Index: lib/Target/NDS32/NDS32Instr16Bit.td
===================================================================
--- /dev/null
+++ lib/Target/NDS32/NDS32Instr16Bit.td
@@ -0,0 +1,72 @@
+//===-- NDS32InstrInfo.td - NDS32 16 bit Instruction defs --*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the NDS32 16 bit instructions in TableGen format.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Move Instructions
+//
+
+def MOV55: MOV55Form<(outs GPR:$Rt), (ins GPR:$Ra),
+                     "mov55\t$Rt, $Ra", []>,
+                     Requires<[Has16Bit]>;
+
+let isReMaterializable = 1, isAsCheapAsAMove = 1, isMoveImm = 1 in
+def MOVI55 : MOVI55Form<(outs GPR:$Rt), (ins imm5s:$imm),
+                        "movi55\t$Rt, $imm",
+                        [(set GPR:$Rt, (imm5s:$imm))]>,
+                        Requires<[Has16Bit]>;
+
+
+//===----------------------------------------------------------------------===//
+// Arithmetic Instructions
+//
+
+let isAdd = 1 in
+def ADD333 : ADD333Form<(outs lGPR:$Rt), (ins lGPR:$Ra, lGPR:$Rb),
+                        "add333\t$Rt, $Ra, $Rb",
+                        [(set lGPR:$Rt, (add lGPR:$Ra, lGPR:$Rb))]>,
+                        Requires<[Has16Bit]>;
+
+let isAdd = 1 in
+def ADDI333 : ADDI333Form<(outs lGPR:$Rt), (ins lGPR:$Ra, imm3u:$imm),
+                          "addi333\t$Rt, $Ra, $imm",
+                          [(set lGPR:$Rt, (add lGPR:$Ra, imm3u:$imm))]>,
+                          Requires<[Has16Bit]>;
+
+def SUB333 : SUB333Form<(outs lGPR:$Rt), (ins lGPR:$Ra, lGPR:$Rb),
+                        "sub333\t$Rt, $Ra, $Rb",
+                        [(set lGPR:$Rt, (sub lGPR:$Ra, lGPR:$Rb))]>,
+                        Requires<[Has16Bit]>;
+
+def SLLI333: SLLI333Form<(outs lGPR:$Rt), (ins lGPR:$Ra, imm3u:$imm),
+                         "slli333\t$Rt, $Ra, $imm",
+                         [(set lGPR:$Rt, (shl lGPR:$Ra, imm3u:$imm))]>,
+                         Requires<[Has16Bit]>;
+
+class  ALU33 <string opstr, SDPatternOperator Op, bits<3> subop_encode> :
+  MISC33Form<(outs lGPR:$Rt_wb), (ins lGPR:$Rt, lGPR:$Ra),
+             !strconcat(opstr, "\t$Rt, $Ra"),
+             [(set lGPR:$Rt_wb, (Op lGPR:$Rt, lGPR:$Ra))],
+             subop_encode>,
+             Requires<[Has16Bit]> {
+  let Constraints = "$Rt = $Rt_wb";
+}
+
+def AND33     : ALU33< "and33", and, 0b110>;
+def MUL33     : ALU33< "mul33", mul, 0b100>;
+def OR33      : ALU33< "or33" ,  or, 0b111>;
+def XOR33     : ALU33< "xor33", xor, 0b101>;
+
+def NOT33 : MISC33Form<(outs lGPR:$Rt), (ins lGPR:$Ra),
+                       "not33\t$Rt, $Ra",
+                       [(set lGPR:$Rt, (not lGPR:$Ra))], 0b011>,
+                       Requires<[Has16Bit]>;
Index: lib/Target/NDS32/NDS32Instr16Formats.td
===================================================================
--- /dev/null
+++ lib/Target/NDS32/NDS32Instr16Formats.td
@@ -0,0 +1,133 @@
+//===-- NDS32Instr16Formats.td - NDS32 Instruction Formats -*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//  Describe NDS32 16 bit instructions format here
+//
+
+class 16BitInst4BitOpcode<bits<4> opcode,
+                dag outs, dag ins, string asmstr, list<dag> pattern>
+  : NDS32Inst<outs, ins, asmstr> {
+  field bits<16> Inst;
+  let Size = 2;
+  let Pattern = pattern;
+
+  let Inst{15} = 1;
+  let Inst{14-11} = opcode;
+}
+
+class 16BitInst5BitOpcode<bits<5> opcode,
+                dag outs, dag ins, string asmstr, list<dag> pattern>
+  : NDS32Inst<outs, ins, asmstr> {
+  field bits<16> Inst;
+  let Size = 2;
+  let Pattern = pattern;
+
+  let Inst{15} = 1;
+  let Inst{14-10} = opcode;
+}
+
+class 16BitInst6BitOpcode<bits<6> opcode,
+                dag outs, dag ins, string asmstr, list<dag> pattern>
+  : NDS32Inst<outs, ins, asmstr> {
+  field bits<16> Inst;
+  let Size = 2;
+  let Pattern = pattern;
+
+  let Inst{15} = 1;
+  let Inst{14-9} = opcode;
+}
+
+class 16BitInst7BitOpcode<bits<7> opcode,
+                dag outs, dag ins, string asmstr, list<dag> pattern>
+  : NDS32Inst<outs, ins, asmstr> {
+  field bits<16> Inst;
+  let Size = 2;
+  let Pattern = pattern;
+
+  let Inst{15} = 1;
+  let Inst{14-8} = opcode;
+}
+
+class 16BitInst10BitOpcode<bits<10> opcode,
+                dag outs, dag ins, string asmstr, list<dag> pattern>
+  : NDS32Inst<outs, ins, asmstr> {
+  field bits<16> Inst;
+  let Size = 2;
+  let Pattern = pattern;
+
+  let Inst{15} = 1;
+  let Inst{14-5} = opcode;
+}
+
+class MOV55Form<dag outs, dag ins, string asmstr, list<dag> pattern>
+  : 16BitInst5BitOpcode<0b00000, outs, ins, asmstr, pattern> {
+  bits<5> Rt;
+  bits<5> Ra;
+  let Inst{9-5} = Rt;
+  let Inst{4-0} = Ra;
+}
+
+class MOVI55Form<dag outs, dag ins, string asmstr, list<dag> pattern>
+  : 16BitInst5BitOpcode<0b00001, outs, ins, asmstr, pattern> {
+  bits<5> Rt;
+  bits<5> imm;
+  let Inst{9-5} = Rt;
+  let Inst{4-0} = imm;
+}
+
+class ADD333Form<dag outs, dag ins, string asmstr, list<dag> pattern>
+  : 16BitInst6BitOpcode<0b001100, outs, ins, asmstr, pattern> {
+  bits<3> Rt;
+  bits<3> Ra;
+  bits<3> Rb;
+  let Inst{8-6} = Rt;
+  let Inst{5-3} = Ra;
+  let Inst{2-0} = Rb;
+}
+
+class ADDI333Form<dag outs, dag ins, string asmstr, list<dag> pattern>
+  : 16BitInst6BitOpcode<0b001110, outs, ins, asmstr, pattern> {
+  bits<3> Rt;
+  bits<3> Ra;
+  bits<3> imm;
+  let Inst{8-6} = Rt;
+  let Inst{5-3} = Ra;
+  let Inst{2-0} = imm;
+}
+
+class SLLI333Form<dag outs, dag ins, string asmstr, list<dag> pattern>
+  : 16BitInst6BitOpcode<0b001010, outs, ins, asmstr, pattern> {
+  bits<3> Rt;
+  bits<3> Ra;
+  bits<3> imm;
+  let Inst{8-6} = Rt;
+  let Inst{5-3} = Ra;
+  let Inst{2-0} = imm;
+}
+
+class SUB333Form<dag outs, dag ins, string asmstr, list<dag> pattern>
+  : 16BitInst6BitOpcode<0b001101, outs, ins, asmstr, pattern> {
+  bits<3> Rt;
+  bits<3> Ra;
+  bits<3> Rb;
+  let Inst{8-6} = Rt;
+  let Inst{5-3} = Ra;
+  let Inst{2-0} = Rb;
+}
+
+class MISC33Form<dag outs, dag ins, string asmstr, list<dag> pattern,
+		 bits<3> subop_encode>
+  : 16BitInst6BitOpcode<0b111111, outs, ins, asmstr, pattern> {
+  bits<3> Rt;
+  bits<3> Ra;
+  let Inst{8-6} = Rt;
+  let Inst{5-3} = Ra;
+  let Inst{2-0} = subop_encode;
+}
Index: lib/Target/NDS32/NDS32InstrInfo.cpp
===================================================================
--- lib/Target/NDS32/NDS32InstrInfo.cpp
+++ lib/Target/NDS32/NDS32InstrInfo.cpp
@@ -56,14 +56,24 @@
                                  MachineBasicBlock::iterator I,
                                  const DebugLoc &DL, unsigned DestReg,
                                  unsigned SrcReg, bool KillSrc) const {
+  MachineFunction &MF = *I->getParent()->getParent();
+  const NDS32Subtarget &Subtarget = MF.getSubtarget<NDS32Subtarget>();
   unsigned Opc;
 
+  // Generate 32-bit ADDI when no-16bit is enabled
   if (NDS32::GPRRegClass.contains(DestReg, SrcReg)) {
-    Opc = NDS32::ADDI;
+    if (Subtarget.has16Bit())
+      Opc = NDS32::MOV55;
+    else
+      Opc = NDS32::ADDI;
   } else
     llvm_unreachable("Impossible reg-to-reg copy");
 
-  BuildMI(MBB, I, DL, get(Opc), DestReg)
+  if (Opc == NDS32::MOV55)
+    BuildMI(MBB, I, DL, get(Opc), DestReg)
+    .addReg(SrcReg, getKillRegState(KillSrc));
+  else
+    BuildMI(MBB, I, DL, get(Opc), DestReg)
     .addReg(SrcReg, getKillRegState(KillSrc)).addImm(0);
 }
 
Index: lib/Target/NDS32/NDS32InstrInfo.td
===================================================================
--- lib/Target/NDS32/NDS32InstrInfo.td
+++ lib/Target/NDS32/NDS32InstrInfo.td
@@ -45,6 +45,14 @@
 def NDS32udivrem : SDNode<"NDS32ISD::UDIVREM", SDTIntBinHiLoOp>;
 
 //===----------------------------------------------------------------------===//
+// 16 bit Instructions
+//
+
+include "NDS32Instr16Formats.td"
+include "NDS32Instr16Bit.td"
+
+
+//===----------------------------------------------------------------------===//
 // ADJCALLSTACKDOWN/UP implicitly use/def SP because they may be expanded into
 // a stack adjustment and the codegen must know that they may modify the stack
 // pointer before prolog-epilog rewriting occurs.
Index: lib/Target/NDS32/NDS32Predicate.td
===================================================================
--- lib/Target/NDS32/NDS32Predicate.td
+++ lib/Target/NDS32/NDS32Predicate.td
@@ -12,6 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 //===----------------------------------------------------------------------===//
+// NDS32 Instruction Predicate Definitions.
+//
+
+def Has16Bit            : Predicate<"Subtarget->has16Bit()">;
+
+
+//===----------------------------------------------------------------------===//
 // Immediate Operand Predicates
 //
 
@@ -27,6 +34,16 @@
 
 class ImmAsmOperand : AsmOperandClass { let RenderMethod = "addImmOperands"; }
 
+/// imm5s predicate - Immediate in the range [-(1 << 4) , (1 << 4)].
+def Imm5sAsmOperand: ImmAsmOperand {
+  let Name = "Imm5s";
+  let DiagnosticType = "ImmRange5s";
+}
+def imm5s : Operand<i32>, ImmLeaf<i32, [{
+  return Imm >= -(1 << 4) && Imm < (1 << 4);
+}]> {
+}
+
 /// imm11s predicate - Immediate in the range [-(1 << 10) , (1 << 10)].
 def Imm11sAsmOperand: ImmAsmOperand {
   let Name = "Imm11s";
@@ -57,6 +74,15 @@
 }]> {
 }
 
+/// imm3u predicate - Immediate in the range [0 , (1 << 3)].
+def Imm3uAsmOperand: ImmAsmOperand {
+  let Name = "Imm3u";
+  let DiagnosticType = "ImmRange3u";
+}
+def imm3u : Operand<i32>, ImmLeaf<i32, [{
+  return Imm >= 0 && Imm < (1 << 3);
+}]> {
+}
 
 /// imm5u predicate - Immediate in the range [0 , (1 << 5)].
 def Imm5uAsmOperand: ImmAsmOperand {
Index: test/CodeGen/NDS32/16-bit-alu.ll
===================================================================
--- /dev/null
+++ test/CodeGen/NDS32/16-bit-alu.ll
@@ -0,0 +1,89 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "e-m:e-p:32:32-i64:64-a:0:32-n32-S64"
+target triple = "nds32le---elf"
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @mov55(i32 %a, i32 returned %b) local_unnamed_addr #0 {
+entry:
+  ret i32 %b
+; CHECK: mov55   $r0, $r1
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @movi55() local_unnamed_addr #0 {
+entry:
+  ret i32 2
+; CHECK: movi55  $r0, 2
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @add333(i32 %a, i32 %b) local_unnamed_addr #0 {
+entry:
+  %add = add nsw i32 %b, %a
+; CHECK: add333  $r0, $r1, $r0
+  ret i32 %add
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @addi333(i32 %a) local_unnamed_addr #0 {
+entry:
+  %add = add nsw i32 %a, 2
+; CHECK: addi333 $r0, $r0, 2
+  ret i32 %add
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @sub333(i32 %a, i32 %b) local_unnamed_addr #0 {
+entry:
+  %sub = sub nsw i32 %a, %b
+; CHECK: sub333  $r0, $r0, $r1
+  ret i32 %sub
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @slli333(i32 %a) local_unnamed_addr #0 {
+entry:
+  %shl = shl i32 %a, 4
+; CHECK: slli333 $r0, $r0, 4
+  ret i32 %shl
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @and33(i32 %a, i32 %b) local_unnamed_addr #0 {
+entry:
+  %and = and i32 %b, %a
+; CHECK: and33   $r1, $r0
+  ret i32 %and
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @mul33(i32 %a, i32 %b) local_unnamed_addr #0 {
+entry:
+  %mul = mul nsw i32 %b, %a
+; CHECK: mul33   $r1, $r0
+  ret i32 %mul
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @or33(i32 %a, i32 %b) local_unnamed_addr #0 {
+entry:
+  %or = or i32 %b, %a
+; CHECK: or33    $r1, $r0
+  ret i32 %or
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @xor33(i32 %a, i32 %b) local_unnamed_addr #0 {
+entry:
+  %xor = xor i32 %b, %a
+; CHECK: xor33   $r1, $r0
+  ret i32 %xor
+}
+
+; Function Attrs: norecurse nounwind readnone
+define i32 @not33(i32 %a) local_unnamed_addr #0 {
+entry:
+  %neg = xor i32 %a, -1
+; CHECK: not33   $r0, $r0
+  ret i32 %neg
+}
Index: test/CodeGen/NDS32/alu-insns.ll
===================================================================
--- test/CodeGen/NDS32/alu-insns.ll
+++ test/CodeGen/NDS32/alu-insns.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s | FileCheck %s
+; RUN: llc -mattr=+no-16bit < %s | FileCheck %s
 target datalayout = "e-m:e-p:32:32-i64:64-a:0:32-n32-S64"
 target triple = "nds32le---elf"
 
Index: test/CodeGen/NDS32/post-inc.ll
===================================================================
--- test/CodeGen/NDS32/post-inc.ll
+++ test/CodeGen/NDS32/post-inc.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s | FileCheck %s
+; RUN: llc -mattr=+no-16bit < %s | FileCheck %s
 target datalayout = "e-m:e-p:32:32-i64:64-a:0:32-n32-S64"
 target triple = "nds32le---elf"