MachineFunction.cpp revision 360784 
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
77using namespace llvm;
78
79#define DEBUG_TYPE "codegen"
80
81static 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
87static 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.
104void MachineFunction::Delegate::anchor() {}
105
106void 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.
121MachineFunctionInfo::~MachineFunctionInfo() = default;
122
123void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
124  MBB->getParent()->DeleteMachineBasicBlock(MBB);
125}
126
127static 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
134MachineFunction::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
143void MachineFunction::handleInsertion(MachineInstr &MI) {
144  if (TheDelegate)
145    TheDelegate->MF_HandleInsertion(MI);
146}
147
148void MachineFunction::handleRemoval(MachineInstr &MI) {
149  if (TheDelegate)
150    TheDelegate->MF_HandleRemoval(MI);
151}
152
153void 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
208MachineFunction::~MachineFunction() {
209  clear();
210}
211
212void 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
258const 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.
264MachineJumpTableInfo *MachineFunction::
265getOrCreateJumpTableInfo(unsigned EntryKind) {
266  if (JumpTableInfo) return JumpTableInfo;
267
268  JumpTableInfo = new (Allocator)
269    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
270  return JumpTableInfo;
271}
272
273DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const {
274  // TODO: Should probably avoid the connection to the IR and store directly
275  // in the MachineFunction.
276  Attribute Attr = F.getFnAttribute("denormal-fp-math");
277
278  // FIXME: This should assume IEEE behavior on an unspecified
279  // attribute. However, the one current user incorrectly assumes a non-IEEE
280  // target by default.
281  StringRef Val = Attr.getValueAsString();
282  if (Val.empty())
283    return DenormalMode::Invalid;
284
285  return parseDenormalFPAttribute(Val);
286}
287
288/// Should we be emitting segmented stack stuff for the function
289bool MachineFunction::shouldSplitStack() const {
290  return getFunction().hasFnAttribute("split-stack");
291}
292
293LLVM_NODISCARD unsigned
294MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
295  FrameInstructions.push_back(Inst);
296  return FrameInstructions.size() - 1;
297}
298
299/// This discards all of the MachineBasicBlock numbers and recomputes them.
300/// This guarantees that the MBB numbers are sequential, dense, and match the
301/// ordering of the blocks within the function.  If a specific MachineBasicBlock
302/// is specified, only that block and those after it are renumbered.
303void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
304  if (empty()) { MBBNumbering.clear(); return; }
305  MachineFunction::iterator MBBI, E = end();
306  if (MBB == nullptr)
307    MBBI = begin();
308  else
309    MBBI = MBB->getIterator();
310
311  // Figure out the block number this should have.
312  unsigned BlockNo = 0;
313  if (MBBI != begin())
314    BlockNo = std::prev(MBBI)->getNumber() + 1;
315
316  for (; MBBI != E; ++MBBI, ++BlockNo) {
317    if (MBBI->getNumber() != (int)BlockNo) {
318      // Remove use of the old number.
319      if (MBBI->getNumber() != -1) {
320        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
321               "MBB number mismatch!");
322        MBBNumbering[MBBI->getNumber()] = nullptr;
323      }
324
325      // If BlockNo is already taken, set that block's number to -1.
326      if (MBBNumbering[BlockNo])
327        MBBNumbering[BlockNo]->setNumber(-1);
328
329      MBBNumbering[BlockNo] = &*MBBI;
330      MBBI->setNumber(BlockNo);
331    }
332  }
333
334  // Okay, all the blocks are renumbered.  If we have compactified the block
335  // numbering, shrink MBBNumbering now.
336  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
337  MBBNumbering.resize(BlockNo);
338}
339
340/// Allocate a new MachineInstr. Use this instead of `new MachineInstr'.
341MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
342                                                  const DebugLoc &DL,
343                                                  bool NoImp) {
344  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
345    MachineInstr(*this, MCID, DL, NoImp);
346}
347
348/// Create a new MachineInstr which is a copy of the 'Orig' instruction,
349/// identical in all ways except the instruction has no parent, prev, or next.
350MachineInstr *
351MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
352  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
353             MachineInstr(*this, *Orig);
354}
355
356MachineInstr &MachineFunction::CloneMachineInstrBundle(MachineBasicBlock &MBB,
357    MachineBasicBlock::iterator InsertBefore, const MachineInstr &Orig) {
358  MachineInstr *FirstClone = nullptr;
359  MachineBasicBlock::const_instr_iterator I = Orig.getIterator();
360  while (true) {
361    MachineInstr *Cloned = CloneMachineInstr(&*I);
362    MBB.insert(InsertBefore, Cloned);
363    if (FirstClone == nullptr) {
364      FirstClone = Cloned;
365    } else {
366      Cloned->bundleWithPred();
367    }
368
369    if (!I->isBundledWithSucc())
370      break;
371    ++I;
372  }
373  return *FirstClone;
374}
375
376/// Delete the given MachineInstr.
377///
378/// This function also serves as the MachineInstr destructor - the real
379/// ~MachineInstr() destructor must be empty.
380void
381MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
382  // Verify that a call site info is at valid state. This assertion should
383  // be triggered during the implementation of support for the
384  // call site info of a new architecture. If the assertion is triggered,
385  // back trace will tell where to insert a call to updateCallSiteInfo().
386  assert((!MI->isCall(MachineInstr::IgnoreBundle) ||
387          CallSitesInfo.find(MI) == CallSitesInfo.end()) &&
388         "Call site info was not updated!");
389  // Strip it for parts. The operand array and the MI object itself are
390  // independently recyclable.
391  if (MI->Operands)
392    deallocateOperandArray(MI->CapOperands, MI->Operands);
393  // Don't call ~MachineInstr() which must be trivial anyway because
394  // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
395  // destructors.
396  InstructionRecycler.Deallocate(Allocator, MI);
397}
398
399/// Allocate a new MachineBasicBlock. Use this instead of
400/// `new MachineBasicBlock'.
401MachineBasicBlock *
402MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
403  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
404             MachineBasicBlock(*this, bb);
405}
406
407/// Delete the given MachineBasicBlock.
408void
409MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
410  assert(MBB->getParent() == this && "MBB parent mismatch!");
411  MBB->~MachineBasicBlock();
412  BasicBlockRecycler.Deallocate(Allocator, MBB);
413}
414
415MachineMemOperand *MachineFunction::getMachineMemOperand(
416    MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
417    unsigned base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
418    SyncScope::ID SSID, AtomicOrdering Ordering,
419    AtomicOrdering FailureOrdering) {
420  return new (Allocator)
421      MachineMemOperand(PtrInfo, f, s, base_alignment, AAInfo, Ranges,
422                        SSID, Ordering, FailureOrdering);
423}
424
425MachineMemOperand *
426MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
427                                      int64_t Offset, uint64_t Size) {
428  const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();
429
430  // If there is no pointer value, the offset isn't tracked so we need to adjust
431  // the base alignment.
432  unsigned Align = PtrInfo.V.isNull()
433                       ? MinAlign(MMO->getBaseAlignment(), Offset)
434                       : MMO->getBaseAlignment();
435
436  return new (Allocator)
437      MachineMemOperand(PtrInfo.getWithOffset(Offset), MMO->getFlags(), Size,
438                        Align, AAMDNodes(), nullptr, MMO->getSyncScopeID(),
439                        MMO->getOrdering(), MMO->getFailureOrdering());
440}
441
442MachineMemOperand *
443MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
444                                      const AAMDNodes &AAInfo) {
445  MachinePointerInfo MPI = MMO->getValue() ?
446             MachinePointerInfo(MMO->getValue(), MMO->getOffset()) :
447             MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset());
448
449  return new (Allocator)
450             MachineMemOperand(MPI, MMO->getFlags(), MMO->getSize(),
451                               MMO->getBaseAlignment(), AAInfo,
452                               MMO->getRanges(), MMO->getSyncScopeID(),
453                               MMO->getOrdering(), MMO->getFailureOrdering());
454}
455
456MachineMemOperand *
457MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
458                                      MachineMemOperand::Flags Flags) {
459  return new (Allocator) MachineMemOperand(
460      MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlignment(),
461      MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),
462      MMO->getOrdering(), MMO->getFailureOrdering());
463}
464
465MachineInstr::ExtraInfo *MachineFunction::createMIExtraInfo(
466    ArrayRef<MachineMemOperand *> MMOs, MCSymbol *PreInstrSymbol,
467    MCSymbol *PostInstrSymbol, MDNode *HeapAllocMarker) {
468  return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol,
469                                         PostInstrSymbol, HeapAllocMarker);
470}
471
472const char *MachineFunction::createExternalSymbolName(StringRef Name) {
473  char *Dest = Allocator.Allocate<char>(Name.size() + 1);
474  llvm::copy(Name, Dest);
475  Dest[Name.size()] = 0;
476  return Dest;
477}
478
479uint32_t *MachineFunction::allocateRegMask() {
480  unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs();
481  unsigned Size = MachineOperand::getRegMaskSize(NumRegs);
482  uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
483  memset(Mask, 0, Size * sizeof(Mask[0]));
484  return Mask;
485}
486
487ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) {
488  int* AllocMask = Allocator.Allocate<int>(Mask.size());
489  copy(Mask, AllocMask);
490  return {AllocMask, Mask.size()};
491}
492
493#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
494LLVM_DUMP_METHOD void MachineFunction::dump() const {
495  print(dbgs());
496}
497#endif
498
499StringRef MachineFunction::getName() const {
500  return getFunction().getName();
501}
502
503void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const {
504  OS << "# Machine code for function " << getName() << ": ";
505  getProperties().print(OS);
506  OS << '\n';
507
508  // Print Frame Information
509  FrameInfo->print(*this, OS);
510
511  // Print JumpTable Information
512  if (JumpTableInfo)
513    JumpTableInfo->print(OS);
514
515  // Print Constant Pool
516  ConstantPool->print(OS);
517
518  const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();
519
520  if (RegInfo && !RegInfo->livein_empty()) {
521    OS << "Function Live Ins: ";
522    for (MachineRegisterInfo::livein_iterator
523         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
524      OS << printReg(I->first, TRI);
525      if (I->second)
526        OS << " in " << printReg(I->second, TRI);
527      if (std::next(I) != E)
528        OS << ", ";
529    }
530    OS << '\n';
531  }
532
533  ModuleSlotTracker MST(getFunction().getParent());
534  MST.incorporateFunction(getFunction());
535  for (const auto &BB : *this) {
536    OS << '\n';
537    // If we print the whole function, print it at its most verbose level.
538    BB.print(OS, MST, Indexes, /*IsStandalone=*/true);
539  }
540
541  OS << "\n# End machine code for function " << getName() << ".\n\n";
542}
543
544/// True if this function needs frame moves for debug or exceptions.
545bool MachineFunction::needsFrameMoves() const {
546  return getMMI().hasDebugInfo() ||
547         getTarget().Options.ForceDwarfFrameSection ||
548         F.needsUnwindTableEntry();
549}
550
551namespace llvm {
552
553  template<>
554  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
555    DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
556
557    static std::string getGraphName(const MachineFunction *F) {
558      return ("CFG for '" + F->getName() + "' function").str();
559    }
560
561    std::string getNodeLabel(const MachineBasicBlock *Node,
562                             const MachineFunction *Graph) {
563      std::string OutStr;
564      {
565        raw_string_ostream OSS(OutStr);
566
567        if (isSimple()) {
568          OSS << printMBBReference(*Node);
569          if (const BasicBlock *BB = Node->getBasicBlock())
570            OSS << ": " << BB->getName();
571        } else
572          Node->print(OSS);
573      }
574
575      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
576
577      // Process string output to make it nicer...
578      for (unsigned i = 0; i != OutStr.length(); ++i)
579        if (OutStr[i] == '\n') {                            // Left justify
580          OutStr[i] = '\\';
581          OutStr.insert(OutStr.begin()+i+1, 'l');
582        }
583      return OutStr;
584    }
585  };
586
587} // end namespace llvm
588
589void MachineFunction::viewCFG() const
590{
591#ifndef NDEBUG
592  ViewGraph(this, "mf" + getName());
593#else
594  errs() << "MachineFunction::viewCFG is only available in debug builds on "
595         << "systems with Graphviz or gv!\n";
596#endif // NDEBUG
597}
598
599void MachineFunction::viewCFGOnly() const
600{
601#ifndef NDEBUG
602  ViewGraph(this, "mf" + getName(), true);
603#else
604  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
605         << "systems with Graphviz or gv!\n";
606#endif // NDEBUG
607}
608
609/// Add the specified physical register as a live-in value and
610/// create a corresponding virtual register for it.
611unsigned MachineFunction::addLiveIn(unsigned PReg,
612                                    const TargetRegisterClass *RC) {
613  MachineRegisterInfo &MRI = getRegInfo();
614  unsigned VReg = MRI.getLiveInVirtReg(PReg);
615  if (VReg) {
616    const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
617    (void)VRegRC;
618    // A physical register can be added several times.
619    // Between two calls, the register class of the related virtual register
620    // may have been constrained to match some operation constraints.
621    // In that case, check that the current register class includes the
622    // physical register and is a sub class of the specified RC.
623    assert((VRegRC == RC || (VRegRC->contains(PReg) &&
624                             RC->hasSubClassEq(VRegRC))) &&
625            "Register class mismatch!");
626    return VReg;
627  }
628  VReg = MRI.createVirtualRegister(RC);
629  MRI.addLiveIn(PReg, VReg);
630  return VReg;
631}
632
633/// Return the MCSymbol for the specified non-empty jump table.
634/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
635/// normal 'L' label is returned.
636MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
637                                        bool isLinkerPrivate) const {
638  const DataLayout &DL = getDataLayout();
639  assert(JumpTableInfo && "No jump tables");
640  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
641
642  StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix()
643                                     : DL.getPrivateGlobalPrefix();
644  SmallString<60> Name;
645  raw_svector_ostream(Name)
646    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
647  return Ctx.getOrCreateSymbol(Name);
648}
649
650/// Return a function-local symbol to represent the PIC base.
651MCSymbol *MachineFunction::getPICBaseSymbol() const {
652  const DataLayout &DL = getDataLayout();
653  return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
654                               Twine(getFunctionNumber()) + "$pb");
655}
656
657/// \name Exception Handling
658/// \{
659
660LandingPadInfo &
661MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) {
662  unsigned N = LandingPads.size();
663  for (unsigned i = 0; i < N; ++i) {
664    LandingPadInfo &LP = LandingPads[i];
665    if (LP.LandingPadBlock == LandingPad)
666      return LP;
667  }
668
669  LandingPads.push_back(LandingPadInfo(LandingPad));
670  return LandingPads[N];
671}
672
673void MachineFunction::addInvoke(MachineBasicBlock *LandingPad,
674                                MCSymbol *BeginLabel, MCSymbol *EndLabel) {
675  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
676  LP.BeginLabels.push_back(BeginLabel);
677  LP.EndLabels.push_back(EndLabel);
678}
679
680MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) {
681  MCSymbol *LandingPadLabel = Ctx.createTempSymbol();
682  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
683  LP.LandingPadLabel = LandingPadLabel;
684
685  const Instruction *FirstI = LandingPad->getBasicBlock()->getFirstNonPHI();
686  if (const auto *LPI = dyn_cast<LandingPadInst>(FirstI)) {
687    if (const auto *PF =
688            dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts()))
689      getMMI().addPersonality(PF);
690
691    if (LPI->isCleanup())
692      addCleanup(LandingPad);
693
694    // FIXME: New EH - Add the clauses in reverse order. This isn't 100%
695    //        correct, but we need to do it this way because of how the DWARF EH
696    //        emitter processes the clauses.
697    for (unsigned I = LPI->getNumClauses(); I != 0; --I) {
698      Value *Val = LPI->getClause(I - 1);
699      if (LPI->isCatch(I - 1)) {
700        addCatchTypeInfo(LandingPad,
701                         dyn_cast<GlobalValue>(Val->stripPointerCasts()));
702      } else {
703        // Add filters in a list.
704        auto *CVal = cast<Constant>(Val);
705        SmallVector<const GlobalValue *, 4> FilterList;
706        for (User::op_iterator II = CVal->op_begin(), IE = CVal->op_end();
707             II != IE; ++II)
708          FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
709
710        addFilterTypeInfo(LandingPad, FilterList);
711      }
712    }
713
714  } else if (const auto *CPI = dyn_cast<CatchPadInst>(FirstI)) {
715    for (unsigned I = CPI->getNumArgOperands(); I != 0; --I) {
716      Value *TypeInfo = CPI->getArgOperand(I - 1)->stripPointerCasts();
717      addCatchTypeInfo(LandingPad, dyn_cast<GlobalValue>(TypeInfo));
718    }
719
720  } else {
721    assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!");
722  }
723
724  return LandingPadLabel;
725}
726
727void MachineFunction::addCatchTypeInfo(MachineBasicBlock *LandingPad,
728                                       ArrayRef<const GlobalValue *> TyInfo) {
729  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
730  for (unsigned N = TyInfo.size(); N; --N)
731    LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
732}
733
734void MachineFunction::addFilterTypeInfo(MachineBasicBlock *LandingPad,
735                                        ArrayRef<const GlobalValue *> TyInfo) {
736  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
737  std::vector<unsigned> IdsInFilter(TyInfo.size());
738  for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
739    IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
740  LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
741}
742
743void MachineFunction::tidyLandingPads(DenseMap<MCSymbol *, uintptr_t> *LPMap,
744                                      bool TidyIfNoBeginLabels) {
745  for (unsigned i = 0; i != LandingPads.size(); ) {
746    LandingPadInfo &LandingPad = LandingPads[i];
747    if (LandingPad.LandingPadLabel &&
748        !LandingPad.LandingPadLabel->isDefined() &&
749        (!LPMap || (*LPMap)[LandingPad.LandingPadLabel] == 0))
750      LandingPad.LandingPadLabel = nullptr;
751
752    // Special case: we *should* emit LPs with null LP MBB. This indicates
753    // "nounwind" case.
754    if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
755      LandingPads.erase(LandingPads.begin() + i);
756      continue;
757    }
758
759    if (TidyIfNoBeginLabels) {
760      for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
761        MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
762        MCSymbol *EndLabel = LandingPad.EndLabels[j];
763        if ((BeginLabel->isDefined() || (LPMap && (*LPMap)[BeginLabel] != 0)) &&
764            (EndLabel->isDefined() || (LPMap && (*LPMap)[EndLabel] != 0)))
765          continue;
766
767        LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
768        LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
769        --j;
770        --e;
771      }
772
773      // Remove landing pads with no try-ranges.
774      if (LandingPads[i].BeginLabels.empty()) {
775        LandingPads.erase(LandingPads.begin() + i);
776        continue;
777      }
778    }
779
780    // If there is no landing pad, ensure that the list of typeids is empty.
781    // If the only typeid is a cleanup, this is the same as having no typeids.
782    if (!LandingPad.LandingPadBlock ||
783        (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
784      LandingPad.TypeIds.clear();
785    ++i;
786  }
787}
788
789void MachineFunction::addCleanup(MachineBasicBlock *LandingPad) {
790  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
791  LP.TypeIds.push_back(0);
792}
793
794void MachineFunction::addSEHCatchHandler(MachineBasicBlock *LandingPad,
795                                         const Function *Filter,
796                                         const BlockAddress *RecoverBA) {
797  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
798  SEHHandler Handler;
799  Handler.FilterOrFinally = Filter;
800  Handler.RecoverBA = RecoverBA;
801  LP.SEHHandlers.push_back(Handler);
802}
803
804void MachineFunction::addSEHCleanupHandler(MachineBasicBlock *LandingPad,
805                                           const Function *Cleanup) {
806  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
807  SEHHandler Handler;
808  Handler.FilterOrFinally = Cleanup;
809  Handler.RecoverBA = nullptr;
810  LP.SEHHandlers.push_back(Handler);
811}
812
813void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,
814                                            ArrayRef<unsigned> Sites) {
815  LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
816}
817
818unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) {
819  for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
820    if (TypeInfos[i] == TI) return i + 1;
821
822  TypeInfos.push_back(TI);
823  return TypeInfos.size();
824}
825
826int MachineFunction::getFilterIDFor(std::vector<unsigned> &TyIds) {
827  // If the new filter coincides with the tail of an existing filter, then
828  // re-use the existing filter.  Folding filters more than this requires
829  // re-ordering filters and/or their elements - probably not worth it.
830  for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
831       E = FilterEnds.end(); I != E; ++I) {
832    unsigned i = *I, j = TyIds.size();
833
834    while (i && j)
835      if (FilterIds[--i] != TyIds[--j])
836        goto try_next;
837
838    if (!j)
839      // The new filter coincides with range [i, end) of the existing filter.
840      return -(1 + i);
841
842try_next:;
843  }
844
845  // Add the new filter.
846  int FilterID = -(1 + FilterIds.size());
847  FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
848  FilterIds.insert(FilterIds.end(), TyIds.begin(), TyIds.end());
849  FilterEnds.push_back(FilterIds.size());
850  FilterIds.push_back(0); // terminator
851  return FilterID;
852}
853
854MachineFunction::CallSiteInfoMap::iterator
855MachineFunction::getCallSiteInfo(const MachineInstr *MI) {
856  assert(MI->isCall() && "Call site info refers only to call instructions!");
857
858  if (!Target.Options.EnableDebugEntryValues)
859    return CallSitesInfo.end();
860  return CallSitesInfo.find(MI);
861}
862
863void MachineFunction::moveCallSiteInfo(const MachineInstr *Old,
864                                       const MachineInstr *New) {
865  assert(New->isCall() && "Call site info refers only to call instructions!");
866
867  CallSiteInfoMap::iterator CSIt = getCallSiteInfo(Old);
868  if (CSIt == CallSitesInfo.end())
869    return;
870
871  CallSiteInfo CSInfo = std::move(CSIt->second);
872  CallSitesInfo.erase(CSIt);
873  CallSitesInfo[New] = CSInfo;
874}
875
876void MachineFunction::eraseCallSiteInfo(const MachineInstr *MI) {
877  CallSiteInfoMap::iterator CSIt = getCallSiteInfo(MI);
878  if (CSIt == CallSitesInfo.end())
879    return;
880  CallSitesInfo.erase(CSIt);
881}
882
883void MachineFunction::copyCallSiteInfo(const MachineInstr *Old,
884                                       const MachineInstr *New) {
885  assert(New->isCall() && "Call site info refers only to call instructions!");
886
887  CallSiteInfoMap::iterator CSIt = getCallSiteInfo(Old);
888  if (CSIt == CallSitesInfo.end())
889    return;
890
891  CallSiteInfo CSInfo = CSIt->second;
892  CallSitesInfo[New] = CSInfo;
893}
894
895/// \}
896
897//===----------------------------------------------------------------------===//
898//  MachineJumpTableInfo implementation
899//===----------------------------------------------------------------------===//
900
901/// Return the size of each entry in the jump table.
902unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
903  // The size of a jump table entry is 4 bytes unless the entry is just the
904  // address of a block, in which case it is the pointer size.
905  switch (getEntryKind()) {
906  case MachineJumpTableInfo::EK_BlockAddress:
907    return TD.getPointerSize();
908  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
909    return 8;
910  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
911  case MachineJumpTableInfo::EK_LabelDifference32:
912  case MachineJumpTableInfo::EK_Custom32:
913    return 4;
914  case MachineJumpTableInfo::EK_Inline:
915    return 0;
916  }
917  llvm_unreachable("Unknown jump table encoding!");
918}
919
920/// Return the alignment of each entry in the jump table.
921unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
922  // The alignment of a jump table entry is the alignment of int32 unless the
923  // entry is just the address of a block, in which case it is the pointer
924  // alignment.
925  switch (getEntryKind()) {
926  case MachineJumpTableInfo::EK_BlockAddress:
927    return TD.getPointerABIAlignment(0).value();
928  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
929    return TD.getABIIntegerTypeAlignment(64).value();
930  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
931  case MachineJumpTableInfo::EK_LabelDifference32:
932  case MachineJumpTableInfo::EK_Custom32:
933    return TD.getABIIntegerTypeAlignment(32).value();
934  case MachineJumpTableInfo::EK_Inline:
935    return 1;
936  }
937  llvm_unreachable("Unknown jump table encoding!");
938}
939
940/// Create a new jump table entry in the jump table info.
941unsigned MachineJumpTableInfo::createJumpTableIndex(
942                               const std::vector<MachineBasicBlock*> &DestBBs) {
943  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
944  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
945  return JumpTables.size()-1;
946}
947
948/// If Old is the target of any jump tables, update the jump tables to branch
949/// to New instead.
950bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
951                                                  MachineBasicBlock *New) {
952  assert(Old != New && "Not making a change?");
953  bool MadeChange = false;
954  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
955    ReplaceMBBInJumpTable(i, Old, New);
956  return MadeChange;
957}
958
959/// If Old is a target of the jump tables, update the jump table to branch to
960/// New instead.
961bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
962                                                 MachineBasicBlock *Old,
963                                                 MachineBasicBlock *New) {
964  assert(Old != New && "Not making a change?");
965  bool MadeChange = false;
966  MachineJumpTableEntry &JTE = JumpTables[Idx];
967  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
968    if (JTE.MBBs[j] == Old) {
969      JTE.MBBs[j] = New;
970      MadeChange = true;
971    }
972  return MadeChange;
973}
974
975void MachineJumpTableInfo::print(raw_ostream &OS) const {
976  if (JumpTables.empty()) return;
977
978  OS << "Jump Tables:\n";
979
980  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
981    OS << printJumpTableEntryReference(i) << ':';
982    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
983      OS << ' ' << printMBBReference(*JumpTables[i].MBBs[j]);
984    if (i != e)
985      OS << '\n';
986  }
987
988  OS << '\n';
989}
990
991#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
992LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); }
993#endif
994
995Printable llvm::printJumpTableEntryReference(unsigned Idx) {
996  return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; });
997}
998
999//===----------------------------------------------------------------------===//
1000//  MachineConstantPool implementation
1001//===----------------------------------------------------------------------===//
1002
1003void MachineConstantPoolValue::anchor() {}
1004
1005Type *MachineConstantPoolEntry::getType() const {
1006  if (isMachineConstantPoolEntry())
1007    return Val.MachineCPVal->getType();
1008  return Val.ConstVal->getType();
1009}
1010
1011bool MachineConstantPoolEntry::needsRelocation() const {
1012  if (isMachineConstantPoolEntry())
1013    return true;
1014  return Val.ConstVal->needsRelocation();
1015}
1016
1017SectionKind
1018MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
1019  if (needsRelocation())
1020    return SectionKind::getReadOnlyWithRel();
1021  switch (DL->getTypeAllocSize(getType())) {
1022  case 4:
1023    return SectionKind::getMergeableConst4();
1024  case 8:
1025    return SectionKind::getMergeableConst8();
1026  case 16:
1027    return SectionKind::getMergeableConst16();
1028  case 32:
1029    return SectionKind::getMergeableConst32();
1030  default:
1031    return SectionKind::getReadOnly();
1032  }
1033}
1034
1035MachineConstantPool::~MachineConstantPool() {
1036  // A constant may be a member of both Constants and MachineCPVsSharingEntries,
1037  // so keep track of which we've deleted to avoid double deletions.
1038  DenseSet<MachineConstantPoolValue*> Deleted;
1039  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
1040    if (Constants[i].isMachineConstantPoolEntry()) {
1041      Deleted.insert(Constants[i].Val.MachineCPVal);
1042      delete Constants[i].Val.MachineCPVal;
1043    }
1044  for (DenseSet<MachineConstantPoolValue*>::iterator I =
1045       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
1046       I != E; ++I) {
1047    if (Deleted.count(*I) == 0)
1048      delete *I;
1049  }
1050}
1051
1052/// Test whether the given two constants can be allocated the same constant pool
1053/// entry.
1054static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
1055                                      const DataLayout &DL) {
1056  // Handle the trivial case quickly.
1057  if (A == B) return true;
1058
1059  // If they have the same type but weren't the same constant, quickly
1060  // reject them.
1061  if (A->getType() == B->getType()) return false;
1062
1063  // We can't handle structs or arrays.
1064  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
1065      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
1066    return false;
1067
1068  // For now, only support constants with the same size.
1069  uint64_t StoreSize = DL.getTypeStoreSize(A->getType());
1070  if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128)
1071    return false;
1072
1073  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
1074
1075  // Try constant folding a bitcast of both instructions to an integer.  If we
1076  // get two identical ConstantInt's, then we are good to share them.  We use
1077  // the constant folding APIs to do this so that we get the benefit of
1078  // DataLayout.
1079  if (isa<PointerType>(A->getType()))
1080    A = ConstantFoldCastOperand(Instruction::PtrToInt,
1081                                const_cast<Constant *>(A), IntTy, DL);
1082  else if (A->getType() != IntTy)
1083    A = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(A),
1084                                IntTy, DL);
1085  if (isa<PointerType>(B->getType()))
1086    B = ConstantFoldCastOperand(Instruction::PtrToInt,
1087                                const_cast<Constant *>(B), IntTy, DL);
1088  else if (B->getType() != IntTy)
1089    B = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(B),
1090                                IntTy, DL);
1091
1092  return A == B;
1093}
1094
1095/// Create a new entry in the constant pool or return an existing one.
1096/// User must specify the log2 of the minimum required alignment for the object.
1097unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
1098                                                   unsigned Alignment) {
1099  assert(Alignment && "Alignment must be specified!");
1100  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
1101
1102  // Check to see if we already have this constant.
1103  //
1104  // FIXME, this could be made much more efficient for large constant pools.
1105  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
1106    if (!Constants[i].isMachineConstantPoolEntry() &&
1107        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) {
1108      if ((unsigned)Constants[i].getAlignment() < Alignment)
1109        Constants[i].Alignment = Alignment;
1110      return i;
1111    }
1112
1113  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
1114  return Constants.size()-1;
1115}
1116
1117unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
1118                                                   unsigned Alignment) {
1119  assert(Alignment && "Alignment must be specified!");
1120  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
1121
1122  // Check to see if we already have this constant.
1123  //
1124  // FIXME, this could be made much more efficient for large constant pools.
1125  int Idx = V->getExistingMachineCPValue(this, Alignment);
1126  if (Idx != -1) {
1127    MachineCPVsSharingEntries.insert(V);
1128    return (unsigned)Idx;
1129  }
1130
1131  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
1132  return Constants.size()-1;
1133}
1134
1135void MachineConstantPool::print(raw_ostream &OS) const {
1136  if (Constants.empty()) return;
1137
1138  OS << "Constant Pool:\n";
1139  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1140    OS << "  cp#" << i << ": ";
1141    if (Constants[i].isMachineConstantPoolEntry())
1142      Constants[i].Val.MachineCPVal->print(OS);
1143    else
1144      Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
1145    OS << ", align=" << Constants[i].getAlignment();
1146    OS << "\n";
1147  }
1148}
1149
1150#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1151LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); }
1152#endif
1153