llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp

//===- HexagonInstrInfo.cpp - Hexagon Instruction Information -------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the Hexagon implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//

#include "HexagonInstrInfo.h"
#include "Hexagon.h"
#include "HexagonFrameLowering.h"
#include "HexagonHazardRecognizer.h"
#include "HexagonRegisterInfo.h"
#include "HexagonSubtarget.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/DFAPacketizer.h"
#include "llvm/CodeGen/LivePhysRegs.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineInstrBundle.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MachineValueType.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <cassert>
#include <cctype>
#include <cstdint>
#include <cstring>
#include <iterator>
#include <string>
#include <utility>

using namespace llvm;

#define DEBUG_TYPE "hexagon-instrinfo"

#define GET_INSTRINFO_CTOR_DTOR
#define GET_INSTRMAP_INFO
#include "HexagonDepTimingClasses.h"
#include "HexagonGenDFAPacketizer.inc"
#include "HexagonGenInstrInfo.inc"

cl::opt<bool> ScheduleInlineAsm("hexagon-sched-inline-asm", cl::Hidden,
  cl::init(false), cl::desc("Do not consider inline-asm a scheduling/"
                            "packetization boundary."));

static cl::opt<bool> EnableBranchPrediction("hexagon-enable-branch-prediction",
  cl::Hidden, cl::init(true), cl::desc("Enable branch prediction"));

static cl::opt<bool> DisableNVSchedule("disable-hexagon-nv-schedule",
  cl::Hidden, cl::ZeroOrMore, cl::init(false),
  cl::desc("Disable schedule adjustment for new value stores."));

static cl::opt<bool> EnableTimingClassLatency(
  "enable-timing-class-latency", cl::Hidden, cl::init(false),
  cl::desc("Enable timing class latency"));

static cl::opt<bool> EnableALUForwarding(
  "enable-alu-forwarding", cl::Hidden, cl::init(true),
  cl::desc("Enable vec alu forwarding"));

static cl::opt<bool> EnableACCForwarding(
  "enable-acc-forwarding", cl::Hidden, cl::init(true),
  cl::desc("Enable vec acc forwarding"));

static cl::opt<bool> BranchRelaxAsmLarge("branch-relax-asm-large",
  cl::init(true), cl::Hidden, cl::ZeroOrMore, cl::desc("branch relax asm"));

static cl::opt<bool> UseDFAHazardRec("dfa-hazard-rec",
  cl::init(true), cl::Hidden, cl::ZeroOrMore,
  cl::desc("Use the DFA based hazard recognizer."));

/// Constants for Hexagon instructions.
const int Hexagon_MEMW_OFFSET_MAX = 4095;
const int Hexagon_MEMW_OFFSET_MIN = -4096;
const int Hexagon_MEMD_OFFSET_MAX = 8191;
const int Hexagon_MEMD_OFFSET_MIN = -8192;
const int Hexagon_MEMH_OFFSET_MAX = 2047;
const int Hexagon_MEMH_OFFSET_MIN = -2048;
const int Hexagon_MEMB_OFFSET_MAX = 1023;
const int Hexagon_MEMB_OFFSET_MIN = -1024;
const int Hexagon_ADDI_OFFSET_MAX = 32767;
const int Hexagon_ADDI_OFFSET_MIN = -32768;

// Pin the vtable to this file.
void HexagonInstrInfo::anchor() {}

HexagonInstrInfo::HexagonInstrInfo(HexagonSubtarget &ST)
  : HexagonGenInstrInfo(Hexagon::ADJCALLSTACKDOWN, Hexagon::ADJCALLSTACKUP),
    Subtarget(ST) {}

static bool isIntRegForSubInst(unsigned Reg) {
  return (Reg >= Hexagon::R0 && Reg <= Hexagon::R7) ||
         (Reg >= Hexagon::R16 && Reg <= Hexagon::R23);
}

static bool isDblRegForSubInst(unsigned Reg, const HexagonRegisterInfo &HRI) {
  return isIntRegForSubInst(HRI.getSubReg(Reg, Hexagon::isub_lo)) &&
         isIntRegForSubInst(HRI.getSubReg(Reg, Hexagon::isub_hi));
}

/// Calculate number of instructions excluding the debug instructions.
static unsigned nonDbgMICount(MachineBasicBlock::const_instr_iterator MIB,
                              MachineBasicBlock::const_instr_iterator MIE) {
  unsigned Count = 0;
  for (; MIB != MIE; ++MIB) {
    if (!MIB->isDebugInstr())
      ++Count;
  }
  return Count;
}

/// Find the hardware loop instruction used to set-up the specified loop.
/// On Hexagon, we have two instructions used to set-up the hardware loop
/// (LOOP0, LOOP1) with corresponding endloop (ENDLOOP0, ENDLOOP1) instructions
/// to indicate the end of a loop.
MachineInstr *HexagonInstrInfo::findLoopInstr(MachineBasicBlock *BB,
      unsigned EndLoopOp, MachineBasicBlock *TargetBB,
      SmallPtrSet<MachineBasicBlock *, 8> &Visited) const {
  unsigned LOOPi;
  unsigned LOOPr;
  if (EndLoopOp == Hexagon::ENDLOOP0) {
    LOOPi = Hexagon::J2_loop0i;
    LOOPr = Hexagon::J2_loop0r;
  } else { // EndLoopOp == Hexagon::EndLOOP1
    LOOPi = Hexagon::J2_loop1i;
    LOOPr = Hexagon::J2_loop1r;
  }

  // The loop set-up instruction will be in a predecessor block
  for (MachineBasicBlock *PB : BB->predecessors()) {
    // If this has been visited, already skip it.
    if (!Visited.insert(PB).second)
      continue;
    if (PB == BB)
      continue;
    for (auto I = PB->instr_rbegin(), E = PB->instr_rend(); I != E; ++I) {
      unsigned Opc = I->getOpcode();
      if (Opc == LOOPi || Opc == LOOPr)
        return &*I;
      // We've reached a different loop, which means the loop01 has been
      // removed.
      if (Opc == EndLoopOp && I->getOperand(0).getMBB() != TargetBB)
        return nullptr;
    }
    // Check the predecessors for the LOOP instruction.
    if (MachineInstr *Loop = findLoopInstr(PB, EndLoopOp, TargetBB, Visited))
      return Loop;
  }
  return nullptr;
}

/// Gather register def/uses from MI.
/// This treats possible (predicated) defs as actually happening ones
/// (conservatively).
static inline void parseOperands(const MachineInstr &MI,
      SmallVector<unsigned, 4> &Defs, SmallVector<unsigned, 8> &Uses) {
  Defs.clear();
  Uses.clear();

  for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
    const MachineOperand &MO = MI.getOperand(i);

    if (!MO.isReg())
      continue;

    unsigned Reg = MO.getReg();
    if (!Reg)
      continue;

    if (MO.isUse())
      Uses.push_back(MO.getReg());

    if (MO.isDef())
      Defs.push_back(MO.getReg());
  }
}

// Position dependent, so check twice for swap.
static bool isDuplexPairMatch(unsigned Ga, unsigned Gb) {
  switch (Ga) {
  case HexagonII::HSIG_None:
  default:
    return false;
  case HexagonII::HSIG_L1:
    return (Gb == HexagonII::HSIG_L1 || Gb == HexagonII::HSIG_A);
  case HexagonII::HSIG_L2:
    return (Gb == HexagonII::HSIG_L1 || Gb == HexagonII::HSIG_L2 ||
            Gb == HexagonII::HSIG_A);
  case HexagonII::HSIG_S1:
    return (Gb == HexagonII::HSIG_L1 || Gb == HexagonII::HSIG_L2 ||
            Gb == HexagonII::HSIG_S1 || Gb == HexagonII::HSIG_A);
  case HexagonII::HSIG_S2:
    return (Gb == HexagonII::HSIG_L1 || Gb == HexagonII::HSIG_L2 ||
            Gb == HexagonII::HSIG_S1 || Gb == HexagonII::HSIG_S2 ||
            Gb == HexagonII::HSIG_A);
  case HexagonII::HSIG_A:
    return (Gb == HexagonII::HSIG_A);
  case HexagonII::HSIG_Compound:
    return (Gb == HexagonII::HSIG_Compound);
  }
  return false;
}

/// isLoadFromStackSlot - If the specified machine instruction is a direct
/// load from a stack slot, return the virtual or physical register number of
/// the destination along with the FrameIndex of the loaded stack slot.  If
/// not, return 0.  This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
unsigned HexagonInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
                                               int &FrameIndex) const {
  switch (MI.getOpcode()) {
    default:
      break;
    case Hexagon::L2_loadri_io:
    case Hexagon::L2_loadrd_io:
    case Hexagon::V6_vL32b_ai:
    case Hexagon::V6_vL32b_nt_ai:
    case Hexagon::V6_vL32Ub_ai:
    case Hexagon::LDriw_pred:
    case Hexagon::LDriw_ctr:
    case Hexagon::PS_vloadrq_ai:
    case Hexagon::PS_vloadrw_ai:
    case Hexagon::PS_vloadrw_nt_ai: {
      const MachineOperand OpFI = MI.getOperand(1);
      if (!OpFI.isFI())
        return 0;
      const MachineOperand OpOff = MI.getOperand(2);
      if (!OpOff.isImm() || OpOff.getImm() != 0)
        return 0;
      FrameIndex = OpFI.getIndex();
      return MI.getOperand(0).getReg();
    }

    case Hexagon::L2_ploadrit_io:
    case Hexagon::L2_ploadrif_io:
    case Hexagon::L2_ploadrdt_io:
    case Hexagon::L2_ploadrdf_io: {
      const MachineOperand OpFI = MI.getOperand(2);
      if (!OpFI.isFI())
        return 0;
      const MachineOperand OpOff = MI.getOperand(3);
      if (!OpOff.isImm() || OpOff.getImm() != 0)
        return 0;
      FrameIndex = OpFI.getIndex();
      return MI.getOperand(0).getReg();
    }
  }

  return 0;
}

/// isStoreToStackSlot - If the specified machine instruction is a direct
/// store to a stack slot, return the virtual or physical register number of
/// the source reg along with the FrameIndex of the loaded stack slot.  If
/// not, return 0.  This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
unsigned HexagonInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
                                              int &FrameIndex) const {
  switch (MI.getOpcode()) {
    default:
      break;
    case Hexagon::S2_storerb_io:
    case Hexagon::S2_storerh_io:
    case Hexagon::S2_storeri_io:
    case Hexagon::S2_storerd_io:
    case Hexagon::V6_vS32b_ai:
    case Hexagon::V6_vS32Ub_ai:
    case Hexagon::STriw_pred:
    case Hexagon::STriw_ctr:
    case Hexagon::PS_vstorerq_ai:
    case Hexagon::PS_vstorerw_ai: {
      const MachineOperand &OpFI = MI.getOperand(0);
      if (!OpFI.isFI())
        return 0;
      const MachineOperand &OpOff = MI.getOperand(1);
      if (!OpOff.isImm() || OpOff.getImm() != 0)
        return 0;
      FrameIndex = OpFI.getIndex();
      return MI.getOperand(2).getReg();
    }

    case Hexagon::S2_pstorerbt_io:
    case Hexagon::S2_pstorerbf_io:
    case Hexagon::S2_pstorerht_io:
    case Hexagon::S2_pstorerhf_io:
    case Hexagon::S2_pstorerit_io:
    case Hexagon::S2_pstorerif_io:
    case Hexagon::S2_pstorerdt_io:
    case Hexagon::S2_pstorerdf_io: {
      const MachineOperand &OpFI = MI.getOperand(1);
      if (!OpFI.isFI())
        return 0;
      const MachineOperand &OpOff = MI.getOperand(2);
      if (!OpOff.isImm() || OpOff.getImm() != 0)
        return 0;
      FrameIndex = OpFI.getIndex();
      return MI.getOperand(3).getReg();
    }
  }

  return 0;
}

/// This function checks if the instruction or bundle of instructions
/// has load from stack slot and returns frameindex and machine memory
/// operand of that instruction if true.
bool HexagonInstrInfo::hasLoadFromStackSlot(const MachineInstr &MI,
                                           const MachineMemOperand *&MMO,
                                           int &FrameIndex) const {
  if (MI.isBundle()) {
    const MachineBasicBlock *MBB = MI.getParent();
    MachineBasicBlock::const_instr_iterator MII = MI.getIterator();
    for (++MII; MII != MBB->instr_end() && MII->isInsideBundle(); ++MII)
      if (TargetInstrInfo::hasLoadFromStackSlot(*MII, MMO, FrameIndex))
        return true;
    return false;
  }

  return TargetInstrInfo::hasLoadFromStackSlot(MI, MMO, FrameIndex);
}

/// This function checks if the instruction or bundle of instructions
/// has store to stack slot and returns frameindex and machine memory
/// operand of that instruction if true.
bool HexagonInstrInfo::hasStoreToStackSlot(const MachineInstr &MI,
                                           const MachineMemOperand *&MMO,
                                           int &FrameIndex) const {
  if (MI.isBundle()) {
    const MachineBasicBlock *MBB = MI.getParent();
    MachineBasicBlock::const_instr_iterator MII = MI.getIterator();
    for (++MII; MII != MBB->instr_end() && MII->isInsideBundle(); ++MII)
      if (TargetInstrInfo::hasStoreToStackSlot(*MII, MMO, FrameIndex))
        return true;
    return false;
  }

  return TargetInstrInfo::hasStoreToStackSlot(MI, MMO, FrameIndex);
}

/// This function can analyze one/two way branching only and should (mostly) be
/// called by target independent side.
/// First entry is always the opcode of the branching instruction, except when
/// the Cond vector is supposed to be empty, e.g., when AnalyzeBranch fails, a
/// BB with only unconditional jump. Subsequent entries depend upon the opcode,
/// e.g. Jump_c p will have
/// Cond[0] = Jump_c
/// Cond[1] = p
/// HW-loop ENDLOOP:
/// Cond[0] = ENDLOOP
/// Cond[1] = MBB
/// New value jump:
/// Cond[0] = Hexagon::CMPEQri_f_Jumpnv_t_V4 -- specific opcode
/// Cond[1] = R
/// Cond[2] = Imm
bool HexagonInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
                                     MachineBasicBlock *&TBB,
                                     MachineBasicBlock *&FBB,
                                     SmallVectorImpl<MachineOperand> &Cond,
                                     bool AllowModify) const {
  TBB = nullptr;
  FBB = nullptr;
  Cond.clear();

  // If the block has no terminators, it just falls into the block after it.
  MachineBasicBlock::instr_iterator I = MBB.instr_end();
  if (I == MBB.instr_begin())
    return false;

  // A basic block may looks like this:
  //
  //  [   insn
  //     EH_LABEL
  //      insn
  //      insn
  //      insn
  //     EH_LABEL
  //      insn     ]
  //
  // It has two succs but does not have a terminator
  // Don't know how to handle it.
  do {
    --I;
    if (I->isEHLabel())
      // Don't analyze EH branches.
      return true;
  } while (I != MBB.instr_begin());

  I = MBB.instr_end();
  --I;

  while (I->isDebugInstr()) {
    if (I == MBB.instr_begin())
      return false;
    --I;
  }

  bool JumpToBlock = I->getOpcode() == Hexagon::J2_jump &&
                     I->getOperand(0).isMBB();
  // Delete the J2_jump if it's equivalent to a fall-through.
  if (AllowModify && JumpToBlock &&
      MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
    LLVM_DEBUG(dbgs() << "\nErasing the jump to successor block\n";);
    I->eraseFromParent();
    I = MBB.instr_end();
    if (I == MBB.instr_begin())
      return false;
    --I;
  }
  if (!isUnpredicatedTerminator(*I))
    return false;

  // Get the last instruction in the block.
  MachineInstr *LastInst = &*I;
  MachineInstr *SecondLastInst = nullptr;
  // Find one more terminator if present.
  while (true) {
    if (&*I != LastInst && !I->isBundle() && isUnpredicatedTerminator(*I)) {
      if (!SecondLastInst)
        SecondLastInst = &*I;
      else
        // This is a third branch.
        return true;
    }
    if (I == MBB.instr_begin())
      break;
    --I;
  }

  int LastOpcode = LastInst->getOpcode();
  int SecLastOpcode = SecondLastInst ? SecondLastInst->getOpcode() : 0;
  // If the branch target is not a basic block, it could be a tail call.
  // (It is, if the target is a function.)
  if (LastOpcode == Hexagon::J2_jump && !LastInst->getOperand(0).isMBB())
    return true;
  if (SecLastOpcode == Hexagon::J2_jump &&
      !SecondLastInst->getOperand(0).isMBB())
    return true;

  bool LastOpcodeHasJMP_c = PredOpcodeHasJMP_c(LastOpcode);
  bool LastOpcodeHasNVJump = isNewValueJump(*LastInst);

  if (LastOpcodeHasJMP_c && !LastInst->getOperand(1).isMBB())
    return true;

  // If there is only one terminator instruction, process it.
  if (LastInst && !SecondLastInst) {
    if (LastOpcode == Hexagon::J2_jump) {
      TBB = LastInst->getOperand(0).getMBB();
      return false;
    }
    if (isEndLoopN(LastOpcode)) {
      TBB = LastInst->getOperand(0).getMBB();
      Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode()));
      Cond.push_back(LastInst->getOperand(0));
      return false;
    }
    if (LastOpcodeHasJMP_c) {
      TBB = LastInst->getOperand(1).getMBB();
      Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode()));
      Cond.push_back(LastInst->getOperand(0));
      return false;
    }
    // Only supporting rr/ri versions of new-value jumps.
    if (LastOpcodeHasNVJump && (LastInst->getNumExplicitOperands() == 3)) {
      TBB = LastInst->getOperand(2).getMBB();
      Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode()));
      Cond.push_back(LastInst->getOperand(0));
      Cond.push_back(LastInst->getOperand(1));
      return false;
    }
    LLVM_DEBUG(dbgs() << "\nCant analyze " << printMBBReference(MBB)
                      << " with one jump\n";);
    // Otherwise, don't know what this is.
    return true;
  }

  bool SecLastOpcodeHasJMP_c = PredOpcodeHasJMP_c(SecLastOpcode);
  bool SecLastOpcodeHasNVJump = isNewValueJump(*SecondLastInst);
  if (SecLastOpcodeHasJMP_c && (LastOpcode == Hexagon::J2_jump)) {
    if (!SecondLastInst->getOperand(1).isMBB())
      return true;
    TBB =  SecondLastInst->getOperand(1).getMBB();
    Cond.push_back(MachineOperand::CreateImm(SecondLastInst->getOpcode()));
    Cond.push_back(SecondLastInst->getOperand(0));
    FBB = LastInst->getOperand(0).getMBB();
    return false;
  }

  // Only supporting rr/ri versions of new-value jumps.
  if (SecLastOpcodeHasNVJump &&
      (SecondLastInst->getNumExplicitOperands() == 3) &&
      (LastOpcode == Hexagon::J2_jump)) {
    TBB = SecondLastInst->getOperand(2).getMBB();
    Cond.push_back(MachineOperand::CreateImm(SecondLastInst->getOpcode()));
    Cond.push_back(SecondLastInst->getOperand(0));
    Cond.push_back(SecondLastInst->getOperand(1));
    FBB = LastInst->getOperand(0).getMBB();
    return false;
  }

  // If the block ends with two Hexagon:JMPs, handle it.  The second one is not
  // executed, so remove it.
  if (SecLastOpcode == Hexagon::J2_jump && LastOpcode == Hexagon::J2_jump) {
    TBB = SecondLastInst->getOperand(0).getMBB();
    I = LastInst->getIterator();
    if (AllowModify)
      I->eraseFromParent();
    return false;
  }

  // If the block ends with an ENDLOOP, and J2_jump, handle it.
  if (isEndLoopN(SecLastOpcode) && LastOpcode == Hexagon::J2_jump) {
    TBB = SecondLastInst->getOperand(0).getMBB();
    Cond.push_back(MachineOperand::CreateImm(SecondLastInst->getOpcode()));
    Cond.push_back(SecondLastInst->getOperand(0));
    FBB = LastInst->getOperand(0).getMBB();
    return false;
  }
  LLVM_DEBUG(dbgs() << "\nCant analyze " << printMBBReference(MBB)
                    << " with two jumps";);
  // Otherwise, can't handle this.
  return true;
}

unsigned HexagonInstrInfo::removeBranch(MachineBasicBlock &MBB,
                                        int *BytesRemoved) const {
  assert(!BytesRemoved && "code size not handled");

  LLVM_DEBUG(dbgs() << "\nRemoving branches out of " << printMBBReference(MBB));
  MachineBasicBlock::iterator I = MBB.end();
  unsigned Count = 0;
  while (I != MBB.begin()) {
    --I;
    if (I->isDebugInstr())
      continue;
    // Only removing branches from end of MBB.
    if (!I->isBranch())
      return Count;
    if (Count && (I->getOpcode() == Hexagon::J2_jump))
      llvm_unreachable("Malformed basic block: unconditional branch not last");
    MBB.erase(&MBB.back());
    I = MBB.end();
    ++Count;
  }
  return Count;
}

unsigned HexagonInstrInfo::insertBranch(MachineBasicBlock &MBB,
                                        MachineBasicBlock *TBB,
                                        MachineBasicBlock *FBB,
                                        ArrayRef<MachineOperand> Cond,
                                        const DebugLoc &DL,
                                        int *BytesAdded) const {
  unsigned BOpc   = Hexagon::J2_jump;
  unsigned BccOpc = Hexagon::J2_jumpt;
  assert(validateBranchCond(Cond) && "Invalid branching condition");
  assert(TBB && "insertBranch must not be told to insert a fallthrough");
  assert(!BytesAdded && "code size not handled");

  // Check if reverseBranchCondition has asked to reverse this branch
  // If we want to reverse the branch an odd number of times, we want
  // J2_jumpf.
  if (!Cond.empty() && Cond[0].isImm())
    BccOpc = Cond[0].getImm();

  if (!FBB) {
    if (Cond.empty()) {
      // Due to a bug in TailMerging/CFG Optimization, we need to add a
      // special case handling of a predicated jump followed by an
      // unconditional jump. If not, Tail Merging and CFG Optimization go
      // into an infinite loop.
      MachineBasicBlock *NewTBB, *NewFBB;
      SmallVector<MachineOperand, 4> Cond;
      auto Term = MBB.getFirstTerminator();
      if (Term != MBB.end() && isPredicated(*Term) &&
          !analyzeBranch(MBB, NewTBB, NewFBB, Cond, false) &&
          MachineFunction::iterator(NewTBB) == ++MBB.getIterator()) {
        reverseBranchCondition(Cond);
        removeBranch(MBB);
        return insertBranch(MBB, TBB, nullptr, Cond, DL);
      }
      BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB);
    } else if (isEndLoopN(Cond[0].getImm())) {
      int EndLoopOp = Cond[0].getImm();
      assert(Cond[1].isMBB());
      // Since we're adding an ENDLOOP, there better be a LOOP instruction.
      // Check for it, and change the BB target if needed.
      SmallPtrSet<MachineBasicBlock *, 8> VisitedBBs;
      MachineInstr *Loop = findLoopInstr(TBB, EndLoopOp, Cond[1].getMBB(),
                                         VisitedBBs);
      assert(Loop != nullptr && "Inserting an ENDLOOP without a LOOP");
      Loop->getOperand(0).setMBB(TBB);
      // Add the ENDLOOP after the finding the LOOP0.
      BuildMI(&MBB, DL, get(EndLoopOp)).addMBB(TBB);
    } else if (isNewValueJump(Cond[0].getImm())) {
      assert((Cond.size() == 3) && "Only supporting rr/ri version of nvjump");
      // New value jump
      // (ins IntRegs:$src1, IntRegs:$src2, brtarget:$offset)
      // (ins IntRegs:$src1, u5Imm:$src2, brtarget:$offset)
      unsigned Flags1 = getUndefRegState(Cond[1].isUndef());
      LLVM_DEBUG(dbgs() << "\nInserting NVJump for "
                        << printMBBReference(MBB););
      if (Cond[2].isReg()) {
        unsigned Flags2 = getUndefRegState(Cond[2].isUndef());
        BuildMI(&MBB, DL, get(BccOpc)).addReg(Cond[1].getReg(), Flags1).
          addReg(Cond[2].getReg(), Flags2).addMBB(TBB);
      } else if(Cond[2].isImm()) {
        BuildMI(&MBB, DL, get(BccOpc)).addReg(Cond[1].getReg(), Flags1).
          addImm(Cond[2].getImm()).addMBB(TBB);
      } else
        llvm_unreachable("Invalid condition for branching");
    } else {
      assert((Cond.size() == 2) && "Malformed cond vector");
      const MachineOperand &RO = Cond[1];
      unsigned Flags = getUndefRegState(RO.isUndef());
      BuildMI(&MBB, DL, get(BccOpc)).addReg(RO.getReg(), Flags).addMBB(TBB);
    }
    return 1;
  }
  assert((!Cond.empty()) &&
         "Cond. cannot be empty when multiple branchings are required");
  assert((!isNewValueJump(Cond[0].getImm())) &&
         "NV-jump cannot be inserted with another branch");
  // Special case for hardware loops.  The condition is a basic block.
  if (isEndLoopN(Cond[0].getImm())) {
    int EndLoopOp = Cond[0].getImm();
    assert(Cond[1].isMBB());
    // Since we're adding an ENDLOOP, there better be a LOOP instruction.
    // Check for it, and change the BB target if needed.
    SmallPtrSet<MachineBasicBlock *, 8> VisitedBBs;
    MachineInstr *Loop = findLoopInstr(TBB, EndLoopOp, Cond[1].getMBB(),
                                       VisitedBBs);
    assert(Loop != nullptr && "Inserting an ENDLOOP without a LOOP");
    Loop->getOperand(0).setMBB(TBB);
    // Add the ENDLOOP after the finding the LOOP0.
    BuildMI(&MBB, DL, get(EndLoopOp)).addMBB(TBB);
  } else {
    const MachineOperand &RO = Cond[1];
    unsigned Flags = getUndefRegState(RO.isUndef());
    BuildMI(&MBB, DL, get(BccOpc)).addReg(RO.getReg(), Flags).addMBB(TBB);
  }
  BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB);

  return 2;
}

/// Analyze the loop code to find the loop induction variable and compare used
/// to compute the number of iterations. Currently, we analyze loop that are
/// controlled using hardware loops.  In this case, the induction variable
/// instruction is null.  For all other cases, this function returns true, which
/// means we're unable to analyze it.
bool HexagonInstrInfo::analyzeLoop(MachineLoop &L,
                                   MachineInstr *&IndVarInst,
                                   MachineInstr *&CmpInst) const {

  MachineBasicBlock *LoopEnd = L.getBottomBlock();
  MachineBasicBlock::iterator I = LoopEnd->getFirstTerminator();
  // We really "analyze" only hardware loops right now.
  if (I != LoopEnd->end() && isEndLoopN(I->getOpcode())) {
    IndVarInst = nullptr;
    CmpInst = &*I;
    return false;
  }
  return true;
}

/// Generate code to reduce the loop iteration by one and check if the loop is
/// finished. Return the value/register of the new loop count. this function
/// assumes the nth iteration is peeled first.
unsigned HexagonInstrInfo::reduceLoopCount(MachineBasicBlock &MBB,
      MachineInstr *IndVar, MachineInstr &Cmp,
      SmallVectorImpl<MachineOperand> &Cond,
      SmallVectorImpl<MachineInstr *> &PrevInsts,
      unsigned Iter, unsigned MaxIter) const {
  // We expect a hardware loop currently. This means that IndVar is set
  // to null, and the compare is the ENDLOOP instruction.
  assert((!IndVar) && isEndLoopN(Cmp.getOpcode())
                   && "Expecting a hardware loop");
  MachineFunction *MF = MBB.getParent();
  DebugLoc DL = Cmp.getDebugLoc();
  SmallPtrSet<MachineBasicBlock *, 8> VisitedBBs;
  MachineInstr *Loop = findLoopInstr(&MBB, Cmp.getOpcode(),
                                     Cmp.getOperand(0).getMBB(), VisitedBBs);
  if (!Loop)
    return 0;
  // If the loop trip count is a compile-time value, then just change the
  // value.
  if (Loop->getOpcode() == Hexagon::J2_loop0i ||
      Loop->getOpcode() == Hexagon::J2_loop1i) {
    int64_t Offset = Loop->getOperand(1).getImm();
    if (Offset <= 1)
      Loop->eraseFromParent();
    else
      Loop->getOperand(1).setImm(Offset - 1);
    return Offset - 1;
  }
  // The loop trip count is a run-time value. We generate code to subtract
  // one from the trip count, and update the loop instruction.
  assert(Loop->getOpcode() == Hexagon::J2_loop0r && "Unexpected instruction");
  unsigned LoopCount = Loop->getOperand(1).getReg();
  // Check if we're done with the loop.
  unsigned LoopEnd = createVR(MF, MVT::i1);
  MachineInstr *NewCmp = BuildMI(&MBB, DL, get(Hexagon::C2_cmpgtui), LoopEnd).
    addReg(LoopCount).addImm(1);
  unsigned NewLoopCount = createVR(MF, MVT::i32);
  MachineInstr *NewAdd = BuildMI(&MBB, DL, get(Hexagon::A2_addi), NewLoopCount).
    addReg(LoopCount).addImm(-1);
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();
  // Update the previously generated instructions with the new loop counter.
  for (SmallVectorImpl<MachineInstr *>::iterator I = PrevInsts.begin(),
         E = PrevInsts.end(); I != E; ++I)
    (*I)->substituteRegister(LoopCount, NewLoopCount, 0, HRI);
  PrevInsts.clear();
  PrevInsts.push_back(NewCmp);
  PrevInsts.push_back(NewAdd);
  // Insert the new loop instruction if this is the last time the loop is
  // decremented.
  if (Iter == MaxIter)
    BuildMI(&MBB, DL, get(Hexagon::J2_loop0r)).
      addMBB(Loop->getOperand(0).getMBB()).addReg(NewLoopCount);
  // Delete the old loop instruction.
  if (Iter == 0)
    Loop->eraseFromParent();
  Cond.push_back(MachineOperand::CreateImm(Hexagon::J2_jumpf));
  Cond.push_back(NewCmp->getOperand(0));
  return NewLoopCount;
}

bool HexagonInstrInfo::isProfitableToIfCvt(MachineBasicBlock &MBB,
      unsigned NumCycles, unsigned ExtraPredCycles,
      BranchProbability Probability) const {
  return nonDbgBBSize(&MBB) <= 3;
}

bool HexagonInstrInfo::isProfitableToIfCvt(MachineBasicBlock &TMBB,
      unsigned NumTCycles, unsigned ExtraTCycles, MachineBasicBlock &FMBB,
      unsigned NumFCycles, unsigned ExtraFCycles, BranchProbability Probability)
      const {
  return nonDbgBBSize(&TMBB) <= 3 && nonDbgBBSize(&FMBB) <= 3;
}

bool HexagonInstrInfo::isProfitableToDupForIfCvt(MachineBasicBlock &MBB,
      unsigned NumInstrs, BranchProbability Probability) const {
  return NumInstrs <= 4;
}

void HexagonInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator I,
                                   const DebugLoc &DL, unsigned DestReg,
                                   unsigned SrcReg, bool KillSrc) const {
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();
  unsigned KillFlag = getKillRegState(KillSrc);

  if (Hexagon::IntRegsRegClass.contains(SrcReg, DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::A2_tfr), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::DoubleRegsRegClass.contains(SrcReg, DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::A2_tfrp), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::PredRegsRegClass.contains(SrcReg, DestReg)) {
    // Map Pd = Ps to Pd = or(Ps, Ps).
    BuildMI(MBB, I, DL, get(Hexagon::C2_or), DestReg)
      .addReg(SrcReg).addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::CtrRegsRegClass.contains(DestReg) &&
      Hexagon::IntRegsRegClass.contains(SrcReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::A2_tfrrcr), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::IntRegsRegClass.contains(DestReg) &&
      Hexagon::CtrRegsRegClass.contains(SrcReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::A2_tfrcrr), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::ModRegsRegClass.contains(DestReg) &&
      Hexagon::IntRegsRegClass.contains(SrcReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::A2_tfrrcr), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::PredRegsRegClass.contains(SrcReg) &&
      Hexagon::IntRegsRegClass.contains(DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::C2_tfrpr), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::IntRegsRegClass.contains(SrcReg) &&
      Hexagon::PredRegsRegClass.contains(DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::C2_tfrrp), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::PredRegsRegClass.contains(SrcReg) &&
      Hexagon::IntRegsRegClass.contains(DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::C2_tfrpr), DestReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::HvxVRRegClass.contains(SrcReg, DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::V6_vassign), DestReg).
      addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::HvxWRRegClass.contains(SrcReg, DestReg)) {
    unsigned LoSrc = HRI.getSubReg(SrcReg, Hexagon::vsub_lo);
    unsigned HiSrc = HRI.getSubReg(SrcReg, Hexagon::vsub_hi);
    BuildMI(MBB, I, DL, get(Hexagon::V6_vcombine), DestReg)
      .addReg(HiSrc, KillFlag)
      .addReg(LoSrc, KillFlag);
    return;
  }
  if (Hexagon::HvxQRRegClass.contains(SrcReg, DestReg)) {
    BuildMI(MBB, I, DL, get(Hexagon::V6_pred_and), DestReg)
      .addReg(SrcReg)
      .addReg(SrcReg, KillFlag);
    return;
  }
  if (Hexagon::HvxQRRegClass.contains(SrcReg) &&
      Hexagon::HvxVRRegClass.contains(DestReg)) {
    llvm_unreachable("Unimplemented pred to vec");
    return;
  }
  if (Hexagon::HvxQRRegClass.contains(DestReg) &&
      Hexagon::HvxVRRegClass.contains(SrcReg)) {
    llvm_unreachable("Unimplemented vec to pred");
    return;
  }

#ifndef NDEBUG
  // Show the invalid registers to ease debugging.
  dbgs() << "Invalid registers for copy in " << printMBBReference(MBB) << ": "
         << printReg(DestReg, &HRI) << " = " << printReg(SrcReg, &HRI) << '\n';
#endif
  llvm_unreachable("Unimplemented");
}

void HexagonInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
      MachineBasicBlock::iterator I, unsigned SrcReg, bool isKill, int FI,
      const TargetRegisterClass *RC, const TargetRegisterInfo *TRI) const {
  DebugLoc DL = MBB.findDebugLoc(I);
  MachineFunction &MF = *MBB.getParent();
  MachineFrameInfo &MFI = MF.getFrameInfo();
  unsigned SlotAlign = MFI.getObjectAlignment(FI);
  unsigned RegAlign = TRI->getSpillAlignment(*RC);
  unsigned KillFlag = getKillRegState(isKill);
  bool HasAlloca = MFI.hasVarSizedObjects();
  const HexagonFrameLowering &HFI = *Subtarget.getFrameLowering();

  MachineMemOperand *MMO = MF.getMachineMemOperand(
      MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
      MFI.getObjectSize(FI), SlotAlign);

  if (Hexagon::IntRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::S2_storeri_io))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMO);
  } else if (Hexagon::DoubleRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::S2_storerd_io))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMO);
  } else if (Hexagon::PredRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::STriw_pred))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMO);
  } else if (Hexagon::ModRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::STriw_ctr))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMO);
  } else if (Hexagon::HvxQRRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::PS_vstorerq_ai))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMO);
  } else if (Hexagon::HvxVRRegClass.hasSubClassEq(RC)) {
    // If there are variable-sized objects, spills will not be aligned.
    if (HasAlloca)
      SlotAlign = HFI.getStackAlignment();
    unsigned Opc = SlotAlign < RegAlign ? Hexagon::V6_vS32Ub_ai
                                        : Hexagon::V6_vS32b_ai;
    MachineMemOperand *MMOA = MF.getMachineMemOperand(
        MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
        MFI.getObjectSize(FI), SlotAlign);
    BuildMI(MBB, I, DL, get(Opc))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMOA);
  } else if (Hexagon::HvxWRRegClass.hasSubClassEq(RC)) {
    // If there are variable-sized objects, spills will not be aligned.
    if (HasAlloca)
      SlotAlign = HFI.getStackAlignment();
    unsigned Opc = SlotAlign < RegAlign ? Hexagon::PS_vstorerwu_ai
                                        : Hexagon::PS_vstorerw_ai;
    MachineMemOperand *MMOA = MF.getMachineMemOperand(
        MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
        MFI.getObjectSize(FI), SlotAlign);
    BuildMI(MBB, I, DL, get(Opc))
      .addFrameIndex(FI).addImm(0)
      .addReg(SrcReg, KillFlag).addMemOperand(MMOA);
  } else {
    llvm_unreachable("Unimplemented");
  }
}

void HexagonInstrInfo::loadRegFromStackSlot(
    MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned DestReg,
    int FI, const TargetRegisterClass *RC,
    const TargetRegisterInfo *TRI) const {
  DebugLoc DL = MBB.findDebugLoc(I);
  MachineFunction &MF = *MBB.getParent();
  MachineFrameInfo &MFI = MF.getFrameInfo();
  unsigned SlotAlign = MFI.getObjectAlignment(FI);
  unsigned RegAlign = TRI->getSpillAlignment(*RC);
  bool HasAlloca = MFI.hasVarSizedObjects();
  const HexagonFrameLowering &HFI = *Subtarget.getFrameLowering();

  MachineMemOperand *MMO = MF.getMachineMemOperand(
      MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
      MFI.getObjectSize(FI), SlotAlign);

  if (Hexagon::IntRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::L2_loadri_io), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
  } else if (Hexagon::DoubleRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::L2_loadrd_io), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
  } else if (Hexagon::PredRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::LDriw_pred), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
  } else if (Hexagon::ModRegsRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::LDriw_ctr), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
  } else if (Hexagon::HvxQRRegClass.hasSubClassEq(RC)) {
    BuildMI(MBB, I, DL, get(Hexagon::PS_vloadrq_ai), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMO);
  } else if (Hexagon::HvxVRRegClass.hasSubClassEq(RC)) {
    // If there are variable-sized objects, spills will not be aligned.
    if (HasAlloca)
      SlotAlign = HFI.getStackAlignment();
    unsigned Opc = SlotAlign < RegAlign ? Hexagon::V6_vL32Ub_ai
                                        : Hexagon::V6_vL32b_ai;
    MachineMemOperand *MMOA = MF.getMachineMemOperand(
        MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
        MFI.getObjectSize(FI), SlotAlign);
    BuildMI(MBB, I, DL, get(Opc), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMOA);
  } else if (Hexagon::HvxWRRegClass.hasSubClassEq(RC)) {
    // If there are variable-sized objects, spills will not be aligned.
    if (HasAlloca)
      SlotAlign = HFI.getStackAlignment();
    unsigned Opc = SlotAlign < RegAlign ? Hexagon::PS_vloadrwu_ai
                                        : Hexagon::PS_vloadrw_ai;
    MachineMemOperand *MMOA = MF.getMachineMemOperand(
        MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
        MFI.getObjectSize(FI), SlotAlign);
    BuildMI(MBB, I, DL, get(Opc), DestReg)
      .addFrameIndex(FI).addImm(0).addMemOperand(MMOA);
  } else {
    llvm_unreachable("Can't store this register to stack slot");
  }
}

static void getLiveRegsAt(LivePhysRegs &Regs, const MachineInstr &MI) {
  const MachineBasicBlock &B = *MI.getParent();
  Regs.addLiveOuts(B);
  auto E = ++MachineBasicBlock::const_iterator(MI.getIterator()).getReverse();
  for (auto I = B.rbegin(); I != E; ++I)
    Regs.stepBackward(*I);
}

/// expandPostRAPseudo - This function is called for all pseudo instructions
/// that remain after register allocation. Many pseudo instructions are
/// created to help register allocation. This is the place to convert them
/// into real instructions. The target can edit MI in place, or it can insert
/// new instructions and erase MI. The function should return true if
/// anything was changed.
bool HexagonInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
  MachineBasicBlock &MBB = *MI.getParent();
  MachineFunction &MF = *MBB.getParent();
  MachineRegisterInfo &MRI = MF.getRegInfo();
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();
  DebugLoc DL = MI.getDebugLoc();
  unsigned Opc = MI.getOpcode();

  auto RealCirc = [&](unsigned Opc, bool HasImm, unsigned MxOp) {
    unsigned Mx = MI.getOperand(MxOp).getReg();
    unsigned CSx = (Mx == Hexagon::M0 ? Hexagon::CS0 : Hexagon::CS1);
    BuildMI(MBB, MI, DL, get(Hexagon::A2_tfrrcr), CSx)
        .add(MI.getOperand((HasImm ? 5 : 4)));
    auto MIB = BuildMI(MBB, MI, DL, get(Opc)).add(MI.getOperand(0))
        .add(MI.getOperand(1)).add(MI.getOperand(2)).add(MI.getOperand(3));
    if (HasImm)
      MIB.add(MI.getOperand(4));
    MIB.addReg(CSx, RegState::Implicit);
    MBB.erase(MI);
    return true;
  };

  switch (Opc) {
    case TargetOpcode::COPY: {
      MachineOperand &MD = MI.getOperand(0);
      MachineOperand &MS = MI.getOperand(1);
      MachineBasicBlock::iterator MBBI = MI.getIterator();
      if (MD.getReg() != MS.getReg() && !MS.isUndef()) {
        copyPhysReg(MBB, MI, DL, MD.getReg(), MS.getReg(), MS.isKill());
        std::prev(MBBI)->copyImplicitOps(*MBB.getParent(), MI);
      }
      MBB.erase(MBBI);
      return true;
    }
    case Hexagon::PS_aligna:
      BuildMI(MBB, MI, DL, get(Hexagon::A2_andir), MI.getOperand(0).getReg())
          .addReg(HRI.getFrameRegister())
          .addImm(-MI.getOperand(1).getImm());
      MBB.erase(MI);
      return true;
    case Hexagon::V6_vassignp: {
      unsigned SrcReg = MI.getOperand(1).getReg();
      unsigned DstReg = MI.getOperand(0).getReg();
      unsigned Kill = getKillRegState(MI.getOperand(1).isKill());
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vcombine), DstReg)
        .addReg(HRI.getSubReg(SrcReg, Hexagon::vsub_hi), Kill)
        .addReg(HRI.getSubReg(SrcReg, Hexagon::vsub_lo), Kill);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::V6_lo: {
      unsigned SrcReg = MI.getOperand(1).getReg();
      unsigned DstReg = MI.getOperand(0).getReg();
      unsigned SrcSubLo = HRI.getSubReg(SrcReg, Hexagon::vsub_lo);
      copyPhysReg(MBB, MI, DL, DstReg, SrcSubLo, MI.getOperand(1).isKill());
      MBB.erase(MI);
      MRI.clearKillFlags(SrcSubLo);
      return true;
    }
    case Hexagon::V6_hi: {
      unsigned SrcReg = MI.getOperand(1).getReg();
      unsigned DstReg = MI.getOperand(0).getReg();
      unsigned SrcSubHi = HRI.getSubReg(SrcReg, Hexagon::vsub_hi);
      copyPhysReg(MBB, MI, DL, DstReg, SrcSubHi, MI.getOperand(1).isKill());
      MBB.erase(MI);
      MRI.clearKillFlags(SrcSubHi);
      return true;
    }
    case Hexagon::PS_vstorerw_ai:
    case Hexagon::PS_vstorerwu_ai: {
      bool Aligned = Opc == Hexagon::PS_vstorerw_ai;
      unsigned SrcReg = MI.getOperand(2).getReg();
      unsigned SrcSubHi = HRI.getSubReg(SrcReg, Hexagon::vsub_hi);
      unsigned SrcSubLo = HRI.getSubReg(SrcReg, Hexagon::vsub_lo);
      unsigned NewOpc = Aligned ? Hexagon::V6_vS32b_ai : Hexagon::V6_vS32Ub_ai;
      unsigned Offset = HRI.getSpillSize(Hexagon::HvxVRRegClass);

      MachineInstr *MI1New = BuildMI(MBB, MI, DL, get(NewOpc))
                                 .add(MI.getOperand(0))
                                 .addImm(MI.getOperand(1).getImm())
                                 .addReg(SrcSubLo)
                                 .cloneMemRefs(MI);
      MI1New->getOperand(0).setIsKill(false);
      BuildMI(MBB, MI, DL, get(NewOpc))
          .add(MI.getOperand(0))
          // The Vectors are indexed in multiples of vector size.
          .addImm(MI.getOperand(1).getImm() + Offset)
          .addReg(SrcSubHi)
          .cloneMemRefs(MI);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_vloadrw_ai:
    case Hexagon::PS_vloadrwu_ai: {
      bool Aligned = Opc == Hexagon::PS_vloadrw_ai;
      unsigned DstReg = MI.getOperand(0).getReg();
      unsigned NewOpc = Aligned ? Hexagon::V6_vL32b_ai : Hexagon::V6_vL32Ub_ai;
      unsigned Offset = HRI.getSpillSize(Hexagon::HvxVRRegClass);

      MachineInstr *MI1New = BuildMI(MBB, MI, DL, get(NewOpc),
                                     HRI.getSubReg(DstReg, Hexagon::vsub_lo))
                                 .add(MI.getOperand(1))
                                 .addImm(MI.getOperand(2).getImm())
                                 .cloneMemRefs(MI);
      MI1New->getOperand(1).setIsKill(false);
      BuildMI(MBB, MI, DL, get(NewOpc), HRI.getSubReg(DstReg, Hexagon::vsub_hi))
          .add(MI.getOperand(1))
          // The Vectors are indexed in multiples of vector size.
          .addImm(MI.getOperand(2).getImm() + Offset)
          .cloneMemRefs(MI);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_true: {
      unsigned Reg = MI.getOperand(0).getReg();
      BuildMI(MBB, MI, DL, get(Hexagon::C2_orn), Reg)
        .addReg(Reg, RegState::Undef)
        .addReg(Reg, RegState::Undef);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_false: {
      unsigned Reg = MI.getOperand(0).getReg();
      BuildMI(MBB, MI, DL, get(Hexagon::C2_andn), Reg)
        .addReg(Reg, RegState::Undef)
        .addReg(Reg, RegState::Undef);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_qtrue: {
      BuildMI(MBB, MI, DL, get(Hexagon::V6_veqw), MI.getOperand(0).getReg())
        .addReg(Hexagon::V0, RegState::Undef)
        .addReg(Hexagon::V0, RegState::Undef);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_qfalse: {
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgtw), MI.getOperand(0).getReg())
        .addReg(Hexagon::V0, RegState::Undef)
        .addReg(Hexagon::V0, RegState::Undef);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_vdd0: {
      unsigned Vd = MI.getOperand(0).getReg();
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vsubw_dv), Vd)
        .addReg(Vd, RegState::Undef)
        .addReg(Vd, RegState::Undef);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_vmulw: {
      // Expand a 64-bit vector multiply into 2 32-bit scalar multiplies.
      unsigned DstReg = MI.getOperand(0).getReg();
      unsigned Src1Reg = MI.getOperand(1).getReg();
      unsigned Src2Reg = MI.getOperand(2).getReg();
      unsigned Src1SubHi = HRI.getSubReg(Src1Reg, Hexagon::isub_hi);
      unsigned Src1SubLo = HRI.getSubReg(Src1Reg, Hexagon::isub_lo);
      unsigned Src2SubHi = HRI.getSubReg(Src2Reg, Hexagon::isub_hi);
      unsigned Src2SubLo = HRI.getSubReg(Src2Reg, Hexagon::isub_lo);
      BuildMI(MBB, MI, MI.getDebugLoc(), get(Hexagon::M2_mpyi),
              HRI.getSubReg(DstReg, Hexagon::isub_hi))
          .addReg(Src1SubHi)
          .addReg(Src2SubHi);
      BuildMI(MBB, MI, MI.getDebugLoc(), get(Hexagon::M2_mpyi),
              HRI.getSubReg(DstReg, Hexagon::isub_lo))
          .addReg(Src1SubLo)
          .addReg(Src2SubLo);
      MBB.erase(MI);
      MRI.clearKillFlags(Src1SubHi);
      MRI.clearKillFlags(Src1SubLo);
      MRI.clearKillFlags(Src2SubHi);
      MRI.clearKillFlags(Src2SubLo);
      return true;
    }
    case Hexagon::PS_vmulw_acc: {
      // Expand 64-bit vector multiply with addition into 2 scalar multiplies.
      unsigned DstReg = MI.getOperand(0).getReg();
      unsigned Src1Reg = MI.getOperand(1).getReg();
      unsigned Src2Reg = MI.getOperand(2).getReg();
      unsigned Src3Reg = MI.getOperand(3).getReg();
      unsigned Src1SubHi = HRI.getSubReg(Src1Reg, Hexagon::isub_hi);
      unsigned Src1SubLo = HRI.getSubReg(Src1Reg, Hexagon::isub_lo);
      unsigned Src2SubHi = HRI.getSubReg(Src2Reg, Hexagon::isub_hi);
      unsigned Src2SubLo = HRI.getSubReg(Src2Reg, Hexagon::isub_lo);
      unsigned Src3SubHi = HRI.getSubReg(Src3Reg, Hexagon::isub_hi);
      unsigned Src3SubLo = HRI.getSubReg(Src3Reg, Hexagon::isub_lo);
      BuildMI(MBB, MI, MI.getDebugLoc(), get(Hexagon::M2_maci),
              HRI.getSubReg(DstReg, Hexagon::isub_hi))
          .addReg(Src1SubHi)
          .addReg(Src2SubHi)
          .addReg(Src3SubHi);
      BuildMI(MBB, MI, MI.getDebugLoc(), get(Hexagon::M2_maci),
              HRI.getSubReg(DstReg, Hexagon::isub_lo))
          .addReg(Src1SubLo)
          .addReg(Src2SubLo)
          .addReg(Src3SubLo);
      MBB.erase(MI);
      MRI.clearKillFlags(Src1SubHi);
      MRI.clearKillFlags(Src1SubLo);
      MRI.clearKillFlags(Src2SubHi);
      MRI.clearKillFlags(Src2SubLo);
      MRI.clearKillFlags(Src3SubHi);
      MRI.clearKillFlags(Src3SubLo);
      return true;
    }
    case Hexagon::PS_pselect: {
      const MachineOperand &Op0 = MI.getOperand(0);
      const MachineOperand &Op1 = MI.getOperand(1);
      const MachineOperand &Op2 = MI.getOperand(2);
      const MachineOperand &Op3 = MI.getOperand(3);
      unsigned Rd = Op0.getReg();
      unsigned Pu = Op1.getReg();
      unsigned Rs = Op2.getReg();
      unsigned Rt = Op3.getReg();
      DebugLoc DL = MI.getDebugLoc();
      unsigned K1 = getKillRegState(Op1.isKill());
      unsigned K2 = getKillRegState(Op2.isKill());
      unsigned K3 = getKillRegState(Op3.isKill());
      if (Rd != Rs)
        BuildMI(MBB, MI, DL, get(Hexagon::A2_tfrpt), Rd)
          .addReg(Pu, (Rd == Rt) ? K1 : 0)
          .addReg(Rs, K2);
      if (Rd != Rt)
        BuildMI(MBB, MI, DL, get(Hexagon::A2_tfrpf), Rd)
          .addReg(Pu, K1)
          .addReg(Rt, K3);
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_vselect: {
      const MachineOperand &Op0 = MI.getOperand(0);
      const MachineOperand &Op1 = MI.getOperand(1);
      const MachineOperand &Op2 = MI.getOperand(2);
      const MachineOperand &Op3 = MI.getOperand(3);
      LivePhysRegs LiveAtMI(HRI);
      getLiveRegsAt(LiveAtMI, MI);
      bool IsDestLive = !LiveAtMI.available(MRI, Op0.getReg());
      unsigned PReg = Op1.getReg();
      assert(Op1.getSubReg() == 0);
      unsigned PState = getRegState(Op1);

      if (Op0.getReg() != Op2.getReg()) {
        unsigned S = Op0.getReg() != Op3.getReg() ? PState & ~RegState::Kill
                                                  : PState;
        auto T = BuildMI(MBB, MI, DL, get(Hexagon::V6_vcmov))
                     .add(Op0)
                     .addReg(PReg, S)
                     .add(Op2);
        if (IsDestLive)
          T.addReg(Op0.getReg(), RegState::Implicit);
        IsDestLive = true;
      }
      if (Op0.getReg() != Op3.getReg()) {
        auto T = BuildMI(MBB, MI, DL, get(Hexagon::V6_vncmov))
                     .add(Op0)
                     .addReg(PReg, PState)
                     .add(Op3);
        if (IsDestLive)
          T.addReg(Op0.getReg(), RegState::Implicit);
      }
      MBB.erase(MI);
      return true;
    }
    case Hexagon::PS_wselect: {
      MachineOperand &Op0 = MI.getOperand(0);
      MachineOperand &Op1 = MI.getOperand(1);
      MachineOperand &Op2 = MI.getOperand(2);
      MachineOperand &Op3 = MI.getOperand(3);
      LivePhysRegs LiveAtMI(HRI);
      getLiveRegsAt(LiveAtMI, MI);
      bool IsDestLive = !LiveAtMI.available(MRI, Op0.getReg());
      unsigned PReg = Op1.getReg();
      assert(Op1.getSubReg() == 0);
      unsigned PState = getRegState(Op1);

      if (Op0.getReg() != Op2.getReg()) {
        unsigned S = Op0.getReg() != Op3.getReg() ? PState & ~RegState::Kill
                                                  : PState;
        unsigned SrcLo = HRI.getSubReg(Op2.getReg(), Hexagon::vsub_lo);
        unsigned SrcHi = HRI.getSubReg(Op2.getReg(), Hexagon::vsub_hi);
        auto T = BuildMI(MBB, MI, DL, get(Hexagon::V6_vccombine))
                     .add(Op0)
                     .addReg(PReg, S)
                     .add(Op1)
                     .addReg(SrcHi)
                     .addReg(SrcLo);
        if (IsDestLive)
          T.addReg(Op0.getReg(), RegState::Implicit);
        IsDestLive = true;
      }
      if (Op0.getReg() != Op3.getReg()) {
        unsigned SrcLo = HRI.getSubReg(Op3.getReg(), Hexagon::vsub_lo);
        unsigned SrcHi = HRI.getSubReg(Op3.getReg(), Hexagon::vsub_hi);
        auto T = BuildMI(MBB, MI, DL, get(Hexagon::V6_vnccombine))
                     .add(Op0)
                     .addReg(PReg, PState)
                     .addReg(SrcHi)
                     .addReg(SrcLo);
        if (IsDestLive)
          T.addReg(Op0.getReg(), RegState::Implicit);
      }
      MBB.erase(MI);
      return true;
    }

    case Hexagon::PS_tailcall_i:
      MI.setDesc(get(Hexagon::J2_jump));
      return true;
    case Hexagon::PS_tailcall_r:
    case Hexagon::PS_jmpret:
      MI.setDesc(get(Hexagon::J2_jumpr));
      return true;
    case Hexagon::PS_jmprett:
      MI.setDesc(get(Hexagon::J2_jumprt));
      return true;
    case Hexagon::PS_jmpretf:
      MI.setDesc(get(Hexagon::J2_jumprf));
      return true;
    case Hexagon::PS_jmprettnewpt:
      MI.setDesc(get(Hexagon::J2_jumprtnewpt));
      return true;
    case Hexagon::PS_jmpretfnewpt:
      MI.setDesc(get(Hexagon::J2_jumprfnewpt));
      return true;
    case Hexagon::PS_jmprettnew:
      MI.setDesc(get(Hexagon::J2_jumprtnew));
      return true;
    case Hexagon::PS_jmpretfnew:
      MI.setDesc(get(Hexagon::J2_jumprfnew));
      return true;

    case Hexagon::V6_vgathermh_pseudo:
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgathermh))
          .add(MI.getOperand(1))
          .add(MI.getOperand(2))
          .add(MI.getOperand(3));
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vS32b_new_ai))
          .add(MI.getOperand(0))
          .addImm(0)
          .addReg(Hexagon::VTMP);
      MBB.erase(MI);
      return true;

    case Hexagon::V6_vgathermw_pseudo:
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgathermw))
          .add(MI.getOperand(1))
          .add(MI.getOperand(2))
          .add(MI.getOperand(3));
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vS32b_new_ai))
          .add(MI.getOperand(0))
          .addImm(0)
          .addReg(Hexagon::VTMP);
      MBB.erase(MI);
      return true;

    case Hexagon::V6_vgathermhw_pseudo:
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgathermhw))
          .add(MI.getOperand(1))
          .add(MI.getOperand(2))
          .add(MI.getOperand(3));
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vS32b_new_ai))
          .add(MI.getOperand(0))
          .addImm(0)
          .addReg(Hexagon::VTMP);
      MBB.erase(MI);
      return true;

    case Hexagon::V6_vgathermhq_pseudo:
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgathermhq))
          .add(MI.getOperand(1))
          .add(MI.getOperand(2))
          .add(MI.getOperand(3))
          .add(MI.getOperand(4));
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vS32b_new_ai))
          .add(MI.getOperand(0))
          .addImm(0)
          .addReg(Hexagon::VTMP);
      MBB.erase(MI);
      return true;

    case Hexagon::V6_vgathermwq_pseudo:
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgathermwq))
          .add(MI.getOperand(1))
          .add(MI.getOperand(2))
          .add(MI.getOperand(3))
          .add(MI.getOperand(4));
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vS32b_new_ai))
          .add(MI.getOperand(0))
          .addImm(0)
          .addReg(Hexagon::VTMP);
      MBB.erase(MI);
      return true;

    case Hexagon::V6_vgathermhwq_pseudo:
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vgathermhwq))
          .add(MI.getOperand(1))
          .add(MI.getOperand(2))
          .add(MI.getOperand(3))
          .add(MI.getOperand(4));
      BuildMI(MBB, MI, DL, get(Hexagon::V6_vS32b_new_ai))
          .add(MI.getOperand(0))
          .addImm(0)
          .addReg(Hexagon::VTMP);
      MBB.erase(MI);
      return true;

    case Hexagon::PS_loadrub_pci:
      return RealCirc(Hexagon::L2_loadrub_pci, /*HasImm*/true,  /*MxOp*/4);
    case Hexagon::PS_loadrb_pci:
      return RealCirc(Hexagon::L2_loadrb_pci,  /*HasImm*/true,  /*MxOp*/4);
    case Hexagon::PS_loadruh_pci:
      return RealCirc(Hexagon::L2_loadruh_pci, /*HasImm*/true,  /*MxOp*/4);
    case Hexagon::PS_loadrh_pci:
      return RealCirc(Hexagon::L2_loadrh_pci,  /*HasImm*/true,  /*MxOp*/4);
    case Hexagon::PS_loadri_pci:
      return RealCirc(Hexagon::L2_loadri_pci,  /*HasImm*/true,  /*MxOp*/4);
    case Hexagon::PS_loadrd_pci:
      return RealCirc(Hexagon::L2_loadrd_pci,  /*HasImm*/true,  /*MxOp*/4);
    case Hexagon::PS_loadrub_pcr:
      return RealCirc(Hexagon::L2_loadrub_pcr, /*HasImm*/false, /*MxOp*/3);
    case Hexagon::PS_loadrb_pcr:
      return RealCirc(Hexagon::L2_loadrb_pcr,  /*HasImm*/false, /*MxOp*/3);
    case Hexagon::PS_loadruh_pcr:
      return RealCirc(Hexagon::L2_loadruh_pcr, /*HasImm*/false, /*MxOp*/3);
    case Hexagon::PS_loadrh_pcr:
      return RealCirc(Hexagon::L2_loadrh_pcr,  /*HasImm*/false, /*MxOp*/3);
    case Hexagon::PS_loadri_pcr:
      return RealCirc(Hexagon::L2_loadri_pcr,  /*HasImm*/false, /*MxOp*/3);
    case Hexagon::PS_loadrd_pcr:
      return RealCirc(Hexagon::L2_loadrd_pcr,  /*HasImm*/false, /*MxOp*/3);
    case Hexagon::PS_storerb_pci:
      return RealCirc(Hexagon::S2_storerb_pci, /*HasImm*/true,  /*MxOp*/3);
    case Hexagon::PS_storerh_pci:
      return RealCirc(Hexagon::S2_storerh_pci, /*HasImm*/true,  /*MxOp*/3);
    case Hexagon::PS_storerf_pci:
      return RealCirc(Hexagon::S2_storerf_pci, /*HasImm*/true,  /*MxOp*/3);
    case Hexagon::PS_storeri_pci:
      return RealCirc(Hexagon::S2_storeri_pci, /*HasImm*/true,  /*MxOp*/3);
    case Hexagon::PS_storerd_pci:
      return RealCirc(Hexagon::S2_storerd_pci, /*HasImm*/true,  /*MxOp*/3);
    case Hexagon::PS_storerb_pcr:
      return RealCirc(Hexagon::S2_storerb_pcr, /*HasImm*/false, /*MxOp*/2);
    case Hexagon::PS_storerh_pcr:
      return RealCirc(Hexagon::S2_storerh_pcr, /*HasImm*/false, /*MxOp*/2);
    case Hexagon::PS_storerf_pcr:
      return RealCirc(Hexagon::S2_storerf_pcr, /*HasImm*/false, /*MxOp*/2);
    case Hexagon::PS_storeri_pcr:
      return RealCirc(Hexagon::S2_storeri_pcr, /*HasImm*/false, /*MxOp*/2);
    case Hexagon::PS_storerd_pcr:
      return RealCirc(Hexagon::S2_storerd_pcr, /*HasImm*/false, /*MxOp*/2);
  }

  return false;
}

// We indicate that we want to reverse the branch by
// inserting the reversed branching opcode.
bool HexagonInstrInfo::reverseBranchCondition(
      SmallVectorImpl<MachineOperand> &Cond) const {
  if (Cond.empty())
    return true;
  assert(Cond[0].isImm() && "First entry in the cond vector not imm-val");
  unsigned opcode = Cond[0].getImm();
  //unsigned temp;
  assert(get(opcode).isBranch() && "Should be a branching condition.");
  if (isEndLoopN(opcode))
    return true;
  unsigned NewOpcode = getInvertedPredicatedOpcode(opcode);
  Cond[0].setImm(NewOpcode);
  return false;
}

void HexagonInstrInfo::insertNoop(MachineBasicBlock &MBB,
      MachineBasicBlock::iterator MI) const {
  DebugLoc DL;
  BuildMI(MBB, MI, DL, get(Hexagon::A2_nop));
}

bool HexagonInstrInfo::isPostIncrement(const MachineInstr &MI) const {
  return getAddrMode(MI) == HexagonII::PostInc;
}

// Returns true if an instruction is predicated irrespective of the predicate
// sense. For example, all of the following will return true.
// if (p0) R1 = add(R2, R3)
// if (!p0) R1 = add(R2, R3)
// if (p0.new) R1 = add(R2, R3)
// if (!p0.new) R1 = add(R2, R3)
// Note: New-value stores are not included here as in the current
// implementation, we don't need to check their predicate sense.
bool HexagonInstrInfo::isPredicated(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::PredicatedPos) & HexagonII::PredicatedMask;
}

bool HexagonInstrInfo::PredicateInstruction(
    MachineInstr &MI, ArrayRef<MachineOperand> Cond) const {
  if (Cond.empty() || isNewValueJump(Cond[0].getImm()) ||
      isEndLoopN(Cond[0].getImm())) {
    LLVM_DEBUG(dbgs() << "\nCannot predicate:"; MI.dump(););
    return false;
  }
  int Opc = MI.getOpcode();
  assert (isPredicable(MI) && "Expected predicable instruction");
  bool invertJump = predOpcodeHasNot(Cond);

  // We have to predicate MI "in place", i.e. after this function returns,
  // MI will need to be transformed into a predicated form. To avoid com-
  // plicated manipulations with the operands (handling tied operands,
  // etc.), build a new temporary instruction, then overwrite MI with it.

  MachineBasicBlock &B = *MI.getParent();
  DebugLoc DL = MI.getDebugLoc();
  unsigned PredOpc = getCondOpcode(Opc, invertJump);
  MachineInstrBuilder T = BuildMI(B, MI, DL, get(PredOpc));
  unsigned NOp = 0, NumOps = MI.getNumOperands();
  while (NOp < NumOps) {
    MachineOperand &Op = MI.getOperand(NOp);
    if (!Op.isReg() || !Op.isDef() || Op.isImplicit())
      break;
    T.add(Op);
    NOp++;
  }

  unsigned PredReg, PredRegPos, PredRegFlags;
  bool GotPredReg = getPredReg(Cond, PredReg, PredRegPos, PredRegFlags);
  (void)GotPredReg;
  assert(GotPredReg);
  T.addReg(PredReg, PredRegFlags);
  while (NOp < NumOps)
    T.add(MI.getOperand(NOp++));

  MI.setDesc(get(PredOpc));
  while (unsigned n = MI.getNumOperands())
    MI.RemoveOperand(n-1);
  for (unsigned i = 0, n = T->getNumOperands(); i < n; ++i)
    MI.addOperand(T->getOperand(i));

  MachineBasicBlock::instr_iterator TI = T->getIterator();
  B.erase(TI);

  MachineRegisterInfo &MRI = B.getParent()->getRegInfo();
  MRI.clearKillFlags(PredReg);
  return true;
}

bool HexagonInstrInfo::SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
      ArrayRef<MachineOperand> Pred2) const {
  // TODO: Fix this
  return false;
}

bool HexagonInstrInfo::DefinesPredicate(MachineInstr &MI,
      std::vector<MachineOperand> &Pred) const {
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();

  for (unsigned oper = 0; oper < MI.getNumOperands(); ++oper) {
    MachineOperand MO = MI.getOperand(oper);
    if (MO.isReg()) {
      if (!MO.isDef())
        continue;
      const TargetRegisterClass* RC = HRI.getMinimalPhysRegClass(MO.getReg());
      if (RC == &Hexagon::PredRegsRegClass) {
        Pred.push_back(MO);
        return true;
      }
      continue;
    } else if (MO.isRegMask()) {
      for (unsigned PR : Hexagon::PredRegsRegClass) {
        if (!MI.modifiesRegister(PR, &HRI))
          continue;
        Pred.push_back(MO);
        return true;
      }
    }
  }
  return false;
}

bool HexagonInstrInfo::isPredicable(const MachineInstr &MI) const {
  if (!MI.getDesc().isPredicable())
    return false;

  if (MI.isCall() || isTailCall(MI)) {
    if (!Subtarget.usePredicatedCalls())
      return false;
  }

  // HVX loads are not predicable on v60, but are on v62.
  if (!Subtarget.hasV62Ops()) {
    switch (MI.getOpcode()) {
      case Hexagon::V6_vL32b_ai:
      case Hexagon::V6_vL32b_pi:
      case Hexagon::V6_vL32b_ppu:
      case Hexagon::V6_vL32b_cur_ai:
      case Hexagon::V6_vL32b_cur_pi:
      case Hexagon::V6_vL32b_cur_ppu:
      case Hexagon::V6_vL32b_nt_ai:
      case Hexagon::V6_vL32b_nt_pi:
      case Hexagon::V6_vL32b_nt_ppu:
      case Hexagon::V6_vL32b_tmp_ai:
      case Hexagon::V6_vL32b_tmp_pi:
      case Hexagon::V6_vL32b_tmp_ppu:
      case Hexagon::V6_vL32b_nt_cur_ai:
      case Hexagon::V6_vL32b_nt_cur_pi:
      case Hexagon::V6_vL32b_nt_cur_ppu:
      case Hexagon::V6_vL32b_nt_tmp_ai:
      case Hexagon::V6_vL32b_nt_tmp_pi:
      case Hexagon::V6_vL32b_nt_tmp_ppu:
        return false;
    }
  }
  return true;
}

bool HexagonInstrInfo::isSchedulingBoundary(const MachineInstr &MI,
                                            const MachineBasicBlock *MBB,
                                            const MachineFunction &MF) const {
  // Debug info is never a scheduling boundary. It's necessary to be explicit
  // due to the special treatment of IT instructions below, otherwise a
  // dbg_value followed by an IT will result in the IT instruction being
  // considered a scheduling hazard, which is wrong. It should be the actual
  // instruction preceding the dbg_value instruction(s), just like it is
  // when debug info is not present.
  if (MI.isDebugInstr())
    return false;

  // Throwing call is a boundary.
  if (MI.isCall()) {
    // Don't mess around with no return calls.
    if (doesNotReturn(MI))
      return true;
    // If any of the block's successors is a landing pad, this could be a
    // throwing call.
    for (auto I : MBB->successors())
      if (I->isEHPad())
        return true;
  }

  // Terminators and labels can't be scheduled around.
  if (MI.getDesc().isTerminator() || MI.isPosition())
    return true;

  if (MI.isInlineAsm() && !ScheduleInlineAsm)
    return true;

  return false;
}

/// Measure the specified inline asm to determine an approximation of its
/// length.
/// Comments (which run till the next SeparatorString or newline) do not
/// count as an instruction.
/// Any other non-whitespace text is considered an instruction, with
/// multiple instructions separated by SeparatorString or newlines.
/// Variable-length instructions are not handled here; this function
/// may be overloaded in the target code to do that.
/// Hexagon counts the number of ##'s and adjust for that many
/// constant exenders.
unsigned HexagonInstrInfo::getInlineAsmLength(const char *Str,
      const MCAsmInfo &MAI) const {
  StringRef AStr(Str);
  // Count the number of instructions in the asm.
  bool atInsnStart = true;
  unsigned Length = 0;
  for (; *Str; ++Str) {
    if (*Str == '\n' || strncmp(Str, MAI.getSeparatorString(),
                                strlen(MAI.getSeparatorString())) == 0)
      atInsnStart = true;
    if (atInsnStart && !std::isspace(static_cast<unsigned char>(*Str))) {
      Length += MAI.getMaxInstLength();
      atInsnStart = false;
    }
    if (atInsnStart && strncmp(Str, MAI.getCommentString().data(),
                               MAI.getCommentString().size()) == 0)
      atInsnStart = false;
  }

  // Add to size number of constant extenders seen * 4.
  StringRef Occ("##");
  Length += AStr.count(Occ)*4;
  return Length;
}

ScheduleHazardRecognizer*
HexagonInstrInfo::CreateTargetPostRAHazardRecognizer(
      const InstrItineraryData *II, const ScheduleDAG *DAG) const {
  if (UseDFAHazardRec)
    return new HexagonHazardRecognizer(II, this, Subtarget);
  return TargetInstrInfo::CreateTargetPostRAHazardRecognizer(II, DAG);
}

/// For a comparison instruction, return the source registers in
/// \p SrcReg and \p SrcReg2 if having two register operands, and the value it
/// compares against in CmpValue. Return true if the comparison instruction
/// can be analyzed.
bool HexagonInstrInfo::analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
                                      unsigned &SrcReg2, int &Mask,
                                      int &Value) const {
  unsigned Opc = MI.getOpcode();

  // Set mask and the first source register.
  switch (Opc) {
    case Hexagon::C2_cmpeq:
    case Hexagon::C2_cmpeqp:
    case Hexagon::C2_cmpgt:
    case Hexagon::C2_cmpgtp:
    case Hexagon::C2_cmpgtu:
    case Hexagon::C2_cmpgtup:
    case Hexagon::C4_cmpneq:
    case Hexagon::C4_cmplte:
    case Hexagon::C4_cmplteu:
    case Hexagon::C2_cmpeqi:
    case Hexagon::C2_cmpgti:
    case Hexagon::C2_cmpgtui:
    case Hexagon::C4_cmpneqi:
    case Hexagon::C4_cmplteui:
    case Hexagon::C4_cmpltei:
      SrcReg = MI.getOperand(1).getReg();
      Mask = ~0;
      break;
    case Hexagon::A4_cmpbeq:
    case Hexagon::A4_cmpbgt:
    case Hexagon::A4_cmpbgtu:
    case Hexagon::A4_cmpbeqi:
    case Hexagon::A4_cmpbgti:
    case Hexagon::A4_cmpbgtui:
      SrcReg = MI.getOperand(1).getReg();
      Mask = 0xFF;
      break;
    case Hexagon::A4_cmpheq:
    case Hexagon::A4_cmphgt:
    case Hexagon::A4_cmphgtu:
    case Hexagon::A4_cmpheqi:
    case Hexagon::A4_cmphgti:
    case Hexagon::A4_cmphgtui:
      SrcReg = MI.getOperand(1).getReg();
      Mask = 0xFFFF;
      break;
  }

  // Set the value/second source register.
  switch (Opc) {
    case Hexagon::C2_cmpeq:
    case Hexagon::C2_cmpeqp:
    case Hexagon::C2_cmpgt:
    case Hexagon::C2_cmpgtp:
    case Hexagon::C2_cmpgtu:
    case Hexagon::C2_cmpgtup:
    case Hexagon::A4_cmpbeq:
    case Hexagon::A4_cmpbgt:
    case Hexagon::A4_cmpbgtu:
    case Hexagon::A4_cmpheq:
    case Hexagon::A4_cmphgt:
    case Hexagon::A4_cmphgtu:
    case Hexagon::C4_cmpneq:
    case Hexagon::C4_cmplte:
    case Hexagon::C4_cmplteu:
      SrcReg2 = MI.getOperand(2).getReg();
      return true;

    case Hexagon::C2_cmpeqi:
    case Hexagon::C2_cmpgtui:
    case Hexagon::C2_cmpgti:
    case Hexagon::C4_cmpneqi:
    case Hexagon::C4_cmplteui:
    case Hexagon::C4_cmpltei:
    case Hexagon::A4_cmpbeqi:
    case Hexagon::A4_cmpbgti:
    case Hexagon::A4_cmpbgtui:
    case Hexagon::A4_cmpheqi:
    case Hexagon::A4_cmphgti:
    case Hexagon::A4_cmphgtui: {
      SrcReg2 = 0;
      const MachineOperand &Op2 = MI.getOperand(2);
      if (!Op2.isImm())
        return false;
      Value = MI.getOperand(2).getImm();
      return true;
    }
  }

  return false;
}

unsigned HexagonInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
                                           const MachineInstr &MI,
                                           unsigned *PredCost) const {
  return getInstrTimingClassLatency(ItinData, MI);
}

DFAPacketizer *HexagonInstrInfo::CreateTargetScheduleState(
    const TargetSubtargetInfo &STI) const {
  const InstrItineraryData *II = STI.getInstrItineraryData();
  return static_cast<const HexagonSubtarget&>(STI).createDFAPacketizer(II);
}

// Inspired by this pair:
//  %r13 = L2_loadri_io %r29, 136; mem:LD4[FixedStack0]
//  S2_storeri_io %r29, 132, killed %r1; flags:  mem:ST4[FixedStack1]
// Currently AA considers the addresses in these instructions to be aliasing.
bool HexagonInstrInfo::areMemAccessesTriviallyDisjoint(
    MachineInstr &MIa, MachineInstr &MIb, AliasAnalysis *AA) const {
  if (MIa.hasUnmodeledSideEffects() || MIb.hasUnmodeledSideEffects() ||
      MIa.hasOrderedMemoryRef() || MIb.hasOrderedMemoryRef())
    return false;

  // Instructions that are pure loads, not loads and stores like memops are not
  // dependent.
  if (MIa.mayLoad() && !isMemOp(MIa) && MIb.mayLoad() && !isMemOp(MIb))
    return true;

  // Get the base register in MIa.
  unsigned BasePosA, OffsetPosA;
  if (!getBaseAndOffsetPosition(MIa, BasePosA, OffsetPosA))
    return false;
  const MachineOperand &BaseA = MIa.getOperand(BasePosA);
  unsigned BaseRegA = BaseA.getReg();
  unsigned BaseSubA = BaseA.getSubReg();

  // Get the base register in MIb.
  unsigned BasePosB, OffsetPosB;
  if (!getBaseAndOffsetPosition(MIb, BasePosB, OffsetPosB))
    return false;
  const MachineOperand &BaseB = MIb.getOperand(BasePosB);
  unsigned BaseRegB = BaseB.getReg();
  unsigned BaseSubB = BaseB.getSubReg();

  if (BaseRegA != BaseRegB || BaseSubA != BaseSubB)
    return false;

  // Get the access sizes.
  unsigned SizeA = getMemAccessSize(MIa);
  unsigned SizeB = getMemAccessSize(MIb);

  // Get the offsets. Handle immediates only for now.
  const MachineOperand &OffA = MIa.getOperand(OffsetPosA);
  const MachineOperand &OffB = MIb.getOperand(OffsetPosB);
  if (!MIa.getOperand(OffsetPosA).isImm() ||
      !MIb.getOperand(OffsetPosB).isImm())
    return false;
  int OffsetA = isPostIncrement(MIa) ? 0 : OffA.getImm();
  int OffsetB = isPostIncrement(MIb) ? 0 : OffB.getImm();

  // This is a mem access with the same base register and known offsets from it.
  // Reason about it.
  if (OffsetA > OffsetB) {
    uint64_t OffDiff = (uint64_t)((int64_t)OffsetA - (int64_t)OffsetB);
    return SizeB <= OffDiff;
  }
  if (OffsetA < OffsetB) {
    uint64_t OffDiff = (uint64_t)((int64_t)OffsetB - (int64_t)OffsetA);
    return SizeA <= OffDiff;
  }

  return false;
}

/// If the instruction is an increment of a constant value, return the amount.
bool HexagonInstrInfo::getIncrementValue(const MachineInstr &MI,
      int &Value) const {
  if (isPostIncrement(MI)) {
    unsigned BasePos = 0, OffsetPos = 0;
    if (!getBaseAndOffsetPosition(MI, BasePos, OffsetPos))
      return false;
    const MachineOperand &OffsetOp = MI.getOperand(OffsetPos);
    if (OffsetOp.isImm()) {
      Value = OffsetOp.getImm();
      return true;
    }
  } else if (MI.getOpcode() == Hexagon::A2_addi) {
    const MachineOperand &AddOp = MI.getOperand(2);
    if (AddOp.isImm()) {
      Value = AddOp.getImm();
      return true;
    }
  }

  return false;
}

std::pair<unsigned, unsigned>
HexagonInstrInfo::decomposeMachineOperandsTargetFlags(unsigned TF) const {
  return std::make_pair(TF & ~HexagonII::MO_Bitmasks,
                        TF & HexagonII::MO_Bitmasks);
}

ArrayRef<std::pair<unsigned, const char*>>
HexagonInstrInfo::getSerializableDirectMachineOperandTargetFlags() const {
  using namespace HexagonII;

  static const std::pair<unsigned, const char*> Flags[] = {
    {MO_PCREL,  "hexagon-pcrel"},
    {MO_GOT,    "hexagon-got"},
    {MO_LO16,   "hexagon-lo16"},
    {MO_HI16,   "hexagon-hi16"},
    {MO_GPREL,  "hexagon-gprel"},
    {MO_GDGOT,  "hexagon-gdgot"},
    {MO_GDPLT,  "hexagon-gdplt"},
    {MO_IE,     "hexagon-ie"},
    {MO_IEGOT,  "hexagon-iegot"},
    {MO_TPREL,  "hexagon-tprel"}
  };
  return makeArrayRef(Flags);
}

ArrayRef<std::pair<unsigned, const char*>>
HexagonInstrInfo::getSerializableBitmaskMachineOperandTargetFlags() const {
  using namespace HexagonII;

  static const std::pair<unsigned, const char*> Flags[] = {
    {HMOTF_ConstExtended, "hexagon-ext"}
  };
  return makeArrayRef(Flags);
}

unsigned HexagonInstrInfo::createVR(MachineFunction *MF, MVT VT) const {
  MachineRegisterInfo &MRI = MF->getRegInfo();
  const TargetRegisterClass *TRC;
  if (VT == MVT::i1) {
    TRC = &Hexagon::PredRegsRegClass;
  } else if (VT == MVT::i32 || VT == MVT::f32) {
    TRC = &Hexagon::IntRegsRegClass;
  } else if (VT == MVT::i64 || VT == MVT::f64) {
    TRC = &Hexagon::DoubleRegsRegClass;
  } else {
    llvm_unreachable("Cannot handle this register class");
  }

  unsigned NewReg = MRI.createVirtualRegister(TRC);
  return NewReg;
}

bool HexagonInstrInfo::isAbsoluteSet(const MachineInstr &MI) const {
  return (getAddrMode(MI) == HexagonII::AbsoluteSet);
}

bool HexagonInstrInfo::isAccumulator(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return((F >> HexagonII::AccumulatorPos) & HexagonII::AccumulatorMask);
}

bool HexagonInstrInfo::isBaseImmOffset(const MachineInstr &MI) const {
  return getAddrMode(MI) == HexagonII::BaseImmOffset;
}

bool HexagonInstrInfo::isComplex(const MachineInstr &MI) const {
  return !isTC1(MI) && !isTC2Early(MI) && !MI.getDesc().mayLoad() &&
         !MI.getDesc().mayStore() &&
         MI.getDesc().getOpcode() != Hexagon::S2_allocframe &&
         MI.getDesc().getOpcode() != Hexagon::L2_deallocframe &&
         !isMemOp(MI) && !MI.isBranch() && !MI.isReturn() && !MI.isCall();
}

// Return true if the instruction is a compund branch instruction.
bool HexagonInstrInfo::isCompoundBranchInstr(const MachineInstr &MI) const {
  return getType(MI) == HexagonII::TypeCJ && MI.isBranch();
}

// TODO: In order to have isExtendable for fpimm/f32Ext, we need to handle
// isFPImm and later getFPImm as well.
bool HexagonInstrInfo::isConstExtended(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  unsigned isExtended = (F >> HexagonII::ExtendedPos) & HexagonII::ExtendedMask;
  if (isExtended) // Instruction must be extended.
    return true;

  unsigned isExtendable =
    (F >> HexagonII::ExtendablePos) & HexagonII::ExtendableMask;
  if (!isExtendable)
    return false;

  if (MI.isCall())
    return false;

  short ExtOpNum = getCExtOpNum(MI);
  const MachineOperand &MO = MI.getOperand(ExtOpNum);
  // Use MO operand flags to determine if MO
  // has the HMOTF_ConstExtended flag set.
  if (MO.getTargetFlags() & HexagonII::HMOTF_ConstExtended)
    return true;
  // If this is a Machine BB address we are talking about, and it is
  // not marked as extended, say so.
  if (MO.isMBB())
    return false;

  // We could be using an instruction with an extendable immediate and shoehorn
  // a global address into it. If it is a global address it will be constant
  // extended. We do this for COMBINE.
  if (MO.isGlobal() || MO.isSymbol() || MO.isBlockAddress() ||
      MO.isJTI() || MO.isCPI() || MO.isFPImm())
    return true;

  // If the extendable operand is not 'Immediate' type, the instruction should
  // have 'isExtended' flag set.
  assert(MO.isImm() && "Extendable operand must be Immediate type");

  int MinValue = getMinValue(MI);
  int MaxValue = getMaxValue(MI);
  int ImmValue = MO.getImm();

  return (ImmValue < MinValue || ImmValue > MaxValue);
}

bool HexagonInstrInfo::isDeallocRet(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::L4_return:
  case Hexagon::L4_return_t:
  case Hexagon::L4_return_f:
  case Hexagon::L4_return_tnew_pnt:
  case Hexagon::L4_return_fnew_pnt:
  case Hexagon::L4_return_tnew_pt:
  case Hexagon::L4_return_fnew_pt:
    return true;
  }
  return false;
}

// Return true when ConsMI uses a register defined by ProdMI.
bool HexagonInstrInfo::isDependent(const MachineInstr &ProdMI,
      const MachineInstr &ConsMI) const {
  if (!ProdMI.getDesc().getNumDefs())
    return false;
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();

  SmallVector<unsigned, 4> DefsA;
  SmallVector<unsigned, 4> DefsB;
  SmallVector<unsigned, 8> UsesA;
  SmallVector<unsigned, 8> UsesB;

  parseOperands(ProdMI, DefsA, UsesA);
  parseOperands(ConsMI, DefsB, UsesB);

  for (auto &RegA : DefsA)
    for (auto &RegB : UsesB) {
      // True data dependency.
      if (RegA == RegB)
        return true;

      if (TargetRegisterInfo::isPhysicalRegister(RegA))
        for (MCSubRegIterator SubRegs(RegA, &HRI); SubRegs.isValid(); ++SubRegs)
          if (RegB == *SubRegs)
            return true;

      if (TargetRegisterInfo::isPhysicalRegister(RegB))
        for (MCSubRegIterator SubRegs(RegB, &HRI); SubRegs.isValid(); ++SubRegs)
          if (RegA == *SubRegs)
            return true;
    }

  return false;
}

// Returns true if the instruction is alread a .cur.
bool HexagonInstrInfo::isDotCurInst(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::V6_vL32b_cur_pi:
  case Hexagon::V6_vL32b_cur_ai:
    return true;
  }
  return false;
}

// Returns true, if any one of the operands is a dot new
// insn, whether it is predicated dot new or register dot new.
bool HexagonInstrInfo::isDotNewInst(const MachineInstr &MI) const {
  if (isNewValueInst(MI) || (isPredicated(MI) && isPredicatedNew(MI)))
    return true;

  return false;
}

/// Symmetrical. See if these two instructions are fit for duplex pair.
bool HexagonInstrInfo::isDuplexPair(const MachineInstr &MIa,
      const MachineInstr &MIb) const {
  HexagonII::SubInstructionGroup MIaG = getDuplexCandidateGroup(MIa);
  HexagonII::SubInstructionGroup MIbG = getDuplexCandidateGroup(MIb);
  return (isDuplexPairMatch(MIaG, MIbG) || isDuplexPairMatch(MIbG, MIaG));
}

bool HexagonInstrInfo::isEarlySourceInstr(const MachineInstr &MI) const {
  if (MI.mayLoad() || MI.mayStore() || MI.isCompare())
    return true;

  // Multiply
  unsigned SchedClass = MI.getDesc().getSchedClass();
  return is_TC4x(SchedClass) || is_TC3x(SchedClass);
}

bool HexagonInstrInfo::isEndLoopN(unsigned Opcode) const {
  return (Opcode == Hexagon::ENDLOOP0 ||
          Opcode == Hexagon::ENDLOOP1);
}

bool HexagonInstrInfo::isExpr(unsigned OpType) const {
  switch(OpType) {
  case MachineOperand::MO_MachineBasicBlock:
  case MachineOperand::MO_GlobalAddress:
  case MachineOperand::MO_ExternalSymbol:
  case MachineOperand::MO_JumpTableIndex:
  case MachineOperand::MO_ConstantPoolIndex:
  case MachineOperand::MO_BlockAddress:
    return true;
  default:
    return false;
  }
}

bool HexagonInstrInfo::isExtendable(const MachineInstr &MI) const {
  const MCInstrDesc &MID = MI.getDesc();
  const uint64_t F = MID.TSFlags;
  if ((F >> HexagonII::ExtendablePos) & HexagonII::ExtendableMask)
    return true;

  // TODO: This is largely obsolete now. Will need to be removed
  // in consecutive patches.
  switch (MI.getOpcode()) {
    // PS_fi and PS_fia remain special cases.
    case Hexagon::PS_fi:
    case Hexagon::PS_fia:
      return true;
    default:
      return false;
  }
  return  false;
}

// This returns true in two cases:
// - The OP code itself indicates that this is an extended instruction.
// - One of MOs has been marked with HMOTF_ConstExtended flag.
bool HexagonInstrInfo::isExtended(const MachineInstr &MI) const {
  // First check if this is permanently extended op code.
  const uint64_t F = MI.getDesc().TSFlags;
  if ((F >> HexagonII::ExtendedPos) & HexagonII::ExtendedMask)
    return true;
  // Use MO operand flags to determine if one of MI's operands
  // has HMOTF_ConstExtended flag set.
  for (const MachineOperand &MO : MI.operands())
    if (MO.getTargetFlags() & HexagonII::HMOTF_ConstExtended)
      return true;
  return  false;
}

bool HexagonInstrInfo::isFloat(const MachineInstr &MI) const {
  unsigned Opcode = MI.getOpcode();
  const uint64_t F = get(Opcode).TSFlags;
  return (F >> HexagonII::FPPos) & HexagonII::FPMask;
}

// No V60 HVX VMEM with A_INDIRECT.
bool HexagonInstrInfo::isHVXMemWithAIndirect(const MachineInstr &I,
      const MachineInstr &J) const {
  if (!isHVXVec(I))
    return false;
  if (!I.mayLoad() && !I.mayStore())
    return false;
  return J.isIndirectBranch() || isIndirectCall(J) || isIndirectL4Return(J);
}

bool HexagonInstrInfo::isIndirectCall(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::J2_callr:
  case Hexagon::J2_callrf:
  case Hexagon::J2_callrt:
  case Hexagon::PS_call_nr:
    return true;
  }
  return false;
}

bool HexagonInstrInfo::isIndirectL4Return(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::L4_return:
  case Hexagon::L4_return_t:
  case Hexagon::L4_return_f:
  case Hexagon::L4_return_fnew_pnt:
  case Hexagon::L4_return_fnew_pt:
  case Hexagon::L4_return_tnew_pnt:
  case Hexagon::L4_return_tnew_pt:
    return true;
  }
  return false;
}

bool HexagonInstrInfo::isJumpR(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::J2_jumpr:
  case Hexagon::J2_jumprt:
  case Hexagon::J2_jumprf:
  case Hexagon::J2_jumprtnewpt:
  case Hexagon::J2_jumprfnewpt:
  case Hexagon::J2_jumprtnew:
  case Hexagon::J2_jumprfnew:
    return true;
  }
  return false;
}

// Return true if a given MI can accommodate given offset.
// Use abs estimate as oppose to the exact number.
// TODO: This will need to be changed to use MC level
// definition of instruction extendable field size.
bool HexagonInstrInfo::isJumpWithinBranchRange(const MachineInstr &MI,
      unsigned offset) const {
  // This selection of jump instructions matches to that what
  // analyzeBranch can parse, plus NVJ.
  if (isNewValueJump(MI)) // r9:2
    return isInt<11>(offset);

  switch (MI.getOpcode()) {
  // Still missing Jump to address condition on register value.
  default:
    return false;
  case Hexagon::J2_jump: // bits<24> dst; // r22:2
  case Hexagon::J2_call:
  case Hexagon::PS_call_nr:
    return isInt<24>(offset);
  case Hexagon::J2_jumpt: //bits<17> dst; // r15:2
  case Hexagon::J2_jumpf:
  case Hexagon::J2_jumptnew:
  case Hexagon::J2_jumptnewpt:
  case Hexagon::J2_jumpfnew:
  case Hexagon::J2_jumpfnewpt:
  case Hexagon::J2_callt:
  case Hexagon::J2_callf:
    return isInt<17>(offset);
  case Hexagon::J2_loop0i:
  case Hexagon::J2_loop0iext:
  case Hexagon::J2_loop0r:
  case Hexagon::J2_loop0rext:
  case Hexagon::J2_loop1i:
  case Hexagon::J2_loop1iext:
  case Hexagon::J2_loop1r:
  case Hexagon::J2_loop1rext:
    return isInt<9>(offset);
  // TODO: Add all the compound branches here. Can we do this in Relation model?
  case Hexagon::J4_cmpeqi_tp0_jump_nt:
  case Hexagon::J4_cmpeqi_tp1_jump_nt:
  case Hexagon::J4_cmpeqn1_tp0_jump_nt:
  case Hexagon::J4_cmpeqn1_tp1_jump_nt:
    return isInt<11>(offset);
  }
}

bool HexagonInstrInfo::isLateInstrFeedsEarlyInstr(const MachineInstr &LRMI,
      const MachineInstr &ESMI) const {
  bool isLate = isLateResultInstr(LRMI);
  bool isEarly = isEarlySourceInstr(ESMI);

  LLVM_DEBUG(dbgs() << "V60" << (isLate ? "-LR  " : " --  "));
  LLVM_DEBUG(LRMI.dump());
  LLVM_DEBUG(dbgs() << "V60" << (isEarly ? "-ES  " : " --  "));
  LLVM_DEBUG(ESMI.dump());

  if (isLate && isEarly) {
    LLVM_DEBUG(dbgs() << "++Is Late Result feeding Early Source\n");
    return true;
  }

  return false;
}

bool HexagonInstrInfo::isLateResultInstr(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case TargetOpcode::EXTRACT_SUBREG:
  case TargetOpcode::INSERT_SUBREG:
  case TargetOpcode::SUBREG_TO_REG:
  case TargetOpcode::REG_SEQUENCE:
  case TargetOpcode::IMPLICIT_DEF:
  case TargetOpcode::COPY:
  case TargetOpcode::INLINEASM:
  case TargetOpcode::PHI:
    return false;
  default:
    break;
  }

  unsigned SchedClass = MI.getDesc().getSchedClass();
  return !is_TC1(SchedClass);
}

bool HexagonInstrInfo::isLateSourceInstr(const MachineInstr &MI) const {
  // Instructions with iclass A_CVI_VX and attribute A_CVI_LATE uses a multiply
  // resource, but all operands can be received late like an ALU instruction.
  return getType(MI) == HexagonII::TypeCVI_VX_LATE;
}

bool HexagonInstrInfo::isLoopN(const MachineInstr &MI) const {
  unsigned Opcode = MI.getOpcode();
  return Opcode == Hexagon::J2_loop0i    ||
         Opcode == Hexagon::J2_loop0r    ||
         Opcode == Hexagon::J2_loop0iext ||
         Opcode == Hexagon::J2_loop0rext ||
         Opcode == Hexagon::J2_loop1i    ||
         Opcode == Hexagon::J2_loop1r    ||
         Opcode == Hexagon::J2_loop1iext ||
         Opcode == Hexagon::J2_loop1rext;
}

bool HexagonInstrInfo::isMemOp(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
    default: return false;
    case Hexagon::L4_iadd_memopw_io:
    case Hexagon::L4_isub_memopw_io:
    case Hexagon::L4_add_memopw_io:
    case Hexagon::L4_sub_memopw_io:
    case Hexagon::L4_and_memopw_io:
    case Hexagon::L4_or_memopw_io:
    case Hexagon::L4_iadd_memoph_io:
    case Hexagon::L4_isub_memoph_io:
    case Hexagon::L4_add_memoph_io:
    case Hexagon::L4_sub_memoph_io:
    case Hexagon::L4_and_memoph_io:
    case Hexagon::L4_or_memoph_io:
    case Hexagon::L4_iadd_memopb_io:
    case Hexagon::L4_isub_memopb_io:
    case Hexagon::L4_add_memopb_io:
    case Hexagon::L4_sub_memopb_io:
    case Hexagon::L4_and_memopb_io:
    case Hexagon::L4_or_memopb_io:
    case Hexagon::L4_ior_memopb_io:
    case Hexagon::L4_ior_memoph_io:
    case Hexagon::L4_ior_memopw_io:
    case Hexagon::L4_iand_memopb_io:
    case Hexagon::L4_iand_memoph_io:
    case Hexagon::L4_iand_memopw_io:
    return true;
  }
  return false;
}

bool HexagonInstrInfo::isNewValue(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::NewValuePos) & HexagonII::NewValueMask;
}

bool HexagonInstrInfo::isNewValue(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  return (F >> HexagonII::NewValuePos) & HexagonII::NewValueMask;
}

bool HexagonInstrInfo::isNewValueInst(const MachineInstr &MI) const {
  return isNewValueJump(MI) || isNewValueStore(MI);
}

bool HexagonInstrInfo::isNewValueJump(const MachineInstr &MI) const {
  return isNewValue(MI) && MI.isBranch();
}

bool HexagonInstrInfo::isNewValueJump(unsigned Opcode) const {
  return isNewValue(Opcode) && get(Opcode).isBranch() && isPredicated(Opcode);
}

bool HexagonInstrInfo::isNewValueStore(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::NVStorePos) & HexagonII::NVStoreMask;
}

bool HexagonInstrInfo::isNewValueStore(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  return (F >> HexagonII::NVStorePos) & HexagonII::NVStoreMask;
}

// Returns true if a particular operand is extendable for an instruction.
bool HexagonInstrInfo::isOperandExtended(const MachineInstr &MI,
    unsigned OperandNum) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return ((F >> HexagonII::ExtendableOpPos) & HexagonII::ExtendableOpMask)
          == OperandNum;
}

bool HexagonInstrInfo::isPredicatedNew(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  assert(isPredicated(MI));
  return (F >> HexagonII::PredicatedNewPos) & HexagonII::PredicatedNewMask;
}

bool HexagonInstrInfo::isPredicatedNew(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  assert(isPredicated(Opcode));
  return (F >> HexagonII::PredicatedNewPos) & HexagonII::PredicatedNewMask;
}

bool HexagonInstrInfo::isPredicatedTrue(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return !((F >> HexagonII::PredicatedFalsePos) &
           HexagonII::PredicatedFalseMask);
}

bool HexagonInstrInfo::isPredicatedTrue(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  // Make sure that the instruction is predicated.
  assert((F>> HexagonII::PredicatedPos) & HexagonII::PredicatedMask);
  return !((F >> HexagonII::PredicatedFalsePos) &
           HexagonII::PredicatedFalseMask);
}

bool HexagonInstrInfo::isPredicated(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  return (F >> HexagonII::PredicatedPos) & HexagonII::PredicatedMask;
}

bool HexagonInstrInfo::isPredicateLate(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  return ~(F >> HexagonII::PredicateLatePos) & HexagonII::PredicateLateMask;
}

bool HexagonInstrInfo::isPredictedTaken(unsigned Opcode) const {
  const uint64_t F = get(Opcode).TSFlags;
  assert(get(Opcode).isBranch() &&
         (isPredicatedNew(Opcode) || isNewValue(Opcode)));
  return (F >> HexagonII::TakenPos) & HexagonII::TakenMask;
}

bool HexagonInstrInfo::isSaveCalleeSavedRegsCall(const MachineInstr &MI) const {
  return MI.getOpcode() == Hexagon::SAVE_REGISTERS_CALL_V4 ||
         MI.getOpcode() == Hexagon::SAVE_REGISTERS_CALL_V4_EXT ||
         MI.getOpcode() == Hexagon::SAVE_REGISTERS_CALL_V4_PIC ||
         MI.getOpcode() == Hexagon::SAVE_REGISTERS_CALL_V4_EXT_PIC;
}

bool HexagonInstrInfo::isSignExtendingLoad(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  // Byte
  case Hexagon::L2_loadrb_io:
  case Hexagon::L4_loadrb_ur:
  case Hexagon::L4_loadrb_ap:
  case Hexagon::L2_loadrb_pr:
  case Hexagon::L2_loadrb_pbr:
  case Hexagon::L2_loadrb_pi:
  case Hexagon::L2_loadrb_pci:
  case Hexagon::L2_loadrb_pcr:
  case Hexagon::L2_loadbsw2_io:
  case Hexagon::L4_loadbsw2_ur:
  case Hexagon::L4_loadbsw2_ap:
  case Hexagon::L2_loadbsw2_pr:
  case Hexagon::L2_loadbsw2_pbr:
  case Hexagon::L2_loadbsw2_pi:
  case Hexagon::L2_loadbsw2_pci:
  case Hexagon::L2_loadbsw2_pcr:
  case Hexagon::L2_loadbsw4_io:
  case Hexagon::L4_loadbsw4_ur:
  case Hexagon::L4_loadbsw4_ap:
  case Hexagon::L2_loadbsw4_pr:
  case Hexagon::L2_loadbsw4_pbr:
  case Hexagon::L2_loadbsw4_pi:
  case Hexagon::L2_loadbsw4_pci:
  case Hexagon::L2_loadbsw4_pcr:
  case Hexagon::L4_loadrb_rr:
  case Hexagon::L2_ploadrbt_io:
  case Hexagon::L2_ploadrbt_pi:
  case Hexagon::L2_ploadrbf_io:
  case Hexagon::L2_ploadrbf_pi:
  case Hexagon::L2_ploadrbtnew_io:
  case Hexagon::L2_ploadrbfnew_io:
  case Hexagon::L4_ploadrbt_rr:
  case Hexagon::L4_ploadrbf_rr:
  case Hexagon::L4_ploadrbtnew_rr:
  case Hexagon::L4_ploadrbfnew_rr:
  case Hexagon::L2_ploadrbtnew_pi:
  case Hexagon::L2_ploadrbfnew_pi:
  case Hexagon::L4_ploadrbt_abs:
  case Hexagon::L4_ploadrbf_abs:
  case Hexagon::L4_ploadrbtnew_abs:
  case Hexagon::L4_ploadrbfnew_abs:
  case Hexagon::L2_loadrbgp:
  // Half
  case Hexagon::L2_loadrh_io:
  case Hexagon::L4_loadrh_ur:
  case Hexagon::L4_loadrh_ap:
  case Hexagon::L2_loadrh_pr:
  case Hexagon::L2_loadrh_pbr:
  case Hexagon::L2_loadrh_pi:
  case Hexagon::L2_loadrh_pci:
  case Hexagon::L2_loadrh_pcr:
  case Hexagon::L4_loadrh_rr:
  case Hexagon::L2_ploadrht_io:
  case Hexagon::L2_ploadrht_pi:
  case Hexagon::L2_ploadrhf_io:
  case Hexagon::L2_ploadrhf_pi:
  case Hexagon::L2_ploadrhtnew_io:
  case Hexagon::L2_ploadrhfnew_io:
  case Hexagon::L4_ploadrht_rr:
  case Hexagon::L4_ploadrhf_rr:
  case Hexagon::L4_ploadrhtnew_rr:
  case Hexagon::L4_ploadrhfnew_rr:
  case Hexagon::L2_ploadrhtnew_pi:
  case Hexagon::L2_ploadrhfnew_pi:
  case Hexagon::L4_ploadrht_abs:
  case Hexagon::L4_ploadrhf_abs:
  case Hexagon::L4_ploadrhtnew_abs:
  case Hexagon::L4_ploadrhfnew_abs:
  case Hexagon::L2_loadrhgp:
    return true;
  default:
    return false;
  }
}

bool HexagonInstrInfo::isSolo(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::SoloPos) & HexagonII::SoloMask;
}

bool HexagonInstrInfo::isSpillPredRegOp(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::STriw_pred:
  case Hexagon::LDriw_pred:
    return true;
  default:
    return false;
  }
}

bool HexagonInstrInfo::isTailCall(const MachineInstr &MI) const {
  if (!MI.isBranch())
    return false;

  for (auto &Op : MI.operands())
    if (Op.isGlobal() || Op.isSymbol())
      return true;
  return false;
}

// Returns true when SU has a timing class TC1.
bool HexagonInstrInfo::isTC1(const MachineInstr &MI) const {
  unsigned SchedClass = MI.getDesc().getSchedClass();
  return is_TC1(SchedClass);
}

bool HexagonInstrInfo::isTC2(const MachineInstr &MI) const {
  unsigned SchedClass = MI.getDesc().getSchedClass();
  return is_TC2(SchedClass);
}

bool HexagonInstrInfo::isTC2Early(const MachineInstr &MI) const {
  unsigned SchedClass = MI.getDesc().getSchedClass();
  return is_TC2early(SchedClass);
}

bool HexagonInstrInfo::isTC4x(const MachineInstr &MI) const {
  unsigned SchedClass = MI.getDesc().getSchedClass();
  return is_TC4x(SchedClass);
}

// Schedule this ASAP.
bool HexagonInstrInfo::isToBeScheduledASAP(const MachineInstr &MI1,
      const MachineInstr &MI2) const {
  if (mayBeCurLoad(MI1)) {
    // if (result of SU is used in Next) return true;
    unsigned DstReg = MI1.getOperand(0).getReg();
    int N = MI2.getNumOperands();
    for (int I = 0; I < N; I++)
      if (MI2.getOperand(I).isReg() && DstReg == MI2.getOperand(I).getReg())
        return true;
  }
  if (mayBeNewStore(MI2))
    if (MI2.getOpcode() == Hexagon::V6_vS32b_pi)
      if (MI1.getOperand(0).isReg() && MI2.getOperand(3).isReg() &&
          MI1.getOperand(0).getReg() == MI2.getOperand(3).getReg())
        return true;
  return false;
}

bool HexagonInstrInfo::isHVXVec(const MachineInstr &MI) const {
  const uint64_t V = getType(MI);
  return HexagonII::TypeCVI_FIRST <= V && V <= HexagonII::TypeCVI_LAST;
}

// Check if the Offset is a valid auto-inc imm by Load/Store Type.
bool HexagonInstrInfo::isValidAutoIncImm(const EVT VT, int Offset) const {
  int Size = VT.getSizeInBits() / 8;
  if (Offset % Size != 0)
    return false;
  int Count = Offset / Size;

  switch (VT.getSimpleVT().SimpleTy) {
    // For scalars the auto-inc is s4
    case MVT::i8:
    case MVT::i16:
    case MVT::i32:
    case MVT::i64:
    case MVT::f32:
    case MVT::f64:
    case MVT::v2i16:
    case MVT::v2i32:
    case MVT::v4i8:
    case MVT::v4i16:
    case MVT::v8i8:
      return isInt<4>(Count);
    // For HVX vectors the auto-inc is s3
    case MVT::v64i8:
    case MVT::v32i16:
    case MVT::v16i32:
    case MVT::v8i64:
    case MVT::v128i8:
    case MVT::v64i16:
    case MVT::v32i32:
    case MVT::v16i64:
      return isInt<3>(Count);
    default:
      break;
  }

  llvm_unreachable("Not an valid type!");
}

bool HexagonInstrInfo::isValidOffset(unsigned Opcode, int Offset,
      const TargetRegisterInfo *TRI, bool Extend) const {
  // This function is to check whether the "Offset" is in the correct range of
  // the given "Opcode". If "Offset" is not in the correct range, "A2_addi" is
  // inserted to calculate the final address. Due to this reason, the function
  // assumes that the "Offset" has correct alignment.
  // We used to assert if the offset was not properly aligned, however,
  // there are cases where a misaligned pointer recast can cause this
  // problem, and we need to allow for it. The front end warns of such
  // misaligns with respect to load size.
  switch (Opcode) {
  case Hexagon::PS_vstorerq_ai:
  case Hexagon::PS_vstorerw_ai:
  case Hexagon::PS_vstorerw_nt_ai:
  case Hexagon::PS_vloadrq_ai:
  case Hexagon::PS_vloadrw_ai:
  case Hexagon::PS_vloadrw_nt_ai:
  case Hexagon::V6_vL32b_ai:
  case Hexagon::V6_vS32b_ai:
  case Hexagon::V6_vL32b_nt_ai:
  case Hexagon::V6_vS32b_nt_ai:
  case Hexagon::V6_vL32Ub_ai:
  case Hexagon::V6_vS32Ub_ai: {
    unsigned VectorSize = TRI->getSpillSize(Hexagon::HvxVRRegClass);
    assert(isPowerOf2_32(VectorSize));
    if (Offset & (VectorSize-1))
      return false;
    return isInt<4>(Offset >> Log2_32(VectorSize));
  }

  case Hexagon::J2_loop0i:
  case Hexagon::J2_loop1i:
    return isUInt<10>(Offset);

  case Hexagon::S4_storeirb_io:
  case Hexagon::S4_storeirbt_io:
  case Hexagon::S4_storeirbf_io:
    return isUInt<6>(Offset);

  case Hexagon::S4_storeirh_io:
  case Hexagon::S4_storeirht_io:
  case Hexagon::S4_storeirhf_io:
    return isShiftedUInt<6,1>(Offset);

  case Hexagon::S4_storeiri_io:
  case Hexagon::S4_storeirit_io:
  case Hexagon::S4_storeirif_io:
    return isShiftedUInt<6,2>(Offset);
  }

  if (Extend)
    return true;

  switch (Opcode) {
  case Hexagon::L2_loadri_io:
  case Hexagon::S2_storeri_io:
    return (Offset >= Hexagon_MEMW_OFFSET_MIN) &&
      (Offset <= Hexagon_MEMW_OFFSET_MAX);

  case Hexagon::L2_loadrd_io:
  case Hexagon::S2_storerd_io:
    return (Offset >= Hexagon_MEMD_OFFSET_MIN) &&
      (Offset <= Hexagon_MEMD_OFFSET_MAX);

  case Hexagon::L2_loadrh_io:
  case Hexagon::L2_loadruh_io:
  case Hexagon::S2_storerh_io:
  case Hexagon::S2_storerf_io:
    return (Offset >= Hexagon_MEMH_OFFSET_MIN) &&
      (Offset <= Hexagon_MEMH_OFFSET_MAX);

  case Hexagon::L2_loadrb_io:
  case Hexagon::L2_loadrub_io:
  case Hexagon::S2_storerb_io:
    return (Offset >= Hexagon_MEMB_OFFSET_MIN) &&
      (Offset <= Hexagon_MEMB_OFFSET_MAX);

  case Hexagon::A2_addi:
    return (Offset >= Hexagon_ADDI_OFFSET_MIN) &&
      (Offset <= Hexagon_ADDI_OFFSET_MAX);

  case Hexagon::L4_iadd_memopw_io:
  case Hexagon::L4_isub_memopw_io:
  case Hexagon::L4_add_memopw_io:
  case Hexagon::L4_sub_memopw_io:
  case Hexagon::L4_and_memopw_io:
  case Hexagon::L4_or_memopw_io:
    return (0 <= Offset && Offset <= 255);

  case Hexagon::L4_iadd_memoph_io:
  case Hexagon::L4_isub_memoph_io:
  case Hexagon::L4_add_memoph_io:
  case Hexagon::L4_sub_memoph_io:
  case Hexagon::L4_and_memoph_io:
  case Hexagon::L4_or_memoph_io:
    return (0 <= Offset && Offset <= 127);

  case Hexagon::L4_iadd_memopb_io:
  case Hexagon::L4_isub_memopb_io:
  case Hexagon::L4_add_memopb_io:
  case Hexagon::L4_sub_memopb_io:
  case Hexagon::L4_and_memopb_io:
  case Hexagon::L4_or_memopb_io:
    return (0 <= Offset && Offset <= 63);

  // LDriw_xxx and STriw_xxx are pseudo operations, so it has to take offset of
  // any size. Later pass knows how to handle it.
  case Hexagon::STriw_pred:
  case Hexagon::LDriw_pred:
  case Hexagon::STriw_ctr:
  case Hexagon::LDriw_ctr:
    return true;

  case Hexagon::PS_fi:
  case Hexagon::PS_fia:
  case Hexagon::INLINEASM:
    return true;

  case Hexagon::L2_ploadrbt_io:
  case Hexagon::L2_ploadrbf_io:
  case Hexagon::L2_ploadrubt_io:
  case Hexagon::L2_ploadrubf_io:
  case Hexagon::S2_pstorerbt_io:
  case Hexagon::S2_pstorerbf_io:
    return isUInt<6>(Offset);

  case Hexagon::L2_ploadrht_io:
  case Hexagon::L2_ploadrhf_io:
  case Hexagon::L2_ploadruht_io:
  case Hexagon::L2_ploadruhf_io:
  case Hexagon::S2_pstorerht_io:
  case Hexagon::S2_pstorerhf_io:
    return isShiftedUInt<6,1>(Offset);

  case Hexagon::L2_ploadrit_io:
  case Hexagon::L2_ploadrif_io:
  case Hexagon::S2_pstorerit_io:
  case Hexagon::S2_pstorerif_io:
    return isShiftedUInt<6,2>(Offset);

  case Hexagon::L2_ploadrdt_io:
  case Hexagon::L2_ploadrdf_io:
  case Hexagon::S2_pstorerdt_io:
  case Hexagon::S2_pstorerdf_io:
    return isShiftedUInt<6,3>(Offset);
  } // switch

  llvm_unreachable("No offset range is defined for this opcode. "
                   "Please define it in the above switch statement!");
}

bool HexagonInstrInfo::isVecAcc(const MachineInstr &MI) const {
  return isHVXVec(MI) && isAccumulator(MI);
}

bool HexagonInstrInfo::isVecALU(const MachineInstr &MI) const {
  const uint64_t F = get(MI.getOpcode()).TSFlags;
  const uint64_t V = ((F >> HexagonII::TypePos) & HexagonII::TypeMask);
  return
    V == HexagonII::TypeCVI_VA         ||
    V == HexagonII::TypeCVI_VA_DV;
}

bool HexagonInstrInfo::isVecUsableNextPacket(const MachineInstr &ProdMI,
      const MachineInstr &ConsMI) const {
  if (EnableACCForwarding && isVecAcc(ProdMI) && isVecAcc(ConsMI))
    return true;

  if (EnableALUForwarding && (isVecALU(ConsMI) || isLateSourceInstr(ConsMI)))
    return true;

  if (mayBeNewStore(ConsMI))
    return true;

  return false;
}

bool HexagonInstrInfo::isZeroExtendingLoad(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  // Byte
  case Hexagon::L2_loadrub_io:
  case Hexagon::L4_loadrub_ur:
  case Hexagon::L4_loadrub_ap:
  case Hexagon::L2_loadrub_pr:
  case Hexagon::L2_loadrub_pbr:
  case Hexagon::L2_loadrub_pi:
  case Hexagon::L2_loadrub_pci:
  case Hexagon::L2_loadrub_pcr:
  case Hexagon::L2_loadbzw2_io:
  case Hexagon::L4_loadbzw2_ur:
  case Hexagon::L4_loadbzw2_ap:
  case Hexagon::L2_loadbzw2_pr:
  case Hexagon::L2_loadbzw2_pbr:
  case Hexagon::L2_loadbzw2_pi:
  case Hexagon::L2_loadbzw2_pci:
  case Hexagon::L2_loadbzw2_pcr:
  case Hexagon::L2_loadbzw4_io:
  case Hexagon::L4_loadbzw4_ur:
  case Hexagon::L4_loadbzw4_ap:
  case Hexagon::L2_loadbzw4_pr:
  case Hexagon::L2_loadbzw4_pbr:
  case Hexagon::L2_loadbzw4_pi:
  case Hexagon::L2_loadbzw4_pci:
  case Hexagon::L2_loadbzw4_pcr:
  case Hexagon::L4_loadrub_rr:
  case Hexagon::L2_ploadrubt_io:
  case Hexagon::L2_ploadrubt_pi:
  case Hexagon::L2_ploadrubf_io:
  case Hexagon::L2_ploadrubf_pi:
  case Hexagon::L2_ploadrubtnew_io:
  case Hexagon::L2_ploadrubfnew_io:
  case Hexagon::L4_ploadrubt_rr:
  case Hexagon::L4_ploadrubf_rr:
  case Hexagon::L4_ploadrubtnew_rr:
  case Hexagon::L4_ploadrubfnew_rr:
  case Hexagon::L2_ploadrubtnew_pi:
  case Hexagon::L2_ploadrubfnew_pi:
  case Hexagon::L4_ploadrubt_abs:
  case Hexagon::L4_ploadrubf_abs:
  case Hexagon::L4_ploadrubtnew_abs:
  case Hexagon::L4_ploadrubfnew_abs:
  case Hexagon::L2_loadrubgp:
  // Half
  case Hexagon::L2_loadruh_io:
  case Hexagon::L4_loadruh_ur:
  case Hexagon::L4_loadruh_ap:
  case Hexagon::L2_loadruh_pr:
  case Hexagon::L2_loadruh_pbr:
  case Hexagon::L2_loadruh_pi:
  case Hexagon::L2_loadruh_pci:
  case Hexagon::L2_loadruh_pcr:
  case Hexagon::L4_loadruh_rr:
  case Hexagon::L2_ploadruht_io:
  case Hexagon::L2_ploadruht_pi:
  case Hexagon::L2_ploadruhf_io:
  case Hexagon::L2_ploadruhf_pi:
  case Hexagon::L2_ploadruhtnew_io:
  case Hexagon::L2_ploadruhfnew_io:
  case Hexagon::L4_ploadruht_rr:
  case Hexagon::L4_ploadruhf_rr:
  case Hexagon::L4_ploadruhtnew_rr:
  case Hexagon::L4_ploadruhfnew_rr:
  case Hexagon::L2_ploadruhtnew_pi:
  case Hexagon::L2_ploadruhfnew_pi:
  case Hexagon::L4_ploadruht_abs:
  case Hexagon::L4_ploadruhf_abs:
  case Hexagon::L4_ploadruhtnew_abs:
  case Hexagon::L4_ploadruhfnew_abs:
  case Hexagon::L2_loadruhgp:
    return true;
  default:
    return false;
  }
}

// Add latency to instruction.
bool HexagonInstrInfo::addLatencyToSchedule(const MachineInstr &MI1,
      const MachineInstr &MI2) const {
  if (isHVXVec(MI1) && isHVXVec(MI2))
    if (!isVecUsableNextPacket(MI1, MI2))
      return true;
  return false;
}

/// Get the base register and byte offset of a load/store instr.
bool HexagonInstrInfo::getMemOpBaseRegImmOfs(MachineInstr &LdSt,
      unsigned &BaseReg, int64_t &Offset, const TargetRegisterInfo *TRI)
      const {
  unsigned AccessSize = 0;
  int OffsetVal = 0;
  BaseReg = getBaseAndOffset(LdSt, OffsetVal, AccessSize);
  Offset = OffsetVal;
  return BaseReg != 0;
}

/// Can these instructions execute at the same time in a bundle.
bool HexagonInstrInfo::canExecuteInBundle(const MachineInstr &First,
      const MachineInstr &Second) const {
  if (Second.mayStore() && First.getOpcode() == Hexagon::S2_allocframe) {
    const MachineOperand &Op = Second.getOperand(0);
    if (Op.isReg() && Op.isUse() && Op.getReg() == Hexagon::R29)
      return true;
  }
  if (DisableNVSchedule)
    return false;
  if (mayBeNewStore(Second)) {
    // Make sure the definition of the first instruction is the value being
    // stored.
    const MachineOperand &Stored =
      Second.getOperand(Second.getNumOperands() - 1);
    if (!Stored.isReg())
      return false;
    for (unsigned i = 0, e = First.getNumOperands(); i < e; ++i) {
      const MachineOperand &Op = First.getOperand(i);
      if (Op.isReg() && Op.isDef() && Op.getReg() == Stored.getReg())
        return true;
    }
  }
  return false;
}

bool HexagonInstrInfo::doesNotReturn(const MachineInstr &CallMI) const {
  unsigned Opc = CallMI.getOpcode();
  return Opc == Hexagon::PS_call_nr || Opc == Hexagon::PS_callr_nr;
}

bool HexagonInstrInfo::hasEHLabel(const MachineBasicBlock *B) const {
  for (auto &I : *B)
    if (I.isEHLabel())
      return true;
  return false;
}

// Returns true if an instruction can be converted into a non-extended
// equivalent instruction.
bool HexagonInstrInfo::hasNonExtEquivalent(const MachineInstr &MI) const {
  short NonExtOpcode;
  // Check if the instruction has a register form that uses register in place
  // of the extended operand, if so return that as the non-extended form.
  if (Hexagon::getRegForm(MI.getOpcode()) >= 0)
    return true;

  if (MI.getDesc().mayLoad() || MI.getDesc().mayStore()) {
    // Check addressing mode and retrieve non-ext equivalent instruction.

    switch (getAddrMode(MI)) {
    case HexagonII::Absolute:
      // Load/store with absolute addressing mode can be converted into
      // base+offset mode.
      NonExtOpcode = Hexagon::changeAddrMode_abs_io(MI.getOpcode());
      break;
    case HexagonII::BaseImmOffset:
      // Load/store with base+offset addressing mode can be converted into
      // base+register offset addressing mode. However left shift operand should
      // be set to 0.
      NonExtOpcode = Hexagon::changeAddrMode_io_rr(MI.getOpcode());
      break;
    case HexagonII::BaseLongOffset:
      NonExtOpcode = Hexagon::changeAddrMode_ur_rr(MI.getOpcode());
      break;
    default:
      return false;
    }
    if (NonExtOpcode < 0)
      return false;
    return true;
  }
  return false;
}

bool HexagonInstrInfo::hasPseudoInstrPair(const MachineInstr &MI) const {
  return Hexagon::getRealHWInstr(MI.getOpcode(),
                                 Hexagon::InstrType_Pseudo) >= 0;
}

bool HexagonInstrInfo::hasUncondBranch(const MachineBasicBlock *B)
      const {
  MachineBasicBlock::const_iterator I = B->getFirstTerminator(), E = B->end();
  while (I != E) {
    if (I->isBarrier())
      return true;
    ++I;
  }
  return false;
}

// Returns true, if a LD insn can be promoted to a cur load.
bool HexagonInstrInfo::mayBeCurLoad(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return ((F >> HexagonII::mayCVLoadPos) & HexagonII::mayCVLoadMask) &&
         Subtarget.hasV60Ops();
}

// Returns true, if a ST insn can be promoted to a new-value store.
bool HexagonInstrInfo::mayBeNewStore(const MachineInstr &MI) const {
  if (MI.mayStore() && !Subtarget.useNewValueStores())
    return false;

  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::mayNVStorePos) & HexagonII::mayNVStoreMask;
}

bool HexagonInstrInfo::producesStall(const MachineInstr &ProdMI,
      const MachineInstr &ConsMI) const {
  // There is no stall when ProdMI is not a V60 vector.
  if (!isHVXVec(ProdMI))
    return false;

  // There is no stall when ProdMI and ConsMI are not dependent.
  if (!isDependent(ProdMI, ConsMI))
    return false;

  // When Forward Scheduling is enabled, there is no stall if ProdMI and ConsMI
  // are scheduled in consecutive packets.
  if (isVecUsableNextPacket(ProdMI, ConsMI))
    return false;

  return true;
}

bool HexagonInstrInfo::producesStall(const MachineInstr &MI,
      MachineBasicBlock::const_instr_iterator BII) const {
  // There is no stall when I is not a V60 vector.
  if (!isHVXVec(MI))
    return false;

  MachineBasicBlock::const_instr_iterator MII = BII;
  MachineBasicBlock::const_instr_iterator MIE = MII->getParent()->instr_end();

  if (!MII->isBundle())
    return producesStall(*MII, MI);

  for (++MII; MII != MIE && MII->isInsideBundle(); ++MII) {
    const MachineInstr &J = *MII;
    if (producesStall(J, MI))
      return true;
  }
  return false;
}

bool HexagonInstrInfo::predCanBeUsedAsDotNew(const MachineInstr &MI,
      unsigned PredReg) const {
  for (const MachineOperand &MO : MI.operands()) {
    // Predicate register must be explicitly defined.
    if (MO.isRegMask() && MO.clobbersPhysReg(PredReg))
      return false;
    if (MO.isReg() && MO.isDef() && MO.isImplicit() && (MO.getReg() == PredReg))
      return false;
  }

  // Instruction that produce late predicate cannot be used as sources of
  // dot-new.
  switch (MI.getOpcode()) {
    case Hexagon::A4_addp_c:
    case Hexagon::A4_subp_c:
    case Hexagon::A4_tlbmatch:
    case Hexagon::A5_ACS:
    case Hexagon::F2_sfinvsqrta:
    case Hexagon::F2_sfrecipa:
    case Hexagon::J2_endloop0:
    case Hexagon::J2_endloop01:
    case Hexagon::J2_ploop1si:
    case Hexagon::J2_ploop1sr:
    case Hexagon::J2_ploop2si:
    case Hexagon::J2_ploop2sr:
    case Hexagon::J2_ploop3si:
    case Hexagon::J2_ploop3sr:
    case Hexagon::S2_cabacdecbin:
    case Hexagon::S2_storew_locked:
    case Hexagon::S4_stored_locked:
      return false;
  }
  return true;
}

bool HexagonInstrInfo::PredOpcodeHasJMP_c(unsigned Opcode) const {
  return Opcode == Hexagon::J2_jumpt      ||
         Opcode == Hexagon::J2_jumptpt    ||
         Opcode == Hexagon::J2_jumpf      ||
         Opcode == Hexagon::J2_jumpfpt    ||
         Opcode == Hexagon::J2_jumptnew   ||
         Opcode == Hexagon::J2_jumpfnew   ||
         Opcode == Hexagon::J2_jumptnewpt ||
         Opcode == Hexagon::J2_jumpfnewpt;
}

bool HexagonInstrInfo::predOpcodeHasNot(ArrayRef<MachineOperand> Cond) const {
  if (Cond.empty() || !isPredicated(Cond[0].getImm()))
    return false;
  return !isPredicatedTrue(Cond[0].getImm());
}

unsigned HexagonInstrInfo::getAddrMode(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::AddrModePos) & HexagonII::AddrModeMask;
}

// Returns the base register in a memory access (load/store). The offset is
// returned in Offset and the access size is returned in AccessSize.
// If the base register has a subregister or the offset field does not contain
// an immediate value, return 0.
unsigned HexagonInstrInfo::getBaseAndOffset(const MachineInstr &MI,
      int &Offset, unsigned &AccessSize) const {
  // Return if it is not a base+offset type instruction or a MemOp.
  if (getAddrMode(MI) != HexagonII::BaseImmOffset &&
      getAddrMode(MI) != HexagonII::BaseLongOffset &&
      !isMemOp(MI) && !isPostIncrement(MI))
    return 0;

  AccessSize = getMemAccessSize(MI);

  unsigned BasePos = 0, OffsetPos = 0;
  if (!getBaseAndOffsetPosition(MI, BasePos, OffsetPos))
    return 0;

  // Post increment updates its EA after the mem access,
  // so we need to treat its offset as zero.
  if (isPostIncrement(MI)) {
    Offset = 0;
  } else {
    const MachineOperand &OffsetOp = MI.getOperand(OffsetPos);
    if (!OffsetOp.isImm())
      return 0;
    Offset = OffsetOp.getImm();
  }

  const MachineOperand &BaseOp = MI.getOperand(BasePos);
  if (BaseOp.getSubReg() != 0)
    return 0;
  return BaseOp.getReg();
}

/// Return the position of the base and offset operands for this instruction.
bool HexagonInstrInfo::getBaseAndOffsetPosition(const MachineInstr &MI,
      unsigned &BasePos, unsigned &OffsetPos) const {
  if (!isAddrModeWithOffset(MI) && !isPostIncrement(MI))
    return false;

  // Deal with memops first.
  if (isMemOp(MI)) {
    BasePos = 0;
    OffsetPos = 1;
  } else if (MI.mayStore()) {
    BasePos = 0;
    OffsetPos = 1;
  } else if (MI.mayLoad()) {
    BasePos = 1;
    OffsetPos = 2;
  } else
    return false;

  if (isPredicated(MI)) {
    BasePos++;
    OffsetPos++;
  }
  if (isPostIncrement(MI)) {
    BasePos++;
    OffsetPos++;
  }

  if (!MI.getOperand(BasePos).isReg() || !MI.getOperand(OffsetPos).isImm())
    return false;

  return true;
}

// Inserts branching instructions in reverse order of their occurrence.
// e.g. jump_t t1 (i1)
// jump t2        (i2)
// Jumpers = {i2, i1}
SmallVector<MachineInstr*, 2> HexagonInstrInfo::getBranchingInstrs(
      MachineBasicBlock& MBB) const {
  SmallVector<MachineInstr*, 2> Jumpers;
  // If the block has no terminators, it just falls into the block after it.
  MachineBasicBlock::instr_iterator I = MBB.instr_end();
  if (I == MBB.instr_begin())
    return Jumpers;

  // A basic block may looks like this:
  //
  //  [   insn
  //     EH_LABEL
  //      insn
  //      insn
  //      insn
  //     EH_LABEL
  //      insn     ]
  //
  // It has two succs but does not have a terminator
  // Don't know how to handle it.
  do {
    --I;
    if (I->isEHLabel())
      return Jumpers;
  } while (I != MBB.instr_begin());

  I = MBB.instr_end();
  --I;

  while (I->isDebugInstr()) {
    if (I == MBB.instr_begin())
      return Jumpers;
    --I;
  }
  if (!isUnpredicatedTerminator(*I))
    return Jumpers;

  // Get the last instruction in the block.
  MachineInstr *LastInst = &*I;
  Jumpers.push_back(LastInst);
  MachineInstr *SecondLastInst = nullptr;
  // Find one more terminator if present.
  do {
    if (&*I != LastInst && !I->isBundle() && isUnpredicatedTerminator(*I)) {
      if (!SecondLastInst) {
        SecondLastInst = &*I;
        Jumpers.push_back(SecondLastInst);
      } else // This is a third branch.
        return Jumpers;
    }
    if (I == MBB.instr_begin())
      break;
    --I;
  } while (true);
  return Jumpers;
}

// Returns Operand Index for the constant extended instruction.
unsigned HexagonInstrInfo::getCExtOpNum(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::ExtendableOpPos) & HexagonII::ExtendableOpMask;
}

// See if instruction could potentially be a duplex candidate.
// If so, return its group. Zero otherwise.
HexagonII::CompoundGroup HexagonInstrInfo::getCompoundCandidateGroup(
      const MachineInstr &MI) const {
  unsigned DstReg, SrcReg, Src1Reg, Src2Reg;

  switch (MI.getOpcode()) {
  default:
    return HexagonII::HCG_None;
  //
  // Compound pairs.
  // "p0=cmp.eq(Rs16,Rt16); if (p0.new) jump:nt #r9:2"
  // "Rd16=#U6 ; jump #r9:2"
  // "Rd16=Rs16 ; jump #r9:2"
  //
  case Hexagon::C2_cmpeq:
  case Hexagon::C2_cmpgt:
  case Hexagon::C2_cmpgtu:
    DstReg = MI.getOperand(0).getReg();
    Src1Reg = MI.getOperand(1).getReg();
    Src2Reg = MI.getOperand(2).getReg();
    if (Hexagon::PredRegsRegClass.contains(DstReg) &&
        (Hexagon::P0 == DstReg || Hexagon::P1 == DstReg) &&
        isIntRegForSubInst(Src1Reg) && isIntRegForSubInst(Src2Reg))
      return HexagonII::HCG_A;
    break;
  case Hexagon::C2_cmpeqi:
  case Hexagon::C2_cmpgti:
  case Hexagon::C2_cmpgtui:
    // P0 = cmp.eq(Rs,#u2)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (Hexagon::PredRegsRegClass.contains(DstReg) &&
        (Hexagon::P0 == DstReg || Hexagon::P1 == DstReg) &&
        isIntRegForSubInst(SrcReg) && MI.getOperand(2).isImm() &&
        ((isUInt<5>(MI.getOperand(2).getImm())) ||
         (MI.getOperand(2).getImm() == -1)))
      return HexagonII::HCG_A;
    break;
  case Hexagon::A2_tfr:
    // Rd = Rs
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg))
      return HexagonII::HCG_A;
    break;
  case Hexagon::A2_tfrsi:
    // Rd = #u6
    // Do not test for #u6 size since the const is getting extended
    // regardless and compound could be formed.
    DstReg = MI.getOperand(0).getReg();
    if (isIntRegForSubInst(DstReg))
      return HexagonII::HCG_A;
    break;
  case Hexagon::S2_tstbit_i:
    DstReg = MI.getOperand(0).getReg();
    Src1Reg = MI.getOperand(1).getReg();
    if (Hexagon::PredRegsRegClass.contains(DstReg) &&
        (Hexagon::P0 == DstReg || Hexagon::P1 == DstReg) &&
        MI.getOperand(2).isImm() &&
        isIntRegForSubInst(Src1Reg) && (MI.getOperand(2).getImm() == 0))
      return HexagonII::HCG_A;
    break;
  // The fact that .new form is used pretty much guarantees
  // that predicate register will match. Nevertheless,
  // there could be some false positives without additional
  // checking.
  case Hexagon::J2_jumptnew:
  case Hexagon::J2_jumpfnew:
  case Hexagon::J2_jumptnewpt:
  case Hexagon::J2_jumpfnewpt:
    Src1Reg = MI.getOperand(0).getReg();
    if (Hexagon::PredRegsRegClass.contains(Src1Reg) &&
        (Hexagon::P0 == Src1Reg || Hexagon::P1 == Src1Reg))
      return HexagonII::HCG_B;
    break;
  // Transfer and jump:
  // Rd=#U6 ; jump #r9:2
  // Rd=Rs ; jump #r9:2
  // Do not test for jump range here.
  case Hexagon::J2_jump:
  case Hexagon::RESTORE_DEALLOC_RET_JMP_V4:
  case Hexagon::RESTORE_DEALLOC_RET_JMP_V4_PIC:
    return HexagonII::HCG_C;
  }

  return HexagonII::HCG_None;
}

// Returns -1 when there is no opcode found.
unsigned HexagonInstrInfo::getCompoundOpcode(const MachineInstr &GA,
      const MachineInstr &GB) const {
  assert(getCompoundCandidateGroup(GA) == HexagonII::HCG_A);
  assert(getCompoundCandidateGroup(GB) == HexagonII::HCG_B);
  if ((GA.getOpcode() != Hexagon::C2_cmpeqi) ||
      (GB.getOpcode() != Hexagon::J2_jumptnew))
    return -1u;
  unsigned DestReg = GA.getOperand(0).getReg();
  if (!GB.readsRegister(DestReg))
    return -1u;
  if (DestReg != Hexagon::P0 && DestReg != Hexagon::P1)
    return -1u;
  // The value compared against must be either u5 or -1.
  const MachineOperand &CmpOp = GA.getOperand(2);
  if (!CmpOp.isImm())
    return -1u;
  int V = CmpOp.getImm();
  if (V == -1)
    return DestReg == Hexagon::P0 ? Hexagon::J4_cmpeqn1_tp0_jump_nt
                                  : Hexagon::J4_cmpeqn1_tp1_jump_nt;
  if (!isUInt<5>(V))
    return -1u;
  return DestReg == Hexagon::P0 ? Hexagon::J4_cmpeqi_tp0_jump_nt
                                : Hexagon::J4_cmpeqi_tp1_jump_nt;
}

int HexagonInstrInfo::getCondOpcode(int Opc, bool invertPredicate) const {
  enum Hexagon::PredSense inPredSense;
  inPredSense = invertPredicate ? Hexagon::PredSense_false :
                                  Hexagon::PredSense_true;
  int CondOpcode = Hexagon::getPredOpcode(Opc, inPredSense);
  if (CondOpcode >= 0) // Valid Conditional opcode/instruction
    return CondOpcode;

  llvm_unreachable("Unexpected predicable instruction");
}

// Return the cur value instruction for a given store.
int HexagonInstrInfo::getDotCurOp(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  default: llvm_unreachable("Unknown .cur type");
  case Hexagon::V6_vL32b_pi:
    return Hexagon::V6_vL32b_cur_pi;
  case Hexagon::V6_vL32b_ai:
    return Hexagon::V6_vL32b_cur_ai;
  case Hexagon::V6_vL32b_nt_pi:
    return Hexagon::V6_vL32b_nt_cur_pi;
  case Hexagon::V6_vL32b_nt_ai:
    return Hexagon::V6_vL32b_nt_cur_ai;
  }
  return 0;
}

// Return the regular version of the .cur instruction.
int HexagonInstrInfo::getNonDotCurOp(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  default: llvm_unreachable("Unknown .cur type");
  case Hexagon::V6_vL32b_cur_pi:
    return Hexagon::V6_vL32b_pi;
  case Hexagon::V6_vL32b_cur_ai:
    return Hexagon::V6_vL32b_ai;
  case Hexagon::V6_vL32b_nt_cur_pi:
    return Hexagon::V6_vL32b_nt_pi;
  case Hexagon::V6_vL32b_nt_cur_ai:
    return Hexagon::V6_vL32b_nt_ai;
  }
  return 0;
}

// The diagram below shows the steps involved in the conversion of a predicated
// store instruction to its .new predicated new-value form.
//
// Note: It doesn't include conditional new-value stores as they can't be
// converted to .new predicate.
//
//               p.new NV store [ if(p0.new)memw(R0+#0)=R2.new ]
//                ^           ^
//               /             \ (not OK. it will cause new-value store to be
//              /               X conditional on p0.new while R2 producer is
//             /                 \ on p0)
//            /                   \.
//     p.new store                 p.old NV store
// [if(p0.new)memw(R0+#0)=R2]    [if(p0)memw(R0+#0)=R2.new]
//            ^                  ^
//             \                /
//              \              /
//               \            /
//                 p.old store
//             [if (p0)memw(R0+#0)=R2]
//
// The following set of instructions further explains the scenario where
// conditional new-value store becomes invalid when promoted to .new predicate
// form.
//
// { 1) if (p0) r0 = add(r1, r2)
//   2) p0 = cmp.eq(r3, #0) }
//
//   3) if (p0) memb(r1+#0) = r0  --> this instruction can't be grouped with
// the first two instructions because in instr 1, r0 is conditional on old value
// of p0 but its use in instr 3 is conditional on p0 modified by instr 2 which
// is not valid for new-value stores.
// Predicated new value stores (i.e. if (p0) memw(..)=r0.new) are excluded
// from the "Conditional Store" list. Because a predicated new value store
// would NOT be promoted to a double dot new store. See diagram below:
// This function returns yes for those stores that are predicated but not
// yet promoted to predicate dot new instructions.
//
//                          +---------------------+
//                    /-----| if (p0) memw(..)=r0 |---------\~
//                   ||     +---------------------+         ||
//          promote  ||       /\       /\                   ||  promote
//                   ||      /||\     /||\                  ||
//                  \||/    demote     ||                  \||/
//                   \/       ||       ||                   \/
//       +-------------------------+   ||   +-------------------------+
//       | if (p0.new) memw(..)=r0 |   ||   | if (p0) memw(..)=r0.new |
//       +-------------------------+   ||   +-------------------------+
//                        ||           ||         ||
//                        ||         demote      \||/
//                      promote        ||         \/ NOT possible
//                        ||           ||         /\~
//                       \||/          ||        /||\~
//                        \/           ||         ||
//                      +-----------------------------+
//                      | if (p0.new) memw(..)=r0.new |
//                      +-----------------------------+
//                           Double Dot New Store
//
// Returns the most basic instruction for the .new predicated instructions and
// new-value stores.
// For example, all of the following instructions will be converted back to the
// same instruction:
// 1) if (p0.new) memw(R0+#0) = R1.new  --->
// 2) if (p0) memw(R0+#0)= R1.new      -------> if (p0) memw(R0+#0) = R1
// 3) if (p0.new) memw(R0+#0) = R1      --->
//
// To understand the translation of instruction 1 to its original form, consider
// a packet with 3 instructions.
// { p0 = cmp.eq(R0,R1)
//   if (p0.new) R2 = add(R3, R4)
//   R5 = add (R3, R1)
// }
// if (p0) memw(R5+#0) = R2 <--- trying to include it in the previous packet
//
// This instruction can be part of the previous packet only if both p0 and R2
// are promoted to .new values. This promotion happens in steps, first
// predicate register is promoted to .new and in the next iteration R2 is
// promoted. Therefore, in case of dependence check failure (due to R5) during
// next iteration, it should be converted back to its most basic form.

// Return the new value instruction for a given store.
int HexagonInstrInfo::getDotNewOp(const MachineInstr &MI) const {
  int NVOpcode = Hexagon::getNewValueOpcode(MI.getOpcode());
  if (NVOpcode >= 0) // Valid new-value store instruction.
    return NVOpcode;

  switch (MI.getOpcode()) {
  default:
    report_fatal_error(std::string("Unknown .new type: ") +
      std::to_string(MI.getOpcode()));
  case Hexagon::S4_storerb_ur:
    return Hexagon::S4_storerbnew_ur;

  case Hexagon::S2_storerb_pci:
    return Hexagon::S2_storerb_pci;

  case Hexagon::S2_storeri_pci:
    return Hexagon::S2_storeri_pci;

  case Hexagon::S2_storerh_pci:
    return Hexagon::S2_storerh_pci;

  case Hexagon::S2_storerd_pci:
    return Hexagon::S2_storerd_pci;

  case Hexagon::S2_storerf_pci:
    return Hexagon::S2_storerf_pci;

  case Hexagon::V6_vS32b_ai:
    return Hexagon::V6_vS32b_new_ai;

  case Hexagon::V6_vS32b_pi:
    return Hexagon::V6_vS32b_new_pi;
  }
  return 0;
}

// Returns the opcode to use when converting MI, which is a conditional jump,
// into a conditional instruction which uses the .new value of the predicate.
// We also use branch probabilities to add a hint to the jump.
// If MBPI is null, all edges will be treated as equally likely for the
// purposes of establishing a predication hint.
int HexagonInstrInfo::getDotNewPredJumpOp(const MachineInstr &MI,
      const MachineBranchProbabilityInfo *MBPI) const {
  // We assume that block can have at most two successors.
  const MachineBasicBlock *Src = MI.getParent();
  const MachineOperand &BrTarget = MI.getOperand(1);
  bool Taken = false;
  const BranchProbability OneHalf(1, 2);

  auto getEdgeProbability = [MBPI] (const MachineBasicBlock *Src,
                                    const MachineBasicBlock *Dst) {
    if (MBPI)
      return MBPI->getEdgeProbability(Src, Dst);
    return BranchProbability(1, Src->succ_size());
  };

  if (BrTarget.isMBB()) {
    const MachineBasicBlock *Dst = BrTarget.getMBB();
    Taken = getEdgeProbability(Src, Dst) >= OneHalf;
  } else {
    // The branch target is not a basic block (most likely a function).
    // Since BPI only gives probabilities for targets that are basic blocks,
    // try to identify another target of this branch (potentially a fall-
    // -through) and check the probability of that target.
    //
    // The only handled branch combinations are:
    // - one conditional branch,
    // - one conditional branch followed by one unconditional branch.
    // Otherwise, assume not-taken.
    assert(MI.isConditionalBranch());
    const MachineBasicBlock &B = *MI.getParent();
    bool SawCond = false, Bad = false;
    for (const MachineInstr &I : B) {
      if (!I.isBranch())
        continue;
      if (I.isConditionalBranch()) {
        SawCond = true;
        if (&I != &MI) {
          Bad = true;
          break;
        }
      }
      if (I.isUnconditionalBranch() && !SawCond) {
        Bad = true;
        break;
      }
    }
    if (!Bad) {
      MachineBasicBlock::const_instr_iterator It(MI);
      MachineBasicBlock::const_instr_iterator NextIt = std::next(It);
      if (NextIt == B.instr_end()) {
        // If this branch is the last, look for the fall-through block.
        for (const MachineBasicBlock *SB : B.successors()) {
          if (!B.isLayoutSuccessor(SB))
            continue;
          Taken = getEdgeProbability(Src, SB) < OneHalf;
          break;
        }
      } else {
        assert(NextIt->isUnconditionalBranch());
        // Find the first MBB operand and assume it's the target.
        const MachineBasicBlock *BT = nullptr;
        for (const MachineOperand &Op : NextIt->operands()) {
          if (!Op.isMBB())
            continue;
          BT = Op.getMBB();
          break;
        }
        Taken = BT && getEdgeProbability(Src, BT) < OneHalf;
      }
    } // if (!Bad)
  }

  // The Taken flag should be set to something reasonable by this point.

  switch (MI.getOpcode()) {
  case Hexagon::J2_jumpt:
    return Taken ? Hexagon::J2_jumptnewpt : Hexagon::J2_jumptnew;
  case Hexagon::J2_jumpf:
    return Taken ? Hexagon::J2_jumpfnewpt : Hexagon::J2_jumpfnew;

  default:
    llvm_unreachable("Unexpected jump instruction.");
  }
}

// Return .new predicate version for an instruction.
int HexagonInstrInfo::getDotNewPredOp(const MachineInstr &MI,
      const MachineBranchProbabilityInfo *MBPI) const {
  switch (MI.getOpcode()) {
  // Condtional Jumps
  case Hexagon::J2_jumpt:
  case Hexagon::J2_jumpf:
    return getDotNewPredJumpOp(MI, MBPI);
  }

  int NewOpcode = Hexagon::getPredNewOpcode(MI.getOpcode());
  if (NewOpcode >= 0)
    return NewOpcode;
  return 0;
}

int HexagonInstrInfo::getDotOldOp(const MachineInstr &MI) const {
  int NewOp = MI.getOpcode();
  if (isPredicated(NewOp) && isPredicatedNew(NewOp)) { // Get predicate old form
    NewOp = Hexagon::getPredOldOpcode(NewOp);
    // All Hexagon architectures have prediction bits on dot-new branches,
    // but only Hexagon V60+ has prediction bits on dot-old ones. Make sure
    // to pick the right opcode when converting back to dot-old.
    if (!Subtarget.getFeatureBits()[Hexagon::ArchV60]) {
      switch (NewOp) {
      case Hexagon::J2_jumptpt:
        NewOp = Hexagon::J2_jumpt;
        break;
      case Hexagon::J2_jumpfpt:
        NewOp = Hexagon::J2_jumpf;
        break;
      case Hexagon::J2_jumprtpt:
        NewOp = Hexagon::J2_jumprt;
        break;
      case Hexagon::J2_jumprfpt:
        NewOp = Hexagon::J2_jumprf;
        break;
      }
    }
    assert(NewOp >= 0 &&
           "Couldn't change predicate new instruction to its old form.");
  }

  if (isNewValueStore(NewOp)) { // Convert into non-new-value format
    NewOp = Hexagon::getNonNVStore(NewOp);
    assert(NewOp >= 0 && "Couldn't change new-value store to its old form.");
  }

  if (Subtarget.hasV60Ops())
    return NewOp;

  // Subtargets prior to V60 didn't support 'taken' forms of predicated jumps.
  switch (NewOp) {
  case Hexagon::J2_jumpfpt:
    return Hexagon::J2_jumpf;
  case Hexagon::J2_jumptpt:
    return Hexagon::J2_jumpt;
  case Hexagon::J2_jumprfpt:
    return Hexagon::J2_jumprf;
  case Hexagon::J2_jumprtpt:
    return Hexagon::J2_jumprt;
  }
  return NewOp;
}

// See if instruction could potentially be a duplex candidate.
// If so, return its group. Zero otherwise.
HexagonII::SubInstructionGroup HexagonInstrInfo::getDuplexCandidateGroup(
      const MachineInstr &MI) const {
  unsigned DstReg, SrcReg, Src1Reg, Src2Reg;
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();

  switch (MI.getOpcode()) {
  default:
    return HexagonII::HSIG_None;
  //
  // Group L1:
  //
  // Rd = memw(Rs+#u4:2)
  // Rd = memub(Rs+#u4:0)
  case Hexagon::L2_loadri_io:
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    // Special case this one from Group L2.
    // Rd = memw(r29+#u5:2)
    if (isIntRegForSubInst(DstReg)) {
      if (Hexagon::IntRegsRegClass.contains(SrcReg) &&
          HRI.getStackRegister() == SrcReg &&
          MI.getOperand(2).isImm() &&
          isShiftedUInt<5,2>(MI.getOperand(2).getImm()))
        return HexagonII::HSIG_L2;
      // Rd = memw(Rs+#u4:2)
      if (isIntRegForSubInst(SrcReg) &&
          (MI.getOperand(2).isImm() &&
          isShiftedUInt<4,2>(MI.getOperand(2).getImm())))
        return HexagonII::HSIG_L1;
    }
    break;
  case Hexagon::L2_loadrub_io:
    // Rd = memub(Rs+#u4:0)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg) &&
        MI.getOperand(2).isImm() && isUInt<4>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_L1;
    break;
  //
  // Group L2:
  //
  // Rd = memh/memuh(Rs+#u3:1)
  // Rd = memb(Rs+#u3:0)
  // Rd = memw(r29+#u5:2) - Handled above.
  // Rdd = memd(r29+#u5:3)
  // deallocframe
  // [if ([!]p0[.new])] dealloc_return
  // [if ([!]p0[.new])] jumpr r31
  case Hexagon::L2_loadrh_io:
  case Hexagon::L2_loadruh_io:
    // Rd = memh/memuh(Rs+#u3:1)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg) &&
        MI.getOperand(2).isImm() &&
        isShiftedUInt<3,1>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_L2;
    break;
  case Hexagon::L2_loadrb_io:
    // Rd = memb(Rs+#u3:0)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg) &&
        MI.getOperand(2).isImm() &&
        isUInt<3>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_L2;
    break;
  case Hexagon::L2_loadrd_io:
    // Rdd = memd(r29+#u5:3)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isDblRegForSubInst(DstReg, HRI) &&
        Hexagon::IntRegsRegClass.contains(SrcReg) &&
        HRI.getStackRegister() == SrcReg &&
        MI.getOperand(2).isImm() &&
        isShiftedUInt<5,3>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_L2;
    break;
  // dealloc_return is not documented in Hexagon Manual, but marked
  // with A_SUBINSN attribute in iset_v4classic.py.
  case Hexagon::RESTORE_DEALLOC_RET_JMP_V4:
  case Hexagon::RESTORE_DEALLOC_RET_JMP_V4_PIC:
  case Hexagon::L4_return:
  case Hexagon::L2_deallocframe:
    return HexagonII::HSIG_L2;
  case Hexagon::EH_RETURN_JMPR:
  case Hexagon::PS_jmpret:
  case Hexagon::SL2_jumpr31:
    // jumpr r31
    // Actual form JMPR implicit-def %pc, implicit %r31, implicit internal %r0
    DstReg = MI.getOperand(0).getReg();
    if (Hexagon::IntRegsRegClass.contains(DstReg) && (Hexagon::R31 == DstReg))
      return HexagonII::HSIG_L2;
    break;
  case Hexagon::PS_jmprett:
  case Hexagon::PS_jmpretf:
  case Hexagon::PS_jmprettnewpt:
  case Hexagon::PS_jmpretfnewpt:
  case Hexagon::PS_jmprettnew:
  case Hexagon::PS_jmpretfnew:
  case Hexagon::SL2_jumpr31_t:
  case Hexagon::SL2_jumpr31_f:
  case Hexagon::SL2_jumpr31_tnew:
    DstReg = MI.getOperand(1).getReg();
    SrcReg = MI.getOperand(0).getReg();
    // [if ([!]p0[.new])] jumpr r31
    if ((Hexagon::PredRegsRegClass.contains(SrcReg) &&
        (Hexagon::P0 == SrcReg)) &&
        (Hexagon::IntRegsRegClass.contains(DstReg) && (Hexagon::R31 == DstReg)))
      return HexagonII::HSIG_L2;
    break;
  case Hexagon::L4_return_t:
  case Hexagon::L4_return_f:
  case Hexagon::L4_return_tnew_pnt:
  case Hexagon::L4_return_fnew_pnt:
  case Hexagon::L4_return_tnew_pt:
  case Hexagon::L4_return_fnew_pt:
    // [if ([!]p0[.new])] dealloc_return
    SrcReg = MI.getOperand(0).getReg();
    if (Hexagon::PredRegsRegClass.contains(SrcReg) && (Hexagon::P0 == SrcReg))
      return HexagonII::HSIG_L2;
    break;
  //
  // Group S1:
  //
  // memw(Rs+#u4:2) = Rt
  // memb(Rs+#u4:0) = Rt
  case Hexagon::S2_storeri_io:
    // Special case this one from Group S2.
    // memw(r29+#u5:2) = Rt
    Src1Reg = MI.getOperand(0).getReg();
    Src2Reg = MI.getOperand(2).getReg();
    if (Hexagon::IntRegsRegClass.contains(Src1Reg) &&
        isIntRegForSubInst(Src2Reg) &&
        HRI.getStackRegister() == Src1Reg && MI.getOperand(1).isImm() &&
        isShiftedUInt<5,2>(MI.getOperand(1).getImm()))
      return HexagonII::HSIG_S2;
    // memw(Rs+#u4:2) = Rt
    if (isIntRegForSubInst(Src1Reg) && isIntRegForSubInst(Src2Reg) &&
        MI.getOperand(1).isImm() &&
        isShiftedUInt<4,2>(MI.getOperand(1).getImm()))
      return HexagonII::HSIG_S1;
    break;
  case Hexagon::S2_storerb_io:
    // memb(Rs+#u4:0) = Rt
    Src1Reg = MI.getOperand(0).getReg();
    Src2Reg = MI.getOperand(2).getReg();
    if (isIntRegForSubInst(Src1Reg) && isIntRegForSubInst(Src2Reg) &&
        MI.getOperand(1).isImm() && isUInt<4>(MI.getOperand(1).getImm()))
      return HexagonII::HSIG_S1;
    break;
  //
  // Group S2:
  //
  // memh(Rs+#u3:1) = Rt
  // memw(r29+#u5:2) = Rt
  // memd(r29+#s6:3) = Rtt
  // memw(Rs+#u4:2) = #U1
  // memb(Rs+#u4) = #U1
  // allocframe(#u5:3)
  case Hexagon::S2_storerh_io:
    // memh(Rs+#u3:1) = Rt
    Src1Reg = MI.getOperand(0).getReg();
    Src2Reg = MI.getOperand(2).getReg();
    if (isIntRegForSubInst(Src1Reg) && isIntRegForSubInst(Src2Reg) &&
        MI.getOperand(1).isImm() &&
        isShiftedUInt<3,1>(MI.getOperand(1).getImm()))
      return HexagonII::HSIG_S1;
    break;
  case Hexagon::S2_storerd_io:
    // memd(r29+#s6:3) = Rtt
    Src1Reg = MI.getOperand(0).getReg();
    Src2Reg = MI.getOperand(2).getReg();
    if (isDblRegForSubInst(Src2Reg, HRI) &&
        Hexagon::IntRegsRegClass.contains(Src1Reg) &&
        HRI.getStackRegister() == Src1Reg && MI.getOperand(1).isImm() &&
        isShiftedInt<6,3>(MI.getOperand(1).getImm()))
      return HexagonII::HSIG_S2;
    break;
  case Hexagon::S4_storeiri_io:
    // memw(Rs+#u4:2) = #U1
    Src1Reg = MI.getOperand(0).getReg();
    if (isIntRegForSubInst(Src1Reg) && MI.getOperand(1).isImm() &&
        isShiftedUInt<4,2>(MI.getOperand(1).getImm()) &&
        MI.getOperand(2).isImm() && isUInt<1>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_S2;
    break;
  case Hexagon::S4_storeirb_io:
    // memb(Rs+#u4) = #U1
    Src1Reg = MI.getOperand(0).getReg();
    if (isIntRegForSubInst(Src1Reg) &&
        MI.getOperand(1).isImm() && isUInt<4>(MI.getOperand(1).getImm()) &&
        MI.getOperand(2).isImm() && isUInt<1>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_S2;
    break;
  case Hexagon::S2_allocframe:
    if (MI.getOperand(2).isImm() &&
        isShiftedUInt<5,3>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_S1;
    break;
  //
  // Group A:
  //
  // Rx = add(Rx,#s7)
  // Rd = Rs
  // Rd = #u6
  // Rd = #-1
  // if ([!]P0[.new]) Rd = #0
  // Rd = add(r29,#u6:2)
  // Rx = add(Rx,Rs)
  // P0 = cmp.eq(Rs,#u2)
  // Rdd = combine(#0,Rs)
  // Rdd = combine(Rs,#0)
  // Rdd = combine(#u2,#U2)
  // Rd = add(Rs,#1)
  // Rd = add(Rs,#-1)
  // Rd = sxth/sxtb/zxtb/zxth(Rs)
  // Rd = and(Rs,#1)
  case Hexagon::A2_addi:
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg)) {
      // Rd = add(r29,#u6:2)
      if (Hexagon::IntRegsRegClass.contains(SrcReg) &&
        HRI.getStackRegister() == SrcReg && MI.getOperand(2).isImm() &&
        isShiftedUInt<6,2>(MI.getOperand(2).getImm()))
        return HexagonII::HSIG_A;
      // Rx = add(Rx,#s7)
      if ((DstReg == SrcReg) && MI.getOperand(2).isImm() &&
          isInt<7>(MI.getOperand(2).getImm()))
        return HexagonII::HSIG_A;
      // Rd = add(Rs,#1)
      // Rd = add(Rs,#-1)
      if (isIntRegForSubInst(SrcReg) && MI.getOperand(2).isImm() &&
          ((MI.getOperand(2).getImm() == 1) ||
          (MI.getOperand(2).getImm() == -1)))
        return HexagonII::HSIG_A;
    }
    break;
  case Hexagon::A2_add:
    // Rx = add(Rx,Rs)
    DstReg = MI.getOperand(0).getReg();
    Src1Reg = MI.getOperand(1).getReg();
    Src2Reg = MI.getOperand(2).getReg();
    if (isIntRegForSubInst(DstReg) && (DstReg == Src1Reg) &&
        isIntRegForSubInst(Src2Reg))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A2_andir:
    // Same as zxtb.
    // Rd16=and(Rs16,#255)
    // Rd16=and(Rs16,#1)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg) &&
        MI.getOperand(2).isImm() &&
        ((MI.getOperand(2).getImm() == 1) ||
        (MI.getOperand(2).getImm() == 255)))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A2_tfr:
    // Rd = Rs
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A2_tfrsi:
    // Rd = #u6
    // Do not test for #u6 size since the const is getting extended
    // regardless and compound could be formed.
    // Rd = #-1
    DstReg = MI.getOperand(0).getReg();
    if (isIntRegForSubInst(DstReg))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::C2_cmoveit:
  case Hexagon::C2_cmovenewit:
  case Hexagon::C2_cmoveif:
  case Hexagon::C2_cmovenewif:
    // if ([!]P0[.new]) Rd = #0
    // Actual form:
    // %r16 = C2_cmovenewit internal %p0, 0, implicit undef %r16;
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) &&
        Hexagon::PredRegsRegClass.contains(SrcReg) && Hexagon::P0 == SrcReg &&
        MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0)
      return HexagonII::HSIG_A;
    break;
  case Hexagon::C2_cmpeqi:
    // P0 = cmp.eq(Rs,#u2)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (Hexagon::PredRegsRegClass.contains(DstReg) &&
        Hexagon::P0 == DstReg && isIntRegForSubInst(SrcReg) &&
        MI.getOperand(2).isImm() && isUInt<2>(MI.getOperand(2).getImm()))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A2_combineii:
  case Hexagon::A4_combineii:
    // Rdd = combine(#u2,#U2)
    DstReg = MI.getOperand(0).getReg();
    if (isDblRegForSubInst(DstReg, HRI) &&
        ((MI.getOperand(1).isImm() && isUInt<2>(MI.getOperand(1).getImm())) ||
        (MI.getOperand(1).isGlobal() &&
        isUInt<2>(MI.getOperand(1).getOffset()))) &&
        ((MI.getOperand(2).isImm() && isUInt<2>(MI.getOperand(2).getImm())) ||
        (MI.getOperand(2).isGlobal() &&
        isUInt<2>(MI.getOperand(2).getOffset()))))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A4_combineri:
    // Rdd = combine(Rs,#0)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isDblRegForSubInst(DstReg, HRI) && isIntRegForSubInst(SrcReg) &&
        ((MI.getOperand(2).isImm() && MI.getOperand(2).getImm() == 0) ||
        (MI.getOperand(2).isGlobal() && MI.getOperand(2).getOffset() == 0)))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A4_combineir:
    // Rdd = combine(#0,Rs)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(2).getReg();
    if (isDblRegForSubInst(DstReg, HRI) && isIntRegForSubInst(SrcReg) &&
        ((MI.getOperand(1).isImm() && MI.getOperand(1).getImm() == 0) ||
        (MI.getOperand(1).isGlobal() && MI.getOperand(1).getOffset() == 0)))
      return HexagonII::HSIG_A;
    break;
  case Hexagon::A2_sxtb:
  case Hexagon::A2_sxth:
  case Hexagon::A2_zxtb:
  case Hexagon::A2_zxth:
    // Rd = sxth/sxtb/zxtb/zxth(Rs)
    DstReg = MI.getOperand(0).getReg();
    SrcReg = MI.getOperand(1).getReg();
    if (isIntRegForSubInst(DstReg) && isIntRegForSubInst(SrcReg))
      return HexagonII::HSIG_A;
    break;
  }

  return HexagonII::HSIG_None;
}

short HexagonInstrInfo::getEquivalentHWInstr(const MachineInstr &MI) const {
  return Hexagon::getRealHWInstr(MI.getOpcode(), Hexagon::InstrType_Real);
}

unsigned HexagonInstrInfo::getInstrTimingClassLatency(
      const InstrItineraryData *ItinData, const MachineInstr &MI) const {
  // Default to one cycle for no itinerary. However, an "empty" itinerary may
  // still have a MinLatency property, which getStageLatency checks.
  if (!ItinData)
    return getInstrLatency(ItinData, MI);

  if (MI.isTransient())
    return 0;
  return ItinData->getStageLatency(MI.getDesc().getSchedClass());
}

/// getOperandLatency - Compute and return the use operand latency of a given
/// pair of def and use.
/// In most cases, the static scheduling itinerary was enough to determine the
/// operand latency. But it may not be possible for instructions with variable
/// number of defs / uses.
///
/// This is a raw interface to the itinerary that may be directly overriden by
/// a target. Use computeOperandLatency to get the best estimate of latency.
int HexagonInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
                                        const MachineInstr &DefMI,
                                        unsigned DefIdx,
                                        const MachineInstr &UseMI,
                                        unsigned UseIdx) const {
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();

  // Get DefIdx and UseIdx for super registers.
  const MachineOperand &DefMO = DefMI.getOperand(DefIdx);

  if (DefMO.isReg() && HRI.isPhysicalRegister(DefMO.getReg())) {
    if (DefMO.isImplicit()) {
      for (MCSuperRegIterator SR(DefMO.getReg(), &HRI); SR.isValid(); ++SR) {
        int Idx = DefMI.findRegisterDefOperandIdx(*SR, false, false, &HRI);
        if (Idx != -1) {
          DefIdx = Idx;
          break;
        }
      }
    }

    const MachineOperand &UseMO = UseMI.getOperand(UseIdx);
    if (UseMO.isImplicit()) {
      for (MCSuperRegIterator SR(UseMO.getReg(), &HRI); SR.isValid(); ++SR) {
        int Idx = UseMI.findRegisterUseOperandIdx(*SR, false, &HRI);
        if (Idx != -1) {
          UseIdx = Idx;
          break;
        }
      }
    }
  }

  int Latency = TargetInstrInfo::getOperandLatency(ItinData, DefMI, DefIdx,
                                                   UseMI, UseIdx);
  if (!Latency)
    // We should never have 0 cycle latency between two instructions unless
    // they can be packetized together. However, this decision can't be made
    // here.
    Latency = 1;
  return Latency;
}

// inverts the predication logic.
// p -> NotP
// NotP -> P
bool HexagonInstrInfo::getInvertedPredSense(
      SmallVectorImpl<MachineOperand> &Cond) const {
  if (Cond.empty())
    return false;
  unsigned Opc = getInvertedPredicatedOpcode(Cond[0].getImm());
  Cond[0].setImm(Opc);
  return true;
}

unsigned HexagonInstrInfo::getInvertedPredicatedOpcode(const int Opc) const {
  int InvPredOpcode;
  InvPredOpcode = isPredicatedTrue(Opc) ? Hexagon::getFalsePredOpcode(Opc)
                                        : Hexagon::getTruePredOpcode(Opc);
  if (InvPredOpcode >= 0) // Valid instruction with the inverted predicate.
    return InvPredOpcode;

  llvm_unreachable("Unexpected predicated instruction");
}

// Returns the max value that doesn't need to be extended.
int HexagonInstrInfo::getMaxValue(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  unsigned isSigned = (F >> HexagonII::ExtentSignedPos)
                    & HexagonII::ExtentSignedMask;
  unsigned bits =  (F >> HexagonII::ExtentBitsPos)
                    & HexagonII::ExtentBitsMask;

  if (isSigned) // if value is signed
    return ~(-1U << (bits - 1));
  else
    return ~(-1U << bits);
}


bool HexagonInstrInfo::isAddrModeWithOffset(const MachineInstr &MI) const {
  switch (MI.getOpcode()) {
  case Hexagon::L2_loadrbgp:
  case Hexagon::L2_loadrdgp:
  case Hexagon::L2_loadrhgp:
  case Hexagon::L2_loadrigp:
  case Hexagon::L2_loadrubgp:
  case Hexagon::L2_loadruhgp:
  case Hexagon::S2_storerbgp:
  case Hexagon::S2_storerbnewgp:
  case Hexagon::S2_storerhgp:
  case Hexagon::S2_storerhnewgp:
  case Hexagon::S2_storerigp:
  case Hexagon::S2_storerinewgp:
  case Hexagon::S2_storerdgp:
  case Hexagon::S2_storerfgp:
    return true;
  }
  const uint64_t F = MI.getDesc().TSFlags;
  unsigned addrMode =
    ((F >> HexagonII::AddrModePos) & HexagonII::AddrModeMask);
  // Disallow any base+offset instruction. The assembler does not yet reorder
  // based up any zero offset instruction.
  return (addrMode == HexagonII::BaseRegOffset ||
          addrMode == HexagonII::BaseImmOffset ||
          addrMode == HexagonII::BaseLongOffset);
}

unsigned HexagonInstrInfo::getMemAccessSize(const MachineInstr &MI) const {
  using namespace HexagonII;

  const uint64_t F = MI.getDesc().TSFlags;
  unsigned S = (F >> MemAccessSizePos) & MemAccesSizeMask;
  unsigned Size = getMemAccessSizeInBytes(MemAccessSize(S));
  if (Size != 0)
    return Size;

  // Handle vector access sizes.
  const HexagonRegisterInfo &HRI = *Subtarget.getRegisterInfo();
  switch (S) {
    case HexagonII::HVXVectorAccess:
      return HRI.getSpillSize(Hexagon::HvxVRRegClass);
    default:
      llvm_unreachable("Unexpected instruction");
  }
}

// Returns the min value that doesn't need to be extended.
int HexagonInstrInfo::getMinValue(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  unsigned isSigned = (F >> HexagonII::ExtentSignedPos)
                    & HexagonII::ExtentSignedMask;
  unsigned bits =  (F >> HexagonII::ExtentBitsPos)
                    & HexagonII::ExtentBitsMask;

  if (isSigned) // if value is signed
    return -1U << (bits - 1);
  else
    return 0;
}

// Returns opcode of the non-extended equivalent instruction.
short HexagonInstrInfo::getNonExtOpcode(const MachineInstr &MI) const {
  // Check if the instruction has a register form that uses register in place
  // of the extended operand, if so return that as the non-extended form.
  short NonExtOpcode = Hexagon::getRegForm(MI.getOpcode());
    if (NonExtOpcode >= 0)
      return NonExtOpcode;

  if (MI.getDesc().mayLoad() || MI.getDesc().mayStore()) {
    // Check addressing mode and retrieve non-ext equivalent instruction.
    switch (getAddrMode(MI)) {
    case HexagonII::Absolute:
      return Hexagon::changeAddrMode_abs_io(MI.getOpcode());
    case HexagonII::BaseImmOffset:
      return Hexagon::changeAddrMode_io_rr(MI.getOpcode());
    case HexagonII::BaseLongOffset:
      return Hexagon::changeAddrMode_ur_rr(MI.getOpcode());

    default:
      return -1;
    }
  }
  return -1;
}

bool HexagonInstrInfo::getPredReg(ArrayRef<MachineOperand> Cond,
      unsigned &PredReg, unsigned &PredRegPos, unsigned &PredRegFlags) const {
  if (Cond.empty())
    return false;
  assert(Cond.size() == 2);
  if (isNewValueJump(Cond[0].getImm()) || Cond[1].isMBB()) {
    LLVM_DEBUG(dbgs() << "No predregs for new-value jumps/endloop");
    return false;
  }
  PredReg = Cond[1].getReg();
  PredRegPos = 1;
  // See IfConversion.cpp why we add RegState::Implicit | RegState::Undef
  PredRegFlags = 0;
  if (Cond[1].isImplicit())
    PredRegFlags = RegState::Implicit;
  if (Cond[1].isUndef())
    PredRegFlags |= RegState::Undef;
  return true;
}

short HexagonInstrInfo::getPseudoInstrPair(const MachineInstr &MI) const {
  return Hexagon::getRealHWInstr(MI.getOpcode(), Hexagon::InstrType_Pseudo);
}

short HexagonInstrInfo::getRegForm(const MachineInstr &MI) const {
  return Hexagon::getRegForm(MI.getOpcode());
}

// Return the number of bytes required to encode the instruction.
// Hexagon instructions are fixed length, 4 bytes, unless they
// use a constant extender, which requires another 4 bytes.
// For debug instructions and prolog labels, return 0.
unsigned HexagonInstrInfo::getSize(const MachineInstr &MI) const {
  if (MI.isDebugInstr() || MI.isPosition())
    return 0;

  unsigned Size = MI.getDesc().getSize();
  if (!Size)
    // Assume the default insn size in case it cannot be determined
    // for whatever reason.
    Size = HEXAGON_INSTR_SIZE;

  if (isConstExtended(MI) || isExtended(MI))
    Size += HEXAGON_INSTR_SIZE;

  // Try and compute number of instructions in asm.
  if (BranchRelaxAsmLarge && MI.getOpcode() == Hexagon::INLINEASM) {
    const MachineBasicBlock &MBB = *MI.getParent();
    const MachineFunction *MF = MBB.getParent();
    const MCAsmInfo *MAI = MF->getTarget().getMCAsmInfo();

    // Count the number of register definitions to find the asm string.
    unsigned NumDefs = 0;
    for (; MI.getOperand(NumDefs).isReg() && MI.getOperand(NumDefs).isDef();
         ++NumDefs)
      assert(NumDefs != MI.getNumOperands()-2 && "No asm string?");

    assert(MI.getOperand(NumDefs).isSymbol() && "No asm string?");
    // Disassemble the AsmStr and approximate number of instructions.
    const char *AsmStr = MI.getOperand(NumDefs).getSymbolName();
    Size = getInlineAsmLength(AsmStr, *MAI);
  }

  return Size;
}

uint64_t HexagonInstrInfo::getType(const MachineInstr &MI) const {
  const uint64_t F = MI.getDesc().TSFlags;
  return (F >> HexagonII::TypePos) & HexagonII::TypeMask;
}

unsigned HexagonInstrInfo::getUnits(const MachineInstr &MI) const {
  const InstrItineraryData &II = *Subtarget.getInstrItineraryData();
  const InstrStage &IS = *II.beginStage(MI.getDesc().getSchedClass());

  return IS.getUnits();
}

// Calculate size of the basic block without debug instructions.
unsigned HexagonInstrInfo::nonDbgBBSize(const MachineBasicBlock *BB) const {
  return nonDbgMICount(BB->instr_begin(), BB->instr_end());
}

unsigned HexagonInstrInfo::nonDbgBundleSize(
      MachineBasicBlock::const_iterator BundleHead) const {
  assert(BundleHead->isBundle() && "Not a bundle header");
  auto MII = BundleHead.getInstrIterator();
  // Skip the bundle header.
  return nonDbgMICount(++MII, getBundleEnd(BundleHead.getInstrIterator()));
}

/// immediateExtend - Changes the instruction in place to one using an immediate
/// extender.
void HexagonInstrInfo::immediateExtend(MachineInstr &MI) const {
  assert((isExtendable(MI)||isConstExtended(MI)) &&
                               "Instruction must be extendable");
  // Find which operand is extendable.
  short ExtOpNum = getCExtOpNum(MI);
  MachineOperand &MO = MI.getOperand(ExtOpNum);
  // This needs to be something we understand.
  assert((MO.isMBB() || MO.isImm()) &&
         "Branch with unknown extendable field type");
  // Mark given operand as extended.
  MO.addTargetFlag(HexagonII::HMOTF_ConstExtended);
}

bool HexagonInstrInfo::invertAndChangeJumpTarget(
      MachineInstr &MI, MachineBasicBlock *NewTarget) const {
  LLVM_DEBUG(dbgs() << "\n[invertAndChangeJumpTarget] to "
                    << printMBBReference(*NewTarget);
             MI.dump(););
  assert(MI.isBranch());
  unsigned NewOpcode = getInvertedPredicatedOpcode(MI.getOpcode());
  int TargetPos = MI.getNumOperands() - 1;
  // In general branch target is the last operand,
  // but some implicit defs added at the end might change it.
  while ((TargetPos > -1) && !MI.getOperand(TargetPos).isMBB())
    --TargetPos;
  assert((TargetPos >= 0) && MI.getOperand(TargetPos).isMBB());
  MI.getOperand(TargetPos).setMBB(NewTarget);
  if (EnableBranchPrediction && isPredicatedNew(MI)) {
    NewOpcode = reversePrediction(NewOpcode);
  }
  MI.setDesc(get(NewOpcode));
  return true;
}

void HexagonInstrInfo::genAllInsnTimingClasses(MachineFunction &MF) const {
  /* +++ The code below is used to generate complete set of Hexagon Insn +++ */
  MachineFunction::iterator A = MF.begin();
  MachineBasicBlock &B = *A;
  MachineBasicBlock::iterator I = B.begin();
  DebugLoc DL = I->getDebugLoc();
  MachineInstr *NewMI;

  for (unsigned insn = TargetOpcode::GENERIC_OP_END+1;
       insn < Hexagon::INSTRUCTION_LIST_END; ++insn) {
    NewMI = BuildMI(B, I, DL, get(insn));
    LLVM_DEBUG(dbgs() << "\n"
                      << getName(NewMI->getOpcode())
                      << "  Class: " << NewMI->getDesc().getSchedClass());
    NewMI->eraseFromParent();
  }
  /* --- The code above is used to generate complete set of Hexagon Insn --- */
}

// inverts the predication logic.
// p -> NotP
// NotP -> P
bool HexagonInstrInfo::reversePredSense(MachineInstr &MI) const {
  LLVM_DEBUG(dbgs() << "\nTrying to reverse pred. sense of:"; MI.dump());
  MI.setDesc(get(getInvertedPredicatedOpcode(MI.getOpcode())));
  return true;
}

// Reverse the branch prediction.
unsigned HexagonInstrInfo::reversePrediction(unsigned Opcode) const {
  int PredRevOpcode = -1;
  if (isPredictedTaken(Opcode))
    PredRevOpcode = Hexagon::notTakenBranchPrediction(Opcode);
  else
    PredRevOpcode = Hexagon::takenBranchPrediction(Opcode);
  assert(PredRevOpcode > 0);
  return PredRevOpcode;
}

// TODO: Add more rigorous validation.
bool HexagonInstrInfo::validateBranchCond(const ArrayRef<MachineOperand> &Cond)
      const {
  return Cond.empty() || (Cond[0].isImm() && (Cond.size() != 1));
}

void HexagonInstrInfo::
setBundleNoShuf(MachineBasicBlock::instr_iterator MIB) const {
  assert(MIB->isBundle());
  MachineOperand &Operand = MIB->getOperand(0);
  if (Operand.isImm())
    Operand.setImm(Operand.getImm() | memShufDisabledMask);
  else
    MIB->addOperand(MachineOperand::CreateImm(memShufDisabledMask));
}

bool HexagonInstrInfo::getBundleNoShuf(const MachineInstr &MIB) const {
  assert(MIB.isBundle());
  const MachineOperand &Operand = MIB.getOperand(0);
  return (Operand.isImm() && (Operand.getImm() & memShufDisabledMask) != 0);
}

// Addressing mode relations.
short HexagonInstrInfo::changeAddrMode_abs_io(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_abs_io(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_io_abs(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_io_abs(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_io_pi(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_io_pi(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_io_rr(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_io_rr(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_pi_io(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_pi_io(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_rr_io(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_rr_io(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_rr_ur(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_rr_ur(Opc) : Opc;
}

short HexagonInstrInfo::changeAddrMode_ur_rr(short Opc) const {
  return Opc >= 0 ? Hexagon::changeAddrMode_ur_rr(Opc) : Opc;
}