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      1 //===----- HexagonNewValueJump.cpp - Hexagon Backend New Value Jump -------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This implements NewValueJump pass in Hexagon.
     11 // Ideally, we should merge this as a Peephole pass prior to register
     12 // allocation, but because we have a spill in between the feeder and new value
     13 // jump instructions, we are forced to write after register allocation.
     14 // Having said that, we should re-attempt to pull this earlier at some point
     15 // in future.
     16 
     17 // The basic approach looks for sequence of predicated jump, compare instruciton
     18 // that genereates the predicate and, the feeder to the predicate. Once it finds
     19 // all, it collapses compare and jump instruction into a new valu jump
     20 // intstructions.
     21 //
     22 //
     23 //===----------------------------------------------------------------------===//
     24 #define DEBUG_TYPE "hexagon-nvj"
     25 #include "Hexagon.h"
     26 #include "HexagonInstrInfo.h"
     27 #include "HexagonMachineFunctionInfo.h"
     28 #include "HexagonRegisterInfo.h"
     29 #include "HexagonSubtarget.h"
     30 #include "HexagonTargetMachine.h"
     31 #include "llvm/ADT/DenseMap.h"
     32 #include "llvm/ADT/Statistic.h"
     33 #include "llvm/CodeGen/LiveVariables.h"
     34 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
     35 #include "llvm/CodeGen/MachineFunctionPass.h"
     36 #include "llvm/CodeGen/MachineInstrBuilder.h"
     37 #include "llvm/CodeGen/MachineRegisterInfo.h"
     38 #include "llvm/CodeGen/Passes.h"
     39 #include "llvm/CodeGen/ScheduleDAGInstrs.h"
     40 #include "llvm/PassSupport.h"
     41 #include "llvm/Support/CommandLine.h"
     42 #include "llvm/Support/Compiler.h"
     43 #include "llvm/Support/Debug.h"
     44 #include "llvm/Target/TargetInstrInfo.h"
     45 #include "llvm/Target/TargetMachine.h"
     46 #include "llvm/Target/TargetRegisterInfo.h"
     47 #include <map>
     48 using namespace llvm;
     49 
     50 STATISTIC(NumNVJGenerated, "Number of New Value Jump Instructions created");
     51 
     52 static cl::opt<int>
     53 DbgNVJCount("nvj-count", cl::init(-1), cl::Hidden, cl::desc(
     54   "Maximum number of predicated jumps to be converted to New Value Jump"));
     55 
     56 static cl::opt<bool> DisableNewValueJumps("disable-nvjump", cl::Hidden,
     57     cl::ZeroOrMore, cl::init(false),
     58     cl::desc("Disable New Value Jumps"));
     59 
     60 namespace {
     61   struct HexagonNewValueJump : public MachineFunctionPass {
     62     const HexagonInstrInfo    *QII;
     63     const HexagonRegisterInfo *QRI;
     64 
     65   public:
     66     static char ID;
     67 
     68     HexagonNewValueJump() : MachineFunctionPass(ID) { }
     69 
     70     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
     71       MachineFunctionPass::getAnalysisUsage(AU);
     72     }
     73 
     74     const char *getPassName() const {
     75       return "Hexagon NewValueJump";
     76     }
     77 
     78     virtual bool runOnMachineFunction(MachineFunction &Fn);
     79 
     80   private:
     81 
     82   };
     83 
     84 } // end of anonymous namespace
     85 
     86 char HexagonNewValueJump::ID = 0;
     87 
     88 // We have identified this II could be feeder to NVJ,
     89 // verify that it can be.
     90 static bool canBeFeederToNewValueJump(const HexagonInstrInfo *QII,
     91                                       const TargetRegisterInfo *TRI,
     92                                       MachineBasicBlock::iterator II,
     93                                       MachineBasicBlock::iterator end,
     94                                       MachineBasicBlock::iterator skip,
     95                                       MachineFunction &MF) {
     96 
     97   // Predicated instruction can not be feeder to NVJ.
     98   if (QII->isPredicated(II))
     99     return false;
    100 
    101   // Bail out if feederReg is a paired register (double regs in
    102   // our case). One would think that we can check to see if a given
    103   // register cmpReg1 or cmpReg2 is a sub register of feederReg
    104   // using -- if (QRI->isSubRegister(feederReg, cmpReg1) logic
    105   // before the callsite of this function
    106   // But we can not as it comes in the following fashion.
    107   //    %D0<def> = Hexagon_S2_lsr_r_p %D0<kill>, %R2<kill>
    108   //    %R0<def> = KILL %R0, %D0<imp-use,kill>
    109   //    %P0<def> = CMPEQri %R0<kill>, 0
    110   // Hence, we need to check if it's a KILL instruction.
    111   if (II->getOpcode() == TargetOpcode::KILL)
    112     return false;
    113 
    114 
    115   // Make sure there there is no 'def' or 'use' of any of the uses of
    116   // feeder insn between it's definition, this MI and jump, jmpInst
    117   // skipping compare, cmpInst.
    118   // Here's the example.
    119   //    r21=memub(r22+r24<<#0)
    120   //    p0 = cmp.eq(r21, #0)
    121   //    r4=memub(r3+r21<<#0)
    122   //    if (p0.new) jump:t .LBB29_45
    123   // Without this check, it will be converted into
    124   //    r4=memub(r3+r21<<#0)
    125   //    r21=memub(r22+r24<<#0)
    126   //    p0 = cmp.eq(r21, #0)
    127   //    if (p0.new) jump:t .LBB29_45
    128   // and result WAR hazards if converted to New Value Jump.
    129 
    130   for (unsigned i = 0; i < II->getNumOperands(); ++i) {
    131     if (II->getOperand(i).isReg() &&
    132         (II->getOperand(i).isUse() || II->getOperand(i).isDef())) {
    133       MachineBasicBlock::iterator localII = II;
    134       ++localII;
    135       unsigned Reg = II->getOperand(i).getReg();
    136       for (MachineBasicBlock::iterator localBegin = localII;
    137                         localBegin != end; ++localBegin) {
    138         if (localBegin == skip ) continue;
    139         // Check for Subregisters too.
    140         if (localBegin->modifiesRegister(Reg, TRI) ||
    141             localBegin->readsRegister(Reg, TRI))
    142           return false;
    143       }
    144     }
    145   }
    146   return true;
    147 }
    148 
    149 // These are the common checks that need to performed
    150 // to determine if
    151 // 1. compare instruction can be moved before jump.
    152 // 2. feeder to the compare instruction can be moved before jump.
    153 static bool commonChecksToProhibitNewValueJump(bool afterRA,
    154                           MachineBasicBlock::iterator MII) {
    155 
    156   // If store in path, bail out.
    157   if (MII->getDesc().mayStore())
    158     return false;
    159 
    160   // if call in path, bail out.
    161   if (MII->getOpcode() == Hexagon::CALLv3)
    162     return false;
    163 
    164   // if NVJ is running prior to RA, do the following checks.
    165   if (!afterRA) {
    166     // The following Target Opcode instructions are spurious
    167     // to new value jump. If they are in the path, bail out.
    168     // KILL sets kill flag on the opcode. It also sets up a
    169     // single register, out of pair.
    170     //    %D0<def> = Hexagon_S2_lsr_r_p %D0<kill>, %R2<kill>
    171     //    %R0<def> = KILL %R0, %D0<imp-use,kill>
    172     //    %P0<def> = CMPEQri %R0<kill>, 0
    173     // PHI can be anything after RA.
    174     // COPY can remateriaze things in between feeder, compare and nvj.
    175     if (MII->getOpcode() == TargetOpcode::KILL ||
    176         MII->getOpcode() == TargetOpcode::PHI  ||
    177         MII->getOpcode() == TargetOpcode::COPY)
    178       return false;
    179 
    180     // The following pseudo Hexagon instructions sets "use" and "def"
    181     // of registers by individual passes in the backend. At this time,
    182     // we don't know the scope of usage and definitions of these
    183     // instructions.
    184     if (MII->getOpcode() == Hexagon::TFR_condset_rr ||
    185         MII->getOpcode() == Hexagon::TFR_condset_ii ||
    186         MII->getOpcode() == Hexagon::TFR_condset_ri ||
    187         MII->getOpcode() == Hexagon::TFR_condset_ir ||
    188         MII->getOpcode() == Hexagon::LDriw_pred     ||
    189         MII->getOpcode() == Hexagon::STriw_pred)
    190       return false;
    191   }
    192 
    193   return true;
    194 }
    195 
    196 static bool canCompareBeNewValueJump(const HexagonInstrInfo *QII,
    197                                      const TargetRegisterInfo *TRI,
    198                                      MachineBasicBlock::iterator II,
    199                                      unsigned pReg,
    200                                      bool secondReg,
    201                                      bool optLocation,
    202                                      MachineBasicBlock::iterator end,
    203                                      MachineFunction &MF) {
    204 
    205   MachineInstr *MI = II;
    206 
    207   // If the second operand of the compare is an imm, make sure it's in the
    208   // range specified by the arch.
    209   if (!secondReg) {
    210     int64_t v = MI->getOperand(2).getImm();
    211     if (MI->getOpcode() == Hexagon::CMPGEri ||
    212        (MI->getOpcode() == Hexagon::CMPGEUri && v > 0))
    213       --v;
    214 
    215     if (!(isUInt<5>(v) ||
    216          ((MI->getOpcode() == Hexagon::CMPEQri ||
    217            MI->getOpcode() == Hexagon::CMPGTri ||
    218            MI->getOpcode() == Hexagon::CMPGEri) &&
    219           (v == -1))))
    220       return false;
    221   }
    222 
    223   unsigned cmpReg1, cmpOp2 = 0; // cmpOp2 assignment silences compiler warning.
    224   cmpReg1 = MI->getOperand(1).getReg();
    225 
    226   if (secondReg) {
    227     cmpOp2 = MI->getOperand(2).getReg();
    228 
    229     // Make sure that that second register is not from COPY
    230     // At machine code level, we don't need this, but if we decide
    231     // to move new value jump prior to RA, we would be needing this.
    232     MachineRegisterInfo &MRI = MF.getRegInfo();
    233     if (secondReg && !TargetRegisterInfo::isPhysicalRegister(cmpOp2)) {
    234       MachineInstr *def = MRI.getVRegDef(cmpOp2);
    235       if (def->getOpcode() == TargetOpcode::COPY)
    236         return false;
    237     }
    238   }
    239 
    240   // Walk the instructions after the compare (predicate def) to the jump,
    241   // and satisfy the following conditions.
    242   ++II ;
    243   for (MachineBasicBlock::iterator localII = II; localII != end;
    244        ++localII) {
    245 
    246     // Check 1.
    247     // If "common" checks fail, bail out.
    248     if (!commonChecksToProhibitNewValueJump(optLocation, localII))
    249       return false;
    250 
    251     // Check 2.
    252     // If there is a def or use of predicate (result of compare), bail out.
    253     if (localII->modifiesRegister(pReg, TRI) ||
    254         localII->readsRegister(pReg, TRI))
    255       return false;
    256 
    257     // Check 3.
    258     // If there is a def of any of the use of the compare (operands of compare),
    259     // bail out.
    260     // Eg.
    261     //    p0 = cmp.eq(r2, r0)
    262     //    r2 = r4
    263     //    if (p0.new) jump:t .LBB28_3
    264     if (localII->modifiesRegister(cmpReg1, TRI) ||
    265         (secondReg && localII->modifiesRegister(cmpOp2, TRI)))
    266       return false;
    267   }
    268   return true;
    269 }
    270 
    271 // Given a compare operator, return a matching New Value Jump
    272 // compare operator. Make sure that MI here is included in
    273 // HexagonInstrInfo.cpp::isNewValueJumpCandidate
    274 static unsigned getNewValueJumpOpcode(const MachineInstr *MI, int reg,
    275                                       bool secondRegNewified) {
    276   switch (MI->getOpcode()) {
    277     case Hexagon::CMPEQrr:
    278       return Hexagon::JMP_EQrrPt_nv_V4;
    279 
    280     case Hexagon::CMPEQri: {
    281       if (reg >= 0)
    282         return Hexagon::JMP_EQriPt_nv_V4;
    283       else
    284         return Hexagon::JMP_EQriPtneg_nv_V4;
    285     }
    286 
    287     case Hexagon::CMPLTrr:
    288     case Hexagon::CMPGTrr: {
    289       if (secondRegNewified)
    290         return Hexagon::JMP_GTrrdnPt_nv_V4;
    291       else
    292         return Hexagon::JMP_GTrrPt_nv_V4;
    293     }
    294 
    295     case Hexagon::CMPGEri: {
    296       if (reg >= 1)
    297         return Hexagon::JMP_GTriPt_nv_V4;
    298       else
    299         return Hexagon::JMP_GTriPtneg_nv_V4;
    300     }
    301 
    302     case Hexagon::CMPGTri: {
    303       if (reg >= 0)
    304         return Hexagon::JMP_GTriPt_nv_V4;
    305       else
    306         return Hexagon::JMP_GTriPtneg_nv_V4;
    307     }
    308 
    309     case Hexagon::CMPLTUrr:
    310     case Hexagon::CMPGTUrr: {
    311       if (secondRegNewified)
    312         return Hexagon::JMP_GTUrrdnPt_nv_V4;
    313       else
    314         return Hexagon::JMP_GTUrrPt_nv_V4;
    315     }
    316 
    317     case Hexagon::CMPGTUri:
    318       return Hexagon::JMP_GTUriPt_nv_V4;
    319 
    320     case Hexagon::CMPGEUri: {
    321       if (reg == 0)
    322         return Hexagon::JMP_EQrrPt_nv_V4;
    323       else
    324         return Hexagon::JMP_GTUriPt_nv_V4;
    325     }
    326 
    327     default:
    328        llvm_unreachable("Could not find matching New Value Jump instruction.");
    329   }
    330   // return *some value* to avoid compiler warning
    331   return 0;
    332 }
    333 
    334 bool HexagonNewValueJump::runOnMachineFunction(MachineFunction &MF) {
    335 
    336   DEBUG(dbgs() << "********** Hexagon New Value Jump **********\n"
    337                << "********** Function: "
    338                << MF.getName() << "\n");
    339 
    340 #if 0
    341   // for now disable this, if we move NewValueJump before register
    342   // allocation we need this information.
    343   LiveVariables &LVs = getAnalysis<LiveVariables>();
    344 #endif
    345 
    346   QII = static_cast<const HexagonInstrInfo *>(MF.getTarget().getInstrInfo());
    347   QRI =
    348     static_cast<const HexagonRegisterInfo *>(MF.getTarget().getRegisterInfo());
    349 
    350   if (!QRI->Subtarget.hasV4TOps() ||
    351       DisableNewValueJumps) {
    352     return false;
    353   }
    354 
    355   int nvjCount = DbgNVJCount;
    356   int nvjGenerated = 0;
    357 
    358   // Loop through all the bb's of the function
    359   for (MachineFunction::iterator MBBb = MF.begin(), MBBe = MF.end();
    360         MBBb != MBBe; ++MBBb) {
    361     MachineBasicBlock* MBB = MBBb;
    362 
    363     DEBUG(dbgs() << "** dumping bb ** "
    364                  << MBB->getNumber() << "\n");
    365     DEBUG(MBB->dump());
    366     DEBUG(dbgs() << "\n" << "********** dumping instr bottom up **********\n");
    367     bool foundJump    = false;
    368     bool foundCompare = false;
    369     bool invertPredicate = false;
    370     unsigned predReg = 0; // predicate reg of the jump.
    371     unsigned cmpReg1 = 0;
    372     int cmpOp2 = 0;
    373     bool MO1IsKill = false;
    374     bool MO2IsKill = false;
    375     MachineBasicBlock::iterator jmpPos;
    376     MachineBasicBlock::iterator cmpPos;
    377     MachineInstr *cmpInstr = NULL, *jmpInstr = NULL;
    378     MachineBasicBlock *jmpTarget = NULL;
    379     bool afterRA = false;
    380     bool isSecondOpReg = false;
    381     bool isSecondOpNewified = false;
    382     // Traverse the basic block - bottom up
    383     for (MachineBasicBlock::iterator MII = MBB->end(), E = MBB->begin();
    384              MII != E;) {
    385       MachineInstr *MI = --MII;
    386       if (MI->isDebugValue()) {
    387         continue;
    388       }
    389 
    390       if ((nvjCount == 0) || (nvjCount > -1 && nvjCount <= nvjGenerated))
    391         break;
    392 
    393       DEBUG(dbgs() << "Instr: "; MI->dump(); dbgs() << "\n");
    394 
    395       if (!foundJump &&
    396          (MI->getOpcode() == Hexagon::JMP_c ||
    397           MI->getOpcode() == Hexagon::JMP_cNot ||
    398           MI->getOpcode() == Hexagon::JMP_cdnPt ||
    399           MI->getOpcode() == Hexagon::JMP_cdnPnt ||
    400           MI->getOpcode() == Hexagon::JMP_cdnNotPt ||
    401           MI->getOpcode() == Hexagon::JMP_cdnNotPnt)) {
    402         // This is where you would insert your compare and
    403         // instr that feeds compare
    404         jmpPos = MII;
    405         jmpInstr = MI;
    406         predReg = MI->getOperand(0).getReg();
    407         afterRA = TargetRegisterInfo::isPhysicalRegister(predReg);
    408 
    409         // If ifconverter had not messed up with the kill flags of the
    410         // operands, the following check on the kill flag would suffice.
    411         // if(!jmpInstr->getOperand(0).isKill()) break;
    412 
    413         // This predicate register is live out out of BB
    414         // this would only work if we can actually use Live
    415         // variable analysis on phy regs - but LLVM does not
    416         // provide LV analysis on phys regs.
    417         //if(LVs.isLiveOut(predReg, *MBB)) break;
    418 
    419         // Get all the successors of this block - which will always
    420         // be 2. Check if the predicate register is live in in those
    421         // successor. If yes, we can not delete the predicate -
    422         // I am doing this only because LLVM does not provide LiveOut
    423         // at the BB level.
    424         bool predLive = false;
    425         for (MachineBasicBlock::const_succ_iterator SI = MBB->succ_begin(),
    426                             SIE = MBB->succ_end(); SI != SIE; ++SI) {
    427           MachineBasicBlock* succMBB = *SI;
    428          if (succMBB->isLiveIn(predReg)) {
    429             predLive = true;
    430           }
    431         }
    432         if (predLive)
    433           break;
    434 
    435         jmpTarget = MI->getOperand(1).getMBB();
    436         foundJump = true;
    437         if (MI->getOpcode() == Hexagon::JMP_cNot ||
    438             MI->getOpcode() == Hexagon::JMP_cdnNotPt ||
    439             MI->getOpcode() == Hexagon::JMP_cdnNotPnt) {
    440           invertPredicate = true;
    441         }
    442         continue;
    443       }
    444 
    445       // No new value jump if there is a barrier. A barrier has to be in its
    446       // own packet. A barrier has zero operands. We conservatively bail out
    447       // here if we see any instruction with zero operands.
    448       if (foundJump && MI->getNumOperands() == 0)
    449         break;
    450 
    451       if (foundJump &&
    452          !foundCompare &&
    453           MI->getOperand(0).isReg() &&
    454           MI->getOperand(0).getReg() == predReg) {
    455 
    456         // Not all compares can be new value compare. Arch Spec: 7.6.1.1
    457         if (QII->isNewValueJumpCandidate(MI)) {
    458 
    459           assert((MI->getDesc().isCompare()) &&
    460               "Only compare instruction can be collapsed into New Value Jump");
    461           isSecondOpReg = MI->getOperand(2).isReg();
    462 
    463           if (!canCompareBeNewValueJump(QII, QRI, MII, predReg, isSecondOpReg,
    464                                         afterRA, jmpPos, MF))
    465             break;
    466 
    467           cmpInstr = MI;
    468           cmpPos = MII;
    469           foundCompare = true;
    470 
    471           // We need cmpReg1 and cmpOp2(imm or reg) while building
    472           // new value jump instruction.
    473           cmpReg1 = MI->getOperand(1).getReg();
    474           if (MI->getOperand(1).isKill())
    475             MO1IsKill = true;
    476 
    477           if (isSecondOpReg) {
    478             cmpOp2 = MI->getOperand(2).getReg();
    479             if (MI->getOperand(2).isKill())
    480               MO2IsKill = true;
    481           } else
    482             cmpOp2 = MI->getOperand(2).getImm();
    483           continue;
    484         }
    485       }
    486 
    487       if (foundCompare && foundJump) {
    488 
    489         // If "common" checks fail, bail out on this BB.
    490         if (!commonChecksToProhibitNewValueJump(afterRA, MII))
    491           break;
    492 
    493         bool foundFeeder = false;
    494         MachineBasicBlock::iterator feederPos = MII;
    495         if (MI->getOperand(0).isReg() &&
    496             MI->getOperand(0).isDef() &&
    497            (MI->getOperand(0).getReg() == cmpReg1 ||
    498             (isSecondOpReg &&
    499              MI->getOperand(0).getReg() == (unsigned) cmpOp2))) {
    500 
    501           unsigned feederReg = MI->getOperand(0).getReg();
    502 
    503           // First try to see if we can get the feeder from the first operand
    504           // of the compare. If we can not, and if secondOpReg is true
    505           // (second operand of the compare is also register), try that one.
    506           // TODO: Try to come up with some heuristic to figure out which
    507           // feeder would benefit.
    508 
    509           if (feederReg == cmpReg1) {
    510             if (!canBeFeederToNewValueJump(QII, QRI, MII, jmpPos, cmpPos, MF)) {
    511               if (!isSecondOpReg)
    512                 break;
    513               else
    514                 continue;
    515             } else
    516               foundFeeder = true;
    517           }
    518 
    519           if (!foundFeeder &&
    520                isSecondOpReg &&
    521                feederReg == (unsigned) cmpOp2)
    522             if (!canBeFeederToNewValueJump(QII, QRI, MII, jmpPos, cmpPos, MF))
    523               break;
    524 
    525           if (isSecondOpReg) {
    526             // In case of CMPLT, or CMPLTU, or EQ with the second register
    527             // to newify, swap the operands.
    528             if (cmpInstr->getOpcode() == Hexagon::CMPLTrr  ||
    529                 cmpInstr->getOpcode() == Hexagon::CMPLTUrr ||
    530                 (cmpInstr->getOpcode() == Hexagon::CMPEQrr &&
    531                                      feederReg == (unsigned) cmpOp2)) {
    532               unsigned tmp = cmpReg1;
    533               bool tmpIsKill = MO1IsKill;
    534               cmpReg1 = cmpOp2;
    535               MO1IsKill = MO2IsKill;
    536               cmpOp2 = tmp;
    537               MO2IsKill = tmpIsKill;
    538             }
    539 
    540             // Now we have swapped the operands, all we need to check is,
    541             // if the second operand (after swap) is the feeder.
    542             // And if it is, make a note.
    543             if (feederReg == (unsigned)cmpOp2)
    544               isSecondOpNewified = true;
    545           }
    546 
    547           // Now that we are moving feeder close the jump,
    548           // make sure we are respecting the kill values of
    549           // the operands of the feeder.
    550 
    551           bool updatedIsKill = false;
    552           for (unsigned i = 0; i < MI->getNumOperands(); i++) {
    553             MachineOperand &MO = MI->getOperand(i);
    554             if (MO.isReg() && MO.isUse()) {
    555               unsigned feederReg = MO.getReg();
    556               for (MachineBasicBlock::iterator localII = feederPos,
    557                    end = jmpPos; localII != end; localII++) {
    558                 MachineInstr *localMI = localII;
    559                 for (unsigned j = 0; j < localMI->getNumOperands(); j++) {
    560                   MachineOperand &localMO = localMI->getOperand(j);
    561                   if (localMO.isReg() && localMO.isUse() &&
    562                       localMO.isKill() && feederReg == localMO.getReg()) {
    563                     // We found that there is kill of a use register
    564                     // Set up a kill flag on the register
    565                     localMO.setIsKill(false);
    566                     MO.setIsKill();
    567                     updatedIsKill = true;
    568                     break;
    569                   }
    570                 }
    571                 if (updatedIsKill) break;
    572               }
    573             }
    574             if (updatedIsKill) break;
    575           }
    576 
    577           MBB->splice(jmpPos, MI->getParent(), MI);
    578           MBB->splice(jmpPos, MI->getParent(), cmpInstr);
    579           DebugLoc dl = MI->getDebugLoc();
    580           MachineInstr *NewMI;
    581 
    582            assert((QII->isNewValueJumpCandidate(cmpInstr)) &&
    583                       "This compare is not a New Value Jump candidate.");
    584           unsigned opc = getNewValueJumpOpcode(cmpInstr, cmpOp2,
    585                                                isSecondOpNewified);
    586           if (invertPredicate)
    587             opc = QII->getInvertedPredicatedOpcode(opc);
    588 
    589           // Manage the conversions from CMPGEUri to either CMPEQrr
    590           // or CMPGTUri properly. See Arch spec for CMPGEUri instructions.
    591           // This has to be after the getNewValueJumpOpcode function call as
    592           // second operand of the compare could be modified in this logic.
    593           if (cmpInstr->getOpcode() == Hexagon::CMPGEUri) {
    594             if (cmpOp2 == 0) {
    595               cmpOp2 = cmpReg1;
    596               MO2IsKill = MO1IsKill;
    597               isSecondOpReg = true;
    598             } else
    599               --cmpOp2;
    600           }
    601 
    602           // Manage the conversions from CMPGEri to CMPGTUri properly.
    603           // See Arch spec for CMPGEri instructions.
    604           if (cmpInstr->getOpcode() == Hexagon::CMPGEri)
    605             --cmpOp2;
    606 
    607           if (isSecondOpReg) {
    608             NewMI = BuildMI(*MBB, jmpPos, dl,
    609                                   QII->get(opc))
    610                                     .addReg(cmpReg1, getKillRegState(MO1IsKill))
    611                                     .addReg(cmpOp2, getKillRegState(MO2IsKill))
    612                                     .addMBB(jmpTarget);
    613           }
    614           else {
    615             NewMI = BuildMI(*MBB, jmpPos, dl,
    616                                   QII->get(opc))
    617                                     .addReg(cmpReg1, getKillRegState(MO1IsKill))
    618                                     .addImm(cmpOp2)
    619                                     .addMBB(jmpTarget);
    620           }
    621 
    622           assert(NewMI && "New Value Jump Instruction Not created!");
    623           if (cmpInstr->getOperand(0).isReg() &&
    624               cmpInstr->getOperand(0).isKill())
    625             cmpInstr->getOperand(0).setIsKill(false);
    626           if (cmpInstr->getOperand(1).isReg() &&
    627               cmpInstr->getOperand(1).isKill())
    628             cmpInstr->getOperand(1).setIsKill(false);
    629           cmpInstr->eraseFromParent();
    630           jmpInstr->eraseFromParent();
    631           ++nvjGenerated;
    632           ++NumNVJGenerated;
    633           break;
    634         }
    635       }
    636     }
    637   }
    638 
    639   return true;
    640 
    641 }
    642 
    643 FunctionPass *llvm::createHexagonNewValueJump() {
    644   return new HexagonNewValueJump();
    645 }
    646