[ARM] Add the non-MVE instructions in Arm v8.1-M.

This adds support for the new family of conditional selection /
increment / negation instructions; the low-overhead branch
instructions (e.g. BF, WLS, DLS); the CLRM instruction to zero a whole
list of registers at once; the new VMRS/VMSR and VLDR/VSTR
instructions to get data in and out of 8.1-M system registers,
particularly including the new VPR register used by MVE vector
predication.

To support this, we also add a register name 'zr' (used by the CSEL
family to force one of the inputs to the constant 0), and operand
types for lists of registers that are also allowed to include APSR or
VPR (used by CLRM). The VLDR/VSTR instructions also need a new
addressing mode.

The low-overhead branch instructions exist in their own separate
architecture extension, which we treat as enabled by default, but you
can say -mattr=-lob or equivalent to turn it off.

Reviewers: dmgreen, samparker, SjoerdMeijer, t.p.northover

Reviewed By: samparker

Subscribers: miyuki, javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62667

llvm-svn: 363039

1 files changed, 351 insertions, 15 deletions

diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 6948f7af469..df6a9a15099 100644
--- a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -144,12 +144,17 @@ static bool Check(DecodeStatus &Out, DecodeStatus In) {
 // Definitions are further down.
 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
                                    uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
+                                   uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
                                                unsigned RegNo, uint64_t Address,
                                                const void *Decoder);
 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
                                                unsigned RegNo, uint64_t Address,
                                                const void *Decoder);
+static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
+                                               unsigned RegNo, uint64_t Address,
+                                               const void *Decoder);
 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
                                    uint64_t Address, const void *Decoder);
 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
@@ -361,8 +366,13 @@ static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
                                uint64_t Address, const void* Decoder);
 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
                                uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
+                               uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
                                uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
+                                           uint64_t Address,
+                                           const void *Decoder);
 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
                                uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
@@ -411,6 +421,23 @@ static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
                                          uint64_t Address, const void *Decoder);
 
+template <bool isSigned, bool isNeg, int size>
+static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
+                                         uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
+                                               uint64_t Address,
+                                               const void *Decoder);
+static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
+                                          uint64_t Address,
+                                          const void *Decoder);
+static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
+                                 const void *Decoder);
+static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
+                                  const void *Decoder);
+template<bool Writeback>
+static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
+                                          uint64_t Address,
+                                          const void *Decoder);
 #include "ARMGenDisassemblerTables.inc"
 
 static MCDisassembler *createARMDisassembler(const Target &T,
@@ -604,6 +631,10 @@ ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
     case ARM::t2CPS3p:
     case ARM::t2CPS2p:
     case ARM::t2CPS1p:
+    case ARM::t2CSEL:
+    case ARM::t2CSINC:
+    case ARM::t2CSINV:
+    case ARM::t2CSNEG:
     case ARM::tMOVSr:
     case ARM::tSETEND:
       // Some instructions (mostly conditional branches) are not
@@ -892,6 +923,13 @@ static const uint16_t GPRDecoderTable[] = {
   ARM::R12, ARM::SP, ARM::LR, ARM::PC
 };
 
+static const uint16_t CLRMGPRDecoderTable[] = {
+  ARM::R0, ARM::R1, ARM::R2, ARM::R3,
+  ARM::R4, ARM::R5, ARM::R6, ARM::R7,
+  ARM::R8, ARM::R9, ARM::R10, ARM::R11,
+  ARM::R12, 0, ARM::LR, ARM::APSR
+};
+
 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
                                    uint64_t Address, const void *Decoder) {
   if (RegNo > 15)
@@ -902,6 +940,20 @@ static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
+                                               uint64_t Address,
+                                               const void *Decoder) {
+  if (RegNo > 15)
+    return MCDisassembler::Fail;
+
+  unsigned Register = CLRMGPRDecoderTable[RegNo];
+  if (Register == 0)
+    return MCDisassembler::Fail;
+
+  Inst.addOperand(MCOperand::createReg(Register));
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus
 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
                            uint64_t Address, const void *Decoder) {
@@ -930,6 +982,24 @@ DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
   return S;
 }
 
+static DecodeStatus
+DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
+                             uint64_t Address, const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+
+  if (RegNo == 15)
+  {
+    Inst.addOperand(MCOperand::createReg(ARM::ZR));
+    return MCDisassembler::Success;
+  }
+
+  if (RegNo == 13)
+    S = MCDisassembler::SoftFail;
+
+  Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
+  return S;
+}
+
 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
                                    uint64_t Address, const void *Decoder) {
   if (RegNo > 7)
@@ -1239,6 +1309,7 @@ static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
 
   bool NeedDisjointWriteback = false;
   unsigned WritebackReg = 0;
+  bool CLRM = false;
   switch (Inst.getOpcode()) {
   default:
     break;
@@ -1253,17 +1324,26 @@ static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
     NeedDisjointWriteback = true;
     WritebackReg = Inst.getOperand(0).getReg();
     break;
+  case ARM::t2CLRM:
+    CLRM = true;
+    break;
   }
 
   // Empty register lists are not allowed.
   if (Val == 0) return MCDisassembler::Fail;
   for (unsigned i = 0; i < 16; ++i) {
     if (Val & (1 << i)) {
-      if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
-        return MCDisassembler::Fail;
-      // Writeback not allowed if Rn is in the target list.
-      if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
-        Check(S, MCDisassembler::SoftFail);
+      if (CLRM) {
+        if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
+          return MCDisassembler::Fail;
+        }
+      } else {
+        if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
+          return MCDisassembler::Fail;
+        // Writeback not allowed if Rn is in the target list.
+        if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
+          Check(S, MCDisassembler::SoftFail);
+      }
     }
   }
 
@@ -1356,6 +1436,8 @@ static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
   unsigned imm = fieldFromInstruction(Insn, 0, 8);
   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
   unsigned U = fieldFromInstruction(Insn, 23, 1);
+  const FeatureBitset &featureBits =
+    ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
 
   switch (Inst.getOpcode()) {
     case ARM::LDC_OFFSET:
@@ -1390,15 +1472,42 @@ static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
     case ARM::t2STCL_PRE:
     case ARM::t2STCL_POST:
     case ARM::t2STCL_OPTION:
-      if (coproc == 0xA || coproc == 0xB)
+    case ARM::t2LDC2_OFFSET:
+    case ARM::t2LDC2L_OFFSET:
+    case ARM::t2LDC2_PRE:
+    case ARM::t2LDC2L_PRE:
+    case ARM::t2STC2_OFFSET:
+    case ARM::t2STC2L_OFFSET:
+    case ARM::t2STC2_PRE:
+    case ARM::t2STC2L_PRE:
+    case ARM::LDC2_OFFSET:
+    case ARM::LDC2L_OFFSET:
+    case ARM::LDC2_PRE:
+    case ARM::LDC2L_PRE:
+    case ARM::STC2_OFFSET:
+    case ARM::STC2L_OFFSET:
+    case ARM::STC2_PRE:
+    case ARM::STC2L_PRE:
+    case ARM::t2LDC2_OPTION:
+    case ARM::t2STC2_OPTION:
+    case ARM::t2LDC2_POST:
+    case ARM::t2LDC2L_POST:
+    case ARM::t2STC2_POST:
+    case ARM::t2STC2L_POST:
+    case ARM::LDC2_POST:
+    case ARM::LDC2L_POST:
+    case ARM::STC2_POST:
+    case ARM::STC2L_POST:
+      if (coproc == 0xA || coproc == 0xB ||
+          (featureBits[ARM::HasV8_1MMainlineOps] &&
+           (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
+            coproc == 0xE || coproc == 0xF)))
         return MCDisassembler::Fail;
       break;
     default:
       break;
   }
 
-  const FeatureBitset &featureBits =
-    ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
     return MCDisassembler::Fail;
 
@@ -3735,6 +3844,21 @@ static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
+                                   const void *Decoder) {
+  if (Val == 0)
+    Inst.addOperand(MCOperand::createImm(INT32_MIN));
+  else {
+    int imm = Val & 0x7F;
+
+    if (!(Val & 0x80))
+      imm *= -1;
+    Inst.addOperand(MCOperand::createImm(imm * 4));
+  }
+
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
                                    uint64_t Address, const void *Decoder) {
   DecodeStatus S = MCDisassembler::Success;
@@ -3750,6 +3874,22 @@ static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
   return S;
 }
 
+static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
+                                           uint64_t Address,
+                                           const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+
+  unsigned Rn = fieldFromInstruction(Val, 8, 4);
+  unsigned imm = fieldFromInstruction(Val, 0, 8);
+
+  if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
+    return MCDisassembler::Fail;
+  if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
+    return MCDisassembler::Fail;
+
+  return S;
+}
+
 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
                                    uint64_t Address, const void *Decoder) {
   DecodeStatus S = MCDisassembler::Success;
@@ -4005,6 +4145,13 @@ static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
     return MCDisassembler::Fail;
 
+  // For Armv8.1-M Mainline coprocessors matching 100x,101x or 111x should
+  // decode as VFP/MVE instructions.
+  if (featureBits[ARM::HasV8_1MMainlineOps] &&
+      ((Val & 0xE) == 0x8 || (Val & 0xE) == 0xA ||
+       (Val & 0xE) == 0xE))
+    return MCDisassembler::Fail;
+
   Inst.addOperand(MCOperand::createImm(Val));
   return MCDisassembler::Success;
 }
@@ -5370,14 +5517,37 @@ static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
   DecodeStatus S = MCDisassembler::Success;
 
-  unsigned Rt = fieldFromInstruction(Val, 12, 4);
+  // Add explicit operand for the destination sysreg, for cases where
+  // we have to model it for code generation purposes.
+  switch (Inst.getOpcode()) {
+  case ARM::VMSR_FPSCR_NZCVQC:
+    Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
+    break;
+  case ARM::VMSR_P0:
+    Inst.addOperand(MCOperand::createReg(ARM::VPR));
+    break;
+  }
 
-  if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
-    if (Rt == 13 || Rt == 15)
-      S = MCDisassembler::SoftFail;
-    Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
-  } else
-    Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
+  if (Inst.getOpcode() != ARM::FMSTAT) {
+    unsigned Rt = fieldFromInstruction(Val, 12, 4);
+
+    if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
+      if (Rt == 13 || Rt == 15)
+        S = MCDisassembler::SoftFail;
+      Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
+    } else
+      Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
+  }
+
+  // Add explicit operand for the source sysreg, similarly to above.
+  switch (Inst.getOpcode()) {
+  case ARM::VMRS_FPSCR_NZCVQC:
+    Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
+    break;
+  case ARM::VMRS_P0:
+    Inst.addOperand(MCOperand::createReg(ARM::VPR));
+    break;
+  }
 
   if (featureBits[ARM::ModeThumb]) {
     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
@@ -5390,3 +5560,169 @@ static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
 
   return S;
 }
+
+template <bool isSigned, bool isNeg, int size>
+static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
+                                         uint64_t Address,
+                                         const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+  if (Val == 0)
+    S = MCDisassembler::SoftFail;
+
+  uint64_t DecVal;
+  if (isSigned)
+    DecVal = SignExtend32<size + 1>(Val << 1);
+  else
+    DecVal = (Val << 1);
+
+  if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
+                                Decoder))
+    Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
+  return S;
+}
+
+static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
+                                               uint64_t Address,
+                                               const void *Decoder) {
+
+  uint64_t LocImm = Inst.getOperand(0).getImm();
+  Val = LocImm + (2 << Val);
+  if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
+                                Decoder))
+    Inst.addOperand(MCOperand::createImm(Val));
+  return MCDisassembler::Success;
+}
+
+static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
+                                          uint64_t Address,
+                                          const void *Decoder) {
+  if (Val >= ARMCC::AL)  // also exclude the non-condition NV
+    return MCDisassembler::Fail;
+  Inst.addOperand(MCOperand::createImm(Val));
+  return MCDisassembler::Success;
+}
+
+static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
+                                 const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+
+  unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
+                 fieldFromInstruction(Insn, 1, 10) << 1;
+  switch (Inst.getOpcode()) {
+  case ARM::t2LEUpdate:
+    Inst.addOperand(MCOperand::createReg(ARM::LR));
+    Inst.addOperand(MCOperand::createReg(ARM::LR));
+    LLVM_FALLTHROUGH;
+  case ARM::t2LE:
+    if (!Check(S, DecodeBFLabelOperand<false, true, 11>(Inst, Imm, Address,
+                                                        Decoder)))
+      return MCDisassembler::Fail;
+    break;
+  case ARM::t2WLS:
+    Inst.addOperand(MCOperand::createReg(ARM::LR));
+    if (!Check(S,
+               DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
+                                       Address, Decoder)) ||
+        !Check(S, DecodeBFLabelOperand<false, false, 11>(Inst, Imm, Address,
+                                                         Decoder)))
+      return MCDisassembler::Fail;
+    break;
+  case ARM::t2DLS:
+    unsigned Rn = fieldFromInstruction(Insn, 16, 4);
+    if (Rn == 0xF) {
+      return MCDisassembler::Fail;
+    } else {
+      Inst.addOperand(MCOperand::createReg(ARM::LR));
+      if (!Check(S, DecoderGPRRegisterClass(Inst,
+                                            fieldFromInstruction(Insn, 16, 4),
+                                            Address, Decoder)))
+        return MCDisassembler::Fail;
+    }
+    break;
+  }
+  return S;
+}
+
+static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
+                                  const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+
+  Inst.addOperand(MCOperand::createImm(ARMCC::AL));
+  Inst.addOperand(MCOperand::createReg(0));
+  if (Inst.getOpcode() == ARM::VSCCLRMD) {
+    unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
+                       (fieldFromInstruction(Insn, 12, 4) << 8) |
+                       (fieldFromInstruction(Insn, 22, 1) << 12);
+    if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
+      return MCDisassembler::Fail;
+    }
+  } else {
+    unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
+                       (fieldFromInstruction(Insn, 22, 1) << 8) |
+                       (fieldFromInstruction(Insn, 12, 4) << 9);
+    if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
+      return MCDisassembler::Fail;
+    }
+  }
+  Inst.addOperand(MCOperand::createReg(ARM::VPR));
+
+  return S;
+}
+
+static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
+  switch (Opcode) {
+  case ARM::VSTR_P0_off:
+  case ARM::VSTR_P0_pre:
+  case ARM::VSTR_P0_post:
+  case ARM::VLDR_P0_off:
+  case ARM::VLDR_P0_pre:
+  case ARM::VLDR_P0_post:
+    return ARM::P0;
+  default:
+    return 0;
+  }
+}
+
+template<bool Writeback>
+static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
+                                          uint64_t Address,
+                                          const void *Decoder) {
+  switch (Inst.getOpcode()) {
+  case ARM::VSTR_FPSCR_pre:
+  case ARM::VSTR_FPSCR_NZCVQC_pre:
+  case ARM::VLDR_FPSCR_pre:
+  case ARM::VLDR_FPSCR_NZCVQC_pre:
+  case ARM::VSTR_FPSCR_off:
+  case ARM::VSTR_FPSCR_NZCVQC_off:
+  case ARM::VLDR_FPSCR_off:
+  case ARM::VLDR_FPSCR_NZCVQC_off:
+  case ARM::VSTR_FPSCR_post:
+  case ARM::VSTR_FPSCR_NZCVQC_post:
+  case ARM::VLDR_FPSCR_post:
+  case ARM::VLDR_FPSCR_NZCVQC_post:
+    const FeatureBitset &featureBits =
+        ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
+
+    if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
+      return MCDisassembler::Fail;
+  }
+
+  DecodeStatus S = MCDisassembler::Success;
+  if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
+    Inst.addOperand(MCOperand::createReg(Sysreg));
+  unsigned Rn = fieldFromInstruction(Val, 16, 4);
+  unsigned addr = fieldFromInstruction(Val, 0, 7) |
+                  (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
+
+  if (Writeback) {
+    if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
+      return MCDisassembler::Fail;
+  }
+  if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
+    return MCDisassembler::Fail;
+
+  Inst.addOperand(MCOperand::createImm(ARMCC::AL));
+  Inst.addOperand(MCOperand::createReg(0));
+
+  return S;
+}