lib/CodeGen/MachineFunction.cpp

   1 //===- MachineFunction.cpp ------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Collect native machine code information for a function.  This allows
  10 // target-specific information about the generated code to be stored with each
  11 // function.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/CodeGen/MachineFunction.h"
  16 #include "llvm/ADT/BitVector.h"
  17 #include "llvm/ADT/DenseMap.h"
  18 #include "llvm/ADT/DenseSet.h"
  19 #include "llvm/ADT/STLExtras.h"
  20 #include "llvm/ADT/SmallString.h"
  21 #include "llvm/ADT/SmallVector.h"
  22 #include "llvm/ADT/StringRef.h"
  23 #include "llvm/ADT/Twine.h"
  24 #include "llvm/Analysis/ConstantFolding.h"
  25 #include "llvm/Analysis/EHPersonalities.h"
  26 #include "llvm/CodeGen/MachineBasicBlock.h"
  27 #include "llvm/CodeGen/MachineConstantPool.h"
  28 #include "llvm/CodeGen/MachineFrameInfo.h"
  29 #include "llvm/CodeGen/MachineInstr.h"
  30 #include "llvm/CodeGen/MachineJumpTableInfo.h"
  31 #include "llvm/CodeGen/MachineMemOperand.h"
  32 #include "llvm/CodeGen/MachineModuleInfo.h"
  33 #include "llvm/CodeGen/MachineRegisterInfo.h"
  34 #include "llvm/CodeGen/PseudoSourceValue.h"
  35 #include "llvm/CodeGen/TargetFrameLowering.h"
  36 #include "llvm/CodeGen/TargetLowering.h"
  37 #include "llvm/CodeGen/TargetRegisterInfo.h"
  38 #include "llvm/CodeGen/TargetSubtargetInfo.h"
  39 #include "llvm/CodeGen/WasmEHFuncInfo.h"
  40 #include "llvm/CodeGen/WinEHFuncInfo.h"
  41 #include "llvm/Config/llvm-config.h"
  42 #include "llvm/IR/Attributes.h"
  43 #include "llvm/IR/BasicBlock.h"
  44 #include "llvm/IR/Constant.h"
  45 #include "llvm/IR/DataLayout.h"
  46 #include "llvm/IR/DebugInfoMetadata.h"
  47 #include "llvm/IR/DerivedTypes.h"
  48 #include "llvm/IR/Function.h"
  49 #include "llvm/IR/GlobalValue.h"
  50 #include "llvm/IR/Instruction.h"
  51 #include "llvm/IR/Instructions.h"
  52 #include "llvm/IR/Metadata.h"
  53 #include "llvm/IR/Module.h"
  54 #include "llvm/IR/ModuleSlotTracker.h"
  55 #include "llvm/IR/Value.h"
  56 #include "llvm/MC/MCContext.h"
  57 #include "llvm/MC/MCSymbol.h"
  58 #include "llvm/MC/SectionKind.h"
  59 #include "llvm/Support/Casting.h"
  60 #include "llvm/Support/CommandLine.h"
  61 #include "llvm/Support/Compiler.h"
  62 #include "llvm/Support/DOTGraphTraits.h"
  63 #include "llvm/Support/Debug.h"
  64 #include "llvm/Support/ErrorHandling.h"
  65 #include "llvm/Support/GraphWriter.h"
  66 #include "llvm/Support/raw_ostream.h"
  67 #include "llvm/Target/TargetMachine.h"
  68 #include <algorithm>
  69 #include <cassert>
  70 #include <cstddef>
  71 #include <cstdint>
  72 #include <iterator>
  73 #include <string>
  74 #include <utility>
  75 #include <vector>
  76
  77 using namespace llvm;
  78
  79 #define DEBUG_TYPE "codegen"
  80
  81 static cl::opt<unsigned> AlignAllFunctions(
  82     "align-all-functions",
  83     cl::desc("Force the alignment of all functions in log2 format (e.g. 4 "
  84              "means align on 16B boundaries)."),
  85     cl::init(0), cl::Hidden);
  86
  87 static const char *getPropertyName(MachineFunctionProperties::Property Prop) {
  88   using P = MachineFunctionProperties::Property;
  89
  90   switch(Prop) {
  91   case P::FailedISel: return "FailedISel";
  92   case P::IsSSA: return "IsSSA";
  93   case P::Legalized: return "Legalized";
  94   case P::NoPHIs: return "NoPHIs";
  95   case P::NoVRegs: return "NoVRegs";
  96   case P::RegBankSelected: return "RegBankSelected";
  97   case P::Selected: return "Selected";
  98   case P::TracksLiveness: return "TracksLiveness";
  99   }
 100   llvm_unreachable("Invalid machine function property");
 101 }
 102
 103 // Pin the vtable to this file.
 104 void MachineFunction::Delegate::anchor() {}
 105
 106 void MachineFunctionProperties::print(raw_ostream &OS) const {
 107   const char *Separator = "";
 108   for (BitVector::size_type I = 0; I < Properties.size(); ++I) {
 109     if (!Properties[I])
 110       continue;
 111     OS << Separator << getPropertyName(static_cast<Property>(I));
 112     Separator = ", ";
 113   }
 114 }
 115
 116 //===----------------------------------------------------------------------===//
 117 // MachineFunction implementation
 118 //===----------------------------------------------------------------------===//
 119
 120 // Out-of-line virtual method.
 121 MachineFunctionInfo::~MachineFunctionInfo() = default;
 122
 123 void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
 124   MBB->getParent()->DeleteMachineBasicBlock(MBB);
 125 }
 126
 127 static inline unsigned getFnStackAlignment(const TargetSubtargetInfo *STI,
 128                                            const Function &F) {
 129   if (F.hasFnAttribute(Attribute::StackAlignment))
 130     return F.getFnStackAlignment();
 131   return STI->getFrameLowering()->getStackAlignment();
 132 }
 133
 134 MachineFunction::MachineFunction(const Function &F,
 135                                  const LLVMTargetMachine &Target,
 136                                  const TargetSubtargetInfo &STI,
 137                                  unsigned FunctionNum, MachineModuleInfo &mmi)
 138     : F(F), Target(Target), STI(&STI), Ctx(mmi.getContext()), MMI(mmi) {
 139   FunctionNumber = FunctionNum;
 140   init();
 141 }
 142
 143 void MachineFunction::handleInsertion(MachineInstr &MI) {
 144   if (TheDelegate)
 145     TheDelegate->MF_HandleInsertion(MI);
 146 }
 147
 148 void MachineFunction::handleRemoval(MachineInstr &MI) {
 149   if (TheDelegate)
 150     TheDelegate->MF_HandleRemoval(MI);
 151 }
 152
 153 void MachineFunction::init() {
 154   // Assume the function starts in SSA form with correct liveness.
 155   Properties.set(MachineFunctionProperties::Property::IsSSA);
 156   Properties.set(MachineFunctionProperties::Property::TracksLiveness);
 157   if (STI->getRegisterInfo())
 158     RegInfo = new (Allocator) MachineRegisterInfo(this);
 159   else
 160     RegInfo = nullptr;
 161
 162   MFInfo = nullptr;
 163   // We can realign the stack if the target supports it and the user hasn't
 164   // explicitly asked us not to.
 165   bool CanRealignSP = STI->getFrameLowering()->isStackRealignable() &&
 166                       !F.hasFnAttribute("no-realign-stack");
 167   FrameInfo = new (Allocator) MachineFrameInfo(
 168       getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP,
 169       /*ForcedRealign=*/CanRealignSP &&
 170           F.hasFnAttribute(Attribute::StackAlignment));
 171
 172   if (F.hasFnAttribute(Attribute::StackAlignment))
 173     FrameInfo->ensureMaxAlignment(F.getFnStackAlignment());
 174
 175   ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
 176   Alignment = STI->getTargetLowering()->getMinFunctionAlignment();
 177
 178   // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
 179   // FIXME: Use Function::hasOptSize().
 180   if (!F.hasFnAttribute(Attribute::OptimizeForSize))
 181     Alignment = std::max(Alignment,
 182                          STI->getTargetLowering()->getPrefFunctionAlignment());
 183
 184   if (AlignAllFunctions)
 185     Alignment = Align(1ULL << AlignAllFunctions);
 186
 187   JumpTableInfo = nullptr;
 188
 189   if (isFuncletEHPersonality(classifyEHPersonality(
 190           F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
 191     WinEHInfo = new (Allocator) WinEHFuncInfo();
 192   }
 193
 194   if (isScopedEHPersonality(classifyEHPersonality(
 195           F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
 196     WasmEHInfo = new (Allocator) WasmEHFuncInfo();
 197   }
 198
 199   assert(Target.isCompatibleDataLayout(getDataLayout()) &&
 200          "Can't create a MachineFunction using a Module with a "
 201          "Target-incompatible DataLayout attached\n");
 202
 203   PSVManager =
 204     std::make_unique<PseudoSourceValueManager>(*(getSubtarget().
 205                                                   getInstrInfo()));
 206 }
 207
 208 MachineFunction::~MachineFunction() {
 209   clear();
 210 }
 211
 212 void MachineFunction::clear() {
 213   Properties.reset();
 214   // Don't call destructors on MachineInstr and MachineOperand. All of their
 215   // memory comes from the BumpPtrAllocator which is about to be purged.
 216   //
 217   // Do call MachineBasicBlock destructors, it contains std::vectors.
 218   for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
 219     I->Insts.clearAndLeakNodesUnsafely();
 220   MBBNumbering.clear();
 221
 222   InstructionRecycler.clear(Allocator);
 223   OperandRecycler.clear(Allocator);
 224   BasicBlockRecycler.clear(Allocator);
 225   CodeViewAnnotations.clear();
 226   VariableDbgInfos.clear();
 227   if (RegInfo) {
 228     RegInfo->~MachineRegisterInfo();
 229     Allocator.Deallocate(RegInfo);
 230   }
 231   if (MFInfo) {
 232     MFInfo->~MachineFunctionInfo();
 233     Allocator.Deallocate(MFInfo);
 234   }
 235
 236   FrameInfo->~MachineFrameInfo();
 237   Allocator.Deallocate(FrameInfo);
 238
 239   ConstantPool->~MachineConstantPool();
 240   Allocator.Deallocate(ConstantPool);
 241
 242   if (JumpTableInfo) {
 243     JumpTableInfo->~MachineJumpTableInfo();
 244     Allocator.Deallocate(JumpTableInfo);
 245   }
 246
 247   if (WinEHInfo) {
 248     WinEHInfo->~WinEHFuncInfo();
 249     Allocator.Deallocate(WinEHInfo);
 250   }
 251
 252   if (WasmEHInfo) {
 253     WasmEHInfo->~WasmEHFuncInfo();
 254     Allocator.Deallocate(WasmEHInfo);
 255   }
 256 }
 257
 258 const DataLayout &MachineFunction::getDataLayout() const {
 259   return F.getParent()->getDataLayout();
 260 }
 261
 262 /// Get the JumpTableInfo for this function.
 263 /// If it does not already exist, allocate one.
 264 MachineJumpTableInfo *MachineFunction::
 265 getOrCreateJumpTableInfo(unsigned EntryKind) {
 266   if (JumpTableInfo) return JumpTableInfo;
 267
 268   JumpTableInfo = new (Allocator)
 269     MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
 270   return JumpTableInfo;
 271 }
 272
 273 /// Should we be emitting segmented stack stuff for the function
 274 bool MachineFunction::shouldSplitStack() const {
 275   return getFunction().hasFnAttribute("split-stack");
 276 }
 277
 278 LLVM_NODISCARD unsigned
 279 MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
 280   FrameInstructions.push_back(Inst);
 281   return FrameInstructions.size() - 1;
 282 }
 283
 284 /// This discards all of the MachineBasicBlock numbers and recomputes them.
 285 /// This guarantees that the MBB numbers are sequential, dense, and match the
 286 /// ordering of the blocks within the function.  If a specific MachineBasicBlock
 287 /// is specified, only that block and those after it are renumbered.
 288 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
 289   if (empty()) { MBBNumbering.clear(); return; }
 290   MachineFunction::iterator MBBI, E = end();
 291   if (MBB == nullptr)
 292     MBBI = begin();
 293   else
 294     MBBI = MBB->getIterator();
 295
 296   // Figure out the block number this should have.
 297   unsigned BlockNo = 0;
 298   if (MBBI != begin())
 299     BlockNo = std::prev(MBBI)->getNumber() + 1;
 300
 301   for (; MBBI != E; ++MBBI, ++BlockNo) {
 302     if (MBBI->getNumber() != (int)BlockNo) {
 303       // Remove use of the old number.
 304       if (MBBI->getNumber() != -1) {
 305         assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
 306                "MBB number mismatch!");
 307         MBBNumbering[MBBI->getNumber()] = nullptr;
 308       }
 309
 310       // If BlockNo is already taken, set that block's number to -1.
 311       if (MBBNumbering[BlockNo])
 312         MBBNumbering[BlockNo]->setNumber(-1);
 313
 314       MBBNumbering[BlockNo] = &*MBBI;
 315       MBBI->setNumber(BlockNo);
 316     }
 317   }
 318
 319   // Okay, all the blocks are renumbered.  If we have compactified the block
 320   // numbering, shrink MBBNumbering now.
 321   assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
 322   MBBNumbering.resize(BlockNo);
 323 }
 324
 325 /// Allocate a new MachineInstr. Use this instead of `new MachineInstr'.
 326 MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
 327                                                   const DebugLoc &DL,
 328                                                   bool NoImp) {
 329   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
 330     MachineInstr(*this, MCID, DL, NoImp);
 331 }
 332
 333 /// Create a new MachineInstr which is a copy of the 'Orig' instruction,
 334 /// identical in all ways except the instruction has no parent, prev, or next.
 335 MachineInstr *
 336 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
 337   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
 338              MachineInstr(*this, *Orig);
 339 }
 340
 341 MachineInstr &MachineFunction::CloneMachineInstrBundle(MachineBasicBlock &MBB,
 342     MachineBasicBlock::iterator InsertBefore, const MachineInstr &Orig) {
 343   MachineInstr *FirstClone = nullptr;
 344   MachineBasicBlock::const_instr_iterator I = Orig.getIterator();
 345   while (true) {
 346     MachineInstr *Cloned = CloneMachineInstr(&*I);
 347     MBB.insert(InsertBefore, Cloned);
 348     if (FirstClone == nullptr) {
 349       FirstClone = Cloned;
 350     } else {
 351       Cloned->bundleWithPred();
 352     }
 353
 354     if (!I->isBundledWithSucc())
 355       break;
 356     ++I;
 357   }
 358   return *FirstClone;
 359 }
 360
 361 /// Delete the given MachineInstr.
 362 ///
 363 /// This function also serves as the MachineInstr destructor - the real
 364 /// ~MachineInstr() destructor must be empty.
 365 void
 366 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
 367   // Verify that a call site info is at valid state. This assertion should
 368   // be triggered during the implementation of support for the
 369   // call site info of a new architecture. If the assertion is triggered,
 370   // back trace will tell where to insert a call to updateCallSiteInfo().
 371   assert((!MI->isCall(MachineInstr::IgnoreBundle) ||
 372           CallSitesInfo.find(MI) == CallSitesInfo.end()) &&
 373          "Call site info was not updated!");
 374   // Strip it for parts. The operand array and the MI object itself are
 375   // independently recyclable.
 376   if (MI->Operands)
 377     deallocateOperandArray(MI->CapOperands, MI->Operands);
 378   // Don't call ~MachineInstr() which must be trivial anyway because
 379   // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
 380   // destructors.
 381   InstructionRecycler.Deallocate(Allocator, MI);
 382 }
 383
 384 /// Allocate a new MachineBasicBlock. Use this instead of
 385 /// `new MachineBasicBlock'.
 386 MachineBasicBlock *
 387 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
 388   return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
 389              MachineBasicBlock(*this, bb);
 390 }
 391
 392 /// Delete the given MachineBasicBlock.
 393 void
 394 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
 395   assert(MBB->getParent() == this && "MBB parent mismatch!");
 396   MBB->~MachineBasicBlock();
 397   BasicBlockRecycler.Deallocate(Allocator, MBB);
 398 }
 399
 400 MachineMemOperand *MachineFunction::getMachineMemOperand(
 401     MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
 402     unsigned base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
 403     SyncScope::ID SSID, AtomicOrdering Ordering,
 404     AtomicOrdering FailureOrdering) {
 405   return new (Allocator)
 406       MachineMemOperand(PtrInfo, f, s, base_alignment, AAInfo, Ranges,
 407                         SSID, Ordering, FailureOrdering);
 408 }
 409
 410 MachineMemOperand *
 411 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
 412                                       int64_t Offset, uint64_t Size) {
 413   const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();
 414
 415   // If there is no pointer value, the offset isn't tracked so we need to adjust
 416   // the base alignment.
 417   unsigned Align = PtrInfo.V.isNull()
 418                        ? MinAlign(MMO->getBaseAlignment(), Offset)
 419                        : MMO->getBaseAlignment();
 420
 421   return new (Allocator)
 422       MachineMemOperand(PtrInfo.getWithOffset(Offset), MMO->getFlags(), Size,
 423                         Align, AAMDNodes(), nullptr, MMO->getSyncScopeID(),
 424                         MMO->getOrdering(), MMO->getFailureOrdering());
 425 }
 426
 427 MachineMemOperand *
 428 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
 429                                       const AAMDNodes &AAInfo) {
 430   MachinePointerInfo MPI = MMO->getValue() ?
 431              MachinePointerInfo(MMO->getValue(), MMO->getOffset()) :
 432              MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset());
 433
 434   return new (Allocator)
 435              MachineMemOperand(MPI, MMO->getFlags(), MMO->getSize(),
 436                                MMO->getBaseAlignment(), AAInfo,
 437                                MMO->getRanges(), MMO->getSyncScopeID(),
 438                                MMO->getOrdering(), MMO->getFailureOrdering());
 439 }
 440
 441 MachineMemOperand *
 442 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
 443                                       MachineMemOperand::Flags Flags) {
 444   return new (Allocator) MachineMemOperand(
 445       MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlignment(),
 446       MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),
 447       MMO->getOrdering(), MMO->getFailureOrdering());
 448 }
 449
 450 MachineInstr::ExtraInfo *
 451 MachineFunction::createMIExtraInfo(ArrayRef<MachineMemOperand *> MMOs,
 452                                    MCSymbol *PreInstrSymbol,
 453                                    MCSymbol *PostInstrSymbol) {
 454   return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol,
 455                                          PostInstrSymbol);
 456 }
 457
 458 const char *MachineFunction::createExternalSymbolName(StringRef Name) {
 459   char *Dest = Allocator.Allocate<char>(Name.size() + 1);
 460   llvm::copy(Name, Dest);
 461   Dest[Name.size()] = 0;
 462   return Dest;
 463 }
 464
 465 uint32_t *MachineFunction::allocateRegMask() {
 466   unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs();
 467   unsigned Size = MachineOperand::getRegMaskSize(NumRegs);
 468   uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
 469   memset(Mask, 0, Size * sizeof(Mask[0]));
 470   return Mask;
 471 }
 472
 473 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 474 LLVM_DUMP_METHOD void MachineFunction::dump() const {
 475   print(dbgs());
 476 }
 477 #endif
 478
 479 StringRef MachineFunction::getName() const {
 480   return getFunction().getName();
 481 }
 482
 483 void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const {
 484   OS << "# Machine code for function " << getName() << ": ";
 485   getProperties().print(OS);
 486   OS << '\n';
 487
 488   // Print Frame Information
 489   FrameInfo->print(*this, OS);
 490
 491   // Print JumpTable Information
 492   if (JumpTableInfo)
 493     JumpTableInfo->print(OS);
 494
 495   // Print Constant Pool
 496   ConstantPool->print(OS);
 497
 498   const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();
 499
 500   if (RegInfo && !RegInfo->livein_empty()) {
 501     OS << "Function Live Ins: ";
 502     for (MachineRegisterInfo::livein_iterator
 503          I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
 504       OS << printReg(I->first, TRI);
 505       if (I->second)
 506         OS << " in " << printReg(I->second, TRI);
 507       if (std::next(I) != E)
 508         OS << ", ";
 509     }
 510     OS << '\n';
 511   }
 512
 513   ModuleSlotTracker MST(getFunction().getParent());
 514   MST.incorporateFunction(getFunction());
 515   for (const auto &BB : *this) {
 516     OS << '\n';
 517     // If we print the whole function, print it at its most verbose level.
 518     BB.print(OS, MST, Indexes, /*IsStandalone=*/true);
 519   }
 520
 521   OS << "\n# End machine code for function " << getName() << ".\n\n";
 522 }
 523
 524 namespace llvm {
 525
 526   template<>
 527   struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
 528     DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
 529
 530     static std::string getGraphName(const MachineFunction *F) {
 531       return ("CFG for '" + F->getName() + "' function").str();
 532     }
 533
 534     std::string getNodeLabel(const MachineBasicBlock *Node,
 535                              const MachineFunction *Graph) {
 536       std::string OutStr;
 537       {
 538         raw_string_ostream OSS(OutStr);
 539
 540         if (isSimple()) {
 541           OSS << printMBBReference(*Node);
 542           if (const BasicBlock *BB = Node->getBasicBlock())
 543             OSS << ": " << BB->getName();
 544         } else
 545           Node->print(OSS);
 546       }
 547
 548       if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
 549
 550       // Process string output to make it nicer...
 551       for (unsigned i = 0; i != OutStr.length(); ++i)
 552         if (OutStr[i] == '\n') {                            // Left justify
 553           OutStr[i] = '\\';
 554           OutStr.insert(OutStr.begin()+i+1, 'l');
 555         }
 556       return OutStr;
 557     }
 558   };
 559
 560 } // end namespace llvm
 561
 562 void MachineFunction::viewCFG() const
 563 {
 564 #ifndef NDEBUG
 565   ViewGraph(this, "mf" + getName());
 566 #else
 567   errs() << "MachineFunction::viewCFG is only available in debug builds on "
 568          << "systems with Graphviz or gv!\n";
 569 #endif // NDEBUG
 570 }
 571
 572 void MachineFunction::viewCFGOnly() const
 573 {
 574 #ifndef NDEBUG
 575   ViewGraph(this, "mf" + getName(), true);
 576 #else
 577   errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
 578          << "systems with Graphviz or gv!\n";
 579 #endif // NDEBUG
 580 }
 581
 582 /// Add the specified physical register as a live-in value and
 583 /// create a corresponding virtual register for it.
 584 unsigned MachineFunction::addLiveIn(unsigned PReg,
 585                                     const TargetRegisterClass *RC) {
 586   MachineRegisterInfo &MRI = getRegInfo();
 587   unsigned VReg = MRI.getLiveInVirtReg(PReg);
 588   if (VReg) {
 589     const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
 590     (void)VRegRC;
 591     // A physical register can be added several times.
 592     // Between two calls, the register class of the related virtual register
 593     // may have been constrained to match some operation constraints.
 594     // In that case, check that the current register class includes the
 595     // physical register and is a sub class of the specified RC.
 596     assert((VRegRC == RC || (VRegRC->contains(PReg) &&
 597                              RC->hasSubClassEq(VRegRC))) &&
 598             "Register class mismatch!");
 599     return VReg;
 600   }
 601   VReg = MRI.createVirtualRegister(RC);
 602   MRI.addLiveIn(PReg, VReg);
 603   return VReg;
 604 }
 605
 606 /// Return the MCSymbol for the specified non-empty jump table.
 607 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
 608 /// normal 'L' label is returned.
 609 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
 610                                         bool isLinkerPrivate) const {
 611   const DataLayout &DL = getDataLayout();
 612   assert(JumpTableInfo && "No jump tables");
 613   assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
 614
 615   StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix()
 616                                      : DL.getPrivateGlobalPrefix();
 617   SmallString<60> Name;
 618   raw_svector_ostream(Name)
 619     << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
 620   return Ctx.getOrCreateSymbol(Name);
 621 }
 622
 623 /// Return a function-local symbol to represent the PIC base.
 624 MCSymbol *MachineFunction::getPICBaseSymbol() const {
 625   const DataLayout &DL = getDataLayout();
 626   return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
 627                                Twine(getFunctionNumber()) + "$pb");
 628 }
 629
 630 /// \name Exception Handling
 631 /// \{
 632
 633 LandingPadInfo &
 634 MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) {
 635   unsigned N = LandingPads.size();
 636   for (unsigned i = 0; i < N; ++i) {
 637     LandingPadInfo &LP = LandingPads[i];
 638     if (LP.LandingPadBlock == LandingPad)
 639       return LP;
 640   }
 641
 642   LandingPads.push_back(LandingPadInfo(LandingPad));
 643   return LandingPads[N];
 644 }
 645
 646 void MachineFunction::addInvoke(MachineBasicBlock *LandingPad,
 647                                 MCSymbol *BeginLabel, MCSymbol *EndLabel) {
 648   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 649   LP.BeginLabels.push_back(BeginLabel);
 650   LP.EndLabels.push_back(EndLabel);
 651 }
 652
 653 MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) {
 654   MCSymbol *LandingPadLabel = Ctx.createTempSymbol();
 655   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 656   LP.LandingPadLabel = LandingPadLabel;
 657
 658   const Instruction *FirstI = LandingPad->getBasicBlock()->getFirstNonPHI();
 659   if (const auto *LPI = dyn_cast<LandingPadInst>(FirstI)) {
 660     if (const auto *PF =
 661             dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts()))
 662       getMMI().addPersonality(PF);
 663
 664     if (LPI->isCleanup())
 665       addCleanup(LandingPad);
 666
 667     // FIXME: New EH - Add the clauses in reverse order. This isn't 100%
 668     //        correct, but we need to do it this way because of how the DWARF EH
 669     //        emitter processes the clauses.
 670     for (unsigned I = LPI->getNumClauses(); I != 0; --I) {
 671       Value *Val = LPI->getClause(I - 1);
 672       if (LPI->isCatch(I - 1)) {
 673         addCatchTypeInfo(LandingPad,
 674                          dyn_cast<GlobalValue>(Val->stripPointerCasts()));
 675       } else {
 676         // Add filters in a list.
 677         auto *CVal = cast<Constant>(Val);
 678         SmallVector<const GlobalValue *, 4> FilterList;
 679         for (User::op_iterator II = CVal->op_begin(), IE = CVal->op_end();
 680              II != IE; ++II)
 681           FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
 682
 683         addFilterTypeInfo(LandingPad, FilterList);
 684       }
 685     }
 686
 687   } else if (const auto *CPI = dyn_cast<CatchPadInst>(FirstI)) {
 688     for (unsigned I = CPI->getNumArgOperands(); I != 0; --I) {
 689       Value *TypeInfo = CPI->getArgOperand(I - 1)->stripPointerCasts();
 690       addCatchTypeInfo(LandingPad, dyn_cast<GlobalValue>(TypeInfo));
 691     }
 692
 693   } else {
 694     assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!");
 695   }
 696
 697   return LandingPadLabel;
 698 }
 699
 700 void MachineFunction::addCatchTypeInfo(MachineBasicBlock *LandingPad,
 701                                        ArrayRef<const GlobalValue *> TyInfo) {
 702   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 703   for (unsigned N = TyInfo.size(); N; --N)
 704     LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
 705 }
 706
 707 void MachineFunction::addFilterTypeInfo(MachineBasicBlock *LandingPad,
 708                                         ArrayRef<const GlobalValue *> TyInfo) {
 709   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 710   std::vector<unsigned> IdsInFilter(TyInfo.size());
 711   for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
 712     IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
 713   LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
 714 }
 715
 716 void MachineFunction::tidyLandingPads(DenseMap<MCSymbol *, uintptr_t> *LPMap,
 717                                       bool TidyIfNoBeginLabels) {
 718   for (unsigned i = 0; i != LandingPads.size(); ) {
 719     LandingPadInfo &LandingPad = LandingPads[i];
 720     if (LandingPad.LandingPadLabel &&
 721         !LandingPad.LandingPadLabel->isDefined() &&
 722         (!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0))
 723       LandingPad.LandingPadLabel = nullptr;
 724
 725     // Special case: we *should* emit LPs with null LP MBB. This indicates
 726     // "nounwind" case.
 727     if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
 728       LandingPads.erase(LandingPads.begin() + i);
 729       continue;
 730     }
 731
 732     if (TidyIfNoBeginLabels) {
 733       for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
 734         MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
 735         MCSymbol *EndLabel = LandingPad.EndLabels[j];
 736         if ((BeginLabel->isDefined() || (LPMap && (*LPMap)[BeginLabel] != 0)) &&
 737             (EndLabel->isDefined() || (LPMap && (*LPMap)[EndLabel] != 0)))
 738           continue;
 739
 740         LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
 741         LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
 742         --j;
 743         --e;
 744       }
 745
 746       // Remove landing pads with no try-ranges.
 747       if (LandingPads[i].BeginLabels.empty()) {
 748         LandingPads.erase(LandingPads.begin() + i);
 749         continue;
 750       }
 751     }
 752
 753     // If there is no landing pad, ensure that the list of typeids is empty.
 754     // If the only typeid is a cleanup, this is the same as having no typeids.
 755     if (!LandingPad.LandingPadBlock ||
 756         (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
 757       LandingPad.TypeIds.clear();
 758     ++i;
 759   }
 760 }
 761
 762 void MachineFunction::addCleanup(MachineBasicBlock *LandingPad) {
 763   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 764   LP.TypeIds.push_back(0);
 765 }
 766
 767 void MachineFunction::addSEHCatchHandler(MachineBasicBlock *LandingPad,
 768                                          const Function *Filter,
 769                                          const BlockAddress *RecoverBA) {
 770   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 771   SEHHandler Handler;
 772   Handler.FilterOrFinally = Filter;
 773   Handler.RecoverBA = RecoverBA;
 774   LP.SEHHandlers.push_back(Handler);
 775 }
 776
 777 void MachineFunction::addSEHCleanupHandler(MachineBasicBlock *LandingPad,
 778                                            const Function *Cleanup) {
 779   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
 780   SEHHandler Handler;
 781   Handler.FilterOrFinally = Cleanup;
 782   Handler.RecoverBA = nullptr;
 783   LP.SEHHandlers.push_back(Handler);
 784 }
 785
 786 void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,
 787                                             ArrayRef<unsigned> Sites) {
 788   LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
 789 }
 790
 791 unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) {
 792   for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
 793     if (TypeInfos[i] == TI) return i + 1;
 794
 795   TypeInfos.push_back(TI);
 796   return TypeInfos.size();
 797 }
 798
 799 int MachineFunction::getFilterIDFor(std::vector<unsigned> &TyIds) {
 800   // If the new filter coincides with the tail of an existing filter, then
 801   // re-use the existing filter.  Folding filters more than this requires
 802   // re-ordering filters and/or their elements - probably not worth it.
 803   for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
 804        E = FilterEnds.end(); I != E; ++I) {
 805     unsigned i = *I, j = TyIds.size();
 806
 807     while (i && j)
 808       if (FilterIds[--i] != TyIds[--j])
 809         goto try_next;
 810
 811     if (!j)
 812       // The new filter coincides with range [i, end) of the existing filter.
 813       return -(1 + i);
 814
 815 try_next:;
 816   }
 817
 818   // Add the new filter.
 819   int FilterID = -(1 + FilterIds.size());
 820   FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
 821   FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end());
 822   FilterEnds.push_back(FilterIds.size());
 823   FilterIds.push_back(0); // terminator
 824   return FilterID;
 825 }
 826
 827 void MachineFunction::addCodeViewHeapAllocSite(MachineInstr *I,
 828                                                const MDNode *MD) {
 829   MCSymbol *BeginLabel = Ctx.createTempSymbol("heapallocsite", true);
 830   MCSymbol *EndLabel = Ctx.createTempSymbol("heapallocsite", true);
 831   I->setPreInstrSymbol(*this, BeginLabel);
 832   I->setPostInstrSymbol(*this, EndLabel);
 833
 834   const DIType *DI = dyn_cast<DIType>(MD);
 835   CodeViewHeapAllocSites.push_back(std::make_tuple(BeginLabel, EndLabel, DI));
 836 }
 837
 838 void MachineFunction::moveCallSiteInfo(const MachineInstr *Old,
 839                                        const MachineInstr *New) {
 840   assert(New->isCall() && "Call site info refers only to call instructions!");
 841
 842   CallSiteInfoMap::iterator CSIt = getCallSiteInfo(Old);
 843   if (CSIt == CallSitesInfo.end())
 844     return;
 845
 846   CallSiteInfo CSInfo = std::move(CSIt->second);
 847   CallSitesInfo.erase(CSIt);
 848   CallSitesInfo[New] = CSInfo;
 849 }
 850
 851 void MachineFunction::eraseCallSiteInfo(const MachineInstr *MI) {
 852   CallSiteInfoMap::iterator CSIt = getCallSiteInfo(MI);
 853   if (CSIt == CallSitesInfo.end())
 854     return;
 855   CallSitesInfo.erase(CSIt);
 856 }
 857
 858 void MachineFunction::copyCallSiteInfo(const MachineInstr *Old,
 859                                        const MachineInstr *New) {
 860   assert(New->isCall() && "Call site info refers only to call instructions!");
 861
 862   CallSiteInfoMap::iterator CSIt = getCallSiteInfo(Old);
 863   if (CSIt == CallSitesInfo.end())
 864     return;
 865
 866   CallSiteInfo CSInfo = CSIt->second;
 867   CallSitesInfo[New] = CSInfo;
 868 }
 869
 870 /// \}
 871
 872 //===----------------------------------------------------------------------===//
 873 //  MachineJumpTableInfo implementation
 874 //===----------------------------------------------------------------------===//
 875
 876 /// Return the size of each entry in the jump table.
 877 unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
 878   // The size of a jump table entry is 4 bytes unless the entry is just the
 879   // address of a block, in which case it is the pointer size.
 880   switch (getEntryKind()) {
 881   case MachineJumpTableInfo::EK_BlockAddress:
 882     return TD.getPointerSize();
 883   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
 884     return 8;
 885   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
 886   case MachineJumpTableInfo::EK_LabelDifference32:
 887   case MachineJumpTableInfo::EK_Custom32:
 888     return 4;
 889   case MachineJumpTableInfo::EK_Inline:
 890     return 0;
 891   }
 892   llvm_unreachable("Unknown jump table encoding!");
 893 }
 894
 895 /// Return the alignment of each entry in the jump table.
 896 unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
 897   // The alignment of a jump table entry is the alignment of int32 unless the
 898   // entry is just the address of a block, in which case it is the pointer
 899   // alignment.
 900   switch (getEntryKind()) {
 901   case MachineJumpTableInfo::EK_BlockAddress:
 902     return TD.getPointerABIAlignment(0).value();
 903   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
 904     return TD.getABIIntegerTypeAlignment(64).value();
 905   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
 906   case MachineJumpTableInfo::EK_LabelDifference32:
 907   case MachineJumpTableInfo::EK_Custom32:
 908     return TD.getABIIntegerTypeAlignment(32).value();
 909   case MachineJumpTableInfo::EK_Inline:
 910     return 1;
 911   }
 912   llvm_unreachable("Unknown jump table encoding!");
 913 }
 914
 915 /// Create a new jump table entry in the jump table info.
 916 unsigned MachineJumpTableInfo::createJumpTableIndex(
 917                                const std::vector<MachineBasicBlock*> &DestBBs) {
 918   assert(!DestBBs.empty() && "Cannot create an empty jump table!");
 919   JumpTables.push_back(MachineJumpTableEntry(DestBBs));
 920   return JumpTables.size()-1;
 921 }
 922
 923 /// If Old is the target of any jump tables, update the jump tables to branch
 924 /// to New instead.
 925 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
 926                                                   MachineBasicBlock *New) {
 927   assert(Old != New && "Not making a change?");
 928   bool MadeChange = false;
 929   for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
 930     ReplaceMBBInJumpTable(i, Old, New);
 931   return MadeChange;
 932 }
 933
 934 /// If Old is a target of the jump tables, update the jump table to branch to
 935 /// New instead.
 936 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
 937                                                  MachineBasicBlock *Old,
 938                                                  MachineBasicBlock *New) {
 939   assert(Old != New && "Not making a change?");
 940   bool MadeChange = false;
 941   MachineJumpTableEntry &JTE = JumpTables[Idx];
 942   for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
 943     if (JTE.MBBs[j] == Old) {
 944       JTE.MBBs[j] = New;
 945       MadeChange = true;
 946     }
 947   return MadeChange;
 948 }
 949
 950 void MachineJumpTableInfo::print(raw_ostream &OS) const {
 951   if (JumpTables.empty()) return;
 952
 953   OS << "Jump Tables:\n";
 954
 955   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
 956     OS << printJumpTableEntryReference(i) << ':';
 957     for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
 958       OS << ' ' << printMBBReference(*JumpTables[i].MBBs[j]);
 959     if (i != e)
 960       OS << '\n';
 961   }
 962
 963   OS << '\n';
 964 }
 965
 966 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 967 LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); }
 968 #endif
 969
 970 Printable llvm::printJumpTableEntryReference(unsigned Idx) {
 971   return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; });
 972 }
 973
 974 //===----------------------------------------------------------------------===//
 975 //  MachineConstantPool implementation
 976 //===----------------------------------------------------------------------===//
 977
 978 void MachineConstantPoolValue::anchor() {}
 979
 980 Type *MachineConstantPoolEntry::getType() const {
 981   if (isMachineConstantPoolEntry())
 982     return Val.MachineCPVal->getType();
 983   return Val.ConstVal->getType();
 984 }
 985
 986 bool MachineConstantPoolEntry::needsRelocation() const {
 987   if (isMachineConstantPoolEntry())
 988     return true;
 989   return Val.ConstVal->needsRelocation();
 990 }
 991
 992 SectionKind
 993 MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
 994   if (needsRelocation())
 995     return SectionKind::getReadOnlyWithRel();
 996   switch (DL->getTypeAllocSize(getType())) {
 997   case 4:
 998     return SectionKind::getMergeableConst4();
 999   case 8:
1000     return SectionKind::getMergeableConst8();
1001   case 16:
1002     return SectionKind::getMergeableConst16();
1003   case 32:
1004     return SectionKind::getMergeableConst32();
1005   default:
1006     return SectionKind::getReadOnly();
1007   }
1008 }
1009
1010 MachineConstantPool::~MachineConstantPool() {
1011   // A constant may be a member of both Constants and MachineCPVsSharingEntries,
1012   // so keep track of which we've deleted to avoid double deletions.
1013   DenseSet<MachineConstantPoolValue*> Deleted;
1014   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
1015     if (Constants[i].isMachineConstantPoolEntry()) {
1016       Deleted.insert(Constants[i].Val.MachineCPVal);
1017       delete Constants[i].Val.MachineCPVal;
1018     }
1019   for (DenseSet<MachineConstantPoolValue*>::iterator I =
1020        MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
1021        I != E; ++I) {
1022     if (Deleted.count(*I) == 0)
1023       delete *I;
1024   }
1025 }
1026
1027 /// Test whether the given two constants can be allocated the same constant pool
1028 /// entry.
1029 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
1030                                       const DataLayout &DL) {
1031   // Handle the trivial case quickly.
1032   if (A == B) return true;
1033
1034   // If they have the same type but weren't the same constant, quickly
1035   // reject them.
1036   if (A->getType() == B->getType()) return false;
1037
1038   // We can't handle structs or arrays.
1039   if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
1040       isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
1041     return false;
1042
1043   // For now, only support constants with the same size.
1044   uint64_t StoreSize = DL.getTypeStoreSize(A->getType());
1045   if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128)
1046     return false;
1047
1048   Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
1049
1050   // Try constant folding a bitcast of both instructions to an integer.  If we
1051   // get two identical ConstantInt's, then we are good to share them.  We use
1052   // the constant folding APIs to do this so that we get the benefit of
1053   // DataLayout.
1054   if (isa<PointerType>(A->getType()))
1055     A = ConstantFoldCastOperand(Instruction::PtrToInt,
1056                                 const_cast<Constant *>(A), IntTy, DL);
1057   else if (A->getType() != IntTy)
1058     A = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(A),
1059                                 IntTy, DL);
1060   if (isa<PointerType>(B->getType()))
1061     B = ConstantFoldCastOperand(Instruction::PtrToInt,
1062                                 const_cast<Constant *>(B), IntTy, DL);
1063   else if (B->getType() != IntTy)
1064     B = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(B),
1065                                 IntTy, DL);
1066
1067   return A == B;
1068 }
1069
1070 /// Create a new entry in the constant pool or return an existing one.
1071 /// User must specify the log2 of the minimum required alignment for the object.
1072 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
1073                                                    unsigned Alignment) {
1074   assert(Alignment && "Alignment must be specified!");
1075   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
1076
1077   // Check to see if we already have this constant.
1078   //
1079   // FIXME, this could be made much more efficient for large constant pools.
1080   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
1081     if (!Constants[i].isMachineConstantPoolEntry() &&
1082         CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) {
1083       if ((unsigned)Constants[i].getAlignment() < Alignment)
1084         Constants[i].Alignment = Alignment;
1085       return i;
1086     }
1087
1088   Constants.push_back(MachineConstantPoolEntry(C, Alignment));
1089   return Constants.size()-1;
1090 }
1091
1092 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
1093                                                    unsigned Alignment) {
1094   assert(Alignment && "Alignment must be specified!");
1095   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
1096
1097   // Check to see if we already have this constant.
1098   //
1099   // FIXME, this could be made much more efficient for large constant pools.
1100   int Idx = V->getExistingMachineCPValue(this, Alignment);
1101   if (Idx != -1) {
1102     MachineCPVsSharingEntries.insert(V);
1103     return (unsigned)Idx;
1104   }
1105
1106   Constants.push_back(MachineConstantPoolEntry(V, Alignment));
1107   return Constants.size()-1;
1108 }
1109
1110 void MachineConstantPool::print(raw_ostream &OS) const {
1111   if (Constants.empty()) return;
1112
1113   OS << "Constant Pool:\n";
1114   for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1115     OS << "  cp#" << i << ": ";
1116     if (Constants[i].isMachineConstantPoolEntry())
1117       Constants[i].Val.MachineCPVal->print(OS);
1118     else
1119       Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
1120     OS << ", align=" << Constants[i].getAlignment();
1121     OS << "\n";
1122   }
1123 }
1124
1125 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1126 LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); }
1127 #endif