) * 2) {
+      Size = 2;
+      return DecodeStatus::Fail;
+    }
     Insn |= (uint64_t)support::endian::read16le(Bytes.data() + 2) << 16;
     ++Words;
     break;
@@ -259,6 +263,10 @@
   case amIndexed:
   case amSymbolic:
   case amAbsolute:
+    if (Bytes.size() < (Words + 1) * 2) {
+      Size = 2;
+      return DecodeStatus::Fail;
+    }
     Insn |= (uint64_t)support::endian::read16le(Bytes.data() + Words * 2)
         << (Words * 16);
     ++Words;
@@ -296,6 +304,10 @@
   case amSymbolic:
   case amImmediate:
   case amAbsolute:
+    if (Bytes.size() < (Words + 1) * 2) {
+      Size = 2;
+      return DecodeStatus::Fail;
+    }
     Insn |= (uint64_t)support::endian::read16le(Bytes.data() + 2) << 16;
     ++Words;
     break;
Index: lib/Target/MSP430/MCTargetDesc/MSP430MCCodeEmitter.cpp
===================================================================
--- lib/Target/MSP430/MCTargetDesc/MSP430MCCodeEmitter.cpp
+++ lib/Target/MSP430/MCTargetDesc/MSP430MCCodeEmitter.cpp
@@ -128,7 +128,7 @@
   const MCOperand &MO2 = MI.getOperand(Op + 1);
   if (MO2.isImm()) {
     Offset += 2;
-    return (MO2.getImm() << 4) | Reg;
+    return ((unsigned)MO2.getImm() << 4) | Reg;
   }
 
   assert(MO2.isExpr() && "Expr operand expected");
Index: test/MC/Disassembler/MSP430/unknown.txt
===================================================================
--- /dev/null
+++ test/MC/Disassembler/MSP430/unknown.txt
@@ -0,0 +1,13 @@
+# RUN: not llvm-mc -disassemble -triple=msp430 %s 2>&1 | FileCheck %s
+
+# This should not decode as 'and.b @r15+, (0)r1' [0xf1,0xff,0x00,0x00]
+[0xf1 0xff]
+# CHECK: warning: invalid instruction encoding
+
+# This should not decode as 'add 6(r7), 6(r5)' [0x95 0x57 0x06 0x00 0x06 0x00]
+[0x95 0x57 0x06 0x00]
+# CHECK: warning: invalid instruction encoding
+
+# This should not decode as 'call 6(r7)' [0x97 0x12 0x06 0x00]
+[0x97 0x12]
+# CHECK: warning: invalid instruction encoding
Index: test/MC/MSP430/addrmode.s
===================================================================
--- test/MC/MSP430/addrmode.s
+++ test/MC/MSP430/addrmode.s
@@ -21,11 +21,13 @@
   mov #42, 12(r15)
   mov #42, &disp
   mov disp, disp+2
+  mov r7, @r15
 
 ; CHECK: mov #42, r15          ; encoding: [0x3f,0x40,0x2a,0x00]
 ; CHECK: mov #42, 12(r15)      ; encoding: [0xbf,0x40,0x2a,0x00,0x0c,0x00]
 ; CHECK: mov #42, &disp        ; encoding: [0xb2,0x40,0x2a,0x00,A,A]
 ; CHECK: mov disp, disp+2      ; encoding: [0x90,0x40,A,A,B,B]
+; CHECK: mov r7, 0(r15)        ; encoding: [0x8f,0x47,0x00,0x00]
 
   add r7, r8
   add 6(r7), r8
Index: test/MC/MSP430/invalid.s
===================================================================
--- test/MC/MSP430/invalid.s
+++ test/MC/MSP430/invalid.s
@@ -4,7 +4,6 @@
   mov    r7        ; CHECK: :[[@LINE]]:3: error: too few operands for instruction
 
   ;; invalid destination addressing modes
-  mov    r7, @r15  ; CHECK: :[[@LINE]]:14: error: invalid operand for instruction
   mov    r7, @r15+ ; CHECK: :[[@LINE]]:14: error: invalid operand for instruction
   mov    r7, #0    ; CHECK: :[[@LINE]]:14: error: invalid operand for instruction
   mov    r7, #123  ; CHECK: :[[@LINE]]:14: error: invalid operand for instruction