1 //===-- ARMBaseInstrInfo.cpp - ARM Instruction Information ----------------===//
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 file contains the Base ARM implementation of the TargetInstrInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ARM.h"
15 #include "ARMBaseInstrInfo.h"
16 #include "ARMBaseRegisterInfo.h"
17 #include "ARMConstantPoolValue.h"
18 #include "ARMFeatures.h"
19 #include "ARMHazardRecognizer.h"
20 #include "ARMMachineFunctionInfo.h"
21 #include "MCTargetDesc/ARMAddressingModes.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/CodeGen/LiveVariables.h"
24 #include "llvm/CodeGen/MachineConstantPool.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineJumpTableInfo.h"
28 #include "llvm/CodeGen/MachineMemOperand.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/CodeGen/SelectionDAGNodes.h"
31 #include "llvm/CodeGen/TargetSchedule.h"
32 #include "llvm/IR/Constants.h"
33 #include "llvm/IR/Function.h"
34 #include "llvm/IR/GlobalValue.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCExpr.h"
37 #include "llvm/Support/BranchProbability.h"
38 #include "llvm/Support/CommandLine.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/raw_ostream.h"
42 
43 using namespace llvm;
44 
45 #define DEBUG_TYPE "arm-instrinfo"
46 
47 #define GET_INSTRINFO_CTOR_DTOR
48 #include "ARMGenInstrInfo.inc"
49 
50 static cl::opt<bool>
51 EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden,
52                cl::desc("Enable ARM 2-addr to 3-addr conv"));
53 
54 /// ARM_MLxEntry - Record information about MLA / MLS instructions.
55 struct ARM_MLxEntry {
56   uint16_t MLxOpc;     // MLA / MLS opcode
57   uint16_t MulOpc;     // Expanded multiplication opcode
58   uint16_t AddSubOpc;  // Expanded add / sub opcode
59   bool NegAcc;         // True if the acc is negated before the add / sub.
60   bool HasLane;        // True if instruction has an extra "lane" operand.
61 };
62 
63 static const ARM_MLxEntry ARM_MLxTable[] = {
64   // MLxOpc,          MulOpc,           AddSubOpc,       NegAcc, HasLane
65   // fp scalar ops
66   { ARM::VMLAS,       ARM::VMULS,       ARM::VADDS,      false,  false },
67   { ARM::VMLSS,       ARM::VMULS,       ARM::VSUBS,      false,  false },
68   { ARM::VMLAD,       ARM::VMULD,       ARM::VADDD,      false,  false },
69   { ARM::VMLSD,       ARM::VMULD,       ARM::VSUBD,      false,  false },
70   { ARM::VNMLAS,      ARM::VNMULS,      ARM::VSUBS,      true,   false },
71   { ARM::VNMLSS,      ARM::VMULS,       ARM::VSUBS,      true,   false },
72   { ARM::VNMLAD,      ARM::VNMULD,      ARM::VSUBD,      true,   false },
73   { ARM::VNMLSD,      ARM::VMULD,       ARM::VSUBD,      true,   false },
74 
75   // fp SIMD ops
76   { ARM::VMLAfd,      ARM::VMULfd,      ARM::VADDfd,     false,  false },
77   { ARM::VMLSfd,      ARM::VMULfd,      ARM::VSUBfd,     false,  false },
78   { ARM::VMLAfq,      ARM::VMULfq,      ARM::VADDfq,     false,  false },
79   { ARM::VMLSfq,      ARM::VMULfq,      ARM::VSUBfq,     false,  false },
80   { ARM::VMLAslfd,    ARM::VMULslfd,    ARM::VADDfd,     false,  true  },
81   { ARM::VMLSslfd,    ARM::VMULslfd,    ARM::VSUBfd,     false,  true  },
82   { ARM::VMLAslfq,    ARM::VMULslfq,    ARM::VADDfq,     false,  true  },
83   { ARM::VMLSslfq,    ARM::VMULslfq,    ARM::VSUBfq,     false,  true  },
84 };
85 
86 ARMBaseInstrInfo::ARMBaseInstrInfo(const ARMSubtarget& STI)
87   : ARMGenInstrInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
88     Subtarget(STI) {
89   for (unsigned i = 0, e = array_lengthof(ARM_MLxTable); i != e; ++i) {
90     if (!MLxEntryMap.insert(std::make_pair(ARM_MLxTable[i].MLxOpc, i)).second)
91       llvm_unreachable("Duplicated entries?");
92     MLxHazardOpcodes.insert(ARM_MLxTable[i].AddSubOpc);
93     MLxHazardOpcodes.insert(ARM_MLxTable[i].MulOpc);
94   }
95 }
96 
97 // Use a ScoreboardHazardRecognizer for prepass ARM scheduling. TargetInstrImpl
98 // currently defaults to no prepass hazard recognizer.
99 ScheduleHazardRecognizer *
100 ARMBaseInstrInfo::CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
101                                                const ScheduleDAG *DAG) const {
102   if (usePreRAHazardRecognizer()) {
103     const InstrItineraryData *II =
104         static_cast<const ARMSubtarget *>(STI)->getInstrItineraryData();
105     return new ScoreboardHazardRecognizer(II, DAG, "pre-RA-sched");
106   }
107   return TargetInstrInfo::CreateTargetHazardRecognizer(STI, DAG);
108 }
109 
110 ScheduleHazardRecognizer *ARMBaseInstrInfo::
111 CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
112                                    const ScheduleDAG *DAG) const {
113   if (Subtarget.isThumb2() || Subtarget.hasVFP2())
114     return (ScheduleHazardRecognizer *)new ARMHazardRecognizer(II, DAG);
115   return TargetInstrInfo::CreateTargetPostRAHazardRecognizer(II, DAG);
116 }
117 
118 MachineInstr *ARMBaseInstrInfo::convertToThreeAddress(
119     MachineFunction::iterator &MFI, MachineInstr &MI, LiveVariables *LV) const {
120   // FIXME: Thumb2 support.
121 
122   if (!EnableARM3Addr)
123     return nullptr;
124 
125   MachineFunction &MF = *MI.getParent()->getParent();
126   uint64_t TSFlags = MI.getDesc().TSFlags;
127   bool isPre = false;
128   switch ((TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift) {
129   default: return nullptr;
130   case ARMII::IndexModePre:
131     isPre = true;
132     break;
133   case ARMII::IndexModePost:
134     break;
135   }
136 
137   // Try splitting an indexed load/store to an un-indexed one plus an add/sub
138   // operation.
139   unsigned MemOpc = getUnindexedOpcode(MI.getOpcode());
140   if (MemOpc == 0)
141     return nullptr;
142 
143   MachineInstr *UpdateMI = nullptr;
144   MachineInstr *MemMI = nullptr;
145   unsigned AddrMode = (TSFlags & ARMII::AddrModeMask);
146   const MCInstrDesc &MCID = MI.getDesc();
147   unsigned NumOps = MCID.getNumOperands();
148   bool isLoad = !MI.mayStore();
149   const MachineOperand &WB = isLoad ? MI.getOperand(1) : MI.getOperand(0);
150   const MachineOperand &Base = MI.getOperand(2);
151   const MachineOperand &Offset = MI.getOperand(NumOps - 3);
152   unsigned WBReg = WB.getReg();
153   unsigned BaseReg = Base.getReg();
154   unsigned OffReg = Offset.getReg();
155   unsigned OffImm = MI.getOperand(NumOps - 2).getImm();
156   ARMCC::CondCodes Pred = (ARMCC::CondCodes)MI.getOperand(NumOps - 1).getImm();
157   switch (AddrMode) {
158   default: llvm_unreachable("Unknown indexed op!");
159   case ARMII::AddrMode2: {
160     bool isSub = ARM_AM::getAM2Op(OffImm) == ARM_AM::sub;
161     unsigned Amt = ARM_AM::getAM2Offset(OffImm);
162     if (OffReg == 0) {
163       if (ARM_AM::getSOImmVal(Amt) == -1)
164         // Can't encode it in a so_imm operand. This transformation will
165         // add more than 1 instruction. Abandon!
166         return nullptr;
167       UpdateMI = BuildMI(MF, MI.getDebugLoc(),
168                          get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
169                      .addReg(BaseReg)
170                      .addImm(Amt)
171                      .addImm(Pred)
172                      .addReg(0)
173                      .addReg(0);
174     } else if (Amt != 0) {
175       ARM_AM::ShiftOpc ShOpc = ARM_AM::getAM2ShiftOpc(OffImm);
176       unsigned SOOpc = ARM_AM::getSORegOpc(ShOpc, Amt);
177       UpdateMI = BuildMI(MF, MI.getDebugLoc(),
178                          get(isSub ? ARM::SUBrsi : ARM::ADDrsi), WBReg)
179                      .addReg(BaseReg)
180                      .addReg(OffReg)
181                      .addReg(0)
182                      .addImm(SOOpc)
183                      .addImm(Pred)
184                      .addReg(0)
185                      .addReg(0);
186     } else
187       UpdateMI = BuildMI(MF, MI.getDebugLoc(),
188                          get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
189                      .addReg(BaseReg)
190                      .addReg(OffReg)
191                      .addImm(Pred)
192                      .addReg(0)
193                      .addReg(0);
194     break;
195   }
196   case ARMII::AddrMode3 : {
197     bool isSub = ARM_AM::getAM3Op(OffImm) == ARM_AM::sub;
198     unsigned Amt = ARM_AM::getAM3Offset(OffImm);
199     if (OffReg == 0)
200       // Immediate is 8-bits. It's guaranteed to fit in a so_imm operand.
201       UpdateMI = BuildMI(MF, MI.getDebugLoc(),
202                          get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
203                      .addReg(BaseReg)
204                      .addImm(Amt)
205                      .addImm(Pred)
206                      .addReg(0)
207                      .addReg(0);
208     else
209       UpdateMI = BuildMI(MF, MI.getDebugLoc(),
210                          get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
211                      .addReg(BaseReg)
212                      .addReg(OffReg)
213                      .addImm(Pred)
214                      .addReg(0)
215                      .addReg(0);
216     break;
217   }
218   }
219 
220   std::vector<MachineInstr*> NewMIs;
221   if (isPre) {
222     if (isLoad)
223       MemMI =
224           BuildMI(MF, MI.getDebugLoc(), get(MemOpc), MI.getOperand(0).getReg())
225               .addReg(WBReg)
226               .addImm(0)
227               .addImm(Pred);
228     else
229       MemMI = BuildMI(MF, MI.getDebugLoc(), get(MemOpc))
230                   .addReg(MI.getOperand(1).getReg())
231                   .addReg(WBReg)
232                   .addReg(0)
233                   .addImm(0)
234                   .addImm(Pred);
235     NewMIs.push_back(MemMI);
236     NewMIs.push_back(UpdateMI);
237   } else {
238     if (isLoad)
239       MemMI =
240           BuildMI(MF, MI.getDebugLoc(), get(MemOpc), MI.getOperand(0).getReg())
241               .addReg(BaseReg)
242               .addImm(0)
243               .addImm(Pred);
244     else
245       MemMI = BuildMI(MF, MI.getDebugLoc(), get(MemOpc))
246                   .addReg(MI.getOperand(1).getReg())
247                   .addReg(BaseReg)
248                   .addReg(0)
249                   .addImm(0)
250                   .addImm(Pred);
251     if (WB.isDead())
252       UpdateMI->getOperand(0).setIsDead();
253     NewMIs.push_back(UpdateMI);
254     NewMIs.push_back(MemMI);
255   }
256 
257   // Transfer LiveVariables states, kill / dead info.
258   if (LV) {
259     for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
260       MachineOperand &MO = MI.getOperand(i);
261       if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
262         unsigned Reg = MO.getReg();
263 
264         LiveVariables::VarInfo &VI = LV->getVarInfo(Reg);
265         if (MO.isDef()) {
266           MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
267           if (MO.isDead())
268             LV->addVirtualRegisterDead(Reg, *NewMI);
269         }
270         if (MO.isUse() && MO.isKill()) {
271           for (unsigned j = 0; j < 2; ++j) {
272             // Look at the two new MI's in reverse order.
273             MachineInstr *NewMI = NewMIs[j];
274             if (!NewMI->readsRegister(Reg))
275               continue;
276             LV->addVirtualRegisterKilled(Reg, *NewMI);
277             if (VI.removeKill(MI))
278               VI.Kills.push_back(NewMI);
279             break;
280           }
281         }
282       }
283     }
284   }
285 
286   MachineBasicBlock::iterator MBBI = MI.getIterator();
287   MFI->insert(MBBI, NewMIs[1]);
288   MFI->insert(MBBI, NewMIs[0]);
289   return NewMIs[0];
290 }
291 
292 // Branch analysis.
293 bool ARMBaseInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
294                                      MachineBasicBlock *&TBB,
295                                      MachineBasicBlock *&FBB,
296                                      SmallVectorImpl<MachineOperand> &Cond,
297                                      bool AllowModify) const {
298   TBB = nullptr;
299   FBB = nullptr;
300 
301   MachineBasicBlock::iterator I = MBB.end();
302   if (I == MBB.begin())
303     return false; // Empty blocks are easy.
304   --I;
305 
306   // Walk backwards from the end of the basic block until the branch is
307   // analyzed or we give up.
308   while (isPredicated(*I) || I->isTerminator() || I->isDebugValue()) {
309 
310     // Flag to be raised on unanalyzeable instructions. This is useful in cases
311     // where we want to clean up on the end of the basic block before we bail
312     // out.
313     bool CantAnalyze = false;
314 
315     // Skip over DEBUG values and predicated nonterminators.
316     while (I->isDebugValue() || !I->isTerminator()) {
317       if (I == MBB.begin())
318         return false;
319       --I;
320     }
321 
322     if (isIndirectBranchOpcode(I->getOpcode()) ||
323         isJumpTableBranchOpcode(I->getOpcode())) {
324       // Indirect branches and jump tables can't be analyzed, but we still want
325       // to clean up any instructions at the tail of the basic block.
326       CantAnalyze = true;
327     } else if (isUncondBranchOpcode(I->getOpcode())) {
328       TBB = I->getOperand(0).getMBB();
329     } else if (isCondBranchOpcode(I->getOpcode())) {
330       // Bail out if we encounter multiple conditional branches.
331       if (!Cond.empty())
332         return true;
333 
334       assert(!FBB && "FBB should have been null.");
335       FBB = TBB;
336       TBB = I->getOperand(0).getMBB();
337       Cond.push_back(I->getOperand(1));
338       Cond.push_back(I->getOperand(2));
339     } else if (I->isReturn()) {
340       // Returns can't be analyzed, but we should run cleanup.
341       CantAnalyze = !isPredicated(*I);
342     } else {
343       // We encountered other unrecognized terminator. Bail out immediately.
344       return true;
345     }
346 
347     // Cleanup code - to be run for unpredicated unconditional branches and
348     //                returns.
349     if (!isPredicated(*I) &&
350           (isUncondBranchOpcode(I->getOpcode()) ||
351            isIndirectBranchOpcode(I->getOpcode()) ||
352            isJumpTableBranchOpcode(I->getOpcode()) ||
353            I->isReturn())) {
354       // Forget any previous condition branch information - it no longer applies.
355       Cond.clear();
356       FBB = nullptr;
357 
358       // If we can modify the function, delete everything below this
359       // unconditional branch.
360       if (AllowModify) {
361         MachineBasicBlock::iterator DI = std::next(I);
362         while (DI != MBB.end()) {
363           MachineInstr &InstToDelete = *DI;
364           ++DI;
365           InstToDelete.eraseFromParent();
366         }
367       }
368     }
369 
370     if (CantAnalyze)
371       return true;
372 
373     if (I == MBB.begin())
374       return false;
375 
376     --I;
377   }
378 
379   // We made it past the terminators without bailing out - we must have
380   // analyzed this branch successfully.
381   return false;
382 }
383 
384 
385 unsigned ARMBaseInstrInfo::removeBranch(MachineBasicBlock &MBB,
386                                         int *BytesRemoved) const {
387   assert(!BytesRemoved && "code size not handled");
388 
389   MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
390   if (I == MBB.end())
391     return 0;
392 
393   if (!isUncondBranchOpcode(I->getOpcode()) &&
394       !isCondBranchOpcode(I->getOpcode()))
395     return 0;
396 
397   // Remove the branch.
398   I->eraseFromParent();
399 
400   I = MBB.end();
401 
402   if (I == MBB.begin()) return 1;
403   --I;
404   if (!isCondBranchOpcode(I->getOpcode()))
405     return 1;
406 
407   // Remove the branch.
408   I->eraseFromParent();
409   return 2;
410 }
411 
412 unsigned ARMBaseInstrInfo::insertBranch(MachineBasicBlock &MBB,
413                                         MachineBasicBlock *TBB,
414                                         MachineBasicBlock *FBB,
415                                         ArrayRef<MachineOperand> Cond,
416                                         const DebugLoc &DL,
417                                         int *BytesAdded) const {
418   assert(!BytesAdded && "code size not handled");
419   ARMFunctionInfo *AFI = MBB.getParent()->getInfo<ARMFunctionInfo>();
420   int BOpc   = !AFI->isThumbFunction()
421     ? ARM::B : (AFI->isThumb2Function() ? ARM::t2B : ARM::tB);
422   int BccOpc = !AFI->isThumbFunction()
423     ? ARM::Bcc : (AFI->isThumb2Function() ? ARM::t2Bcc : ARM::tBcc);
424   bool isThumb = AFI->isThumbFunction() || AFI->isThumb2Function();
425 
426   // Shouldn't be a fall through.
427   assert(TBB && "insertBranch must not be told to insert a fallthrough");
428   assert((Cond.size() == 2 || Cond.size() == 0) &&
429          "ARM branch conditions have two components!");
430 
431   // For conditional branches, we use addOperand to preserve CPSR flags.
432 
433   if (!FBB) {
434     if (Cond.empty()) { // Unconditional branch?
435       if (isThumb)
436         BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB).addImm(ARMCC::AL).addReg(0);
437       else
438         BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB);
439     } else
440       BuildMI(&MBB, DL, get(BccOpc))
441           .addMBB(TBB)
442           .addImm(Cond[0].getImm())
443           .add(Cond[1]);
444     return 1;
445   }
446 
447   // Two-way conditional branch.
448   BuildMI(&MBB, DL, get(BccOpc))
449       .addMBB(TBB)
450       .addImm(Cond[0].getImm())
451       .add(Cond[1]);
452   if (isThumb)
453     BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB).addImm(ARMCC::AL).addReg(0);
454   else
455     BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB);
456   return 2;
457 }
458 
459 bool ARMBaseInstrInfo::
460 reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
461   ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
462   Cond[0].setImm(ARMCC::getOppositeCondition(CC));
463   return false;
464 }
465 
466 bool ARMBaseInstrInfo::isPredicated(const MachineInstr &MI) const {
467   if (MI.isBundle()) {
468     MachineBasicBlock::const_instr_iterator I = MI.getIterator();
469     MachineBasicBlock::const_instr_iterator E = MI.getParent()->instr_end();
470     while (++I != E && I->isInsideBundle()) {
471       int PIdx = I->findFirstPredOperandIdx();
472       if (PIdx != -1 && I->getOperand(PIdx).getImm() != ARMCC::AL)
473         return true;
474     }
475     return false;
476   }
477 
478   int PIdx = MI.findFirstPredOperandIdx();
479   return PIdx != -1 && MI.getOperand(PIdx).getImm() != ARMCC::AL;
480 }
481 
482 bool ARMBaseInstrInfo::PredicateInstruction(
483     MachineInstr &MI, ArrayRef<MachineOperand> Pred) const {
484   unsigned Opc = MI.getOpcode();
485   if (isUncondBranchOpcode(Opc)) {
486     MI.setDesc(get(getMatchingCondBranchOpcode(Opc)));
487     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
488       .addImm(Pred[0].getImm())
489       .addReg(Pred[1].getReg());
490     return true;
491   }
492 
493   int PIdx = MI.findFirstPredOperandIdx();
494   if (PIdx != -1) {
495     MachineOperand &PMO = MI.getOperand(PIdx);
496     PMO.setImm(Pred[0].getImm());
497     MI.getOperand(PIdx+1).setReg(Pred[1].getReg());
498     return true;
499   }
500   return false;
501 }
502 
503 bool ARMBaseInstrInfo::SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
504                                          ArrayRef<MachineOperand> Pred2) const {
505   if (Pred1.size() > 2 || Pred2.size() > 2)
506     return false;
507 
508   ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm();
509   ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm();
510   if (CC1 == CC2)
511     return true;
512 
513   switch (CC1) {
514   default:
515     return false;
516   case ARMCC::AL:
517     return true;
518   case ARMCC::HS:
519     return CC2 == ARMCC::HI;
520   case ARMCC::LS:
521     return CC2 == ARMCC::LO || CC2 == ARMCC::EQ;
522   case ARMCC::GE:
523     return CC2 == ARMCC::GT;
524   case ARMCC::LE:
525     return CC2 == ARMCC::LT;
526   }
527 }
528 
529 bool ARMBaseInstrInfo::DefinesPredicate(
530     MachineInstr &MI, std::vector<MachineOperand> &Pred) const {
531   bool Found = false;
532   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
533     const MachineOperand &MO = MI.getOperand(i);
534     if ((MO.isRegMask() && MO.clobbersPhysReg(ARM::CPSR)) ||
535         (MO.isReg() && MO.isDef() && MO.getReg() == ARM::CPSR)) {
536       Pred.push_back(MO);
537       Found = true;
538     }
539   }
540 
541   return Found;
542 }
543 
544 static bool isCPSRDefined(const MachineInstr *MI) {
545   for (const auto &MO : MI->operands())
546     if (MO.isReg() && MO.getReg() == ARM::CPSR && MO.isDef() && !MO.isDead())
547       return true;
548   return false;
549 }
550 
551 static bool isEligibleForITBlock(const MachineInstr *MI) {
552   switch (MI->getOpcode()) {
553   default: return true;
554   case ARM::tADC:   // ADC (register) T1
555   case ARM::tADDi3: // ADD (immediate) T1
556   case ARM::tADDi8: // ADD (immediate) T2
557   case ARM::tADDrr: // ADD (register) T1
558   case ARM::tAND:   // AND (register) T1
559   case ARM::tASRri: // ASR (immediate) T1
560   case ARM::tASRrr: // ASR (register) T1
561   case ARM::tBIC:   // BIC (register) T1
562   case ARM::tEOR:   // EOR (register) T1
563   case ARM::tLSLri: // LSL (immediate) T1
564   case ARM::tLSLrr: // LSL (register) T1
565   case ARM::tLSRri: // LSR (immediate) T1
566   case ARM::tLSRrr: // LSR (register) T1
567   case ARM::tMUL:   // MUL T1
568   case ARM::tMVN:   // MVN (register) T1
569   case ARM::tORR:   // ORR (register) T1
570   case ARM::tROR:   // ROR (register) T1
571   case ARM::tRSB:   // RSB (immediate) T1
572   case ARM::tSBC:   // SBC (register) T1
573   case ARM::tSUBi3: // SUB (immediate) T1
574   case ARM::tSUBi8: // SUB (immediate) T2
575   case ARM::tSUBrr: // SUB (register) T1
576     return !isCPSRDefined(MI);
577   }
578 }
579 
580 /// isPredicable - Return true if the specified instruction can be predicated.
581 /// By default, this returns true for every instruction with a
582 /// PredicateOperand.
583 bool ARMBaseInstrInfo::isPredicable(MachineInstr &MI) const {
584   if (!MI.isPredicable())
585     return false;
586 
587   if (MI.isBundle())
588     return false;
589 
590   if (!isEligibleForITBlock(&MI))
591     return false;
592 
593   ARMFunctionInfo *AFI =
594       MI.getParent()->getParent()->getInfo<ARMFunctionInfo>();
595 
596   if (AFI->isThumb2Function()) {
597     if (getSubtarget().restrictIT())
598       return isV8EligibleForIT(&MI);
599   } else { // non-Thumb
600     if ((MI.getDesc().TSFlags & ARMII::DomainMask) == ARMII::DomainNEON)
601       return false;
602   }
603 
604   return true;
605 }
606 
607 namespace llvm {
608 template <> bool IsCPSRDead<MachineInstr>(MachineInstr *MI) {
609   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
610     const MachineOperand &MO = MI->getOperand(i);
611     if (!MO.isReg() || MO.isUndef() || MO.isUse())
612       continue;
613     if (MO.getReg() != ARM::CPSR)
614       continue;
615     if (!MO.isDead())
616       return false;
617   }
618   // all definitions of CPSR are dead
619   return true;
620 }
621 }
622 
623 /// GetInstSize - Return the size of the specified MachineInstr.
624 ///
625 unsigned ARMBaseInstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
626   const MachineBasicBlock &MBB = *MI.getParent();
627   const MachineFunction *MF = MBB.getParent();
628   const MCAsmInfo *MAI = MF->getTarget().getMCAsmInfo();
629 
630   const MCInstrDesc &MCID = MI.getDesc();
631   if (MCID.getSize())
632     return MCID.getSize();
633 
634   // If this machine instr is an inline asm, measure it.
635   if (MI.getOpcode() == ARM::INLINEASM)
636     return getInlineAsmLength(MI.getOperand(0).getSymbolName(), *MAI);
637   unsigned Opc = MI.getOpcode();
638   switch (Opc) {
639   default:
640     // pseudo-instruction sizes are zero.
641     return 0;
642   case TargetOpcode::BUNDLE:
643     return getInstBundleLength(MI);
644   case ARM::MOVi16_ga_pcrel:
645   case ARM::MOVTi16_ga_pcrel:
646   case ARM::t2MOVi16_ga_pcrel:
647   case ARM::t2MOVTi16_ga_pcrel:
648     return 4;
649   case ARM::MOVi32imm:
650   case ARM::t2MOVi32imm:
651     return 8;
652   case ARM::CONSTPOOL_ENTRY:
653   case ARM::JUMPTABLE_INSTS:
654   case ARM::JUMPTABLE_ADDRS:
655   case ARM::JUMPTABLE_TBB:
656   case ARM::JUMPTABLE_TBH:
657     // If this machine instr is a constant pool entry, its size is recorded as
658     // operand #2.
659     return MI.getOperand(2).getImm();
660   case ARM::Int_eh_sjlj_longjmp:
661     return 16;
662   case ARM::tInt_eh_sjlj_longjmp:
663     return 10;
664   case ARM::tInt_WIN_eh_sjlj_longjmp:
665     return 12;
666   case ARM::Int_eh_sjlj_setjmp:
667   case ARM::Int_eh_sjlj_setjmp_nofp:
668     return 20;
669   case ARM::tInt_eh_sjlj_setjmp:
670   case ARM::t2Int_eh_sjlj_setjmp:
671   case ARM::t2Int_eh_sjlj_setjmp_nofp:
672     return 12;
673   case ARM::SPACE:
674     return MI.getOperand(1).getImm();
675   }
676 }
677 
678 unsigned ARMBaseInstrInfo::getInstBundleLength(const MachineInstr &MI) const {
679   unsigned Size = 0;
680   MachineBasicBlock::const_instr_iterator I = MI.getIterator();
681   MachineBasicBlock::const_instr_iterator E = MI.getParent()->instr_end();
682   while (++I != E && I->isInsideBundle()) {
683     assert(!I->isBundle() && "No nested bundle!");
684     Size += getInstSizeInBytes(*I);
685   }
686   return Size;
687 }
688 
689 void ARMBaseInstrInfo::copyFromCPSR(MachineBasicBlock &MBB,
690                                     MachineBasicBlock::iterator I,
691                                     unsigned DestReg, bool KillSrc,
692                                     const ARMSubtarget &Subtarget) const {
693   unsigned Opc = Subtarget.isThumb()
694                      ? (Subtarget.isMClass() ? ARM::t2MRS_M : ARM::t2MRS_AR)
695                      : ARM::MRS;
696 
697   MachineInstrBuilder MIB =
698       BuildMI(MBB, I, I->getDebugLoc(), get(Opc), DestReg);
699 
700   // There is only 1 A/R class MRS instruction, and it always refers to
701   // APSR. However, there are lots of other possibilities on M-class cores.
702   if (Subtarget.isMClass())
703     MIB.addImm(0x800);
704 
705   MIB.add(predOps(ARMCC::AL))
706      .addReg(ARM::CPSR, RegState::Implicit | getKillRegState(KillSrc));
707 }
708 
709 void ARMBaseInstrInfo::copyToCPSR(MachineBasicBlock &MBB,
710                                   MachineBasicBlock::iterator I,
711                                   unsigned SrcReg, bool KillSrc,
712                                   const ARMSubtarget &Subtarget) const {
713   unsigned Opc = Subtarget.isThumb()
714                      ? (Subtarget.isMClass() ? ARM::t2MSR_M : ARM::t2MSR_AR)
715                      : ARM::MSR;
716 
717   MachineInstrBuilder MIB = BuildMI(MBB, I, I->getDebugLoc(), get(Opc));
718 
719   if (Subtarget.isMClass())
720     MIB.addImm(0x800);
721   else
722     MIB.addImm(8);
723 
724   MIB.addReg(SrcReg, getKillRegState(KillSrc))
725      .add(predOps(ARMCC::AL))
726      .addReg(ARM::CPSR, RegState::Implicit | RegState::Define);
727 }
728 
729 void ARMBaseInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
730                                    MachineBasicBlock::iterator I,
731                                    const DebugLoc &DL, unsigned DestReg,
732                                    unsigned SrcReg, bool KillSrc) const {
733   bool GPRDest = ARM::GPRRegClass.contains(DestReg);
734   bool GPRSrc = ARM::GPRRegClass.contains(SrcReg);
735 
736   if (GPRDest && GPRSrc) {
737     BuildMI(MBB, I, DL, get(ARM::MOVr), DestReg)
738         .addReg(SrcReg, getKillRegState(KillSrc))
739         .add(predOps(ARMCC::AL))
740         .add(condCodeOp());
741     return;
742   }
743 
744   bool SPRDest = ARM::SPRRegClass.contains(DestReg);
745   bool SPRSrc = ARM::SPRRegClass.contains(SrcReg);
746 
747   unsigned Opc = 0;
748   if (SPRDest && SPRSrc)
749     Opc = ARM::VMOVS;
750   else if (GPRDest && SPRSrc)
751     Opc = ARM::VMOVRS;
752   else if (SPRDest && GPRSrc)
753     Opc = ARM::VMOVSR;
754   else if (ARM::DPRRegClass.contains(DestReg, SrcReg) && !Subtarget.isFPOnlySP())
755     Opc = ARM::VMOVD;
756   else if (ARM::QPRRegClass.contains(DestReg, SrcReg))
757     Opc = ARM::VORRq;
758 
759   if (Opc) {
760     MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc), DestReg);
761     MIB.addReg(SrcReg, getKillRegState(KillSrc));
762     if (Opc == ARM::VORRq)
763       MIB.addReg(SrcReg, getKillRegState(KillSrc));
764     MIB.add(predOps(ARMCC::AL));
765     return;
766   }
767 
768   // Handle register classes that require multiple instructions.
769   unsigned BeginIdx = 0;
770   unsigned SubRegs = 0;
771   int Spacing = 1;
772 
773   // Use VORRq when possible.
774   if (ARM::QQPRRegClass.contains(DestReg, SrcReg)) {
775     Opc = ARM::VORRq;
776     BeginIdx = ARM::qsub_0;
777     SubRegs = 2;
778   } else if (ARM::QQQQPRRegClass.contains(DestReg, SrcReg)) {
779     Opc = ARM::VORRq;
780     BeginIdx = ARM::qsub_0;
781     SubRegs = 4;
782   // Fall back to VMOVD.
783   } else if (ARM::DPairRegClass.contains(DestReg, SrcReg)) {
784     Opc = ARM::VMOVD;
785     BeginIdx = ARM::dsub_0;
786     SubRegs = 2;
787   } else if (ARM::DTripleRegClass.contains(DestReg, SrcReg)) {
788     Opc = ARM::VMOVD;
789     BeginIdx = ARM::dsub_0;
790     SubRegs = 3;
791   } else if (ARM::DQuadRegClass.contains(DestReg, SrcReg)) {
792     Opc = ARM::VMOVD;
793     BeginIdx = ARM::dsub_0;
794     SubRegs = 4;
795   } else if (ARM::GPRPairRegClass.contains(DestReg, SrcReg)) {
796     Opc = Subtarget.isThumb2() ? ARM::tMOVr : ARM::MOVr;
797     BeginIdx = ARM::gsub_0;
798     SubRegs = 2;
799   } else if (ARM::DPairSpcRegClass.contains(DestReg, SrcReg)) {
800     Opc = ARM::VMOVD;
801     BeginIdx = ARM::dsub_0;
802     SubRegs = 2;
803     Spacing = 2;
804   } else if (ARM::DTripleSpcRegClass.contains(DestReg, SrcReg)) {
805     Opc = ARM::VMOVD;
806     BeginIdx = ARM::dsub_0;
807     SubRegs = 3;
808     Spacing = 2;
809   } else if (ARM::DQuadSpcRegClass.contains(DestReg, SrcReg)) {
810     Opc = ARM::VMOVD;
811     BeginIdx = ARM::dsub_0;
812     SubRegs = 4;
813     Spacing = 2;
814   } else if (ARM::DPRRegClass.contains(DestReg, SrcReg) && Subtarget.isFPOnlySP()) {
815     Opc = ARM::VMOVS;
816     BeginIdx = ARM::ssub_0;
817     SubRegs = 2;
818   } else if (SrcReg == ARM::CPSR) {
819     copyFromCPSR(MBB, I, DestReg, KillSrc, Subtarget);
820     return;
821   } else if (DestReg == ARM::CPSR) {
822     copyToCPSR(MBB, I, SrcReg, KillSrc, Subtarget);
823     return;
824   }
825 
826   assert(Opc && "Impossible reg-to-reg copy");
827 
828   const TargetRegisterInfo *TRI = &getRegisterInfo();
829   MachineInstrBuilder Mov;
830 
831   // Copy register tuples backward when the first Dest reg overlaps with SrcReg.
832   if (TRI->regsOverlap(SrcReg, TRI->getSubReg(DestReg, BeginIdx))) {
833     BeginIdx = BeginIdx + ((SubRegs - 1) * Spacing);
834     Spacing = -Spacing;
835   }
836 #ifndef NDEBUG
837   SmallSet<unsigned, 4> DstRegs;
838 #endif
839   for (unsigned i = 0; i != SubRegs; ++i) {
840     unsigned Dst = TRI->getSubReg(DestReg, BeginIdx + i * Spacing);
841     unsigned Src = TRI->getSubReg(SrcReg, BeginIdx + i * Spacing);
842     assert(Dst && Src && "Bad sub-register");
843 #ifndef NDEBUG
844     assert(!DstRegs.count(Src) && "destructive vector copy");
845     DstRegs.insert(Dst);
846 #endif
847     Mov = BuildMI(MBB, I, I->getDebugLoc(), get(Opc), Dst).addReg(Src);
848     // VORR takes two source operands.
849     if (Opc == ARM::VORRq)
850       Mov.addReg(Src);
851     Mov = Mov.add(predOps(ARMCC::AL));
852     // MOVr can set CC.
853     if (Opc == ARM::MOVr)
854       Mov = Mov.add(condCodeOp());
855   }
856   // Add implicit super-register defs and kills to the last instruction.
857   Mov->addRegisterDefined(DestReg, TRI);
858   if (KillSrc)
859     Mov->addRegisterKilled(SrcReg, TRI);
860 }
861 
862 const MachineInstrBuilder &
863 ARMBaseInstrInfo::AddDReg(MachineInstrBuilder &MIB, unsigned Reg,
864                           unsigned SubIdx, unsigned State,
865                           const TargetRegisterInfo *TRI) const {
866   if (!SubIdx)
867     return MIB.addReg(Reg, State);
868 
869   if (TargetRegisterInfo::isPhysicalRegister(Reg))
870     return MIB.addReg(TRI->getSubReg(Reg, SubIdx), State);
871   return MIB.addReg(Reg, State, SubIdx);
872 }
873 
874 void ARMBaseInstrInfo::
875 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
876                     unsigned SrcReg, bool isKill, int FI,
877                     const TargetRegisterClass *RC,
878                     const TargetRegisterInfo *TRI) const {
879   DebugLoc DL;
880   if (I != MBB.end()) DL = I->getDebugLoc();
881   MachineFunction &MF = *MBB.getParent();
882   MachineFrameInfo &MFI = MF.getFrameInfo();
883   unsigned Align = MFI.getObjectAlignment(FI);
884 
885   MachineMemOperand *MMO = MF.getMachineMemOperand(
886       MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
887       MFI.getObjectSize(FI), Align);
888 
889   switch (RC->getSize()) {
890     case 4:
891       if (ARM::GPRRegClass.hasSubClassEq(RC)) {
892         BuildMI(MBB, I, DL, get(ARM::STRi12))
893             .addReg(SrcReg, getKillRegState(isKill))
894             .addFrameIndex(FI)
895             .addImm(0)
896             .addMemOperand(MMO)
897             .add(predOps(ARMCC::AL));
898       } else if (ARM::SPRRegClass.hasSubClassEq(RC)) {
899         BuildMI(MBB, I, DL, get(ARM::VSTRS))
900             .addReg(SrcReg, getKillRegState(isKill))
901             .addFrameIndex(FI)
902             .addImm(0)
903             .addMemOperand(MMO)
904             .add(predOps(ARMCC::AL));
905       } else
906         llvm_unreachable("Unknown reg class!");
907       break;
908     case 8:
909       if (ARM::DPRRegClass.hasSubClassEq(RC)) {
910         BuildMI(MBB, I, DL, get(ARM::VSTRD))
911             .addReg(SrcReg, getKillRegState(isKill))
912             .addFrameIndex(FI)
913             .addImm(0)
914             .addMemOperand(MMO)
915             .add(predOps(ARMCC::AL));
916       } else if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
917         if (Subtarget.hasV5TEOps()) {
918           MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::STRD));
919           AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill), TRI);
920           AddDReg(MIB, SrcReg, ARM::gsub_1, 0, TRI);
921           MIB.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO)
922              .add(predOps(ARMCC::AL));
923         } else {
924           // Fallback to STM instruction, which has existed since the dawn of
925           // time.
926           MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::STMIA))
927                                         .addFrameIndex(FI)
928                                         .addMemOperand(MMO)
929                                         .add(predOps(ARMCC::AL));
930           AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill), TRI);
931           AddDReg(MIB, SrcReg, ARM::gsub_1, 0, TRI);
932         }
933       } else
934         llvm_unreachable("Unknown reg class!");
935       break;
936     case 16:
937       if (ARM::DPairRegClass.hasSubClassEq(RC)) {
938         // Use aligned spills if the stack can be realigned.
939         if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
940           BuildMI(MBB, I, DL, get(ARM::VST1q64))
941               .addFrameIndex(FI)
942               .addImm(16)
943               .addReg(SrcReg, getKillRegState(isKill))
944               .addMemOperand(MMO)
945               .add(predOps(ARMCC::AL));
946         } else {
947           BuildMI(MBB, I, DL, get(ARM::VSTMQIA))
948               .addReg(SrcReg, getKillRegState(isKill))
949               .addFrameIndex(FI)
950               .addMemOperand(MMO)
951               .add(predOps(ARMCC::AL));
952         }
953       } else
954         llvm_unreachable("Unknown reg class!");
955       break;
956     case 24:
957       if (ARM::DTripleRegClass.hasSubClassEq(RC)) {
958         // Use aligned spills if the stack can be realigned.
959         if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
960           BuildMI(MBB, I, DL, get(ARM::VST1d64TPseudo))
961               .addFrameIndex(FI)
962               .addImm(16)
963               .addReg(SrcReg, getKillRegState(isKill))
964               .addMemOperand(MMO)
965               .add(predOps(ARMCC::AL));
966         } else {
967           MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VSTMDIA))
968                                         .addFrameIndex(FI)
969                                         .add(predOps(ARMCC::AL))
970                                         .addMemOperand(MMO);
971           MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
972           MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
973           AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
974         }
975       } else
976         llvm_unreachable("Unknown reg class!");
977       break;
978     case 32:
979       if (ARM::QQPRRegClass.hasSubClassEq(RC) || ARM::DQuadRegClass.hasSubClassEq(RC)) {
980         if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
981           // FIXME: It's possible to only store part of the QQ register if the
982           // spilled def has a sub-register index.
983           BuildMI(MBB, I, DL, get(ARM::VST1d64QPseudo))
984               .addFrameIndex(FI)
985               .addImm(16)
986               .addReg(SrcReg, getKillRegState(isKill))
987               .addMemOperand(MMO)
988               .add(predOps(ARMCC::AL));
989         } else {
990           MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VSTMDIA))
991                                         .addFrameIndex(FI)
992                                         .add(predOps(ARMCC::AL))
993                                         .addMemOperand(MMO);
994           MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
995           MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
996           MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
997                 AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
998         }
999       } else
1000         llvm_unreachable("Unknown reg class!");
1001       break;
1002     case 64:
1003       if (ARM::QQQQPRRegClass.hasSubClassEq(RC)) {
1004         MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VSTMDIA))
1005                                       .addFrameIndex(FI)
1006                                       .add(predOps(ARMCC::AL))
1007                                       .addMemOperand(MMO);
1008         MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
1009         MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
1010         MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
1011         MIB = AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
1012         MIB = AddDReg(MIB, SrcReg, ARM::dsub_4, 0, TRI);
1013         MIB = AddDReg(MIB, SrcReg, ARM::dsub_5, 0, TRI);
1014         MIB = AddDReg(MIB, SrcReg, ARM::dsub_6, 0, TRI);
1015               AddDReg(MIB, SrcReg, ARM::dsub_7, 0, TRI);
1016       } else
1017         llvm_unreachable("Unknown reg class!");
1018       break;
1019     default:
1020       llvm_unreachable("Unknown reg class!");
1021   }
1022 }
1023 
1024 unsigned ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
1025                                               int &FrameIndex) const {
1026   switch (MI.getOpcode()) {
1027   default: break;
1028   case ARM::STRrs:
1029   case ARM::t2STRs: // FIXME: don't use t2STRs to access frame.
1030     if (MI.getOperand(1).isFI() && MI.getOperand(2).isReg() &&
1031         MI.getOperand(3).isImm() && MI.getOperand(2).getReg() == 0 &&
1032         MI.getOperand(3).getImm() == 0) {
1033       FrameIndex = MI.getOperand(1).getIndex();
1034       return MI.getOperand(0).getReg();
1035     }
1036     break;
1037   case ARM::STRi12:
1038   case ARM::t2STRi12:
1039   case ARM::tSTRspi:
1040   case ARM::VSTRD:
1041   case ARM::VSTRS:
1042     if (MI.getOperand(1).isFI() && MI.getOperand(2).isImm() &&
1043         MI.getOperand(2).getImm() == 0) {
1044       FrameIndex = MI.getOperand(1).getIndex();
1045       return MI.getOperand(0).getReg();
1046     }
1047     break;
1048   case ARM::VST1q64:
1049   case ARM::VST1d64TPseudo:
1050   case ARM::VST1d64QPseudo:
1051     if (MI.getOperand(0).isFI() && MI.getOperand(2).getSubReg() == 0) {
1052       FrameIndex = MI.getOperand(0).getIndex();
1053       return MI.getOperand(2).getReg();
1054     }
1055     break;
1056   case ARM::VSTMQIA:
1057     if (MI.getOperand(1).isFI() && MI.getOperand(0).getSubReg() == 0) {
1058       FrameIndex = MI.getOperand(1).getIndex();
1059       return MI.getOperand(0).getReg();
1060     }
1061     break;
1062   }
1063 
1064   return 0;
1065 }
1066 
1067 unsigned ARMBaseInstrInfo::isStoreToStackSlotPostFE(const MachineInstr &MI,
1068                                                     int &FrameIndex) const {
1069   const MachineMemOperand *Dummy;
1070   return MI.mayStore() && hasStoreToStackSlot(MI, Dummy, FrameIndex);
1071 }
1072 
1073 void ARMBaseInstrInfo::
1074 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
1075                      unsigned DestReg, int FI,
1076                      const TargetRegisterClass *RC,
1077                      const TargetRegisterInfo *TRI) const {
1078   DebugLoc DL;
1079   if (I != MBB.end()) DL = I->getDebugLoc();
1080   MachineFunction &MF = *MBB.getParent();
1081   MachineFrameInfo &MFI = MF.getFrameInfo();
1082   unsigned Align = MFI.getObjectAlignment(FI);
1083   MachineMemOperand *MMO = MF.getMachineMemOperand(
1084       MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
1085       MFI.getObjectSize(FI), Align);
1086 
1087   switch (RC->getSize()) {
1088   case 4:
1089     if (ARM::GPRRegClass.hasSubClassEq(RC)) {
1090       BuildMI(MBB, I, DL, get(ARM::LDRi12), DestReg)
1091           .addFrameIndex(FI)
1092           .addImm(0)
1093           .addMemOperand(MMO)
1094           .add(predOps(ARMCC::AL));
1095 
1096     } else if (ARM::SPRRegClass.hasSubClassEq(RC)) {
1097       BuildMI(MBB, I, DL, get(ARM::VLDRS), DestReg)
1098           .addFrameIndex(FI)
1099           .addImm(0)
1100           .addMemOperand(MMO)
1101           .add(predOps(ARMCC::AL));
1102     } else
1103       llvm_unreachable("Unknown reg class!");
1104     break;
1105   case 8:
1106     if (ARM::DPRRegClass.hasSubClassEq(RC)) {
1107       BuildMI(MBB, I, DL, get(ARM::VLDRD), DestReg)
1108           .addFrameIndex(FI)
1109           .addImm(0)
1110           .addMemOperand(MMO)
1111           .add(predOps(ARMCC::AL));
1112     } else if (ARM::GPRPairRegClass.hasSubClassEq(RC)) {
1113       MachineInstrBuilder MIB;
1114 
1115       if (Subtarget.hasV5TEOps()) {
1116         MIB = BuildMI(MBB, I, DL, get(ARM::LDRD));
1117         AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead, TRI);
1118         AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead, TRI);
1119         MIB.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO)
1120            .add(predOps(ARMCC::AL));
1121       } else {
1122         // Fallback to LDM instruction, which has existed since the dawn of
1123         // time.
1124         MIB = BuildMI(MBB, I, DL, get(ARM::LDMIA))
1125                   .addFrameIndex(FI)
1126                   .addMemOperand(MMO)
1127                   .add(predOps(ARMCC::AL));
1128         MIB = AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead, TRI);
1129         MIB = AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead, TRI);
1130       }
1131 
1132       if (TargetRegisterInfo::isPhysicalRegister(DestReg))
1133         MIB.addReg(DestReg, RegState::ImplicitDefine);
1134     } else
1135       llvm_unreachable("Unknown reg class!");
1136     break;
1137   case 16:
1138     if (ARM::DPairRegClass.hasSubClassEq(RC)) {
1139       if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
1140         BuildMI(MBB, I, DL, get(ARM::VLD1q64), DestReg)
1141             .addFrameIndex(FI)
1142             .addImm(16)
1143             .addMemOperand(MMO)
1144             .add(predOps(ARMCC::AL));
1145       } else {
1146         BuildMI(MBB, I, DL, get(ARM::VLDMQIA), DestReg)
1147             .addFrameIndex(FI)
1148             .addMemOperand(MMO)
1149             .add(predOps(ARMCC::AL));
1150       }
1151     } else
1152       llvm_unreachable("Unknown reg class!");
1153     break;
1154   case 24:
1155     if (ARM::DTripleRegClass.hasSubClassEq(RC)) {
1156       if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
1157         BuildMI(MBB, I, DL, get(ARM::VLD1d64TPseudo), DestReg)
1158             .addFrameIndex(FI)
1159             .addImm(16)
1160             .addMemOperand(MMO)
1161             .add(predOps(ARMCC::AL));
1162       } else {
1163         MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
1164                                       .addFrameIndex(FI)
1165                                       .addMemOperand(MMO)
1166                                       .add(predOps(ARMCC::AL));
1167         MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead, TRI);
1168         MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead, TRI);
1169         MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead, TRI);
1170         if (TargetRegisterInfo::isPhysicalRegister(DestReg))
1171           MIB.addReg(DestReg, RegState::ImplicitDefine);
1172       }
1173     } else
1174       llvm_unreachable("Unknown reg class!");
1175     break;
1176    case 32:
1177     if (ARM::QQPRRegClass.hasSubClassEq(RC) || ARM::DQuadRegClass.hasSubClassEq(RC)) {
1178       if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
1179         BuildMI(MBB, I, DL, get(ARM::VLD1d64QPseudo), DestReg)
1180             .addFrameIndex(FI)
1181             .addImm(16)
1182             .addMemOperand(MMO)
1183             .add(predOps(ARMCC::AL));
1184       } else {
1185         MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
1186                                       .addFrameIndex(FI)
1187                                       .add(predOps(ARMCC::AL))
1188                                       .addMemOperand(MMO);
1189         MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead, TRI);
1190         MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead, TRI);
1191         MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead, TRI);
1192         MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::DefineNoRead, TRI);
1193         if (TargetRegisterInfo::isPhysicalRegister(DestReg))
1194           MIB.addReg(DestReg, RegState::ImplicitDefine);
1195       }
1196     } else
1197       llvm_unreachable("Unknown reg class!");
1198     break;
1199   case 64:
1200     if (ARM::QQQQPRRegClass.hasSubClassEq(RC)) {
1201       MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLDMDIA))
1202                                     .addFrameIndex(FI)
1203                                     .add(predOps(ARMCC::AL))
1204                                     .addMemOperand(MMO);
1205       MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::DefineNoRead, TRI);
1206       MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::DefineNoRead, TRI);
1207       MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::DefineNoRead, TRI);
1208       MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::DefineNoRead, TRI);
1209       MIB = AddDReg(MIB, DestReg, ARM::dsub_4, RegState::DefineNoRead, TRI);
1210       MIB = AddDReg(MIB, DestReg, ARM::dsub_5, RegState::DefineNoRead, TRI);
1211       MIB = AddDReg(MIB, DestReg, ARM::dsub_6, RegState::DefineNoRead, TRI);
1212       MIB = AddDReg(MIB, DestReg, ARM::dsub_7, RegState::DefineNoRead, TRI);
1213       if (TargetRegisterInfo::isPhysicalRegister(DestReg))
1214         MIB.addReg(DestReg, RegState::ImplicitDefine);
1215     } else
1216       llvm_unreachable("Unknown reg class!");
1217     break;
1218   default:
1219     llvm_unreachable("Unknown regclass!");
1220   }
1221 }
1222 
1223 unsigned ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
1224                                                int &FrameIndex) const {
1225   switch (MI.getOpcode()) {
1226   default: break;
1227   case ARM::LDRrs:
1228   case ARM::t2LDRs:  // FIXME: don't use t2LDRs to access frame.
1229     if (MI.getOperand(1).isFI() && MI.getOperand(2).isReg() &&
1230         MI.getOperand(3).isImm() && MI.getOperand(2).getReg() == 0 &&
1231         MI.getOperand(3).getImm() == 0) {
1232       FrameIndex = MI.getOperand(1).getIndex();
1233       return MI.getOperand(0).getReg();
1234     }
1235     break;
1236   case ARM::LDRi12:
1237   case ARM::t2LDRi12:
1238   case ARM::tLDRspi:
1239   case ARM::VLDRD:
1240   case ARM::VLDRS:
1241     if (MI.getOperand(1).isFI() && MI.getOperand(2).isImm() &&
1242         MI.getOperand(2).getImm() == 0) {
1243       FrameIndex = MI.getOperand(1).getIndex();
1244       return MI.getOperand(0).getReg();
1245     }
1246     break;
1247   case ARM::VLD1q64:
1248   case ARM::VLD1d64TPseudo:
1249   case ARM::VLD1d64QPseudo:
1250     if (MI.getOperand(1).isFI() && MI.getOperand(0).getSubReg() == 0) {
1251       FrameIndex = MI.getOperand(1).getIndex();
1252       return MI.getOperand(0).getReg();
1253     }
1254     break;
1255   case ARM::VLDMQIA:
1256     if (MI.getOperand(1).isFI() && MI.getOperand(0).getSubReg() == 0) {
1257       FrameIndex = MI.getOperand(1).getIndex();
1258       return MI.getOperand(0).getReg();
1259     }
1260     break;
1261   }
1262 
1263   return 0;
1264 }
1265 
1266 unsigned ARMBaseInstrInfo::isLoadFromStackSlotPostFE(const MachineInstr &MI,
1267                                                      int &FrameIndex) const {
1268   const MachineMemOperand *Dummy;
1269   return MI.mayLoad() && hasLoadFromStackSlot(MI, Dummy, FrameIndex);
1270 }
1271 
1272 /// \brief Expands MEMCPY to either LDMIA/STMIA or LDMIA_UPD/STMID_UPD
1273 /// depending on whether the result is used.
1274 void ARMBaseInstrInfo::expandMEMCPY(MachineBasicBlock::iterator MI) const {
1275   bool isThumb1 = Subtarget.isThumb1Only();
1276   bool isThumb2 = Subtarget.isThumb2();
1277   const ARMBaseInstrInfo *TII = Subtarget.getInstrInfo();
1278 
1279   DebugLoc dl = MI->getDebugLoc();
1280   MachineBasicBlock *BB = MI->getParent();
1281 
1282   MachineInstrBuilder LDM, STM;
1283   if (isThumb1 || !MI->getOperand(1).isDead()) {
1284     LDM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2LDMIA_UPD
1285                                                  : isThumb1 ? ARM::tLDMIA_UPD
1286                                                             : ARM::LDMIA_UPD))
1287               .add(MI->getOperand(1));
1288   } else {
1289     LDM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2LDMIA : ARM::LDMIA));
1290   }
1291 
1292   if (isThumb1 || !MI->getOperand(0).isDead()) {
1293     STM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2STMIA_UPD
1294                                                  : isThumb1 ? ARM::tSTMIA_UPD
1295                                                             : ARM::STMIA_UPD))
1296               .add(MI->getOperand(0));
1297   } else {
1298     STM = BuildMI(*BB, MI, dl, TII->get(isThumb2 ? ARM::t2STMIA : ARM::STMIA));
1299   }
1300 
1301   LDM.add(MI->getOperand(3)).add(predOps(ARMCC::AL));
1302   STM.add(MI->getOperand(2)).add(predOps(ARMCC::AL));
1303 
1304   // Sort the scratch registers into ascending order.
1305   const TargetRegisterInfo &TRI = getRegisterInfo();
1306   llvm::SmallVector<unsigned, 6> ScratchRegs;
1307   for(unsigned I = 5; I < MI->getNumOperands(); ++I)
1308     ScratchRegs.push_back(MI->getOperand(I).getReg());
1309   std::sort(ScratchRegs.begin(), ScratchRegs.end(),
1310             [&TRI](const unsigned &Reg1,
1311                    const unsigned &Reg2) -> bool {
1312               return TRI.getEncodingValue(Reg1) <
1313                      TRI.getEncodingValue(Reg2);
1314             });
1315 
1316   for (const auto &Reg : ScratchRegs) {
1317     LDM.addReg(Reg, RegState::Define);
1318     STM.addReg(Reg, RegState::Kill);
1319   }
1320 
1321   BB->erase(MI);
1322 }
1323 
1324 
1325 bool ARMBaseInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
1326   if (MI.getOpcode() == TargetOpcode::LOAD_STACK_GUARD) {
1327     assert(getSubtarget().getTargetTriple().isOSBinFormatMachO() &&
1328            "LOAD_STACK_GUARD currently supported only for MachO.");
1329     expandLoadStackGuard(MI);
1330     MI.getParent()->erase(MI);
1331     return true;
1332   }
1333 
1334   if (MI.getOpcode() == ARM::MEMCPY) {
1335     expandMEMCPY(MI);
1336     return true;
1337   }
1338 
1339   // This hook gets to expand COPY instructions before they become
1340   // copyPhysReg() calls.  Look for VMOVS instructions that can legally be
1341   // widened to VMOVD.  We prefer the VMOVD when possible because it may be
1342   // changed into a VORR that can go down the NEON pipeline.
1343   if (!MI.isCopy() || Subtarget.dontWidenVMOVS() || Subtarget.isFPOnlySP())
1344     return false;
1345 
1346   // Look for a copy between even S-registers.  That is where we keep floats
1347   // when using NEON v2f32 instructions for f32 arithmetic.
1348   unsigned DstRegS = MI.getOperand(0).getReg();
1349   unsigned SrcRegS = MI.getOperand(1).getReg();
1350   if (!ARM::SPRRegClass.contains(DstRegS, SrcRegS))
1351     return false;
1352 
1353   const TargetRegisterInfo *TRI = &getRegisterInfo();
1354   unsigned DstRegD = TRI->getMatchingSuperReg(DstRegS, ARM::ssub_0,
1355                                               &ARM::DPRRegClass);
1356   unsigned SrcRegD = TRI->getMatchingSuperReg(SrcRegS, ARM::ssub_0,
1357                                               &ARM::DPRRegClass);
1358   if (!DstRegD || !SrcRegD)
1359     return false;
1360 
1361   // We want to widen this into a DstRegD = VMOVD SrcRegD copy.  This is only
1362   // legal if the COPY already defines the full DstRegD, and it isn't a
1363   // sub-register insertion.
1364   if (!MI.definesRegister(DstRegD, TRI) || MI.readsRegister(DstRegD, TRI))
1365     return false;
1366 
1367   // A dead copy shouldn't show up here, but reject it just in case.
1368   if (MI.getOperand(0).isDead())
1369     return false;
1370 
1371   // All clear, widen the COPY.
1372   DEBUG(dbgs() << "widening:    " << MI);
1373   MachineInstrBuilder MIB(*MI.getParent()->getParent(), MI);
1374 
1375   // Get rid of the old <imp-def> of DstRegD.  Leave it if it defines a Q-reg
1376   // or some other super-register.
1377   int ImpDefIdx = MI.findRegisterDefOperandIdx(DstRegD);
1378   if (ImpDefIdx != -1)
1379     MI.RemoveOperand(ImpDefIdx);
1380 
1381   // Change the opcode and operands.
1382   MI.setDesc(get(ARM::VMOVD));
1383   MI.getOperand(0).setReg(DstRegD);
1384   MI.getOperand(1).setReg(SrcRegD);
1385   MIB.add(predOps(ARMCC::AL));
1386 
1387   // We are now reading SrcRegD instead of SrcRegS.  This may upset the
1388   // register scavenger and machine verifier, so we need to indicate that we
1389   // are reading an undefined value from SrcRegD, but a proper value from
1390   // SrcRegS.
1391   MI.getOperand(1).setIsUndef();
1392   MIB.addReg(SrcRegS, RegState::Implicit);
1393 
1394   // SrcRegD may actually contain an unrelated value in the ssub_1
1395   // sub-register.  Don't kill it.  Only kill the ssub_0 sub-register.
1396   if (MI.getOperand(1).isKill()) {
1397     MI.getOperand(1).setIsKill(false);
1398     MI.addRegisterKilled(SrcRegS, TRI, true);
1399   }
1400 
1401   DEBUG(dbgs() << "replaced by: " << MI);
1402   return true;
1403 }
1404 
1405 /// Create a copy of a const pool value. Update CPI to the new index and return
1406 /// the label UID.
1407 static unsigned duplicateCPV(MachineFunction &MF, unsigned &CPI) {
1408   MachineConstantPool *MCP = MF.getConstantPool();
1409   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1410 
1411   const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
1412   assert(MCPE.isMachineConstantPoolEntry() &&
1413          "Expecting a machine constantpool entry!");
1414   ARMConstantPoolValue *ACPV =
1415     static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
1416 
1417   unsigned PCLabelId = AFI->createPICLabelUId();
1418   ARMConstantPoolValue *NewCPV = nullptr;
1419 
1420   // FIXME: The below assumes PIC relocation model and that the function
1421   // is Thumb mode (t1 or t2). PCAdjustment would be 8 for ARM mode PIC, and
1422   // zero for non-PIC in ARM or Thumb. The callers are all of thumb LDR
1423   // instructions, so that's probably OK, but is PIC always correct when
1424   // we get here?
1425   if (ACPV->isGlobalValue())
1426     NewCPV = ARMConstantPoolConstant::Create(
1427         cast<ARMConstantPoolConstant>(ACPV)->getGV(), PCLabelId, ARMCP::CPValue,
1428         4, ACPV->getModifier(), ACPV->mustAddCurrentAddress());
1429   else if (ACPV->isExtSymbol())
1430     NewCPV = ARMConstantPoolSymbol::
1431       Create(MF.getFunction()->getContext(),
1432              cast<ARMConstantPoolSymbol>(ACPV)->getSymbol(), PCLabelId, 4);
1433   else if (ACPV->isBlockAddress())
1434     NewCPV = ARMConstantPoolConstant::
1435       Create(cast<ARMConstantPoolConstant>(ACPV)->getBlockAddress(), PCLabelId,
1436              ARMCP::CPBlockAddress, 4);
1437   else if (ACPV->isLSDA())
1438     NewCPV = ARMConstantPoolConstant::Create(MF.getFunction(), PCLabelId,
1439                                              ARMCP::CPLSDA, 4);
1440   else if (ACPV->isMachineBasicBlock())
1441     NewCPV = ARMConstantPoolMBB::
1442       Create(MF.getFunction()->getContext(),
1443              cast<ARMConstantPoolMBB>(ACPV)->getMBB(), PCLabelId, 4);
1444   else
1445     llvm_unreachable("Unexpected ARM constantpool value type!!");
1446   CPI = MCP->getConstantPoolIndex(NewCPV, MCPE.getAlignment());
1447   return PCLabelId;
1448 }
1449 
1450 void ARMBaseInstrInfo::reMaterialize(MachineBasicBlock &MBB,
1451                                      MachineBasicBlock::iterator I,
1452                                      unsigned DestReg, unsigned SubIdx,
1453                                      const MachineInstr &Orig,
1454                                      const TargetRegisterInfo &TRI) const {
1455   unsigned Opcode = Orig.getOpcode();
1456   switch (Opcode) {
1457   default: {
1458     MachineInstr *MI = MBB.getParent()->CloneMachineInstr(&Orig);
1459     MI->substituteRegister(Orig.getOperand(0).getReg(), DestReg, SubIdx, TRI);
1460     MBB.insert(I, MI);
1461     break;
1462   }
1463   case ARM::tLDRpci_pic:
1464   case ARM::t2LDRpci_pic: {
1465     MachineFunction &MF = *MBB.getParent();
1466     unsigned CPI = Orig.getOperand(1).getIndex();
1467     unsigned PCLabelId = duplicateCPV(MF, CPI);
1468     MachineInstrBuilder MIB =
1469         BuildMI(MBB, I, Orig.getDebugLoc(), get(Opcode), DestReg)
1470             .addConstantPoolIndex(CPI)
1471             .addImm(PCLabelId);
1472     MIB->setMemRefs(Orig.memoperands_begin(), Orig.memoperands_end());
1473     break;
1474   }
1475   }
1476 }
1477 
1478 MachineInstr *ARMBaseInstrInfo::duplicate(MachineInstr &Orig,
1479                                           MachineFunction &MF) const {
1480   MachineInstr *MI = TargetInstrInfo::duplicate(Orig, MF);
1481   switch (Orig.getOpcode()) {
1482   case ARM::tLDRpci_pic:
1483   case ARM::t2LDRpci_pic: {
1484     unsigned CPI = Orig.getOperand(1).getIndex();
1485     unsigned PCLabelId = duplicateCPV(MF, CPI);
1486     Orig.getOperand(1).setIndex(CPI);
1487     Orig.getOperand(2).setImm(PCLabelId);
1488     break;
1489   }
1490   }
1491   return MI;
1492 }
1493 
1494 bool ARMBaseInstrInfo::produceSameValue(const MachineInstr &MI0,
1495                                         const MachineInstr &MI1,
1496                                         const MachineRegisterInfo *MRI) const {
1497   unsigned Opcode = MI0.getOpcode();
1498   if (Opcode == ARM::t2LDRpci ||
1499       Opcode == ARM::t2LDRpci_pic ||
1500       Opcode == ARM::tLDRpci ||
1501       Opcode == ARM::tLDRpci_pic ||
1502       Opcode == ARM::LDRLIT_ga_pcrel ||
1503       Opcode == ARM::LDRLIT_ga_pcrel_ldr ||
1504       Opcode == ARM::tLDRLIT_ga_pcrel ||
1505       Opcode == ARM::MOV_ga_pcrel ||
1506       Opcode == ARM::MOV_ga_pcrel_ldr ||
1507       Opcode == ARM::t2MOV_ga_pcrel) {
1508     if (MI1.getOpcode() != Opcode)
1509       return false;
1510     if (MI0.getNumOperands() != MI1.getNumOperands())
1511       return false;
1512 
1513     const MachineOperand &MO0 = MI0.getOperand(1);
1514     const MachineOperand &MO1 = MI1.getOperand(1);
1515     if (MO0.getOffset() != MO1.getOffset())
1516       return false;
1517 
1518     if (Opcode == ARM::LDRLIT_ga_pcrel ||
1519         Opcode == ARM::LDRLIT_ga_pcrel_ldr ||
1520         Opcode == ARM::tLDRLIT_ga_pcrel ||
1521         Opcode == ARM::MOV_ga_pcrel ||
1522         Opcode == ARM::MOV_ga_pcrel_ldr ||
1523         Opcode == ARM::t2MOV_ga_pcrel)
1524       // Ignore the PC labels.
1525       return MO0.getGlobal() == MO1.getGlobal();
1526 
1527     const MachineFunction *MF = MI0.getParent()->getParent();
1528     const MachineConstantPool *MCP = MF->getConstantPool();
1529     int CPI0 = MO0.getIndex();
1530     int CPI1 = MO1.getIndex();
1531     const MachineConstantPoolEntry &MCPE0 = MCP->getConstants()[CPI0];
1532     const MachineConstantPoolEntry &MCPE1 = MCP->getConstants()[CPI1];
1533     bool isARMCP0 = MCPE0.isMachineConstantPoolEntry();
1534     bool isARMCP1 = MCPE1.isMachineConstantPoolEntry();
1535     if (isARMCP0 && isARMCP1) {
1536       ARMConstantPoolValue *ACPV0 =
1537         static_cast<ARMConstantPoolValue*>(MCPE0.Val.MachineCPVal);
1538       ARMConstantPoolValue *ACPV1 =
1539         static_cast<ARMConstantPoolValue*>(MCPE1.Val.MachineCPVal);
1540       return ACPV0->hasSameValue(ACPV1);
1541     } else if (!isARMCP0 && !isARMCP1) {
1542       return MCPE0.Val.ConstVal == MCPE1.Val.ConstVal;
1543     }
1544     return false;
1545   } else if (Opcode == ARM::PICLDR) {
1546     if (MI1.getOpcode() != Opcode)
1547       return false;
1548     if (MI0.getNumOperands() != MI1.getNumOperands())
1549       return false;
1550 
1551     unsigned Addr0 = MI0.getOperand(1).getReg();
1552     unsigned Addr1 = MI1.getOperand(1).getReg();
1553     if (Addr0 != Addr1) {
1554       if (!MRI ||
1555           !TargetRegisterInfo::isVirtualRegister(Addr0) ||
1556           !TargetRegisterInfo::isVirtualRegister(Addr1))
1557         return false;
1558 
1559       // This assumes SSA form.
1560       MachineInstr *Def0 = MRI->getVRegDef(Addr0);
1561       MachineInstr *Def1 = MRI->getVRegDef(Addr1);
1562       // Check if the loaded value, e.g. a constantpool of a global address, are
1563       // the same.
1564       if (!produceSameValue(*Def0, *Def1, MRI))
1565         return false;
1566     }
1567 
1568     for (unsigned i = 3, e = MI0.getNumOperands(); i != e; ++i) {
1569       // %vreg12<def> = PICLDR %vreg11, 0, pred:14, pred:%noreg
1570       const MachineOperand &MO0 = MI0.getOperand(i);
1571       const MachineOperand &MO1 = MI1.getOperand(i);
1572       if (!MO0.isIdenticalTo(MO1))
1573         return false;
1574     }
1575     return true;
1576   }
1577 
1578   return MI0.isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
1579 }
1580 
1581 /// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler to
1582 /// determine if two loads are loading from the same base address. It should
1583 /// only return true if the base pointers are the same and the only differences
1584 /// between the two addresses is the offset. It also returns the offsets by
1585 /// reference.
1586 ///
1587 /// FIXME: remove this in favor of the MachineInstr interface once pre-RA-sched
1588 /// is permanently disabled.
1589 bool ARMBaseInstrInfo::areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2,
1590                                                int64_t &Offset1,
1591                                                int64_t &Offset2) const {
1592   // Don't worry about Thumb: just ARM and Thumb2.
1593   if (Subtarget.isThumb1Only()) return false;
1594 
1595   if (!Load1->isMachineOpcode() || !Load2->isMachineOpcode())
1596     return false;
1597 
1598   switch (Load1->getMachineOpcode()) {
1599   default:
1600     return false;
1601   case ARM::LDRi12:
1602   case ARM::LDRBi12:
1603   case ARM::LDRD:
1604   case ARM::LDRH:
1605   case ARM::LDRSB:
1606   case ARM::LDRSH:
1607   case ARM::VLDRD:
1608   case ARM::VLDRS:
1609   case ARM::t2LDRi8:
1610   case ARM::t2LDRBi8:
1611   case ARM::t2LDRDi8:
1612   case ARM::t2LDRSHi8:
1613   case ARM::t2LDRi12:
1614   case ARM::t2LDRBi12:
1615   case ARM::t2LDRSHi12:
1616     break;
1617   }
1618 
1619   switch (Load2->getMachineOpcode()) {
1620   default:
1621     return false;
1622   case ARM::LDRi12:
1623   case ARM::LDRBi12:
1624   case ARM::LDRD:
1625   case ARM::LDRH:
1626   case ARM::LDRSB:
1627   case ARM::LDRSH:
1628   case ARM::VLDRD:
1629   case ARM::VLDRS:
1630   case ARM::t2LDRi8:
1631   case ARM::t2LDRBi8:
1632   case ARM::t2LDRSHi8:
1633   case ARM::t2LDRi12:
1634   case ARM::t2LDRBi12:
1635   case ARM::t2LDRSHi12:
1636     break;
1637   }
1638 
1639   // Check if base addresses and chain operands match.
1640   if (Load1->getOperand(0) != Load2->getOperand(0) ||
1641       Load1->getOperand(4) != Load2->getOperand(4))
1642     return false;
1643 
1644   // Index should be Reg0.
1645   if (Load1->getOperand(3) != Load2->getOperand(3))
1646     return false;
1647 
1648   // Determine the offsets.
1649   if (isa<ConstantSDNode>(Load1->getOperand(1)) &&
1650       isa<ConstantSDNode>(Load2->getOperand(1))) {
1651     Offset1 = cast<ConstantSDNode>(Load1->getOperand(1))->getSExtValue();
1652     Offset2 = cast<ConstantSDNode>(Load2->getOperand(1))->getSExtValue();
1653     return true;
1654   }
1655 
1656   return false;
1657 }
1658 
1659 /// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
1660 /// determine (in conjunction with areLoadsFromSameBasePtr) if two loads should
1661 /// be scheduled togther. On some targets if two loads are loading from
1662 /// addresses in the same cache line, it's better if they are scheduled
1663 /// together. This function takes two integers that represent the load offsets
1664 /// from the common base address. It returns true if it decides it's desirable
1665 /// to schedule the two loads together. "NumLoads" is the number of loads that
1666 /// have already been scheduled after Load1.
1667 ///
1668 /// FIXME: remove this in favor of the MachineInstr interface once pre-RA-sched
1669 /// is permanently disabled.
1670 bool ARMBaseInstrInfo::shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2,
1671                                                int64_t Offset1, int64_t Offset2,
1672                                                unsigned NumLoads) const {
1673   // Don't worry about Thumb: just ARM and Thumb2.
1674   if (Subtarget.isThumb1Only()) return false;
1675 
1676   assert(Offset2 > Offset1);
1677 
1678   if ((Offset2 - Offset1) / 8 > 64)
1679     return false;
1680 
1681   // Check if the machine opcodes are different. If they are different
1682   // then we consider them to not be of the same base address,
1683   // EXCEPT in the case of Thumb2 byte loads where one is LDRBi8 and the other LDRBi12.
1684   // In this case, they are considered to be the same because they are different
1685   // encoding forms of the same basic instruction.
1686   if ((Load1->getMachineOpcode() != Load2->getMachineOpcode()) &&
1687       !((Load1->getMachineOpcode() == ARM::t2LDRBi8 &&
1688          Load2->getMachineOpcode() == ARM::t2LDRBi12) ||
1689         (Load1->getMachineOpcode() == ARM::t2LDRBi12 &&
1690          Load2->getMachineOpcode() == ARM::t2LDRBi8)))
1691     return false;  // FIXME: overly conservative?
1692 
1693   // Four loads in a row should be sufficient.
1694   if (NumLoads >= 3)
1695     return false;
1696 
1697   return true;
1698 }
1699 
1700 bool ARMBaseInstrInfo::isSchedulingBoundary(const MachineInstr &MI,
1701                                             const MachineBasicBlock *MBB,
1702                                             const MachineFunction &MF) const {
1703   // Debug info is never a scheduling boundary. It's necessary to be explicit
1704   // due to the special treatment of IT instructions below, otherwise a
1705   // dbg_value followed by an IT will result in the IT instruction being
1706   // considered a scheduling hazard, which is wrong. It should be the actual
1707   // instruction preceding the dbg_value instruction(s), just like it is
1708   // when debug info is not present.
1709   if (MI.isDebugValue())
1710     return false;
1711 
1712   // Terminators and labels can't be scheduled around.
1713   if (MI.isTerminator() || MI.isPosition())
1714     return true;
1715 
1716   // Treat the start of the IT block as a scheduling boundary, but schedule
1717   // t2IT along with all instructions following it.
1718   // FIXME: This is a big hammer. But the alternative is to add all potential
1719   // true and anti dependencies to IT block instructions as implicit operands
1720   // to the t2IT instruction. The added compile time and complexity does not
1721   // seem worth it.
1722   MachineBasicBlock::const_iterator I = MI;
1723   // Make sure to skip any dbg_value instructions
1724   while (++I != MBB->end() && I->isDebugValue())
1725     ;
1726   if (I != MBB->end() && I->getOpcode() == ARM::t2IT)
1727     return true;
1728 
1729   // Don't attempt to schedule around any instruction that defines
1730   // a stack-oriented pointer, as it's unlikely to be profitable. This
1731   // saves compile time, because it doesn't require every single
1732   // stack slot reference to depend on the instruction that does the
1733   // modification.
1734   // Calls don't actually change the stack pointer, even if they have imp-defs.
1735   // No ARM calling conventions change the stack pointer. (X86 calling
1736   // conventions sometimes do).
1737   if (!MI.isCall() && MI.definesRegister(ARM::SP))
1738     return true;
1739 
1740   return false;
1741 }
1742 
1743 bool ARMBaseInstrInfo::
1744 isProfitableToIfCvt(MachineBasicBlock &MBB,
1745                     unsigned NumCycles, unsigned ExtraPredCycles,
1746                     BranchProbability Probability) const {
1747   if (!NumCycles)
1748     return false;
1749 
1750   // If we are optimizing for size, see if the branch in the predecessor can be
1751   // lowered to cbn?z by the constant island lowering pass, and return false if
1752   // so. This results in a shorter instruction sequence.
1753   if (MBB.getParent()->getFunction()->optForSize()) {
1754     MachineBasicBlock *Pred = *MBB.pred_begin();
1755     if (!Pred->empty()) {
1756       MachineInstr *LastMI = &*Pred->rbegin();
1757       if (LastMI->getOpcode() == ARM::t2Bcc) {
1758         MachineBasicBlock::iterator CmpMI = LastMI;
1759         if (CmpMI != Pred->begin()) {
1760           --CmpMI;
1761           if (CmpMI->getOpcode() == ARM::tCMPi8 ||
1762               CmpMI->getOpcode() == ARM::t2CMPri) {
1763             unsigned Reg = CmpMI->getOperand(0).getReg();
1764             unsigned PredReg = 0;
1765             ARMCC::CondCodes P = getInstrPredicate(*CmpMI, PredReg);
1766             if (P == ARMCC::AL && CmpMI->getOperand(1).getImm() == 0 &&
1767                 isARMLowRegister(Reg))
1768               return false;
1769           }
1770         }
1771       }
1772     }
1773   }
1774 
1775   // Attempt to estimate the relative costs of predication versus branching.
1776   // Here we scale up each component of UnpredCost to avoid precision issue when
1777   // scaling NumCycles by Probability.
1778   const unsigned ScalingUpFactor = 1024;
1779   unsigned UnpredCost = Probability.scale(NumCycles * ScalingUpFactor);
1780   UnpredCost += ScalingUpFactor; // The branch itself
1781   UnpredCost += Subtarget.getMispredictionPenalty() * ScalingUpFactor / 10;
1782 
1783   return (NumCycles + ExtraPredCycles) * ScalingUpFactor <= UnpredCost;
1784 }
1785 
1786 bool ARMBaseInstrInfo::
1787 isProfitableToIfCvt(MachineBasicBlock &TMBB,
1788                     unsigned TCycles, unsigned TExtra,
1789                     MachineBasicBlock &FMBB,
1790                     unsigned FCycles, unsigned FExtra,
1791                     BranchProbability Probability) const {
1792   if (!TCycles || !FCycles)
1793     return false;
1794 
1795   // Attempt to estimate the relative costs of predication versus branching.
1796   // Here we scale up each component of UnpredCost to avoid precision issue when
1797   // scaling TCycles/FCycles by Probability.
1798   const unsigned ScalingUpFactor = 1024;
1799   unsigned TUnpredCost = Probability.scale(TCycles * ScalingUpFactor);
1800   unsigned FUnpredCost =
1801       Probability.getCompl().scale(FCycles * ScalingUpFactor);
1802   unsigned UnpredCost = TUnpredCost + FUnpredCost;
1803   UnpredCost += 1 * ScalingUpFactor; // The branch itself
1804   UnpredCost += Subtarget.getMispredictionPenalty() * ScalingUpFactor / 10;
1805 
1806   return (TCycles + FCycles + TExtra + FExtra) * ScalingUpFactor <= UnpredCost;
1807 }
1808 
1809 bool
1810 ARMBaseInstrInfo::isProfitableToUnpredicate(MachineBasicBlock &TMBB,
1811                                             MachineBasicBlock &FMBB) const {
1812   // Reduce false anti-dependencies to let the target's out-of-order execution
1813   // engine do its thing.
1814   return Subtarget.isProfitableToUnpredicate();
1815 }
1816 
1817 /// getInstrPredicate - If instruction is predicated, returns its predicate
1818 /// condition, otherwise returns AL. It also returns the condition code
1819 /// register by reference.
1820 ARMCC::CondCodes llvm::getInstrPredicate(const MachineInstr &MI,
1821                                          unsigned &PredReg) {
1822   int PIdx = MI.findFirstPredOperandIdx();
1823   if (PIdx == -1) {
1824     PredReg = 0;
1825     return ARMCC::AL;
1826   }
1827 
1828   PredReg = MI.getOperand(PIdx+1).getReg();
1829   return (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
1830 }
1831 
1832 
1833 unsigned llvm::getMatchingCondBranchOpcode(unsigned Opc) {
1834   if (Opc == ARM::B)
1835     return ARM::Bcc;
1836   if (Opc == ARM::tB)
1837     return ARM::tBcc;
1838   if (Opc == ARM::t2B)
1839     return ARM::t2Bcc;
1840 
1841   llvm_unreachable("Unknown unconditional branch opcode!");
1842 }
1843 
1844 MachineInstr *ARMBaseInstrInfo::commuteInstructionImpl(MachineInstr &MI,
1845                                                        bool NewMI,
1846                                                        unsigned OpIdx1,
1847                                                        unsigned OpIdx2) const {
1848   switch (MI.getOpcode()) {
1849   case ARM::MOVCCr:
1850   case ARM::t2MOVCCr: {
1851     // MOVCC can be commuted by inverting the condition.
1852     unsigned PredReg = 0;
1853     ARMCC::CondCodes CC = getInstrPredicate(MI, PredReg);
1854     // MOVCC AL can't be inverted. Shouldn't happen.
1855     if (CC == ARMCC::AL || PredReg != ARM::CPSR)
1856       return nullptr;
1857     MachineInstr *CommutedMI =
1858         TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
1859     if (!CommutedMI)
1860       return nullptr;
1861     // After swapping the MOVCC operands, also invert the condition.
1862     CommutedMI->getOperand(CommutedMI->findFirstPredOperandIdx())
1863         .setImm(ARMCC::getOppositeCondition(CC));
1864     return CommutedMI;
1865   }
1866   }
1867   return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
1868 }
1869 
1870 /// Identify instructions that can be folded into a MOVCC instruction, and
1871 /// return the defining instruction.
1872 static MachineInstr *canFoldIntoMOVCC(unsigned Reg,
1873                                       const MachineRegisterInfo &MRI,
1874                                       const TargetInstrInfo *TII) {
1875   if (!TargetRegisterInfo::isVirtualRegister(Reg))
1876     return nullptr;
1877   if (!MRI.hasOneNonDBGUse(Reg))
1878     return nullptr;
1879   MachineInstr *MI = MRI.getVRegDef(Reg);
1880   if (!MI)
1881     return nullptr;
1882   // MI is folded into the MOVCC by predicating it.
1883   if (!MI->isPredicable())
1884     return nullptr;
1885   // Check if MI has any non-dead defs or physreg uses. This also detects
1886   // predicated instructions which will be reading CPSR.
1887   for (unsigned i = 1, e = MI->getNumOperands(); i != e; ++i) {
1888     const MachineOperand &MO = MI->getOperand(i);
1889     // Reject frame index operands, PEI can't handle the predicated pseudos.
1890     if (MO.isFI() || MO.isCPI() || MO.isJTI())
1891       return nullptr;
1892     if (!MO.isReg())
1893       continue;
1894     // MI can't have any tied operands, that would conflict with predication.
1895     if (MO.isTied())
1896       return nullptr;
1897     if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
1898       return nullptr;
1899     if (MO.isDef() && !MO.isDead())
1900       return nullptr;
1901   }
1902   bool DontMoveAcrossStores = true;
1903   if (!MI->isSafeToMove(/* AliasAnalysis = */ nullptr, DontMoveAcrossStores))
1904     return nullptr;
1905   return MI;
1906 }
1907 
1908 bool ARMBaseInstrInfo::analyzeSelect(const MachineInstr &MI,
1909                                      SmallVectorImpl<MachineOperand> &Cond,
1910                                      unsigned &TrueOp, unsigned &FalseOp,
1911                                      bool &Optimizable) const {
1912   assert((MI.getOpcode() == ARM::MOVCCr || MI.getOpcode() == ARM::t2MOVCCr) &&
1913          "Unknown select instruction");
1914   // MOVCC operands:
1915   // 0: Def.
1916   // 1: True use.
1917   // 2: False use.
1918   // 3: Condition code.
1919   // 4: CPSR use.
1920   TrueOp = 1;
1921   FalseOp = 2;
1922   Cond.push_back(MI.getOperand(3));
1923   Cond.push_back(MI.getOperand(4));
1924   // We can always fold a def.
1925   Optimizable = true;
1926   return false;
1927 }
1928 
1929 MachineInstr *
1930 ARMBaseInstrInfo::optimizeSelect(MachineInstr &MI,
1931                                  SmallPtrSetImpl<MachineInstr *> &SeenMIs,
1932                                  bool PreferFalse) const {
1933   assert((MI.getOpcode() == ARM::MOVCCr || MI.getOpcode() == ARM::t2MOVCCr) &&
1934          "Unknown select instruction");
1935   MachineRegisterInfo &MRI = MI.getParent()->getParent()->getRegInfo();
1936   MachineInstr *DefMI = canFoldIntoMOVCC(MI.getOperand(2).getReg(), MRI, this);
1937   bool Invert = !DefMI;
1938   if (!DefMI)
1939     DefMI = canFoldIntoMOVCC(MI.getOperand(1).getReg(), MRI, this);
1940   if (!DefMI)
1941     return nullptr;
1942 
1943   // Find new register class to use.
1944   MachineOperand FalseReg = MI.getOperand(Invert ? 2 : 1);
1945   unsigned DestReg = MI.getOperand(0).getReg();
1946   const TargetRegisterClass *PreviousClass = MRI.getRegClass(FalseReg.getReg());
1947   if (!MRI.constrainRegClass(DestReg, PreviousClass))
1948     return nullptr;
1949 
1950   // Create a new predicated version of DefMI.
1951   // Rfalse is the first use.
1952   MachineInstrBuilder NewMI =
1953       BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), DefMI->getDesc(), DestReg);
1954 
1955   // Copy all the DefMI operands, excluding its (null) predicate.
1956   const MCInstrDesc &DefDesc = DefMI->getDesc();
1957   for (unsigned i = 1, e = DefDesc.getNumOperands();
1958        i != e && !DefDesc.OpInfo[i].isPredicate(); ++i)
1959     NewMI.add(DefMI->getOperand(i));
1960 
1961   unsigned CondCode = MI.getOperand(3).getImm();
1962   if (Invert)
1963     NewMI.addImm(ARMCC::getOppositeCondition(ARMCC::CondCodes(CondCode)));
1964   else
1965     NewMI.addImm(CondCode);
1966   NewMI.add(MI.getOperand(4));
1967 
1968   // DefMI is not the -S version that sets CPSR, so add an optional %noreg.
1969   if (NewMI->hasOptionalDef())
1970     NewMI.add(condCodeOp());
1971 
1972   // The output register value when the predicate is false is an implicit
1973   // register operand tied to the first def.
1974   // The tie makes the register allocator ensure the FalseReg is allocated the
1975   // same register as operand 0.
1976   FalseReg.setImplicit();
1977   NewMI.add(FalseReg);
1978   NewMI->tieOperands(0, NewMI->getNumOperands() - 1);
1979 
1980   // Update SeenMIs set: register newly created MI and erase removed DefMI.
1981   SeenMIs.insert(NewMI);
1982   SeenMIs.erase(DefMI);
1983 
1984   // If MI is inside a loop, and DefMI is outside the loop, then kill flags on
1985   // DefMI would be invalid when tranferred inside the loop.  Checking for a
1986   // loop is expensive, but at least remove kill flags if they are in different
1987   // BBs.
1988   if (DefMI->getParent() != MI.getParent())
1989     NewMI->clearKillInfo();
1990 
1991   // The caller will erase MI, but not DefMI.
1992   DefMI->eraseFromParent();
1993   return NewMI;
1994 }
1995 
1996 /// Map pseudo instructions that imply an 'S' bit onto real opcodes. Whether the
1997 /// instruction is encoded with an 'S' bit is determined by the optional CPSR
1998 /// def operand.
1999 ///
2000 /// This will go away once we can teach tblgen how to set the optional CPSR def
2001 /// operand itself.
2002 struct AddSubFlagsOpcodePair {
2003   uint16_t PseudoOpc;
2004   uint16_t MachineOpc;
2005 };
2006 
2007 static const AddSubFlagsOpcodePair AddSubFlagsOpcodeMap[] = {
2008   {ARM::ADDSri, ARM::ADDri},
2009   {ARM::ADDSrr, ARM::ADDrr},
2010   {ARM::ADDSrsi, ARM::ADDrsi},
2011   {ARM::ADDSrsr, ARM::ADDrsr},
2012 
2013   {ARM::SUBSri, ARM::SUBri},
2014   {ARM::SUBSrr, ARM::SUBrr},
2015   {ARM::SUBSrsi, ARM::SUBrsi},
2016   {ARM::SUBSrsr, ARM::SUBrsr},
2017 
2018   {ARM::RSBSri, ARM::RSBri},
2019   {ARM::RSBSrsi, ARM::RSBrsi},
2020   {ARM::RSBSrsr, ARM::RSBrsr},
2021 
2022   {ARM::t2ADDSri, ARM::t2ADDri},
2023   {ARM::t2ADDSrr, ARM::t2ADDrr},
2024   {ARM::t2ADDSrs, ARM::t2ADDrs},
2025 
2026   {ARM::t2SUBSri, ARM::t2SUBri},
2027   {ARM::t2SUBSrr, ARM::t2SUBrr},
2028   {ARM::t2SUBSrs, ARM::t2SUBrs},
2029 
2030   {ARM::t2RSBSri, ARM::t2RSBri},
2031   {ARM::t2RSBSrs, ARM::t2RSBrs},
2032 };
2033 
2034 unsigned llvm::convertAddSubFlagsOpcode(unsigned OldOpc) {
2035   for (unsigned i = 0, e = array_lengthof(AddSubFlagsOpcodeMap); i != e; ++i)
2036     if (OldOpc == AddSubFlagsOpcodeMap[i].PseudoOpc)
2037       return AddSubFlagsOpcodeMap[i].MachineOpc;
2038   return 0;
2039 }
2040 
2041 void llvm::emitARMRegPlusImmediate(MachineBasicBlock &MBB,
2042                                    MachineBasicBlock::iterator &MBBI,
2043                                    const DebugLoc &dl, unsigned DestReg,
2044                                    unsigned BaseReg, int NumBytes,
2045                                    ARMCC::CondCodes Pred, unsigned PredReg,
2046                                    const ARMBaseInstrInfo &TII,
2047                                    unsigned MIFlags) {
2048   if (NumBytes == 0 && DestReg != BaseReg) {
2049     BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), DestReg)
2050       .addReg(BaseReg, RegState::Kill)
2051       .addImm((unsigned)Pred).addReg(PredReg).addReg(0)
2052       .setMIFlags(MIFlags);
2053     return;
2054   }
2055 
2056   bool isSub = NumBytes < 0;
2057   if (isSub) NumBytes = -NumBytes;
2058 
2059   while (NumBytes) {
2060     unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
2061     unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
2062     assert(ThisVal && "Didn't extract field correctly");
2063 
2064     // We will handle these bits from offset, clear them.
2065     NumBytes &= ~ThisVal;
2066 
2067     assert(ARM_AM::getSOImmVal(ThisVal) != -1 && "Bit extraction didn't work?");
2068 
2069     // Build the new ADD / SUB.
2070     unsigned Opc = isSub ? ARM::SUBri : ARM::ADDri;
2071     BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
2072       .addReg(BaseReg, RegState::Kill).addImm(ThisVal)
2073       .addImm((unsigned)Pred).addReg(PredReg).addReg(0)
2074       .setMIFlags(MIFlags);
2075     BaseReg = DestReg;
2076   }
2077 }
2078 
2079 bool llvm::tryFoldSPUpdateIntoPushPop(const ARMSubtarget &Subtarget,
2080                                       MachineFunction &MF, MachineInstr *MI,
2081                                       unsigned NumBytes) {
2082   // This optimisation potentially adds lots of load and store
2083   // micro-operations, it's only really a great benefit to code-size.
2084   if (!MF.getFunction()->optForMinSize())
2085     return false;
2086 
2087   // If only one register is pushed/popped, LLVM can use an LDR/STR
2088   // instead. We can't modify those so make sure we're dealing with an
2089   // instruction we understand.
2090   bool IsPop = isPopOpcode(MI->getOpcode());
2091   bool IsPush = isPushOpcode(MI->getOpcode());
2092   if (!IsPush && !IsPop)
2093     return false;
2094 
2095   bool IsVFPPushPop = MI->getOpcode() == ARM::VSTMDDB_UPD ||
2096                       MI->getOpcode() == ARM::VLDMDIA_UPD;
2097   bool IsT1PushPop = MI->getOpcode() == ARM::tPUSH ||
2098                      MI->getOpcode() == ARM::tPOP ||
2099                      MI->getOpcode() == ARM::tPOP_RET;
2100 
2101   assert((IsT1PushPop || (MI->getOperand(0).getReg() == ARM::SP &&
2102                           MI->getOperand(1).getReg() == ARM::SP)) &&
2103          "trying to fold sp update into non-sp-updating push/pop");
2104 
2105   // The VFP push & pop act on D-registers, so we can only fold an adjustment
2106   // by a multiple of 8 bytes in correctly. Similarly rN is 4-bytes. Don't try
2107   // if this is violated.
2108   if (NumBytes % (IsVFPPushPop ? 8 : 4) != 0)
2109     return false;
2110 
2111   // ARM and Thumb2 push/pop insts have explicit "sp, sp" operands (+
2112   // pred) so the list starts at 4. Thumb1 starts after the predicate.
2113   int RegListIdx = IsT1PushPop ? 2 : 4;
2114 
2115   // Calculate the space we'll need in terms of registers.
2116   unsigned RegsNeeded;
2117   const TargetRegisterClass *RegClass;
2118   if (IsVFPPushPop) {
2119     RegsNeeded = NumBytes / 8;
2120     RegClass = &ARM::DPRRegClass;
2121   } else {
2122     RegsNeeded = NumBytes / 4;
2123     RegClass = &ARM::GPRRegClass;
2124   }
2125 
2126   // We're going to have to strip all list operands off before
2127   // re-adding them since the order matters, so save the existing ones
2128   // for later.
2129   SmallVector<MachineOperand, 4> RegList;
2130 
2131   // We're also going to need the first register transferred by this
2132   // instruction, which won't necessarily be the first register in the list.
2133   unsigned FirstRegEnc = -1;
2134 
2135   const TargetRegisterInfo *TRI = MF.getRegInfo().getTargetRegisterInfo();
2136   for (int i = MI->getNumOperands() - 1; i >= RegListIdx; --i) {
2137     MachineOperand &MO = MI->getOperand(i);
2138     RegList.push_back(MO);
2139 
2140     if (MO.isReg() && TRI->getEncodingValue(MO.getReg()) < FirstRegEnc)
2141       FirstRegEnc = TRI->getEncodingValue(MO.getReg());
2142   }
2143 
2144   const MCPhysReg *CSRegs = TRI->getCalleeSavedRegs(&MF);
2145 
2146   // Now try to find enough space in the reglist to allocate NumBytes.
2147   for (int CurRegEnc = FirstRegEnc - 1; CurRegEnc >= 0 && RegsNeeded;
2148        --CurRegEnc) {
2149     unsigned CurReg = RegClass->getRegister(CurRegEnc);
2150     if (!IsPop) {
2151       // Pushing any register is completely harmless, mark the
2152       // register involved as undef since we don't care about it in
2153       // the slightest.
2154       RegList.push_back(MachineOperand::CreateReg(CurReg, false, false,
2155                                                   false, false, true));
2156       --RegsNeeded;
2157       continue;
2158     }
2159 
2160     // However, we can only pop an extra register if it's not live. For
2161     // registers live within the function we might clobber a return value
2162     // register; the other way a register can be live here is if it's
2163     // callee-saved.
2164     if (isCalleeSavedRegister(CurReg, CSRegs) ||
2165         MI->getParent()->computeRegisterLiveness(TRI, CurReg, MI) !=
2166         MachineBasicBlock::LQR_Dead) {
2167       // VFP pops don't allow holes in the register list, so any skip is fatal
2168       // for our transformation. GPR pops do, so we should just keep looking.
2169       if (IsVFPPushPop)
2170         return false;
2171       else
2172         continue;
2173     }
2174 
2175     // Mark the unimportant registers as <def,dead> in the POP.
2176     RegList.push_back(MachineOperand::CreateReg(CurReg, true, false, false,
2177                                                 true));
2178     --RegsNeeded;
2179   }
2180 
2181   if (RegsNeeded > 0)
2182     return false;
2183 
2184   // Finally we know we can profitably perform the optimisation so go
2185   // ahead: strip all existing registers off and add them back again
2186   // in the right order.
2187   for (int i = MI->getNumOperands() - 1; i >= RegListIdx; --i)
2188     MI->RemoveOperand(i);
2189 
2190   // Add the complete list back in.
2191   MachineInstrBuilder MIB(MF, &*MI);
2192   for (int i = RegList.size() - 1; i >= 0; --i)
2193     MIB.add(RegList[i]);
2194 
2195   return true;
2196 }
2197 
2198 bool llvm::rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
2199                                 unsigned FrameReg, int &Offset,
2200                                 const ARMBaseInstrInfo &TII) {
2201   unsigned Opcode = MI.getOpcode();
2202   const MCInstrDesc &Desc = MI.getDesc();
2203   unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
2204   bool isSub = false;
2205 
2206   // Memory operands in inline assembly always use AddrMode2.
2207   if (Opcode == ARM::INLINEASM)
2208     AddrMode = ARMII::AddrMode2;
2209 
2210   if (Opcode == ARM::ADDri) {
2211     Offset += MI.getOperand(FrameRegIdx+1).getImm();
2212     if (Offset == 0) {
2213       // Turn it into a move.
2214       MI.setDesc(TII.get(ARM::MOVr));
2215       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
2216       MI.RemoveOperand(FrameRegIdx+1);
2217       Offset = 0;
2218       return true;
2219     } else if (Offset < 0) {
2220       Offset = -Offset;
2221       isSub = true;
2222       MI.setDesc(TII.get(ARM::SUBri));
2223     }
2224 
2225     // Common case: small offset, fits into instruction.
2226     if (ARM_AM::getSOImmVal(Offset) != -1) {
2227       // Replace the FrameIndex with sp / fp
2228       MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
2229       MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
2230       Offset = 0;
2231       return true;
2232     }
2233 
2234     // Otherwise, pull as much of the immedidate into this ADDri/SUBri
2235     // as possible.
2236     unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
2237     unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
2238 
2239     // We will handle these bits from offset, clear them.
2240     Offset &= ~ThisImmVal;
2241 
2242     // Get the properly encoded SOImmVal field.
2243     assert(ARM_AM::getSOImmVal(ThisImmVal) != -1 &&
2244            "Bit extraction didn't work?");
2245     MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
2246  } else {
2247     unsigned ImmIdx = 0;
2248     int InstrOffs = 0;
2249     unsigned NumBits = 0;
2250     unsigned Scale = 1;
2251     switch (AddrMode) {
2252     case ARMII::AddrMode_i12: {
2253       ImmIdx = FrameRegIdx + 1;
2254       InstrOffs = MI.getOperand(ImmIdx).getImm();
2255       NumBits = 12;
2256       break;
2257     }
2258     case ARMII::AddrMode2: {
2259       ImmIdx = FrameRegIdx+2;
2260       InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
2261       if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
2262         InstrOffs *= -1;
2263       NumBits = 12;
2264       break;
2265     }
2266     case ARMII::AddrMode3: {
2267       ImmIdx = FrameRegIdx+2;
2268       InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
2269       if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
2270         InstrOffs *= -1;
2271       NumBits = 8;
2272       break;
2273     }
2274     case ARMII::AddrMode4:
2275     case ARMII::AddrMode6:
2276       // Can't fold any offset even if it's zero.
2277       return false;
2278     case ARMII::AddrMode5: {
2279       ImmIdx = FrameRegIdx+1;
2280       InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
2281       if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
2282         InstrOffs *= -1;
2283       NumBits = 8;
2284       Scale = 4;
2285       break;
2286     }
2287     default:
2288       llvm_unreachable("Unsupported addressing mode!");
2289     }
2290 
2291     Offset += InstrOffs * Scale;
2292     assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
2293     if (Offset < 0) {
2294       Offset = -Offset;
2295       isSub = true;
2296     }
2297 
2298     // Attempt to fold address comp. if opcode has offset bits
2299     if (NumBits > 0) {
2300       // Common case: small offset, fits into instruction.
2301       MachineOperand &ImmOp = MI.getOperand(ImmIdx);
2302       int ImmedOffset = Offset / Scale;
2303       unsigned Mask = (1 << NumBits) - 1;
2304       if ((unsigned)Offset <= Mask * Scale) {
2305         // Replace the FrameIndex with sp
2306         MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
2307         // FIXME: When addrmode2 goes away, this will simplify (like the
2308         // T2 version), as the LDR.i12 versions don't need the encoding
2309         // tricks for the offset value.
2310         if (isSub) {
2311           if (AddrMode == ARMII::AddrMode_i12)
2312             ImmedOffset = -ImmedOffset;
2313           else
2314             ImmedOffset |= 1 << NumBits;
2315         }
2316         ImmOp.ChangeToImmediate(ImmedOffset);
2317         Offset = 0;
2318         return true;
2319       }
2320 
2321       // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
2322       ImmedOffset = ImmedOffset & Mask;
2323       if (isSub) {
2324         if (AddrMode == ARMII::AddrMode_i12)
2325           ImmedOffset = -ImmedOffset;
2326         else
2327           ImmedOffset |= 1 << NumBits;
2328       }
2329       ImmOp.ChangeToImmediate(ImmedOffset);
2330       Offset &= ~(Mask*Scale);
2331     }
2332   }
2333 
2334   Offset = (isSub) ? -Offset : Offset;
2335   return Offset == 0;
2336 }
2337 
2338 /// analyzeCompare - For a comparison instruction, return the source registers
2339 /// in SrcReg and SrcReg2 if having two register operands, and the value it
2340 /// compares against in CmpValue. Return true if the comparison instruction
2341 /// can be analyzed.
2342 bool ARMBaseInstrInfo::analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
2343                                       unsigned &SrcReg2, int &CmpMask,
2344                                       int &CmpValue) const {
2345   switch (MI.getOpcode()) {
2346   default: break;
2347   case ARM::CMPri:
2348   case ARM::t2CMPri:
2349   case ARM::tCMPi8:
2350     SrcReg = MI.getOperand(0).getReg();
2351     SrcReg2 = 0;
2352     CmpMask = ~0;
2353     CmpValue = MI.getOperand(1).getImm();
2354     return true;
2355   case ARM::CMPrr:
2356   case ARM::t2CMPrr:
2357     SrcReg = MI.getOperand(0).getReg();
2358     SrcReg2 = MI.getOperand(1).getReg();
2359     CmpMask = ~0;
2360     CmpValue = 0;
2361     return true;
2362   case ARM::TSTri:
2363   case ARM::t2TSTri:
2364     SrcReg = MI.getOperand(0).getReg();
2365     SrcReg2 = 0;
2366     CmpMask = MI.getOperand(1).getImm();
2367     CmpValue = 0;
2368     return true;
2369   }
2370 
2371   return false;
2372 }
2373 
2374 /// isSuitableForMask - Identify a suitable 'and' instruction that
2375 /// operates on the given source register and applies the same mask
2376 /// as a 'tst' instruction. Provide a limited look-through for copies.
2377 /// When successful, MI will hold the found instruction.
2378 static bool isSuitableForMask(MachineInstr *&MI, unsigned SrcReg,
2379                               int CmpMask, bool CommonUse) {
2380   switch (MI->getOpcode()) {
2381     case ARM::ANDri:
2382     case ARM::t2ANDri:
2383       if (CmpMask != MI->getOperand(2).getImm())
2384         return false;
2385       if (SrcReg == MI->getOperand(CommonUse ? 1 : 0).getReg())
2386         return true;
2387       break;
2388   }
2389 
2390   return false;
2391 }
2392 
2393 /// getSwappedCondition - assume the flags are set by MI(a,b), return
2394 /// the condition code if we modify the instructions such that flags are
2395 /// set by MI(b,a).
2396 inline static ARMCC::CondCodes getSwappedCondition(ARMCC::CondCodes CC) {
2397   switch (CC) {
2398   default: return ARMCC::AL;
2399   case ARMCC::EQ: return ARMCC::EQ;
2400   case ARMCC::NE: return ARMCC::NE;
2401   case ARMCC::HS: return ARMCC::LS;
2402   case ARMCC::LO: return ARMCC::HI;
2403   case ARMCC::HI: return ARMCC::LO;
2404   case ARMCC::LS: return ARMCC::HS;
2405   case ARMCC::GE: return ARMCC::LE;
2406   case ARMCC::LT: return ARMCC::GT;
2407   case ARMCC::GT: return ARMCC::LT;
2408   case ARMCC::LE: return ARMCC::GE;
2409   }
2410 }
2411 
2412 /// isRedundantFlagInstr - check whether the first instruction, whose only
2413 /// purpose is to update flags, can be made redundant.
2414 /// CMPrr can be made redundant by SUBrr if the operands are the same.
2415 /// CMPri can be made redundant by SUBri if the operands are the same.
2416 /// This function can be extended later on.
2417 inline static bool isRedundantFlagInstr(MachineInstr *CmpI, unsigned SrcReg,
2418                                         unsigned SrcReg2, int ImmValue,
2419                                         MachineInstr *OI) {
2420   if ((CmpI->getOpcode() == ARM::CMPrr ||
2421        CmpI->getOpcode() == ARM::t2CMPrr) &&
2422       (OI->getOpcode() == ARM::SUBrr ||
2423        OI->getOpcode() == ARM::t2SUBrr) &&
2424       ((OI->getOperand(1).getReg() == SrcReg &&
2425         OI->getOperand(2).getReg() == SrcReg2) ||
2426        (OI->getOperand(1).getReg() == SrcReg2 &&
2427         OI->getOperand(2).getReg() == SrcReg)))
2428     return true;
2429 
2430   if ((CmpI->getOpcode() == ARM::CMPri ||
2431        CmpI->getOpcode() == ARM::t2CMPri) &&
2432       (OI->getOpcode() == ARM::SUBri ||
2433        OI->getOpcode() == ARM::t2SUBri) &&
2434       OI->getOperand(1).getReg() == SrcReg &&
2435       OI->getOperand(2).getImm() == ImmValue)
2436     return true;
2437   return false;
2438 }
2439 
2440 /// optimizeCompareInstr - Convert the instruction supplying the argument to the
2441 /// comparison into one that sets the zero bit in the flags register;
2442 /// Remove a redundant Compare instruction if an earlier instruction can set the
2443 /// flags in the same way as Compare.
2444 /// E.g. SUBrr(r1,r2) and CMPrr(r1,r2). We also handle the case where two
2445 /// operands are swapped: SUBrr(r1,r2) and CMPrr(r2,r1), by updating the
2446 /// condition code of instructions which use the flags.
2447 bool ARMBaseInstrInfo::optimizeCompareInstr(
2448     MachineInstr &CmpInstr, unsigned SrcReg, unsigned SrcReg2, int CmpMask,
2449     int CmpValue, const MachineRegisterInfo *MRI) const {
2450   // Get the unique definition of SrcReg.
2451   MachineInstr *MI = MRI->getUniqueVRegDef(SrcReg);
2452   if (!MI) return false;
2453 
2454   // Masked compares sometimes use the same register as the corresponding 'and'.
2455   if (CmpMask != ~0) {
2456     if (!isSuitableForMask(MI, SrcReg, CmpMask, false) || isPredicated(*MI)) {
2457       MI = nullptr;
2458       for (MachineRegisterInfo::use_instr_iterator
2459            UI = MRI->use_instr_begin(SrcReg), UE = MRI->use_instr_end();
2460            UI != UE; ++UI) {
2461         if (UI->getParent() != CmpInstr.getParent())
2462           continue;
2463         MachineInstr *PotentialAND = &*UI;
2464         if (!isSuitableForMask(PotentialAND, SrcReg, CmpMask, true) ||
2465             isPredicated(*PotentialAND))
2466           continue;
2467         MI = PotentialAND;
2468         break;
2469       }
2470       if (!MI) return false;
2471     }
2472   }
2473 
2474   // Get ready to iterate backward from CmpInstr.
2475   MachineBasicBlock::iterator I = CmpInstr, E = MI,
2476                               B = CmpInstr.getParent()->begin();
2477 
2478   // Early exit if CmpInstr is at the beginning of the BB.
2479   if (I == B) return false;
2480 
2481   // There are two possible candidates which can be changed to set CPSR:
2482   // One is MI, the other is a SUB instruction.
2483   // For CMPrr(r1,r2), we are looking for SUB(r1,r2) or SUB(r2,r1).
2484   // For CMPri(r1, CmpValue), we are looking for SUBri(r1, CmpValue).
2485   MachineInstr *Sub = nullptr;
2486   if (SrcReg2 != 0)
2487     // MI is not a candidate for CMPrr.
2488     MI = nullptr;
2489   else if (MI->getParent() != CmpInstr.getParent() || CmpValue != 0) {
2490     // Conservatively refuse to convert an instruction which isn't in the same
2491     // BB as the comparison.
2492     // For CMPri w/ CmpValue != 0, a Sub may still be a candidate.
2493     // Thus we cannot return here.
2494     if (CmpInstr.getOpcode() == ARM::CMPri ||
2495         CmpInstr.getOpcode() == ARM::t2CMPri)
2496       MI = nullptr;
2497     else
2498       return false;
2499   }
2500 
2501   // Check that CPSR isn't set between the comparison instruction and the one we
2502   // want to change. At the same time, search for Sub.
2503   const TargetRegisterInfo *TRI = &getRegisterInfo();
2504   --I;
2505   for (; I != E; --I) {
2506     const MachineInstr &Instr = *I;
2507 
2508     if (Instr.modifiesRegister(ARM::CPSR, TRI) ||
2509         Instr.readsRegister(ARM::CPSR, TRI))
2510       // This instruction modifies or uses CPSR after the one we want to
2511       // change. We can't do this transformation.
2512       return false;
2513 
2514     // Check whether CmpInstr can be made redundant by the current instruction.
2515     if (isRedundantFlagInstr(&CmpInstr, SrcReg, SrcReg2, CmpValue, &*I)) {
2516       Sub = &*I;
2517       break;
2518     }
2519 
2520     if (I == B)
2521       // The 'and' is below the comparison instruction.
2522       return false;
2523   }
2524 
2525   // Return false if no candidates exist.
2526   if (!MI && !Sub)
2527     return false;
2528 
2529   // The single candidate is called MI.
2530   if (!MI) MI = Sub;
2531 
2532   // We can't use a predicated instruction - it doesn't always write the flags.
2533   if (isPredicated(*MI))
2534     return false;
2535 
2536   bool IsThumb1 = false;
2537   switch (MI->getOpcode()) {
2538   default: break;
2539   case ARM::tLSLri:
2540   case ARM::tLSRri:
2541   case ARM::tLSLrr:
2542   case ARM::tLSRrr:
2543   case ARM::tSUBrr:
2544   case ARM::tADDrr:
2545   case ARM::tADDi3:
2546   case ARM::tADDi8:
2547   case ARM::tSUBi3:
2548   case ARM::tSUBi8:
2549     IsThumb1 = true;
2550     LLVM_FALLTHROUGH;
2551   case ARM::RSBrr:
2552   case ARM::RSBri:
2553   case ARM::RSCrr:
2554   case ARM::RSCri:
2555   case ARM::ADDrr:
2556   case ARM::ADDri:
2557   case ARM::ADCrr:
2558   case ARM::ADCri:
2559   case ARM::SUBrr:
2560   case ARM::SUBri:
2561   case ARM::SBCrr:
2562   case ARM::SBCri:
2563   case ARM::t2RSBri:
2564   case ARM::t2ADDrr:
2565   case ARM::t2ADDri:
2566   case ARM::t2ADCrr:
2567   case ARM::t2ADCri:
2568   case ARM::t2SUBrr:
2569   case ARM::t2SUBri:
2570   case ARM::t2SBCrr:
2571   case ARM::t2SBCri:
2572   case ARM::ANDrr:
2573   case ARM::ANDri:
2574   case ARM::t2ANDrr:
2575   case ARM::t2ANDri:
2576   case ARM::ORRrr:
2577   case ARM::ORRri:
2578   case ARM::t2ORRrr:
2579   case ARM::t2ORRri:
2580   case ARM::EORrr:
2581   case ARM::EORri:
2582   case ARM::t2EORrr:
2583   case ARM::t2EORri:
2584   case ARM::t2LSRri:
2585   case ARM::t2LSRrr:
2586   case ARM::t2LSLri:
2587   case ARM::t2LSLrr: {
2588     // Scan forward for the use of CPSR
2589     // When checking against MI: if it's a conditional code that requires
2590     // checking of the V bit or C bit, then this is not safe to do.
2591     // It is safe to remove CmpInstr if CPSR is redefined or killed.
2592     // If we are done with the basic block, we need to check whether CPSR is
2593     // live-out.
2594     SmallVector<std::pair<MachineOperand*, ARMCC::CondCodes>, 4>
2595         OperandsToUpdate;
2596     bool isSafe = false;
2597     I = CmpInstr;
2598     E = CmpInstr.getParent()->end();
2599     while (!isSafe && ++I != E) {
2600       const MachineInstr &Instr = *I;
2601       for (unsigned IO = 0, EO = Instr.getNumOperands();
2602            !isSafe && IO != EO; ++IO) {
2603         const MachineOperand &MO = Instr.getOperand(IO);
2604         if (MO.isRegMask() && MO.clobbersPhysReg(ARM::CPSR)) {
2605           isSafe = true;
2606           break;
2607         }
2608         if (!MO.isReg() || MO.getReg() != ARM::CPSR)
2609           continue;
2610         if (MO.isDef()) {
2611           isSafe = true;
2612           break;
2613         }
2614         // Condition code is after the operand before CPSR except for VSELs.
2615         ARMCC::CondCodes CC;
2616         bool IsInstrVSel = true;
2617         switch (Instr.getOpcode()) {
2618         default:
2619           IsInstrVSel = false;
2620           CC = (ARMCC::CondCodes)Instr.getOperand(IO - 1).getImm();
2621           break;
2622         case ARM::VSELEQD:
2623         case ARM::VSELEQS:
2624           CC = ARMCC::EQ;
2625           break;
2626         case ARM::VSELGTD:
2627         case ARM::VSELGTS:
2628           CC = ARMCC::GT;
2629           break;
2630         case ARM::VSELGED:
2631         case ARM::VSELGES:
2632           CC = ARMCC::GE;
2633           break;
2634         case ARM::VSELVSS:
2635         case ARM::VSELVSD:
2636           CC = ARMCC::VS;
2637           break;
2638         }
2639 
2640         if (Sub) {
2641           ARMCC::CondCodes NewCC = getSwappedCondition(CC);
2642           if (NewCC == ARMCC::AL)
2643             return false;
2644           // If we have SUB(r1, r2) and CMP(r2, r1), the condition code based
2645           // on CMP needs to be updated to be based on SUB.
2646           // Push the condition code operands to OperandsToUpdate.
2647           // If it is safe to remove CmpInstr, the condition code of these
2648           // operands will be modified.
2649           if (SrcReg2 != 0 && Sub->getOperand(1).getReg() == SrcReg2 &&
2650               Sub->getOperand(2).getReg() == SrcReg) {
2651             // VSel doesn't support condition code update.
2652             if (IsInstrVSel)
2653               return false;
2654             OperandsToUpdate.push_back(
2655                 std::make_pair(&((*I).getOperand(IO - 1)), NewCC));
2656           }
2657         } else {
2658           // No Sub, so this is x = <op> y, z; cmp x, 0.
2659           switch (CC) {
2660           case ARMCC::EQ: // Z
2661           case ARMCC::NE: // Z
2662           case ARMCC::MI: // N
2663           case ARMCC::PL: // N
2664           case ARMCC::AL: // none
2665             // CPSR can be used multiple times, we should continue.
2666             break;
2667           case ARMCC::HS: // C
2668           case ARMCC::LO: // C
2669           case ARMCC::VS: // V
2670           case ARMCC::VC: // V
2671           case ARMCC::HI: // C Z
2672           case ARMCC::LS: // C Z
2673           case ARMCC::GE: // N V
2674           case ARMCC::LT: // N V
2675           case ARMCC::GT: // Z N V
2676           case ARMCC::LE: // Z N V
2677             // The instruction uses the V bit or C bit which is not safe.
2678             return false;
2679           }
2680         }
2681       }
2682     }
2683 
2684     // If CPSR is not killed nor re-defined, we should check whether it is
2685     // live-out. If it is live-out, do not optimize.
2686     if (!isSafe) {
2687       MachineBasicBlock *MBB = CmpInstr.getParent();
2688       for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
2689                SE = MBB->succ_end(); SI != SE; ++SI)
2690         if ((*SI)->isLiveIn(ARM::CPSR))
2691           return false;
2692     }
2693 
2694     // Toggle the optional operand to CPSR (if it exists - in Thumb1 we always
2695     // set CPSR so this is represented as an explicit output)
2696     if (!IsThumb1) {
2697       MI->getOperand(5).setReg(ARM::CPSR);
2698       MI->getOperand(5).setIsDef(true);
2699     }
2700     assert(!isPredicated(*MI) && "Can't use flags from predicated instruction");
2701     CmpInstr.eraseFromParent();
2702 
2703     // Modify the condition code of operands in OperandsToUpdate.
2704     // Since we have SUB(r1, r2) and CMP(r2, r1), the condition code needs to
2705     // be changed from r2 > r1 to r1 < r2, from r2 < r1 to r1 > r2, etc.
2706     for (unsigned i = 0, e = OperandsToUpdate.size(); i < e; i++)
2707       OperandsToUpdate[i].first->setImm(OperandsToUpdate[i].second);
2708     return true;
2709   }
2710   }
2711 
2712   return false;
2713 }
2714 
2715 bool ARMBaseInstrInfo::FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
2716                                      unsigned Reg,
2717                                      MachineRegisterInfo *MRI) const {
2718   // Fold large immediates into add, sub, or, xor.
2719   unsigned DefOpc = DefMI.getOpcode();
2720   if (DefOpc != ARM::t2MOVi32imm && DefOpc != ARM::MOVi32imm)
2721     return false;
2722   if (!DefMI.getOperand(1).isImm())
2723     // Could be t2MOVi32imm <ga:xx>
2724     return false;
2725 
2726   if (!MRI->hasOneNonDBGUse(Reg))
2727     return false;
2728 
2729   const MCInstrDesc &DefMCID = DefMI.getDesc();
2730   if (DefMCID.hasOptionalDef()) {
2731     unsigned NumOps = DefMCID.getNumOperands();
2732     const MachineOperand &MO = DefMI.getOperand(NumOps - 1);
2733     if (MO.getReg() == ARM::CPSR && !MO.isDead())
2734       // If DefMI defines CPSR and it is not dead, it's obviously not safe
2735       // to delete DefMI.
2736       return false;
2737   }
2738 
2739   const MCInstrDesc &UseMCID = UseMI.getDesc();
2740   if (UseMCID.hasOptionalDef()) {
2741     unsigned NumOps = UseMCID.getNumOperands();
2742     if (UseMI.getOperand(NumOps - 1).getReg() == ARM::CPSR)
2743       // If the instruction sets the flag, do not attempt this optimization
2744       // since it may change the semantics of the code.
2745       return false;
2746   }
2747 
2748   unsigned UseOpc = UseMI.getOpcode();
2749   unsigned NewUseOpc = 0;
2750   uint32_t ImmVal = (uint32_t)DefMI.getOperand(1).getImm();
2751   uint32_t SOImmValV1 = 0, SOImmValV2 = 0;
2752   bool Commute = false;
2753   switch (UseOpc) {
2754   default: return false;
2755   case ARM::SUBrr:
2756   case ARM::ADDrr:
2757   case ARM::ORRrr:
2758   case ARM::EORrr:
2759   case ARM::t2SUBrr:
2760   case ARM::t2ADDrr:
2761   case ARM::t2ORRrr:
2762   case ARM::t2EORrr: {
2763     Commute = UseMI.getOperand(2).getReg() != Reg;
2764     switch (UseOpc) {
2765     default: break;
2766     case ARM::ADDrr:
2767     case ARM::SUBrr: {
2768       if (UseOpc == ARM::SUBrr && Commute)
2769         return false;
2770 
2771       // ADD/SUB are special because they're essentially the same operation, so
2772       // we can handle a larger range of immediates.
2773       if (ARM_AM::isSOImmTwoPartVal(ImmVal))
2774         NewUseOpc = UseOpc == ARM::ADDrr ? ARM::ADDri : ARM::SUBri;
2775       else if (ARM_AM::isSOImmTwoPartVal(-ImmVal)) {
2776         ImmVal = -ImmVal;
2777         NewUseOpc = UseOpc == ARM::ADDrr ? ARM::SUBri : ARM::ADDri;
2778       } else
2779         return false;
2780       SOImmValV1 = (uint32_t)ARM_AM::getSOImmTwoPartFirst(ImmVal);
2781       SOImmValV2 = (uint32_t)ARM_AM::getSOImmTwoPartSecond(ImmVal);
2782       break;
2783     }
2784     case ARM::ORRrr:
2785     case ARM::EORrr: {
2786       if (!ARM_AM::isSOImmTwoPartVal(ImmVal))
2787         return false;
2788       SOImmValV1 = (uint32_t)ARM_AM::getSOImmTwoPartFirst(ImmVal);
2789       SOImmValV2 = (uint32_t)ARM_AM::getSOImmTwoPartSecond(ImmVal);
2790       switch (UseOpc) {
2791       default: break;
2792       case ARM::ORRrr: NewUseOpc = ARM::ORRri; break;
2793       case ARM::EORrr: NewUseOpc = ARM::EORri; break;
2794       }
2795       break;
2796     }
2797     case ARM::t2ADDrr:
2798     case ARM::t2SUBrr: {
2799       if (UseOpc == ARM::t2SUBrr && Commute)
2800         return false;
2801 
2802       // ADD/SUB are special because they're essentially the same operation, so
2803       // we can handle a larger range of immediates.
2804       if (ARM_AM::isT2SOImmTwoPartVal(ImmVal))
2805         NewUseOpc = UseOpc == ARM::t2ADDrr ? ARM::t2ADDri : ARM::t2SUBri;
2806       else if (ARM_AM::isT2SOImmTwoPartVal(-ImmVal)) {
2807         ImmVal = -ImmVal;
2808         NewUseOpc = UseOpc == ARM::t2ADDrr ? ARM::t2SUBri : ARM::t2ADDri;
2809       } else
2810         return false;
2811       SOImmValV1 = (uint32_t)ARM_AM::getT2SOImmTwoPartFirst(ImmVal);
2812       SOImmValV2 = (uint32_t)ARM_AM::getT2SOImmTwoPartSecond(ImmVal);
2813       break;
2814     }
2815     case ARM::t2ORRrr:
2816     case ARM::t2EORrr: {
2817       if (!ARM_AM::isT2SOImmTwoPartVal(ImmVal))
2818         return false;
2819       SOImmValV1 = (uint32_t)ARM_AM::getT2SOImmTwoPartFirst(ImmVal);
2820       SOImmValV2 = (uint32_t)ARM_AM::getT2SOImmTwoPartSecond(ImmVal);
2821       switch (UseOpc) {
2822       default: break;
2823       case ARM::t2ORRrr: NewUseOpc = ARM::t2ORRri; break;
2824       case ARM::t2EORrr: NewUseOpc = ARM::t2EORri; break;
2825       }
2826       break;
2827     }
2828     }
2829   }
2830   }
2831 
2832   unsigned OpIdx = Commute ? 2 : 1;
2833   unsigned Reg1 = UseMI.getOperand(OpIdx).getReg();
2834   bool isKill = UseMI.getOperand(OpIdx).isKill();
2835   unsigned NewReg = MRI->createVirtualRegister(MRI->getRegClass(Reg));
2836   BuildMI(*UseMI.getParent(), UseMI, UseMI.getDebugLoc(), get(NewUseOpc),
2837           NewReg)
2838       .addReg(Reg1, getKillRegState(isKill))
2839       .addImm(SOImmValV1)
2840       .add(predOps(ARMCC::AL))
2841       .add(condCodeOp());
2842   UseMI.setDesc(get(NewUseOpc));
2843   UseMI.getOperand(1).setReg(NewReg);
2844   UseMI.getOperand(1).setIsKill();
2845   UseMI.getOperand(2).ChangeToImmediate(SOImmValV2);
2846   DefMI.eraseFromParent();
2847   return true;
2848 }
2849 
2850 static unsigned getNumMicroOpsSwiftLdSt(const InstrItineraryData *ItinData,
2851                                         const MachineInstr &MI) {
2852   switch (MI.getOpcode()) {
2853   default: {
2854     const MCInstrDesc &Desc = MI.getDesc();
2855     int UOps = ItinData->getNumMicroOps(Desc.getSchedClass());
2856     assert(UOps >= 0 && "bad # UOps");
2857     return UOps;
2858   }
2859 
2860   case ARM::LDRrs:
2861   case ARM::LDRBrs:
2862   case ARM::STRrs:
2863   case ARM::STRBrs: {
2864     unsigned ShOpVal = MI.getOperand(3).getImm();
2865     bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
2866     unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
2867     if (!isSub &&
2868         (ShImm == 0 ||
2869          ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
2870           ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
2871       return 1;
2872     return 2;
2873   }
2874 
2875   case ARM::LDRH:
2876   case ARM::STRH: {
2877     if (!MI.getOperand(2).getReg())
2878       return 1;
2879 
2880     unsigned ShOpVal = MI.getOperand(3).getImm();
2881     bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
2882     unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
2883     if (!isSub &&
2884         (ShImm == 0 ||
2885          ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
2886           ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
2887       return 1;
2888     return 2;
2889   }
2890 
2891   case ARM::LDRSB:
2892   case ARM::LDRSH:
2893     return (ARM_AM::getAM3Op(MI.getOperand(3).getImm()) == ARM_AM::sub) ? 3 : 2;
2894 
2895   case ARM::LDRSB_POST:
2896   case ARM::LDRSH_POST: {
2897     unsigned Rt = MI.getOperand(0).getReg();
2898     unsigned Rm = MI.getOperand(3).getReg();
2899     return (Rt == Rm) ? 4 : 3;
2900   }
2901 
2902   case ARM::LDR_PRE_REG:
2903   case ARM::LDRB_PRE_REG: {
2904     unsigned Rt = MI.getOperand(0).getReg();
2905     unsigned Rm = MI.getOperand(3).getReg();
2906     if (Rt == Rm)
2907       return 3;
2908     unsigned ShOpVal = MI.getOperand(4).getImm();
2909     bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
2910     unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
2911     if (!isSub &&
2912         (ShImm == 0 ||
2913          ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
2914           ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
2915       return 2;
2916     return 3;
2917   }
2918 
2919   case ARM::STR_PRE_REG:
2920   case ARM::STRB_PRE_REG: {
2921     unsigned ShOpVal = MI.getOperand(4).getImm();
2922     bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
2923     unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
2924     if (!isSub &&
2925         (ShImm == 0 ||
2926          ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
2927           ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
2928       return 2;
2929     return 3;
2930   }
2931 
2932   case ARM::LDRH_PRE:
2933   case ARM::STRH_PRE: {
2934     unsigned Rt = MI.getOperand(0).getReg();
2935     unsigned Rm = MI.getOperand(3).getReg();
2936     if (!Rm)
2937       return 2;
2938     if (Rt == Rm)
2939       return 3;
2940     return (ARM_AM::getAM3Op(MI.getOperand(4).getImm()) == ARM_AM::sub) ? 3 : 2;
2941   }
2942 
2943   case ARM::LDR_POST_REG:
2944   case ARM::LDRB_POST_REG:
2945   case ARM::LDRH_POST: {
2946     unsigned Rt = MI.getOperand(0).getReg();
2947     unsigned Rm = MI.getOperand(3).getReg();
2948     return (Rt == Rm) ? 3 : 2;
2949   }
2950 
2951   case ARM::LDR_PRE_IMM:
2952   case ARM::LDRB_PRE_IMM:
2953   case ARM::LDR_POST_IMM:
2954   case ARM::LDRB_POST_IMM:
2955   case ARM::STRB_POST_IMM:
2956   case ARM::STRB_POST_REG:
2957   case ARM::STRB_PRE_IMM:
2958   case ARM::STRH_POST:
2959   case ARM::STR_POST_IMM:
2960   case ARM::STR_POST_REG:
2961   case ARM::STR_PRE_IMM:
2962     return 2;
2963 
2964   case ARM::LDRSB_PRE:
2965   case ARM::LDRSH_PRE: {
2966     unsigned Rm = MI.getOperand(3).getReg();
2967     if (Rm == 0)
2968       return 3;
2969     unsigned Rt = MI.getOperand(0).getReg();
2970     if (Rt == Rm)
2971       return 4;
2972     unsigned ShOpVal = MI.getOperand(4).getImm();
2973     bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
2974     unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
2975     if (!isSub &&
2976         (ShImm == 0 ||
2977          ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
2978           ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
2979       return 3;
2980     return 4;
2981   }
2982 
2983   case ARM::LDRD: {
2984     unsigned Rt = MI.getOperand(0).getReg();
2985     unsigned Rn = MI.getOperand(2).getReg();
2986     unsigned Rm = MI.getOperand(3).getReg();
2987     if (Rm)
2988       return (ARM_AM::getAM3Op(MI.getOperand(4).getImm()) == ARM_AM::sub) ? 4
2989                                                                           : 3;
2990     return (Rt == Rn) ? 3 : 2;
2991   }
2992 
2993   case ARM::STRD: {
2994     unsigned Rm = MI.getOperand(3).getReg();
2995     if (Rm)
2996       return (ARM_AM::getAM3Op(MI.getOperand(4).getImm()) == ARM_AM::sub) ? 4
2997                                                                           : 3;
2998     return 2;
2999   }
3000 
3001   case ARM::LDRD_POST:
3002   case ARM::t2LDRD_POST:
3003     return 3;
3004 
3005   case ARM::STRD_POST:
3006   case ARM::t2STRD_POST:
3007     return 4;
3008 
3009   case ARM::LDRD_PRE: {
3010     unsigned Rt = MI.getOperand(0).getReg();
3011     unsigned Rn = MI.getOperand(3).getReg();
3012     unsigned Rm = MI.getOperand(4).getReg();
3013     if (Rm)
3014       return (ARM_AM::getAM3Op(MI.getOperand(5).getImm()) == ARM_AM::sub) ? 5
3015                                                                           : 4;
3016     return (Rt == Rn) ? 4 : 3;
3017   }
3018 
3019   case ARM::t2LDRD_PRE: {
3020     unsigned Rt = MI.getOperand(0).getReg();
3021     unsigned Rn = MI.getOperand(3).getReg();
3022     return (Rt == Rn) ? 4 : 3;
3023   }
3024 
3025   case ARM::STRD_PRE: {
3026     unsigned Rm = MI.getOperand(4).getReg();
3027     if (Rm)
3028       return (ARM_AM::getAM3Op(MI.getOperand(5).getImm()) == ARM_AM::sub) ? 5
3029                                                                           : 4;
3030     return 3;
3031   }
3032 
3033   case ARM::t2STRD_PRE:
3034     return 3;
3035 
3036   case ARM::t2LDR_POST:
3037   case ARM::t2LDRB_POST:
3038   case ARM::t2LDRB_PRE:
3039   case ARM::t2LDRSBi12:
3040   case ARM::t2LDRSBi8:
3041   case ARM::t2LDRSBpci:
3042   case ARM::t2LDRSBs:
3043   case ARM::t2LDRH_POST:
3044   case ARM::t2LDRH_PRE:
3045   case ARM::t2LDRSBT:
3046   case ARM::t2LDRSB_POST:
3047   case ARM::t2LDRSB_PRE:
3048   case ARM::t2LDRSH_POST:
3049   case ARM::t2LDRSH_PRE:
3050   case ARM::t2LDRSHi12:
3051   case ARM::t2LDRSHi8:
3052   case ARM::t2LDRSHpci:
3053   case ARM::t2LDRSHs:
3054     return 2;
3055 
3056   case ARM::t2LDRDi8: {
3057     unsigned Rt = MI.getOperand(0).getReg();
3058     unsigned Rn = MI.getOperand(2).getReg();
3059     return (Rt == Rn) ? 3 : 2;
3060   }
3061 
3062   case ARM::t2STRB_POST:
3063   case ARM::t2STRB_PRE:
3064   case ARM::t2STRBs:
3065   case ARM::t2STRDi8:
3066   case ARM::t2STRH_POST:
3067   case ARM::t2STRH_PRE:
3068   case ARM::t2STRHs:
3069   case ARM::t2STR_POST:
3070   case ARM::t2STR_PRE:
3071   case ARM::t2STRs:
3072     return 2;
3073   }
3074 }
3075 
3076 // Return the number of 32-bit words loaded by LDM or stored by STM. If this
3077 // can't be easily determined return 0 (missing MachineMemOperand).
3078 //
3079 // FIXME: The current MachineInstr design does not support relying on machine
3080 // mem operands to determine the width of a memory access. Instead, we expect
3081 // the target to provide this information based on the instruction opcode and
3082 // operands. However, using MachineMemOperand is the best solution now for
3083 // two reasons:
3084 //
3085 // 1) getNumMicroOps tries to infer LDM memory width from the total number of MI
3086 // operands. This is much more dangerous than using the MachineMemOperand
3087 // sizes because CodeGen passes can insert/remove optional machine operands. In
3088 // fact, it's totally incorrect for preRA passes and appears to be wrong for
3089 // postRA passes as well.
3090 //
3091 // 2) getNumLDMAddresses is only used by the scheduling machine model and any
3092 // machine model that calls this should handle the unknown (zero size) case.
3093 //
3094 // Long term, we should require a target hook that verifies MachineMemOperand
3095 // sizes during MC lowering. That target hook should be local to MC lowering
3096 // because we can't ensure that it is aware of other MI forms. Doing this will
3097 // ensure that MachineMemOperands are correctly propagated through all passes.
3098 unsigned ARMBaseInstrInfo::getNumLDMAddresses(const MachineInstr &MI) const {
3099   unsigned Size = 0;
3100   for (MachineInstr::mmo_iterator I = MI.memoperands_begin(),
3101                                   E = MI.memoperands_end();
3102        I != E; ++I) {
3103     Size += (*I)->getSize();
3104   }
3105   return Size / 4;
3106 }
3107 
3108 static unsigned getNumMicroOpsSingleIssuePlusExtras(unsigned Opc,
3109                                                     unsigned NumRegs) {
3110   unsigned UOps = 1 + NumRegs; // 1 for address computation.
3111   switch (Opc) {
3112   default:
3113     break;
3114   case ARM::VLDMDIA_UPD:
3115   case ARM::VLDMDDB_UPD:
3116   case ARM::VLDMSIA_UPD:
3117   case ARM::VLDMSDB_UPD:
3118   case ARM::VSTMDIA_UPD:
3119   case ARM::VSTMDDB_UPD:
3120   case ARM::VSTMSIA_UPD:
3121   case ARM::VSTMSDB_UPD:
3122   case ARM::LDMIA_UPD:
3123   case ARM::LDMDA_UPD:
3124   case ARM::LDMDB_UPD:
3125   case ARM::LDMIB_UPD:
3126   case ARM::STMIA_UPD:
3127   case ARM::STMDA_UPD:
3128   case ARM::STMDB_UPD:
3129   case ARM::STMIB_UPD:
3130   case ARM::tLDMIA_UPD:
3131   case ARM::tSTMIA_UPD:
3132   case ARM::t2LDMIA_UPD:
3133   case ARM::t2LDMDB_UPD:
3134   case ARM::t2STMIA_UPD:
3135   case ARM::t2STMDB_UPD:
3136     ++UOps; // One for base register writeback.
3137     break;
3138   case ARM::LDMIA_RET:
3139   case ARM::tPOP_RET:
3140   case ARM::t2LDMIA_RET:
3141     UOps += 2; // One for base reg wb, one for write to pc.
3142     break;
3143   }
3144   return UOps;
3145 }
3146 
3147 unsigned ARMBaseInstrInfo::getNumMicroOps(const InstrItineraryData *ItinData,
3148                                           const MachineInstr &MI) const {
3149   if (!ItinData || ItinData->isEmpty())
3150     return 1;
3151 
3152   const MCInstrDesc &Desc = MI.getDesc();
3153   unsigned Class = Desc.getSchedClass();
3154   int ItinUOps = ItinData->getNumMicroOps(Class);
3155   if (ItinUOps >= 0) {
3156     if (Subtarget.isSwift() && (Desc.mayLoad() || Desc.mayStore()))
3157       return getNumMicroOpsSwiftLdSt(ItinData, MI);
3158 
3159     return ItinUOps;
3160   }
3161 
3162   unsigned Opc = MI.getOpcode();
3163   switch (Opc) {
3164   default:
3165     llvm_unreachable("Unexpected multi-uops instruction!");
3166   case ARM::VLDMQIA:
3167   case ARM::VSTMQIA:
3168     return 2;
3169 
3170   // The number of uOps for load / store multiple are determined by the number
3171   // registers.
3172   //
3173   // On Cortex-A8, each pair of register loads / stores can be scheduled on the
3174   // same cycle. The scheduling for the first load / store must be done
3175   // separately by assuming the address is not 64-bit aligned.
3176   //
3177   // On Cortex-A9, the formula is simply (#reg / 2) + (#reg % 2). If the address
3178   // is not 64-bit aligned, then AGU would take an extra cycle.  For VFP / NEON
3179   // load / store multiple, the formula is (#reg / 2) + (#reg % 2) + 1.
3180   case ARM::VLDMDIA:
3181   case ARM::VLDMDIA_UPD:
3182   case ARM::VLDMDDB_UPD:
3183   case ARM::VLDMSIA:
3184   case ARM::VLDMSIA_UPD:
3185   case ARM::VLDMSDB_UPD:
3186   case ARM::VSTMDIA:
3187   case ARM::VSTMDIA_UPD:
3188   case ARM::VSTMDDB_UPD:
3189   case ARM::VSTMSIA:
3190   case ARM::VSTMSIA_UPD:
3191   case ARM::VSTMSDB_UPD: {
3192     unsigned NumRegs = MI.getNumOperands() - Desc.getNumOperands();
3193     return (NumRegs / 2) + (NumRegs % 2) + 1;
3194   }
3195 
3196   case ARM::LDMIA_RET:
3197   case ARM::LDMIA:
3198   case ARM::LDMDA:
3199   case ARM::LDMDB:
3200   case ARM::LDMIB:
3201   case ARM::LDMIA_UPD:
3202   case ARM::LDMDA_UPD:
3203   case ARM::LDMDB_UPD:
3204   case ARM::LDMIB_UPD:
3205   case ARM::STMIA:
3206   case ARM::STMDA:
3207   case ARM::STMDB:
3208   case ARM::STMIB:
3209   case ARM::STMIA_UPD:
3210   case ARM::STMDA_UPD:
3211   case ARM::STMDB_UPD:
3212   case ARM::STMIB_UPD:
3213   case ARM::tLDMIA:
3214   case ARM::tLDMIA_UPD:
3215   case ARM::tSTMIA_UPD:
3216   case ARM::tPOP_RET:
3217   case ARM::tPOP:
3218   case ARM::tPUSH:
3219   case ARM::t2LDMIA_RET:
3220   case ARM::t2LDMIA:
3221   case ARM::t2LDMDB:
3222   case ARM::t2LDMIA_UPD:
3223   case ARM::t2LDMDB_UPD:
3224   case ARM::t2STMIA:
3225   case ARM::t2STMDB:
3226   case ARM::t2STMIA_UPD:
3227   case ARM::t2STMDB_UPD: {
3228     unsigned NumRegs = MI.getNumOperands() - Desc.getNumOperands() + 1;
3229     switch (Subtarget.getLdStMultipleTiming()) {
3230     case ARMSubtarget::SingleIssuePlusExtras:
3231       return getNumMicroOpsSingleIssuePlusExtras(Opc, NumRegs);
3232     case ARMSubtarget::SingleIssue:
3233       // Assume the worst.
3234       return NumRegs;
3235     case ARMSubtarget::DoubleIssue: {
3236       if (NumRegs < 4)
3237         return 2;
3238       // 4 registers would be issued: 2, 2.
3239       // 5 registers would be issued: 2, 2, 1.
3240       unsigned UOps = (NumRegs / 2);
3241       if (NumRegs % 2)
3242         ++UOps;
3243       return UOps;
3244     }
3245     case ARMSubtarget::DoubleIssueCheckUnalignedAccess: {
3246       unsigned UOps = (NumRegs / 2);
3247       // If there are odd number of registers or if it's not 64-bit aligned,
3248       // then it takes an extra AGU (Address Generation Unit) cycle.
3249       if ((NumRegs % 2) || !MI.hasOneMemOperand() ||
3250           (*MI.memoperands_begin())->getAlignment() < 8)
3251         ++UOps;
3252       return UOps;
3253       }
3254     }
3255   }
3256   }
3257   llvm_unreachable("Didn't find the number of microops");
3258 }
3259 
3260 int
3261 ARMBaseInstrInfo::getVLDMDefCycle(const InstrItineraryData *ItinData,
3262                                   const MCInstrDesc &DefMCID,
3263                                   unsigned DefClass,
3264                                   unsigned DefIdx, unsigned DefAlign) const {
3265   int RegNo = (int)(DefIdx+1) - DefMCID.getNumOperands() + 1;
3266   if (RegNo <= 0)
3267     // Def is the address writeback.
3268     return ItinData->getOperandCycle(DefClass, DefIdx);
3269 
3270   int DefCycle;
3271   if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
3272     // (regno / 2) + (regno % 2) + 1
3273     DefCycle = RegNo / 2 + 1;
3274     if (RegNo % 2)
3275       ++DefCycle;
3276   } else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
3277     DefCycle = RegNo;
3278     bool isSLoad = false;
3279 
3280     switch (DefMCID.getOpcode()) {
3281     default: break;
3282     case ARM::VLDMSIA:
3283     case ARM::VLDMSIA_UPD:
3284     case ARM::VLDMSDB_UPD:
3285       isSLoad = true;
3286       break;
3287     }
3288 
3289     // If there are odd number of 'S' registers or if it's not 64-bit aligned,
3290     // then it takes an extra cycle.
3291     if ((isSLoad && (RegNo % 2)) || DefAlign < 8)
3292       ++DefCycle;
3293   } else {
3294     // Assume the worst.
3295     DefCycle = RegNo + 2;
3296   }
3297 
3298   return DefCycle;
3299 }
3300 
3301 int
3302 ARMBaseInstrInfo::getLDMDefCycle(const InstrItineraryData *ItinData,
3303                                  const MCInstrDesc &DefMCID,
3304                                  unsigned DefClass,
3305                                  unsigned DefIdx, unsigned DefAlign) const {
3306   int RegNo = (int)(DefIdx+1) - DefMCID.getNumOperands() + 1;
3307   if (RegNo <= 0)
3308     // Def is the address writeback.
3309     return ItinData->getOperandCycle(DefClass, DefIdx);
3310 
3311   int DefCycle;
3312   if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
3313     // 4 registers would be issued: 1, 2, 1.
3314     // 5 registers would be issued: 1, 2, 2.
3315     DefCycle = RegNo / 2;
3316     if (DefCycle < 1)
3317       DefCycle = 1;
3318     // Result latency is issue cycle + 2: E2.
3319     DefCycle += 2;
3320   } else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
3321     DefCycle = (RegNo / 2);
3322     // If there are odd number of registers or if it's not 64-bit aligned,
3323     // then it takes an extra AGU (Address Generation Unit) cycle.
3324     if ((RegNo % 2) || DefAlign < 8)
3325       ++DefCycle;
3326     // Result latency is AGU cycles + 2.
3327     DefCycle += 2;
3328   } else {
3329     // Assume the worst.
3330     DefCycle = RegNo + 2;
3331   }
3332 
3333   return DefCycle;
3334 }
3335 
3336 int
3337 ARMBaseInstrInfo::getVSTMUseCycle(const InstrItineraryData *ItinData,
3338                                   const MCInstrDesc &UseMCID,
3339                                   unsigned UseClass,
3340                                   unsigned UseIdx, unsigned UseAlign) const {
3341   int RegNo = (int)(UseIdx+1) - UseMCID.getNumOperands() + 1;
3342   if (RegNo <= 0)
3343     return ItinData->getOperandCycle(UseClass, UseIdx);
3344 
3345   int UseCycle;
3346   if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
3347     // (regno / 2) + (regno % 2) + 1
3348     UseCycle = RegNo / 2 + 1;
3349     if (RegNo % 2)
3350       ++UseCycle;
3351   } else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
3352     UseCycle = RegNo;
3353     bool isSStore = false;
3354 
3355     switch (UseMCID.getOpcode()) {
3356     default: break;
3357     case ARM::VSTMSIA:
3358     case ARM::VSTMSIA_UPD:
3359     case ARM::VSTMSDB_UPD:
3360       isSStore = true;
3361       break;
3362     }
3363 
3364     // If there are odd number of 'S' registers or if it's not 64-bit aligned,
3365     // then it takes an extra cycle.
3366     if ((isSStore && (RegNo % 2)) || UseAlign < 8)
3367       ++UseCycle;
3368   } else {
3369     // Assume the worst.
3370     UseCycle = RegNo + 2;
3371   }
3372 
3373   return UseCycle;
3374 }
3375 
3376 int
3377 ARMBaseInstrInfo::getSTMUseCycle(const InstrItineraryData *ItinData,
3378                                  const MCInstrDesc &UseMCID,
3379                                  unsigned UseClass,
3380                                  unsigned UseIdx, unsigned UseAlign) const {
3381   int RegNo = (int)(UseIdx+1) - UseMCID.getNumOperands() + 1;
3382   if (RegNo <= 0)
3383     return ItinData->getOperandCycle(UseClass, UseIdx);
3384 
3385   int UseCycle;
3386   if (Subtarget.isCortexA8() || Subtarget.isCortexA7()) {
3387     UseCycle = RegNo / 2;
3388     if (UseCycle < 2)
3389       UseCycle = 2;
3390     // Read in E3.
3391     UseCycle += 2;
3392   } else if (Subtarget.isLikeA9() || Subtarget.isSwift()) {
3393     UseCycle = (RegNo / 2);
3394     // If there are odd number of registers or if it's not 64-bit aligned,
3395     // then it takes an extra AGU (Address Generation Unit) cycle.
3396     if ((RegNo % 2) || UseAlign < 8)
3397       ++UseCycle;
3398   } else {
3399     // Assume the worst.
3400     UseCycle = 1;
3401   }
3402   return UseCycle;
3403 }
3404 
3405 int
3406 ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
3407                                     const MCInstrDesc &DefMCID,
3408                                     unsigned DefIdx, unsigned DefAlign,
3409                                     const MCInstrDesc &UseMCID,
3410                                     unsigned UseIdx, unsigned UseAlign) const {
3411   unsigned DefClass = DefMCID.getSchedClass();
3412   unsigned UseClass = UseMCID.getSchedClass();
3413 
3414   if (DefIdx < DefMCID.getNumDefs() && UseIdx < UseMCID.getNumOperands())
3415     return ItinData->getOperandLatency(DefClass, DefIdx, UseClass, UseIdx);
3416 
3417   // This may be a def / use of a variable_ops instruction, the operand
3418   // latency might be determinable dynamically. Let the target try to
3419   // figure it out.
3420   int DefCycle = -1;
3421   bool LdmBypass = false;
3422   switch (DefMCID.getOpcode()) {
3423   default:
3424     DefCycle = ItinData->getOperandCycle(DefClass, DefIdx);
3425     break;
3426 
3427   case ARM::VLDMDIA:
3428   case ARM::VLDMDIA_UPD:
3429   case ARM::VLDMDDB_UPD:
3430   case ARM::VLDMSIA:
3431   case ARM::VLDMSIA_UPD:
3432   case ARM::VLDMSDB_UPD:
3433     DefCycle = getVLDMDefCycle(ItinData, DefMCID, DefClass, DefIdx, DefAlign);
3434     break;
3435 
3436   case ARM::LDMIA_RET:
3437   case ARM::LDMIA:
3438   case ARM::LDMDA:
3439   case ARM::LDMDB:
3440   case ARM::LDMIB:
3441   case ARM::LDMIA_UPD:
3442   case ARM::LDMDA_UPD:
3443   case ARM::LDMDB_UPD:
3444   case ARM::LDMIB_UPD:
3445   case ARM::tLDMIA:
3446   case ARM::tLDMIA_UPD:
3447   case ARM::tPUSH:
3448   case ARM::t2LDMIA_RET:
3449   case ARM::t2LDMIA:
3450   case ARM::t2LDMDB:
3451   case ARM::t2LDMIA_UPD:
3452   case ARM::t2LDMDB_UPD:
3453     LdmBypass = 1;
3454     DefCycle = getLDMDefCycle(ItinData, DefMCID, DefClass, DefIdx, DefAlign);
3455     break;
3456   }
3457 
3458   if (DefCycle == -1)
3459     // We can't seem to determine the result latency of the def, assume it's 2.
3460     DefCycle = 2;
3461 
3462   int UseCycle = -1;
3463   switch (UseMCID.getOpcode()) {
3464   default:
3465     UseCycle = ItinData->getOperandCycle(UseClass, UseIdx);
3466     break;
3467 
3468   case ARM::VSTMDIA:
3469   case ARM::VSTMDIA_UPD:
3470   case ARM::VSTMDDB_UPD:
3471   case ARM::VSTMSIA:
3472   case ARM::VSTMSIA_UPD:
3473   case ARM::VSTMSDB_UPD:
3474     UseCycle = getVSTMUseCycle(ItinData, UseMCID, UseClass, UseIdx, UseAlign);
3475     break;
3476 
3477   case ARM::STMIA:
3478   case ARM::STMDA:
3479   case ARM::STMDB:
3480   case ARM::STMIB:
3481   case ARM::STMIA_UPD:
3482   case ARM::STMDA_UPD:
3483   case ARM::STMDB_UPD:
3484   case ARM::STMIB_UPD:
3485   case ARM::tSTMIA_UPD:
3486   case ARM::tPOP_RET:
3487   case ARM::tPOP:
3488   case ARM::t2STMIA:
3489   case ARM::t2STMDB:
3490   case ARM::t2STMIA_UPD:
3491   case ARM::t2STMDB_UPD:
3492     UseCycle = getSTMUseCycle(ItinData, UseMCID, UseClass, UseIdx, UseAlign);
3493     break;
3494   }
3495 
3496   if (UseCycle == -1)
3497     // Assume it's read in the first stage.
3498     UseCycle = 1;
3499 
3500   UseCycle = DefCycle - UseCycle + 1;
3501   if (UseCycle > 0) {
3502     if (LdmBypass) {
3503       // It's a variable_ops instruction so we can't use DefIdx here. Just use
3504       // first def operand.
3505       if (ItinData->hasPipelineForwarding(DefClass, DefMCID.getNumOperands()-1,
3506                                           UseClass, UseIdx))
3507         --UseCycle;
3508     } else if (ItinData->hasPipelineForwarding(DefClass, DefIdx,
3509                                                UseClass, UseIdx)) {
3510       --UseCycle;
3511     }
3512   }
3513 
3514   return UseCycle;
3515 }
3516 
3517 static const MachineInstr *getBundledDefMI(const TargetRegisterInfo *TRI,
3518                                            const MachineInstr *MI, unsigned Reg,
3519                                            unsigned &DefIdx, unsigned &Dist) {
3520   Dist = 0;
3521 
3522   MachineBasicBlock::const_iterator I = MI; ++I;
3523   MachineBasicBlock::const_instr_iterator II = std::prev(I.getInstrIterator());
3524   assert(II->isInsideBundle() && "Empty bundle?");
3525 
3526   int Idx = -1;
3527   while (II->isInsideBundle()) {
3528     Idx = II->findRegisterDefOperandIdx(Reg, false, true, TRI);
3529     if (Idx != -1)
3530       break;
3531     --II;
3532     ++Dist;
3533   }
3534 
3535   assert(Idx != -1 && "Cannot find bundled definition!");
3536   DefIdx = Idx;
3537   return &*II;
3538 }
3539 
3540 static const MachineInstr *getBundledUseMI(const TargetRegisterInfo *TRI,
3541                                            const MachineInstr &MI, unsigned Reg,
3542                                            unsigned &UseIdx, unsigned &Dist) {
3543   Dist = 0;
3544 
3545   MachineBasicBlock::const_instr_iterator II = ++MI.getIterator();
3546   assert(II->isInsideBundle() && "Empty bundle?");
3547   MachineBasicBlock::const_instr_iterator E = MI.getParent()->instr_end();
3548 
3549   // FIXME: This doesn't properly handle multiple uses.
3550   int Idx = -1;
3551   while (II != E && II->isInsideBundle()) {
3552     Idx = II->findRegisterUseOperandIdx(Reg, false, TRI);
3553     if (Idx != -1)
3554       break;
3555     if (II->getOpcode() != ARM::t2IT)
3556       ++Dist;
3557     ++II;
3558   }
3559 
3560   if (Idx == -1) {
3561     Dist = 0;
3562     return nullptr;
3563   }
3564 
3565   UseIdx = Idx;
3566   return &*II;
3567 }
3568 
3569 /// Return the number of cycles to add to (or subtract from) the static
3570 /// itinerary based on the def opcode and alignment. The caller will ensure that
3571 /// adjusted latency is at least one cycle.
3572 static int adjustDefLatency(const ARMSubtarget &Subtarget,
3573                             const MachineInstr &DefMI,
3574                             const MCInstrDesc &DefMCID, unsigned DefAlign) {
3575   int Adjust = 0;
3576   if (Subtarget.isCortexA8() || Subtarget.isLikeA9() || Subtarget.isCortexA7()) {
3577     // FIXME: Shifter op hack: no shift (i.e. [r +/- r]) or [r + r << 2]
3578     // variants are one cycle cheaper.
3579     switch (DefMCID.getOpcode()) {
3580     default: break;
3581     case ARM::LDRrs:
3582     case ARM::LDRBrs: {
3583       unsigned ShOpVal = DefMI.getOperand(3).getImm();
3584       unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
3585       if (ShImm == 0 ||
3586           (ShImm == 2 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
3587         --Adjust;
3588       break;
3589     }
3590     case ARM::t2LDRs:
3591     case ARM::t2LDRBs:
3592     case ARM::t2LDRHs:
3593     case ARM::t2LDRSHs: {
3594       // Thumb2 mode: lsl only.
3595       unsigned ShAmt = DefMI.getOperand(3).getImm();
3596       if (ShAmt == 0 || ShAmt == 2)
3597         --Adjust;
3598       break;
3599     }
3600     }
3601   } else if (Subtarget.isSwift()) {
3602     // FIXME: Properly handle all of the latency adjustments for address
3603     // writeback.
3604     switch (DefMCID.getOpcode()) {
3605     default: break;
3606     case ARM::LDRrs:
3607     case ARM::LDRBrs: {
3608       unsigned ShOpVal = DefMI.getOperand(3).getImm();
3609       bool isSub = ARM_AM::getAM2Op(ShOpVal) == ARM_AM::sub;
3610       unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
3611       if (!isSub &&
3612           (ShImm == 0 ||
3613            ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
3614             ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl)))
3615         Adjust -= 2;
3616       else if (!isSub &&
3617                ShImm == 1 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsr)
3618         --Adjust;
3619       break;
3620     }
3621     case ARM::t2LDRs:
3622     case ARM::t2LDRBs:
3623     case ARM::t2LDRHs:
3624     case ARM::t2LDRSHs: {
3625       // Thumb2 mode: lsl only.
3626       unsigned ShAmt = DefMI.getOperand(3).getImm();
3627       if (ShAmt == 0 || ShAmt == 1 || ShAmt == 2 || ShAmt == 3)
3628         Adjust -= 2;
3629       break;
3630     }
3631     }
3632   }
3633 
3634   if (DefAlign < 8 && Subtarget.checkVLDnAccessAlignment()) {
3635     switch (DefMCID.getOpcode()) {
3636     default: break;
3637     case ARM::VLD1q8:
3638     case ARM::VLD1q16:
3639     case ARM::VLD1q32:
3640     case ARM::VLD1q64:
3641     case ARM::VLD1q8wb_fixed:
3642     case ARM::VLD1q16wb_fixed:
3643     case ARM::VLD1q32wb_fixed:
3644     case ARM::VLD1q64wb_fixed:
3645     case ARM::VLD1q8wb_register:
3646     case ARM::VLD1q16wb_register:
3647     case ARM::VLD1q32wb_register:
3648     case ARM::VLD1q64wb_register:
3649     case ARM::VLD2d8:
3650     case ARM::VLD2d16:
3651     case ARM::VLD2d32:
3652     case ARM::VLD2q8:
3653     case ARM::VLD2q16:
3654     case ARM::VLD2q32:
3655     case ARM::VLD2d8wb_fixed:
3656     case ARM::VLD2d16wb_fixed:
3657     case ARM::VLD2d32wb_fixed:
3658     case ARM::VLD2q8wb_fixed:
3659     case ARM::VLD2q16wb_fixed:
3660     case ARM::VLD2q32wb_fixed:
3661     case ARM::VLD2d8wb_register:
3662     case ARM::VLD2d16wb_register:
3663     case ARM::VLD2d32wb_register:
3664     case ARM::VLD2q8wb_register:
3665     case ARM::VLD2q16wb_register:
3666     case ARM::VLD2q32wb_register:
3667     case ARM::VLD3d8:
3668     case ARM::VLD3d16:
3669     case ARM::VLD3d32:
3670     case ARM::VLD1d64T:
3671     case ARM::VLD3d8_UPD:
3672     case ARM::VLD3d16_UPD:
3673     case ARM::VLD3d32_UPD:
3674     case ARM::VLD1d64Twb_fixed:
3675     case ARM::VLD1d64Twb_register:
3676     case ARM::VLD3q8_UPD:
3677     case ARM::VLD3q16_UPD:
3678     case ARM::VLD3q32_UPD:
3679     case ARM::VLD4d8:
3680     case ARM::VLD4d16:
3681     case ARM::VLD4d32:
3682     case ARM::VLD1d64Q:
3683     case ARM::VLD4d8_UPD:
3684     case ARM::VLD4d16_UPD:
3685     case ARM::VLD4d32_UPD:
3686     case ARM::VLD1d64Qwb_fixed:
3687     case ARM::VLD1d64Qwb_register:
3688     case ARM::VLD4q8_UPD:
3689     case ARM::VLD4q16_UPD:
3690     case ARM::VLD4q32_UPD:
3691     case ARM::VLD1DUPq8:
3692     case ARM::VLD1DUPq16:
3693     case ARM::VLD1DUPq32:
3694     case ARM::VLD1DUPq8wb_fixed:
3695     case ARM::VLD1DUPq16wb_fixed:
3696     case ARM::VLD1DUPq32wb_fixed:
3697     case ARM::VLD1DUPq8wb_register:
3698     case ARM::VLD1DUPq16wb_register:
3699     case ARM::VLD1DUPq32wb_register:
3700     case ARM::VLD2DUPd8:
3701     case ARM::VLD2DUPd16:
3702     case ARM::VLD2DUPd32:
3703     case ARM::VLD2DUPd8wb_fixed:
3704     case ARM::VLD2DUPd16wb_fixed:
3705     case ARM::VLD2DUPd32wb_fixed:
3706     case ARM::VLD2DUPd8wb_register:
3707     case ARM::VLD2DUPd16wb_register:
3708     case ARM::VLD2DUPd32wb_register:
3709     case ARM::VLD4DUPd8:
3710     case ARM::VLD4DUPd16:
3711     case ARM::VLD4DUPd32:
3712     case ARM::VLD4DUPd8_UPD:
3713     case ARM::VLD4DUPd16_UPD:
3714     case ARM::VLD4DUPd32_UPD:
3715     case ARM::VLD1LNd8:
3716     case ARM::VLD1LNd16:
3717     case ARM::VLD1LNd32:
3718     case ARM::VLD1LNd8_UPD:
3719     case ARM::VLD1LNd16_UPD:
3720     case ARM::VLD1LNd32_UPD:
3721     case ARM::VLD2LNd8:
3722     case ARM::VLD2LNd16:
3723     case ARM::VLD2LNd32:
3724     case ARM::VLD2LNq16:
3725     case ARM::VLD2LNq32:
3726     case ARM::VLD2LNd8_UPD:
3727     case ARM::VLD2LNd16_UPD:
3728     case ARM::VLD2LNd32_UPD:
3729     case ARM::VLD2LNq16_UPD:
3730     case ARM::VLD2LNq32_UPD:
3731     case ARM::VLD4LNd8:
3732     case ARM::VLD4LNd16:
3733     case ARM::VLD4LNd32:
3734     case ARM::VLD4LNq16:
3735     case ARM::VLD4LNq32:
3736     case ARM::VLD4LNd8_UPD:
3737     case ARM::VLD4LNd16_UPD:
3738     case ARM::VLD4LNd32_UPD:
3739     case ARM::VLD4LNq16_UPD:
3740     case ARM::VLD4LNq32_UPD:
3741       // If the address is not 64-bit aligned, the latencies of these
3742       // instructions increases by one.
3743       ++Adjust;
3744       break;
3745     }
3746   }
3747   return Adjust;
3748 }
3749 
3750 int ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
3751                                         const MachineInstr &DefMI,
3752                                         unsigned DefIdx,
3753                                         const MachineInstr &UseMI,
3754                                         unsigned UseIdx) const {
3755   // No operand latency. The caller may fall back to getInstrLatency.
3756   if (!ItinData || ItinData->isEmpty())
3757     return -1;
3758 
3759   const MachineOperand &DefMO = DefMI.getOperand(DefIdx);
3760   unsigned Reg = DefMO.getReg();
3761 
3762   const MachineInstr *ResolvedDefMI = &DefMI;
3763   unsigned DefAdj = 0;
3764   if (DefMI.isBundle())
3765     ResolvedDefMI =
3766         getBundledDefMI(&getRegisterInfo(), &DefMI, Reg, DefIdx, DefAdj);
3767   if (ResolvedDefMI->isCopyLike() || ResolvedDefMI->isInsertSubreg() ||
3768       ResolvedDefMI->isRegSequence() || ResolvedDefMI->isImplicitDef()) {
3769     return 1;
3770   }
3771 
3772   const MachineInstr *ResolvedUseMI = &UseMI;
3773   unsigned UseAdj = 0;
3774   if (UseMI.isBundle()) {
3775     ResolvedUseMI =
3776         getBundledUseMI(&getRegisterInfo(), UseMI, Reg, UseIdx, UseAdj);
3777     if (!ResolvedUseMI)
3778       return -1;
3779   }
3780 
3781   return getOperandLatencyImpl(
3782       ItinData, *ResolvedDefMI, DefIdx, ResolvedDefMI->getDesc(), DefAdj, DefMO,
3783       Reg, *ResolvedUseMI, UseIdx, ResolvedUseMI->getDesc(), UseAdj);
3784 }
3785 
3786 int ARMBaseInstrInfo::getOperandLatencyImpl(
3787     const InstrItineraryData *ItinData, const MachineInstr &DefMI,
3788     unsigned DefIdx, const MCInstrDesc &DefMCID, unsigned DefAdj,
3789     const MachineOperand &DefMO, unsigned Reg, const MachineInstr &UseMI,
3790     unsigned UseIdx, const MCInstrDesc &UseMCID, unsigned UseAdj) const {
3791   if (Reg == ARM::CPSR) {
3792     if (DefMI.getOpcode() == ARM::FMSTAT) {
3793       // fpscr -> cpsr stalls over 20 cycles on A8 (and earlier?)
3794       return Subtarget.isLikeA9() ? 1 : 20;
3795     }
3796 
3797     // CPSR set and branch can be paired in the same cycle.
3798     if (UseMI.isBranch())
3799       return 0;
3800 
3801     // Otherwise it takes the instruction latency (generally one).
3802     unsigned Latency = getInstrLatency(ItinData, DefMI);
3803 
3804     // For Thumb2 and -Os, prefer scheduling CPSR setting instruction close to
3805     // its uses. Instructions which are otherwise scheduled between them may
3806     // incur a code size penalty (not able to use the CPSR setting 16-bit
3807     // instructions).
3808     if (Latency > 0 && Subtarget.isThumb2()) {
3809       const MachineFunction *MF = DefMI.getParent()->getParent();
3810       // FIXME: Use Function::optForSize().
3811       if (MF->getFunction()->hasFnAttribute(Attribute::OptimizeForSize))
3812         --Latency;
3813     }
3814     return Latency;
3815   }
3816 
3817   if (DefMO.isImplicit() || UseMI.getOperand(UseIdx).isImplicit())
3818     return -1;
3819 
3820   unsigned DefAlign = DefMI.hasOneMemOperand()
3821                           ? (*DefMI.memoperands_begin())->getAlignment()
3822                           : 0;
3823   unsigned UseAlign = UseMI.hasOneMemOperand()
3824                           ? (*UseMI.memoperands_begin())->getAlignment()
3825                           : 0;
3826 
3827   // Get the itinerary's latency if possible, and handle variable_ops.
3828   int Latency = getOperandLatency(ItinData, DefMCID, DefIdx, DefAlign, UseMCID,
3829                                   UseIdx, UseAlign);
3830   // Unable to find operand latency. The caller may resort to getInstrLatency.
3831   if (Latency < 0)
3832     return Latency;
3833 
3834   // Adjust for IT block position.
3835   int Adj = DefAdj + UseAdj;
3836 
3837   // Adjust for dynamic def-side opcode variants not captured by the itinerary.
3838   Adj += adjustDefLatency(Subtarget, DefMI, DefMCID, DefAlign);
3839   if (Adj >= 0 || (int)Latency > -Adj) {
3840     return Latency + Adj;
3841   }
3842   // Return the itinerary latency, which may be zero but not less than zero.
3843   return Latency;
3844 }
3845 
3846 int
3847 ARMBaseInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
3848                                     SDNode *DefNode, unsigned DefIdx,
3849                                     SDNode *UseNode, unsigned UseIdx) const {
3850   if (!DefNode->isMachineOpcode())
3851     return 1;
3852 
3853   const MCInstrDesc &DefMCID = get(DefNode->getMachineOpcode());
3854 
3855   if (isZeroCost(DefMCID.Opcode))
3856     return 0;
3857 
3858   if (!ItinData || ItinData->isEmpty())
3859     return DefMCID.mayLoad() ? 3 : 1;
3860 
3861   if (!UseNode->isMachineOpcode()) {
3862     int Latency = ItinData->getOperandCycle(DefMCID.getSchedClass(), DefIdx);
3863     int Adj = Subtarget.getPreISelOperandLatencyAdjustment();
3864     int Threshold = 1 + Adj;
3865     return Latency <= Threshold ? 1 : Latency - Adj;
3866   }
3867 
3868   const MCInstrDesc &UseMCID = get(UseNode->getMachineOpcode());
3869   const MachineSDNode *DefMN = dyn_cast<MachineSDNode>(DefNode);
3870   unsigned DefAlign = !DefMN->memoperands_empty()
3871     ? (*DefMN->memoperands_begin())->getAlignment() : 0;
3872   const MachineSDNode *UseMN = dyn_cast<MachineSDNode>(UseNode);
3873   unsigned UseAlign = !UseMN->memoperands_empty()
3874     ? (*UseMN->memoperands_begin())->getAlignment() : 0;
3875   int Latency = getOperandLatency(ItinData, DefMCID, DefIdx, DefAlign,
3876                                   UseMCID, UseIdx, UseAlign);
3877 
3878   if (Latency > 1 &&
3879       (Subtarget.isCortexA8() || Subtarget.isLikeA9() ||
3880        Subtarget.isCortexA7())) {
3881     // FIXME: Shifter op hack: no shift (i.e. [r +/- r]) or [r + r << 2]
3882     // variants are one cycle cheaper.
3883     switch (DefMCID.getOpcode()) {
3884     default: break;
3885     case ARM::LDRrs:
3886     case ARM::LDRBrs: {
3887       unsigned ShOpVal =
3888         cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
3889       unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
3890       if (ShImm == 0 ||
3891           (ShImm == 2 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
3892         --Latency;
3893       break;
3894     }
3895     case ARM::t2LDRs:
3896     case ARM::t2LDRBs:
3897     case ARM::t2LDRHs:
3898     case ARM::t2LDRSHs: {
3899       // Thumb2 mode: lsl only.
3900       unsigned ShAmt =
3901         cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
3902       if (ShAmt == 0 || ShAmt == 2)
3903         --Latency;
3904       break;
3905     }
3906     }
3907   } else if (DefIdx == 0 && Latency > 2 && Subtarget.isSwift()) {
3908     // FIXME: Properly handle all of the latency adjustments for address
3909     // writeback.
3910     switch (DefMCID.getOpcode()) {
3911     default: break;
3912     case ARM::LDRrs:
3913     case ARM::LDRBrs: {
3914       unsigned ShOpVal =
3915         cast<ConstantSDNode>(DefNode->getOperand(2))->getZExtValue();
3916       unsigned ShImm = ARM_AM::getAM2Offset(ShOpVal);
3917       if (ShImm == 0 ||
3918           ((ShImm == 1 || ShImm == 2 || ShImm == 3) &&
3919            ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsl))
3920         Latency -= 2;
3921       else if (ShImm == 1 && ARM_AM::getAM2ShiftOpc(ShOpVal) == ARM_AM::lsr)
3922         --Latency;
3923       break;
3924     }
3925     case ARM::t2LDRs:
3926     case ARM::t2LDRBs:
3927     case ARM::t2LDRHs:
3928     case ARM::t2LDRSHs: {
3929       // Thumb2 mode: lsl 0-3 only.
3930       Latency -= 2;
3931       break;
3932     }
3933     }
3934   }
3935 
3936   if (DefAlign < 8 && Subtarget.checkVLDnAccessAlignment())
3937     switch (DefMCID.getOpcode()) {
3938     default: break;
3939     case ARM::VLD1q8:
3940     case ARM::VLD1q16:
3941     case ARM::VLD1q32:
3942     case ARM::VLD1q64:
3943     case ARM::VLD1q8wb_register:
3944     case ARM::VLD1q16wb_register:
3945     case ARM::VLD1q32wb_register:
3946     case ARM::VLD1q64wb_register:
3947     case ARM::VLD1q8wb_fixed:
3948     case ARM::VLD1q16wb_fixed:
3949     case ARM::VLD1q32wb_fixed:
3950     case ARM::VLD1q64wb_fixed:
3951     case ARM::VLD2d8:
3952     case ARM::VLD2d16:
3953     case ARM::VLD2d32:
3954     case ARM::VLD2q8Pseudo:
3955     case ARM::VLD2q16Pseudo:
3956     case ARM::VLD2q32Pseudo:
3957     case ARM::VLD2d8wb_fixed:
3958     case ARM::VLD2d16wb_fixed:
3959     case ARM::VLD2d32wb_fixed:
3960     case ARM::VLD2q8PseudoWB_fixed:
3961     case ARM::VLD2q16PseudoWB_fixed:
3962     case ARM::VLD2q32PseudoWB_fixed:
3963     case ARM::VLD2d8wb_register:
3964     case ARM::VLD2d16wb_register:
3965     case ARM::VLD2d32wb_register:
3966     case ARM::VLD2q8PseudoWB_register:
3967     case ARM::VLD2q16PseudoWB_register:
3968     case ARM::VLD2q32PseudoWB_register:
3969     case ARM::VLD3d8Pseudo:
3970     case ARM::VLD3d16Pseudo:
3971     case ARM::VLD3d32Pseudo:
3972     case ARM::VLD1d64TPseudo:
3973     case ARM::VLD1d64TPseudoWB_fixed:
3974     case ARM::VLD3d8Pseudo_UPD:
3975     case ARM::VLD3d16Pseudo_UPD:
3976     case ARM::VLD3d32Pseudo_UPD:
3977     case ARM::VLD3q8Pseudo_UPD:
3978     case ARM::VLD3q16Pseudo_UPD:
3979     case ARM::VLD3q32Pseudo_UPD:
3980     case ARM::VLD3q8oddPseudo:
3981     case ARM::VLD3q16oddPseudo:
3982     case ARM::VLD3q32oddPseudo:
3983     case ARM::VLD3q8oddPseudo_UPD:
3984     case ARM::VLD3q16oddPseudo_UPD:
3985     case ARM::VLD3q32oddPseudo_UPD:
3986     case ARM::VLD4d8Pseudo:
3987     case ARM::VLD4d16Pseudo:
3988     case ARM::VLD4d32Pseudo:
3989     case ARM::VLD1d64QPseudo:
3990     case ARM::VLD1d64QPseudoWB_fixed:
3991     case ARM::VLD4d8Pseudo_UPD:
3992     case ARM::VLD4d16Pseudo_UPD:
3993     case ARM::VLD4d32Pseudo_UPD:
3994     case ARM::VLD4q8Pseudo_UPD:
3995     case ARM::VLD4q16Pseudo_UPD:
3996     case ARM::VLD4q32Pseudo_UPD:
3997     case ARM::VLD4q8oddPseudo:
3998     case ARM::VLD4q16oddPseudo:
3999     case ARM::VLD4q32oddPseudo:
4000     case ARM::VLD4q8oddPseudo_UPD:
4001     case ARM::VLD4q16oddPseudo_UPD:
4002     case ARM::VLD4q32oddPseudo_UPD:
4003     case ARM::VLD1DUPq8:
4004     case ARM::VLD1DUPq16:
4005     case ARM::VLD1DUPq32:
4006     case ARM::VLD1DUPq8wb_fixed:
4007     case ARM::VLD1DUPq16wb_fixed:
4008     case ARM::VLD1DUPq32wb_fixed:
4009     case ARM::VLD1DUPq8wb_register:
4010     case ARM::VLD1DUPq16wb_register:
4011     case ARM::VLD1DUPq32wb_register:
4012     case ARM::VLD2DUPd8:
4013     case ARM::VLD2DUPd16:
4014     case ARM::VLD2DUPd32:
4015     case ARM::VLD2DUPd8wb_fixed:
4016     case ARM::VLD2DUPd16wb_fixed:
4017     case ARM::VLD2DUPd32wb_fixed:
4018     case ARM::VLD2DUPd8wb_register:
4019     case ARM::VLD2DUPd16wb_register:
4020     case ARM::VLD2DUPd32wb_register:
4021     case ARM::VLD4DUPd8Pseudo:
4022     case ARM::VLD4DUPd16Pseudo:
4023     case ARM::VLD4DUPd32Pseudo:
4024     case ARM::VLD4DUPd8Pseudo_UPD:
4025     case ARM::VLD4DUPd16Pseudo_UPD:
4026     case ARM::VLD4DUPd32Pseudo_UPD:
4027     case ARM::VLD1LNq8Pseudo:
4028     case ARM::VLD1LNq16Pseudo:
4029     case ARM::VLD1LNq32Pseudo:
4030     case ARM::VLD1LNq8Pseudo_UPD:
4031     case ARM::VLD1LNq16Pseudo_UPD:
4032     case ARM::VLD1LNq32Pseudo_UPD:
4033     case ARM::VLD2LNd8Pseudo:
4034     case ARM::VLD2LNd16Pseudo:
4035     case ARM::VLD2LNd32Pseudo:
4036     case ARM::VLD2LNq16Pseudo:
4037     case ARM::VLD2LNq32Pseudo:
4038     case ARM::VLD2LNd8Pseudo_UPD:
4039     case ARM::VLD2LNd16Pseudo_UPD:
4040     case ARM::VLD2LNd32Pseudo_UPD:
4041     case ARM::VLD2LNq16Pseudo_UPD:
4042     case ARM::VLD2LNq32Pseudo_UPD:
4043     case ARM::VLD4LNd8Pseudo:
4044     case ARM::VLD4LNd16Pseudo:
4045     case ARM::VLD4LNd32Pseudo:
4046     case ARM::VLD4LNq16Pseudo:
4047     case ARM::VLD4LNq32Pseudo:
4048     case ARM::VLD4LNd8Pseudo_UPD:
4049     case ARM::VLD4LNd16Pseudo_UPD:
4050     case ARM::VLD4LNd32Pseudo_UPD:
4051     case ARM::VLD4LNq16Pseudo_UPD:
4052     case ARM::VLD4LNq32Pseudo_UPD:
4053       // If the address is not 64-bit aligned, the latencies of these
4054       // instructions increases by one.
4055       ++Latency;
4056       break;
4057     }
4058 
4059   return Latency;
4060 }
4061 
4062 unsigned ARMBaseInstrInfo::getPredicationCost(const MachineInstr &MI) const {
4063   if (MI.isCopyLike() || MI.isInsertSubreg() || MI.isRegSequence() ||
4064       MI.isImplicitDef())
4065     return 0;
4066 
4067   if (MI.isBundle())
4068     return 0;
4069 
4070   const MCInstrDesc &MCID = MI.getDesc();
4071 
4072   if (MCID.isCall() || MCID.hasImplicitDefOfPhysReg(ARM::CPSR)) {
4073     // When predicated, CPSR is an additional source operand for CPSR updating
4074     // instructions, this apparently increases their latencies.
4075     return 1;
4076   }
4077   return 0;
4078 }
4079 
4080 unsigned ARMBaseInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
4081                                            const MachineInstr &MI,
4082                                            unsigned *PredCost) const {
4083   if (MI.isCopyLike() || MI.isInsertSubreg() || MI.isRegSequence() ||
4084       MI.isImplicitDef())
4085     return 1;
4086 
4087   // An instruction scheduler typically runs on unbundled instructions, however
4088   // other passes may query the latency of a bundled instruction.
4089   if (MI.isBundle()) {
4090     unsigned Latency = 0;
4091     MachineBasicBlock::const_instr_iterator I = MI.getIterator();
4092     MachineBasicBlock::const_instr_iterator E = MI.getParent()->instr_end();
4093     while (++I != E && I->isInsideBundle()) {
4094       if (I->getOpcode() != ARM::t2IT)
4095         Latency += getInstrLatency(ItinData, *I, PredCost);
4096     }
4097     return Latency;
4098   }
4099 
4100   const MCInstrDesc &MCID = MI.getDesc();
4101   if (PredCost && (MCID.isCall() || MCID.hasImplicitDefOfPhysReg(ARM::CPSR))) {
4102     // When predicated, CPSR is an additional source operand for CPSR updating
4103     // instructions, this apparently increases their latencies.
4104     *PredCost = 1;
4105   }
4106   // Be sure to call getStageLatency for an empty itinerary in case it has a
4107   // valid MinLatency property.
4108   if (!ItinData)
4109     return MI.mayLoad() ? 3 : 1;
4110 
4111   unsigned Class = MCID.getSchedClass();
4112 
4113   // For instructions with variable uops, use uops as latency.
4114   if (!ItinData->isEmpty() && ItinData->getNumMicroOps(Class) < 0)
4115     return getNumMicroOps(ItinData, MI);
4116 
4117   // For the common case, fall back on the itinerary's latency.
4118   unsigned Latency = ItinData->getStageLatency(Class);
4119 
4120   // Adjust for dynamic def-side opcode variants not captured by the itinerary.
4121   unsigned DefAlign =
4122       MI.hasOneMemOperand() ? (*MI.memoperands_begin())->getAlignment() : 0;
4123   int Adj = adjustDefLatency(Subtarget, MI, MCID, DefAlign);
4124   if (Adj >= 0 || (int)Latency > -Adj) {
4125     return Latency + Adj;
4126   }
4127   return Latency;
4128 }
4129 
4130 int ARMBaseInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
4131                                       SDNode *Node) const {
4132   if (!Node->isMachineOpcode())
4133     return 1;
4134 
4135   if (!ItinData || ItinData->isEmpty())
4136     return 1;
4137 
4138   unsigned Opcode = Node->getMachineOpcode();
4139   switch (Opcode) {
4140   default:
4141     return ItinData->getStageLatency(get(Opcode).getSchedClass());
4142   case ARM::VLDMQIA:
4143   case ARM::VSTMQIA:
4144     return 2;
4145   }
4146 }
4147 
4148 bool ARMBaseInstrInfo::hasHighOperandLatency(const TargetSchedModel &SchedModel,
4149                                              const MachineRegisterInfo *MRI,
4150                                              const MachineInstr &DefMI,
4151                                              unsigned DefIdx,
4152                                              const MachineInstr &UseMI,
4153                                              unsigned UseIdx) const {
4154   unsigned DDomain = DefMI.getDesc().TSFlags & ARMII::DomainMask;
4155   unsigned UDomain = UseMI.getDesc().TSFlags & ARMII::DomainMask;
4156   if (Subtarget.nonpipelinedVFP() &&
4157       (DDomain == ARMII::DomainVFP || UDomain == ARMII::DomainVFP))
4158     return true;
4159 
4160   // Hoist VFP / NEON instructions with 4 or higher latency.
4161   unsigned Latency =
4162       SchedModel.computeOperandLatency(&DefMI, DefIdx, &UseMI, UseIdx);
4163   if (Latency <= 3)
4164     return false;
4165   return DDomain == ARMII::DomainVFP || DDomain == ARMII::DomainNEON ||
4166          UDomain == ARMII::DomainVFP || UDomain == ARMII::DomainNEON;
4167 }
4168 
4169 bool ARMBaseInstrInfo::hasLowDefLatency(const TargetSchedModel &SchedModel,
4170                                         const MachineInstr &DefMI,
4171                                         unsigned DefIdx) const {
4172   const InstrItineraryData *ItinData = SchedModel.getInstrItineraries();
4173   if (!ItinData || ItinData->isEmpty())
4174     return false;
4175 
4176   unsigned DDomain = DefMI.getDesc().TSFlags & ARMII::DomainMask;
4177   if (DDomain == ARMII::DomainGeneral) {
4178     unsigned DefClass = DefMI.getDesc().getSchedClass();
4179     int DefCycle = ItinData->getOperandCycle(DefClass, DefIdx);
4180     return (DefCycle != -1 && DefCycle <= 2);
4181   }
4182   return false;
4183 }
4184 
4185 bool ARMBaseInstrInfo::verifyInstruction(const MachineInstr &MI,
4186                                          StringRef &ErrInfo) const {
4187   if (convertAddSubFlagsOpcode(MI.getOpcode())) {
4188     ErrInfo = "Pseudo flag setting opcodes only exist in Selection DAG";
4189     return false;
4190   }
4191   return true;
4192 }
4193 
4194 // LoadStackGuard has so far only been implemented for MachO. Different code
4195 // sequence is needed for other targets.
4196 void ARMBaseInstrInfo::expandLoadStackGuardBase(MachineBasicBlock::iterator MI,
4197                                                 unsigned LoadImmOpc,
4198                                                 unsigned LoadOpc) const {
4199   assert(!Subtarget.isROPI() && !Subtarget.isRWPI() &&
4200          "ROPI/RWPI not currently supported with stack guard");
4201 
4202   MachineBasicBlock &MBB = *MI->getParent();
4203   DebugLoc DL = MI->getDebugLoc();
4204   unsigned Reg = MI->getOperand(0).getReg();
4205   const GlobalValue *GV =
4206       cast<GlobalValue>((*MI->memoperands_begin())->getValue());
4207   MachineInstrBuilder MIB;
4208 
4209   BuildMI(MBB, MI, DL, get(LoadImmOpc), Reg)
4210       .addGlobalAddress(GV, 0, ARMII::MO_NONLAZY);
4211 
4212   if (Subtarget.isGVIndirectSymbol(GV)) {
4213     MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
4214     MIB.addReg(Reg, RegState::Kill).addImm(0);
4215     auto Flags = MachineMemOperand::MOLoad |
4216                  MachineMemOperand::MODereferenceable |
4217                  MachineMemOperand::MOInvariant;
4218     MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
4219         MachinePointerInfo::getGOT(*MBB.getParent()), Flags, 4, 4);
4220     MIB.addMemOperand(MMO).add(predOps(ARMCC::AL));
4221   }
4222 
4223   MIB = BuildMI(MBB, MI, DL, get(LoadOpc), Reg);
4224   MIB.addReg(Reg, RegState::Kill)
4225      .addImm(0)
4226      .setMemRefs(MI->memoperands_begin(), MI->memoperands_end())
4227      .add(predOps(ARMCC::AL));
4228 }
4229 
4230 bool
4231 ARMBaseInstrInfo::isFpMLxInstruction(unsigned Opcode, unsigned &MulOpc,
4232                                      unsigned &AddSubOpc,
4233                                      bool &NegAcc, bool &HasLane) const {
4234   DenseMap<unsigned, unsigned>::const_iterator I = MLxEntryMap.find(Opcode);
4235   if (I == MLxEntryMap.end())
4236     return false;
4237 
4238   const ARM_MLxEntry &Entry = ARM_MLxTable[I->second];
4239   MulOpc = Entry.MulOpc;
4240   AddSubOpc = Entry.AddSubOpc;
4241   NegAcc = Entry.NegAcc;
4242   HasLane = Entry.HasLane;
4243   return true;
4244 }
4245 
4246 //===----------------------------------------------------------------------===//
4247 // Execution domains.
4248 //===----------------------------------------------------------------------===//
4249 //
4250 // Some instructions go down the NEON pipeline, some go down the VFP pipeline,
4251 // and some can go down both.  The vmov instructions go down the VFP pipeline,
4252 // but they can be changed to vorr equivalents that are executed by the NEON
4253 // pipeline.
4254 //
4255 // We use the following execution domain numbering:
4256 //
4257 enum ARMExeDomain {
4258   ExeGeneric = 0,
4259   ExeVFP = 1,
4260   ExeNEON = 2
4261 };
4262 //
4263 // Also see ARMInstrFormats.td and Domain* enums in ARMBaseInfo.h
4264 //
4265 std::pair<uint16_t, uint16_t>
4266 ARMBaseInstrInfo::getExecutionDomain(const MachineInstr &MI) const {
4267   // If we don't have access to NEON instructions then we won't be able
4268   // to swizzle anything to the NEON domain. Check to make sure.
4269   if (Subtarget.hasNEON()) {
4270     // VMOVD, VMOVRS and VMOVSR are VFP instructions, but can be changed to NEON
4271     // if they are not predicated.
4272     if (MI.getOpcode() == ARM::VMOVD && !isPredicated(MI))
4273       return std::make_pair(ExeVFP, (1 << ExeVFP) | (1 << ExeNEON));
4274 
4275     // CortexA9 is particularly picky about mixing the two and wants these
4276     // converted.
4277     if (Subtarget.useNEONForFPMovs() && !isPredicated(MI) &&
4278         (MI.getOpcode() == ARM::VMOVRS || MI.getOpcode() == ARM::VMOVSR ||
4279          MI.getOpcode() == ARM::VMOVS))
4280       return std::make_pair(ExeVFP, (1 << ExeVFP) | (1 << ExeNEON));
4281   }
4282   // No other instructions can be swizzled, so just determine their domain.
4283   unsigned Domain = MI.getDesc().TSFlags & ARMII::DomainMask;
4284 
4285   if (Domain & ARMII::DomainNEON)
4286     return std::make_pair(ExeNEON, 0);
4287 
4288   // Certain instructions can go either way on Cortex-A8.
4289   // Treat them as NEON instructions.
4290   if ((Domain & ARMII::DomainNEONA8) && Subtarget.isCortexA8())
4291     return std::make_pair(ExeNEON, 0);
4292 
4293   if (Domain & ARMII::DomainVFP)
4294     return std::make_pair(ExeVFP, 0);
4295 
4296   return std::make_pair(ExeGeneric, 0);
4297 }
4298 
4299 static unsigned getCorrespondingDRegAndLane(const TargetRegisterInfo *TRI,
4300                                             unsigned SReg, unsigned &Lane) {
4301   unsigned DReg = TRI->getMatchingSuperReg(SReg, ARM::ssub_0, &ARM::DPRRegClass);
4302   Lane = 0;
4303 
4304   if (DReg != ARM::NoRegister)
4305    return DReg;
4306 
4307   Lane = 1;
4308   DReg = TRI->getMatchingSuperReg(SReg, ARM::ssub_1, &ARM::DPRRegClass);
4309 
4310   assert(DReg && "S-register with no D super-register?");
4311   return DReg;
4312 }
4313 
4314 /// getImplicitSPRUseForDPRUse - Given a use of a DPR register and lane,
4315 /// set ImplicitSReg to a register number that must be marked as implicit-use or
4316 /// zero if no register needs to be defined as implicit-use.
4317 ///
4318 /// If the function cannot determine if an SPR should be marked implicit use or
4319 /// not, it returns false.
4320 ///
4321 /// This function handles cases where an instruction is being modified from taking
4322 /// an SPR to a DPR[Lane]. A use of the DPR is being added, which may conflict
4323 /// with an earlier def of an SPR corresponding to DPR[Lane^1] (i.e. the other
4324 /// lane of the DPR).
4325 ///
4326 /// If the other SPR is defined, an implicit-use of it should be added. Else,
4327 /// (including the case where the DPR itself is defined), it should not.
4328 ///
4329 static bool getImplicitSPRUseForDPRUse(const TargetRegisterInfo *TRI,
4330                                        MachineInstr &MI, unsigned DReg,
4331                                        unsigned Lane, unsigned &ImplicitSReg) {
4332   // If the DPR is defined or used already, the other SPR lane will be chained
4333   // correctly, so there is nothing to be done.
4334   if (MI.definesRegister(DReg, TRI) || MI.readsRegister(DReg, TRI)) {
4335     ImplicitSReg = 0;
4336     return true;
4337   }
4338 
4339   // Otherwise we need to go searching to see if the SPR is set explicitly.
4340   ImplicitSReg = TRI->getSubReg(DReg,
4341                                 (Lane & 1) ? ARM::ssub_0 : ARM::ssub_1);
4342   MachineBasicBlock::LivenessQueryResult LQR =
4343       MI.getParent()->computeRegisterLiveness(TRI, ImplicitSReg, MI);
4344 
4345   if (LQR == MachineBasicBlock::LQR_Live)
4346     return true;
4347   else if (LQR == MachineBasicBlock::LQR_Unknown)
4348     return false;
4349 
4350   // If the register is known not to be live, there is no need to add an
4351   // implicit-use.
4352   ImplicitSReg = 0;
4353   return true;
4354 }
4355 
4356 void ARMBaseInstrInfo::setExecutionDomain(MachineInstr &MI,
4357                                           unsigned Domain) const {
4358   unsigned DstReg, SrcReg, DReg;
4359   unsigned Lane;
4360   MachineInstrBuilder MIB(*MI.getParent()->getParent(), MI);
4361   const TargetRegisterInfo *TRI = &getRegisterInfo();
4362   switch (MI.getOpcode()) {
4363   default:
4364     llvm_unreachable("cannot handle opcode!");
4365     break;
4366   case ARM::VMOVD:
4367     if (Domain != ExeNEON)
4368       break;
4369 
4370     // Zap the predicate operands.
4371     assert(!isPredicated(MI) && "Cannot predicate a VORRd");
4372 
4373     // Make sure we've got NEON instructions.
4374     assert(Subtarget.hasNEON() && "VORRd requires NEON");
4375 
4376     // Source instruction is %DDst = VMOVD %DSrc, 14, %noreg (; implicits)
4377     DstReg = MI.getOperand(0).getReg();
4378     SrcReg = MI.getOperand(1).getReg();
4379 
4380     for (unsigned i = MI.getDesc().getNumOperands(); i; --i)
4381       MI.RemoveOperand(i - 1);
4382 
4383     // Change to a %DDst = VORRd %DSrc, %DSrc, 14, %noreg (; implicits)
4384     MI.setDesc(get(ARM::VORRd));
4385     MIB.addReg(DstReg, RegState::Define)
4386         .addReg(SrcReg)
4387         .addReg(SrcReg)
4388         .add(predOps(ARMCC::AL));
4389     break;
4390   case ARM::VMOVRS:
4391     if (Domain != ExeNEON)
4392       break;
4393     assert(!isPredicated(MI) && "Cannot predicate a VGETLN");
4394 
4395     // Source instruction is %RDst = VMOVRS %SSrc, 14, %noreg (; implicits)
4396     DstReg = MI.getOperand(0).getReg();
4397     SrcReg = MI.getOperand(1).getReg();
4398 
4399     for (unsigned i = MI.getDesc().getNumOperands(); i; --i)
4400       MI.RemoveOperand(i - 1);
4401 
4402     DReg = getCorrespondingDRegAndLane(TRI, SrcReg, Lane);
4403 
4404     // Convert to %RDst = VGETLNi32 %DSrc, Lane, 14, %noreg (; imps)
4405     // Note that DSrc has been widened and the other lane may be undef, which
4406     // contaminates the entire register.
4407     MI.setDesc(get(ARM::VGETLNi32));
4408     MIB.addReg(DstReg, RegState::Define)
4409         .addReg(DReg, RegState::Undef)
4410         .addImm(Lane)
4411         .add(predOps(ARMCC::AL));
4412 
4413     // The old source should be an implicit use, otherwise we might think it
4414     // was dead before here.
4415     MIB.addReg(SrcReg, RegState::Implicit);
4416     break;
4417   case ARM::VMOVSR: {
4418     if (Domain != ExeNEON)
4419       break;
4420     assert(!isPredicated(MI) && "Cannot predicate a VSETLN");
4421 
4422     // Source instruction is %SDst = VMOVSR %RSrc, 14, %noreg (; implicits)
4423     DstReg = MI.getOperand(0).getReg();
4424     SrcReg = MI.getOperand(1).getReg();
4425 
4426     DReg = getCorrespondingDRegAndLane(TRI, DstReg, Lane);
4427 
4428     unsigned ImplicitSReg;
4429     if (!getImplicitSPRUseForDPRUse(TRI, MI, DReg, Lane, ImplicitSReg))
4430       break;
4431 
4432     for (unsigned i = MI.getDesc().getNumOperands(); i; --i)
4433       MI.RemoveOperand(i - 1);
4434 
4435     // Convert to %DDst = VSETLNi32 %DDst, %RSrc, Lane, 14, %noreg (; imps)
4436     // Again DDst may be undefined at the beginning of this instruction.
4437     MI.setDesc(get(ARM::VSETLNi32));
4438     MIB.addReg(DReg, RegState::Define)
4439         .addReg(DReg, getUndefRegState(!MI.readsRegister(DReg, TRI)))
4440         .addReg(SrcReg)
4441         .addImm(Lane)
4442         .add(predOps(ARMCC::AL));
4443 
4444     // The narrower destination must be marked as set to keep previous chains
4445     // in place.
4446     MIB.addReg(DstReg, RegState::Define | RegState::Implicit);
4447     if (ImplicitSReg != 0)
4448       MIB.addReg(ImplicitSReg, RegState::Implicit);
4449     break;
4450     }
4451     case ARM::VMOVS: {
4452       if (Domain != ExeNEON)
4453         break;
4454 
4455       // Source instruction is %SDst = VMOVS %SSrc, 14, %noreg (; implicits)
4456       DstReg = MI.getOperand(0).getReg();
4457       SrcReg = MI.getOperand(1).getReg();
4458 
4459       unsigned DstLane = 0, SrcLane = 0, DDst, DSrc;
4460       DDst = getCorrespondingDRegAndLane(TRI, DstReg, DstLane);
4461       DSrc = getCorrespondingDRegAndLane(TRI, SrcReg, SrcLane);
4462 
4463       unsigned ImplicitSReg;
4464       if (!getImplicitSPRUseForDPRUse(TRI, MI, DSrc, SrcLane, ImplicitSReg))
4465         break;
4466 
4467       for (unsigned i = MI.getDesc().getNumOperands(); i; --i)
4468         MI.RemoveOperand(i - 1);
4469 
4470       if (DSrc == DDst) {
4471         // Destination can be:
4472         //     %DDst = VDUPLN32d %DDst, Lane, 14, %noreg (; implicits)
4473         MI.setDesc(get(ARM::VDUPLN32d));
4474         MIB.addReg(DDst, RegState::Define)
4475             .addReg(DDst, getUndefRegState(!MI.readsRegister(DDst, TRI)))
4476             .addImm(SrcLane)
4477             .add(predOps(ARMCC::AL));
4478 
4479         // Neither the source or the destination are naturally represented any
4480         // more, so add them in manually.
4481         MIB.addReg(DstReg, RegState::Implicit | RegState::Define);
4482         MIB.addReg(SrcReg, RegState::Implicit);
4483         if (ImplicitSReg != 0)
4484           MIB.addReg(ImplicitSReg, RegState::Implicit);
4485         break;
4486       }
4487 
4488       // In general there's no single instruction that can perform an S <-> S
4489       // move in NEON space, but a pair of VEXT instructions *can* do the
4490       // job. It turns out that the VEXTs needed will only use DSrc once, with
4491       // the position based purely on the combination of lane-0 and lane-1
4492       // involved. For example
4493       //     vmov s0, s2 -> vext.32 d0, d0, d1, #1  vext.32 d0, d0, d0, #1
4494       //     vmov s1, s3 -> vext.32 d0, d1, d0, #1  vext.32 d0, d0, d0, #1
4495       //     vmov s0, s3 -> vext.32 d0, d0, d0, #1  vext.32 d0, d1, d0, #1
4496       //     vmov s1, s2 -> vext.32 d0, d0, d0, #1  vext.32 d0, d0, d1, #1
4497       //
4498       // Pattern of the MachineInstrs is:
4499       //     %DDst = VEXTd32 %DSrc1, %DSrc2, Lane, 14, %noreg (;implicits)
4500       MachineInstrBuilder NewMIB;
4501       NewMIB = BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), get(ARM::VEXTd32),
4502                        DDst);
4503 
4504       // On the first instruction, both DSrc and DDst may be <undef> if present.
4505       // Specifically when the original instruction didn't have them as an
4506       // <imp-use>.
4507       unsigned CurReg = SrcLane == 1 && DstLane == 1 ? DSrc : DDst;
4508       bool CurUndef = !MI.readsRegister(CurReg, TRI);
4509       NewMIB.addReg(CurReg, getUndefRegState(CurUndef));
4510 
4511       CurReg = SrcLane == 0 && DstLane == 0 ? DSrc : DDst;
4512       CurUndef = !MI.readsRegister(CurReg, TRI);
4513       NewMIB.addReg(CurReg, getUndefRegState(CurUndef))
4514             .addImm(1)
4515             .add(predOps(ARMCC::AL));
4516 
4517       if (SrcLane == DstLane)
4518         NewMIB.addReg(SrcReg, RegState::Implicit);
4519 
4520       MI.setDesc(get(ARM::VEXTd32));
4521       MIB.addReg(DDst, RegState::Define);
4522 
4523       // On the second instruction, DDst has definitely been defined above, so
4524       // it is not <undef>. DSrc, if present, can be <undef> as above.
4525       CurReg = SrcLane == 1 && DstLane == 0 ? DSrc : DDst;
4526       CurUndef = CurReg == DSrc && !MI.readsRegister(CurReg, TRI);
4527       MIB.addReg(CurReg, getUndefRegState(CurUndef));
4528 
4529       CurReg = SrcLane == 0 && DstLane == 1 ? DSrc : DDst;
4530       CurUndef = CurReg == DSrc && !MI.readsRegister(CurReg, TRI);
4531       MIB.addReg(CurReg, getUndefRegState(CurUndef))
4532          .addImm(1)
4533          .add(predOps(ARMCC::AL));
4534 
4535       if (SrcLane != DstLane)
4536         MIB.addReg(SrcReg, RegState::Implicit);
4537 
4538       // As before, the original destination is no longer represented, add it
4539       // implicitly.
4540       MIB.addReg(DstReg, RegState::Define | RegState::Implicit);
4541       if (ImplicitSReg != 0)
4542         MIB.addReg(ImplicitSReg, RegState::Implicit);
4543       break;
4544     }
4545   }
4546 
4547 }
4548 
4549 //===----------------------------------------------------------------------===//
4550 // Partial register updates
4551 //===----------------------------------------------------------------------===//
4552 //
4553 // Swift renames NEON registers with 64-bit granularity.  That means any
4554 // instruction writing an S-reg implicitly reads the containing D-reg.  The
4555 // problem is mostly avoided by translating f32 operations to v2f32 operations
4556 // on D-registers, but f32 loads are still a problem.
4557 //
4558 // These instructions can load an f32 into a NEON register:
4559 //
4560 // VLDRS - Only writes S, partial D update.
4561 // VLD1LNd32 - Writes all D-regs, explicit partial D update, 2 uops.
4562 // VLD1DUPd32 - Writes all D-regs, no partial reg update, 2 uops.
4563 //
4564 // FCONSTD can be used as a dependency-breaking instruction.
4565 unsigned ARMBaseInstrInfo::getPartialRegUpdateClearance(
4566     const MachineInstr &MI, unsigned OpNum,
4567     const TargetRegisterInfo *TRI) const {
4568   auto PartialUpdateClearance = Subtarget.getPartialUpdateClearance();
4569   if (!PartialUpdateClearance)
4570     return 0;
4571 
4572   assert(TRI && "Need TRI instance");
4573 
4574   const MachineOperand &MO = MI.getOperand(OpNum);
4575   if (MO.readsReg())
4576     return 0;
4577   unsigned Reg = MO.getReg();
4578   int UseOp = -1;
4579 
4580   switch (MI.getOpcode()) {
4581   // Normal instructions writing only an S-register.
4582   case ARM::VLDRS:
4583   case ARM::FCONSTS:
4584   case ARM::VMOVSR:
4585   case ARM::VMOVv8i8:
4586   case ARM::VMOVv4i16:
4587   case ARM::VMOVv2i32:
4588   case ARM::VMOVv2f32:
4589   case ARM::VMOVv1i64:
4590     UseOp = MI.findRegisterUseOperandIdx(Reg, false, TRI);
4591     break;
4592 
4593     // Explicitly reads the dependency.
4594   case ARM::VLD1LNd32:
4595     UseOp = 3;
4596     break;
4597   default:
4598     return 0;
4599   }
4600 
4601   // If this instruction actually reads a value from Reg, there is no unwanted
4602   // dependency.
4603   if (UseOp != -1 && MI.getOperand(UseOp).readsReg())
4604     return 0;
4605 
4606   // We must be able to clobber the whole D-reg.
4607   if (TargetRegisterInfo::isVirtualRegister(Reg)) {
4608     // Virtual register must be a foo:ssub_0<def,undef> operand.
4609     if (!MO.getSubReg() || MI.readsVirtualRegister(Reg))
4610       return 0;
4611   } else if (ARM::SPRRegClass.contains(Reg)) {
4612     // Physical register: MI must define the full D-reg.
4613     unsigned DReg = TRI->getMatchingSuperReg(Reg, ARM::ssub_0,
4614                                              &ARM::DPRRegClass);
4615     if (!DReg || !MI.definesRegister(DReg, TRI))
4616       return 0;
4617   }
4618 
4619   // MI has an unwanted D-register dependency.
4620   // Avoid defs in the previous N instructrions.
4621   return PartialUpdateClearance;
4622 }
4623 
4624 // Break a partial register dependency after getPartialRegUpdateClearance
4625 // returned non-zero.
4626 void ARMBaseInstrInfo::breakPartialRegDependency(
4627     MachineInstr &MI, unsigned OpNum, const TargetRegisterInfo *TRI) const {
4628   assert(OpNum < MI.getDesc().getNumDefs() && "OpNum is not a def");
4629   assert(TRI && "Need TRI instance");
4630 
4631   const MachineOperand &MO = MI.getOperand(OpNum);
4632   unsigned Reg = MO.getReg();
4633   assert(TargetRegisterInfo::isPhysicalRegister(Reg) &&
4634          "Can't break virtual register dependencies.");
4635   unsigned DReg = Reg;
4636 
4637   // If MI defines an S-reg, find the corresponding D super-register.
4638   if (ARM::SPRRegClass.contains(Reg)) {
4639     DReg = ARM::D0 + (Reg - ARM::S0) / 2;
4640     assert(TRI->isSuperRegister(Reg, DReg) && "Register enums broken");
4641   }
4642 
4643   assert(ARM::DPRRegClass.contains(DReg) && "Can only break D-reg deps");
4644   assert(MI.definesRegister(DReg, TRI) && "MI doesn't clobber full D-reg");
4645 
4646   // FIXME: In some cases, VLDRS can be changed to a VLD1DUPd32 which defines
4647   // the full D-register by loading the same value to both lanes.  The
4648   // instruction is micro-coded with 2 uops, so don't do this until we can
4649   // properly schedule micro-coded instructions.  The dispatcher stalls cause
4650   // too big regressions.
4651 
4652   // Insert the dependency-breaking FCONSTD before MI.
4653   // 96 is the encoding of 0.5, but the actual value doesn't matter here.
4654   BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), get(ARM::FCONSTD), DReg)
4655       .addImm(96)
4656       .add(predOps(ARMCC::AL));
4657   MI.addRegisterKilled(DReg, TRI, true);
4658 }
4659 
4660 bool ARMBaseInstrInfo::hasNOP() const {
4661   return Subtarget.getFeatureBits()[ARM::HasV6KOps];
4662 }
4663 
4664 bool ARMBaseInstrInfo::isSwiftFastImmShift(const MachineInstr *MI) const {
4665   if (MI->getNumOperands() < 4)
4666     return true;
4667   unsigned ShOpVal = MI->getOperand(3).getImm();
4668   unsigned ShImm = ARM_AM::getSORegOffset(ShOpVal);
4669   // Swift supports faster shifts for: lsl 2, lsl 1, and lsr 1.
4670   if ((ShImm == 1 && ARM_AM::getSORegShOp(ShOpVal) == ARM_AM::lsr) ||
4671       ((ShImm == 1 || ShImm == 2) &&
4672        ARM_AM::getSORegShOp(ShOpVal) == ARM_AM::lsl))
4673     return true;
4674 
4675   return false;
4676 }
4677 
4678 bool ARMBaseInstrInfo::getRegSequenceLikeInputs(
4679     const MachineInstr &MI, unsigned DefIdx,
4680     SmallVectorImpl<RegSubRegPairAndIdx> &InputRegs) const {
4681   assert(DefIdx < MI.getDesc().getNumDefs() && "Invalid definition index");
4682   assert(MI.isRegSequenceLike() && "Invalid kind of instruction");
4683 
4684   switch (MI.getOpcode()) {
4685   case ARM::VMOVDRR:
4686     // dX = VMOVDRR rY, rZ
4687     // is the same as:
4688     // dX = REG_SEQUENCE rY, ssub_0, rZ, ssub_1
4689     // Populate the InputRegs accordingly.
4690     // rY
4691     const MachineOperand *MOReg = &MI.getOperand(1);
4692     InputRegs.push_back(
4693         RegSubRegPairAndIdx(MOReg->getReg(), MOReg->getSubReg(), ARM::ssub_0));
4694     // rZ
4695     MOReg = &MI.getOperand(2);
4696     InputRegs.push_back(
4697         RegSubRegPairAndIdx(MOReg->getReg(), MOReg->getSubReg(), ARM::ssub_1));
4698     return true;
4699   }
4700   llvm_unreachable("Target dependent opcode missing");
4701 }
4702 
4703 bool ARMBaseInstrInfo::getExtractSubregLikeInputs(
4704     const MachineInstr &MI, unsigned DefIdx,
4705     RegSubRegPairAndIdx &InputReg) const {
4706   assert(DefIdx < MI.getDesc().getNumDefs() && "Invalid definition index");
4707   assert(MI.isExtractSubregLike() && "Invalid kind of instruction");
4708 
4709   switch (MI.getOpcode()) {
4710   case ARM::VMOVRRD:
4711     // rX, rY = VMOVRRD dZ
4712     // is the same as:
4713     // rX = EXTRACT_SUBREG dZ, ssub_0
4714     // rY = EXTRACT_SUBREG dZ, ssub_1
4715     const MachineOperand &MOReg = MI.getOperand(2);
4716     InputReg.Reg = MOReg.getReg();
4717     InputReg.SubReg = MOReg.getSubReg();
4718     InputReg.SubIdx = DefIdx == 0 ? ARM::ssub_0 : ARM::ssub_1;
4719     return true;
4720   }
4721   llvm_unreachable("Target dependent opcode missing");
4722 }
4723 
4724 bool ARMBaseInstrInfo::getInsertSubregLikeInputs(
4725     const MachineInstr &MI, unsigned DefIdx, RegSubRegPair &BaseReg,
4726     RegSubRegPairAndIdx &InsertedReg) const {
4727   assert(DefIdx < MI.getDesc().getNumDefs() && "Invalid definition index");
4728   assert(MI.isInsertSubregLike() && "Invalid kind of instruction");
4729 
4730   switch (MI.getOpcode()) {
4731   case ARM::VSETLNi32:
4732     // dX = VSETLNi32 dY, rZ, imm
4733     const MachineOperand &MOBaseReg = MI.getOperand(1);
4734     const MachineOperand &MOInsertedReg = MI.getOperand(2);
4735     const MachineOperand &MOIndex = MI.getOperand(3);
4736     BaseReg.Reg = MOBaseReg.getReg();
4737     BaseReg.SubReg = MOBaseReg.getSubReg();
4738 
4739     InsertedReg.Reg = MOInsertedReg.getReg();
4740     InsertedReg.SubReg = MOInsertedReg.getSubReg();
4741     InsertedReg.SubIdx = MOIndex.getImm() == 0 ? ARM::ssub_0 : ARM::ssub_1;
4742     return true;
4743   }
4744   llvm_unreachable("Target dependent opcode missing");
4745 }
4746