xref: /llvm-project/llvm/lib/CodeGen/MachineFunction.cpp (revision acec6419e811a46050b0603dfa72fc6a169aa0f7)
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/ProfileSummaryInfo.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/PseudoSourceValueManager.h"
36 #include "llvm/CodeGen/TargetFrameLowering.h"
37 #include "llvm/CodeGen/TargetInstrInfo.h"
38 #include "llvm/CodeGen/TargetLowering.h"
39 #include "llvm/CodeGen/TargetRegisterInfo.h"
40 #include "llvm/CodeGen/TargetSubtargetInfo.h"
41 #include "llvm/CodeGen/WasmEHFuncInfo.h"
42 #include "llvm/CodeGen/WinEHFuncInfo.h"
43 #include "llvm/Config/llvm-config.h"
44 #include "llvm/IR/Attributes.h"
45 #include "llvm/IR/BasicBlock.h"
46 #include "llvm/IR/Constant.h"
47 #include "llvm/IR/DataLayout.h"
48 #include "llvm/IR/DerivedTypes.h"
49 #include "llvm/IR/EHPersonalities.h"
50 #include "llvm/IR/Function.h"
51 #include "llvm/IR/GlobalValue.h"
52 #include "llvm/IR/Instruction.h"
53 #include "llvm/IR/Instructions.h"
54 #include "llvm/IR/Metadata.h"
55 #include "llvm/IR/Module.h"
56 #include "llvm/IR/ModuleSlotTracker.h"
57 #include "llvm/IR/Value.h"
58 #include "llvm/MC/MCContext.h"
59 #include "llvm/MC/MCSymbol.h"
60 #include "llvm/MC/SectionKind.h"
61 #include "llvm/Support/Casting.h"
62 #include "llvm/Support/CommandLine.h"
63 #include "llvm/Support/Compiler.h"
64 #include "llvm/Support/DOTGraphTraits.h"
65 #include "llvm/Support/ErrorHandling.h"
66 #include "llvm/Support/GraphWriter.h"
67 #include "llvm/Support/raw_ostream.h"
68 #include "llvm/Target/TargetMachine.h"
69 #include <algorithm>
70 #include <cassert>
71 #include <cstddef>
72 #include <cstdint>
73 #include <iterator>
74 #include <string>
75 #include <type_traits>
76 #include <utility>
77 #include <vector>
78 
79 #include "LiveDebugValues/LiveDebugValues.h"
80 
81 using namespace llvm;
82 
83 #define DEBUG_TYPE "codegen"
84 
85 static cl::opt<unsigned> AlignAllFunctions(
86     "align-all-functions",
87     cl::desc("Force the alignment of all functions in log2 format (e.g. 4 "
88              "means align on 16B boundaries)."),
89     cl::init(0), cl::Hidden);
90 
91 static const char *getPropertyName(MachineFunctionProperties::Property Prop) {
92   using P = MachineFunctionProperties::Property;
93 
94   // clang-format off
95   switch(Prop) {
96   case P::FailedISel: return "FailedISel";
97   case P::IsSSA: return "IsSSA";
98   case P::Legalized: return "Legalized";
99   case P::NoPHIs: return "NoPHIs";
100   case P::NoVRegs: return "NoVRegs";
101   case P::RegBankSelected: return "RegBankSelected";
102   case P::Selected: return "Selected";
103   case P::TracksLiveness: return "TracksLiveness";
104   case P::TiedOpsRewritten: return "TiedOpsRewritten";
105   case P::FailsVerification: return "FailsVerification";
106   case P::TracksDebugUserValues: return "TracksDebugUserValues";
107   }
108   // clang-format on
109   llvm_unreachable("Invalid machine function property");
110 }
111 
112 void setUnsafeStackSize(const Function &F, MachineFrameInfo &FrameInfo) {
113   if (!F.hasFnAttribute(Attribute::SafeStack))
114     return;
115 
116   auto *Existing =
117       dyn_cast_or_null<MDTuple>(F.getMetadata(LLVMContext::MD_annotation));
118 
119   if (!Existing || Existing->getNumOperands() != 2)
120     return;
121 
122   auto *MetadataName = "unsafe-stack-size";
123   if (auto &N = Existing->getOperand(0)) {
124     if (N.equalsStr(MetadataName)) {
125       if (auto &Op = Existing->getOperand(1)) {
126         auto Val = mdconst::extract<ConstantInt>(Op)->getZExtValue();
127         FrameInfo.setUnsafeStackSize(Val);
128       }
129     }
130   }
131 }
132 
133 // Pin the vtable to this file.
134 void MachineFunction::Delegate::anchor() {}
135 
136 void MachineFunctionProperties::print(raw_ostream &OS) const {
137   const char *Separator = "";
138   for (BitVector::size_type I = 0; I < Properties.size(); ++I) {
139     if (!Properties[I])
140       continue;
141     OS << Separator << getPropertyName(static_cast<Property>(I));
142     Separator = ", ";
143   }
144 }
145 
146 //===----------------------------------------------------------------------===//
147 // MachineFunction implementation
148 //===----------------------------------------------------------------------===//
149 
150 // Out-of-line virtual method.
151 MachineFunctionInfo::~MachineFunctionInfo() = default;
152 
153 void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
154   MBB->getParent()->deleteMachineBasicBlock(MBB);
155 }
156 
157 static inline Align getFnStackAlignment(const TargetSubtargetInfo *STI,
158                                            const Function &F) {
159   if (auto MA = F.getFnStackAlign())
160     return *MA;
161   return STI->getFrameLowering()->getStackAlign();
162 }
163 
164 MachineFunction::MachineFunction(Function &F, const LLVMTargetMachine &Target,
165                                  const TargetSubtargetInfo &STI,
166                                  unsigned FunctionNum, MachineModuleInfo &mmi)
167     : F(F), Target(Target), STI(&STI), Ctx(mmi.getContext()), MMI(mmi) {
168   FunctionNumber = FunctionNum;
169   init();
170 }
171 
172 void MachineFunction::handleInsertion(MachineInstr &MI) {
173   if (TheDelegate)
174     TheDelegate->MF_HandleInsertion(MI);
175 }
176 
177 void MachineFunction::handleRemoval(MachineInstr &MI) {
178   if (TheDelegate)
179     TheDelegate->MF_HandleRemoval(MI);
180 }
181 
182 void MachineFunction::handleChangeDesc(MachineInstr &MI,
183                                        const MCInstrDesc &TID) {
184   if (TheDelegate)
185     TheDelegate->MF_HandleChangeDesc(MI, TID);
186 }
187 
188 void MachineFunction::init() {
189   // Assume the function starts in SSA form with correct liveness.
190   Properties.set(MachineFunctionProperties::Property::IsSSA);
191   Properties.set(MachineFunctionProperties::Property::TracksLiveness);
192   if (STI->getRegisterInfo())
193     RegInfo = new (Allocator) MachineRegisterInfo(this);
194   else
195     RegInfo = nullptr;
196 
197   MFInfo = nullptr;
198 
199   // We can realign the stack if the target supports it and the user hasn't
200   // explicitly asked us not to.
201   bool CanRealignSP = STI->getFrameLowering()->isStackRealignable() &&
202                       !F.hasFnAttribute("no-realign-stack");
203   FrameInfo = new (Allocator) MachineFrameInfo(
204       getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP,
205       /*ForcedRealign=*/CanRealignSP &&
206           F.hasFnAttribute(Attribute::StackAlignment));
207 
208   setUnsafeStackSize(F, *FrameInfo);
209 
210   if (F.hasFnAttribute(Attribute::StackAlignment))
211     FrameInfo->ensureMaxAlignment(*F.getFnStackAlign());
212 
213   ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
214   Alignment = STI->getTargetLowering()->getMinFunctionAlignment();
215 
216   // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
217   // FIXME: Use Function::hasOptSize().
218   if (!F.hasFnAttribute(Attribute::OptimizeForSize))
219     Alignment = std::max(Alignment,
220                          STI->getTargetLowering()->getPrefFunctionAlignment());
221 
222   // -fsanitize=function and -fsanitize=kcfi instrument indirect function calls
223   // to load a type hash before the function label. Ensure functions are aligned
224   // by a least 4 to avoid unaligned access, which is especially important for
225   // -mno-unaligned-access.
226   if (F.hasMetadata(LLVMContext::MD_func_sanitize) ||
227       F.getMetadata(LLVMContext::MD_kcfi_type))
228     Alignment = std::max(Alignment, Align(4));
229 
230   if (AlignAllFunctions)
231     Alignment = Align(1ULL << AlignAllFunctions);
232 
233   JumpTableInfo = nullptr;
234 
235   if (isFuncletEHPersonality(classifyEHPersonality(
236           F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
237     WinEHInfo = new (Allocator) WinEHFuncInfo();
238   }
239 
240   if (isScopedEHPersonality(classifyEHPersonality(
241           F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
242     WasmEHInfo = new (Allocator) WasmEHFuncInfo();
243   }
244 
245   assert(Target.isCompatibleDataLayout(getDataLayout()) &&
246          "Can't create a MachineFunction using a Module with a "
247          "Target-incompatible DataLayout attached\n");
248 
249   PSVManager = std::make_unique<PseudoSourceValueManager>(getTarget());
250 }
251 
252 void MachineFunction::initTargetMachineFunctionInfo(
253     const TargetSubtargetInfo &STI) {
254   assert(!MFInfo && "MachineFunctionInfo already set");
255   MFInfo = Target.createMachineFunctionInfo(Allocator, F, &STI);
256 }
257 
258 MachineFunction::~MachineFunction() {
259   clear();
260 }
261 
262 void MachineFunction::clear() {
263   Properties.reset();
264   // Don't call destructors on MachineInstr and MachineOperand. All of their
265   // memory comes from the BumpPtrAllocator which is about to be purged.
266   //
267   // Do call MachineBasicBlock destructors, it contains std::vectors.
268   for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
269     I->Insts.clearAndLeakNodesUnsafely();
270   MBBNumbering.clear();
271 
272   InstructionRecycler.clear(Allocator);
273   OperandRecycler.clear(Allocator);
274   BasicBlockRecycler.clear(Allocator);
275   CodeViewAnnotations.clear();
276   VariableDbgInfos.clear();
277   if (RegInfo) {
278     RegInfo->~MachineRegisterInfo();
279     Allocator.Deallocate(RegInfo);
280   }
281   if (MFInfo) {
282     MFInfo->~MachineFunctionInfo();
283     Allocator.Deallocate(MFInfo);
284   }
285 
286   FrameInfo->~MachineFrameInfo();
287   Allocator.Deallocate(FrameInfo);
288 
289   ConstantPool->~MachineConstantPool();
290   Allocator.Deallocate(ConstantPool);
291 
292   if (JumpTableInfo) {
293     JumpTableInfo->~MachineJumpTableInfo();
294     Allocator.Deallocate(JumpTableInfo);
295   }
296 
297   if (WinEHInfo) {
298     WinEHInfo->~WinEHFuncInfo();
299     Allocator.Deallocate(WinEHInfo);
300   }
301 
302   if (WasmEHInfo) {
303     WasmEHInfo->~WasmEHFuncInfo();
304     Allocator.Deallocate(WasmEHInfo);
305   }
306 }
307 
308 const DataLayout &MachineFunction::getDataLayout() const {
309   return F.getParent()->getDataLayout();
310 }
311 
312 /// Get the JumpTableInfo for this function.
313 /// If it does not already exist, allocate one.
314 MachineJumpTableInfo *MachineFunction::
315 getOrCreateJumpTableInfo(unsigned EntryKind) {
316   if (JumpTableInfo) return JumpTableInfo;
317 
318   JumpTableInfo = new (Allocator)
319     MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
320   return JumpTableInfo;
321 }
322 
323 DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const {
324   return F.getDenormalMode(FPType);
325 }
326 
327 /// Should we be emitting segmented stack stuff for the function
328 bool MachineFunction::shouldSplitStack() const {
329   return getFunction().hasFnAttribute("split-stack");
330 }
331 
332 [[nodiscard]] unsigned
333 MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
334   FrameInstructions.push_back(Inst);
335   return FrameInstructions.size() - 1;
336 }
337 
338 /// This discards all of the MachineBasicBlock numbers and recomputes them.
339 /// This guarantees that the MBB numbers are sequential, dense, and match the
340 /// ordering of the blocks within the function.  If a specific MachineBasicBlock
341 /// is specified, only that block and those after it are renumbered.
342 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
343   if (empty()) { MBBNumbering.clear(); return; }
344   MachineFunction::iterator MBBI, E = end();
345   if (MBB == nullptr)
346     MBBI = begin();
347   else
348     MBBI = MBB->getIterator();
349 
350   // Figure out the block number this should have.
351   unsigned BlockNo = 0;
352   if (MBBI != begin())
353     BlockNo = std::prev(MBBI)->getNumber() + 1;
354 
355   for (; MBBI != E; ++MBBI, ++BlockNo) {
356     if (MBBI->getNumber() != (int)BlockNo) {
357       // Remove use of the old number.
358       if (MBBI->getNumber() != -1) {
359         assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
360                "MBB number mismatch!");
361         MBBNumbering[MBBI->getNumber()] = nullptr;
362       }
363 
364       // If BlockNo is already taken, set that block's number to -1.
365       if (MBBNumbering[BlockNo])
366         MBBNumbering[BlockNo]->setNumber(-1);
367 
368       MBBNumbering[BlockNo] = &*MBBI;
369       MBBI->setNumber(BlockNo);
370     }
371   }
372 
373   // Okay, all the blocks are renumbered.  If we have compactified the block
374   // numbering, shrink MBBNumbering now.
375   assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
376   MBBNumbering.resize(BlockNo);
377 }
378 
379 /// This method iterates over the basic blocks and assigns their IsBeginSection
380 /// and IsEndSection fields. This must be called after MBB layout is finalized
381 /// and the SectionID's are assigned to MBBs.
382 void MachineFunction::assignBeginEndSections() {
383   front().setIsBeginSection();
384   auto CurrentSectionID = front().getSectionID();
385   for (auto MBBI = std::next(begin()), E = end(); MBBI != E; ++MBBI) {
386     if (MBBI->getSectionID() == CurrentSectionID)
387       continue;
388     MBBI->setIsBeginSection();
389     std::prev(MBBI)->setIsEndSection();
390     CurrentSectionID = MBBI->getSectionID();
391   }
392   back().setIsEndSection();
393 }
394 
395 /// Allocate a new MachineInstr. Use this instead of `new MachineInstr'.
396 MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
397                                                   DebugLoc DL,
398                                                   bool NoImplicit) {
399   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
400       MachineInstr(*this, MCID, std::move(DL), NoImplicit);
401 }
402 
403 /// Create a new MachineInstr which is a copy of the 'Orig' instruction,
404 /// identical in all ways except the instruction has no parent, prev, or next.
405 MachineInstr *
406 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
407   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
408              MachineInstr(*this, *Orig);
409 }
410 
411 MachineInstr &MachineFunction::cloneMachineInstrBundle(
412     MachineBasicBlock &MBB, MachineBasicBlock::iterator InsertBefore,
413     const MachineInstr &Orig) {
414   MachineInstr *FirstClone = nullptr;
415   MachineBasicBlock::const_instr_iterator I = Orig.getIterator();
416   while (true) {
417     MachineInstr *Cloned = CloneMachineInstr(&*I);
418     MBB.insert(InsertBefore, Cloned);
419     if (FirstClone == nullptr) {
420       FirstClone = Cloned;
421     } else {
422       Cloned->bundleWithPred();
423     }
424 
425     if (!I->isBundledWithSucc())
426       break;
427     ++I;
428   }
429   // Copy over call site info to the cloned instruction if needed. If Orig is in
430   // a bundle, copyCallSiteInfo takes care of finding the call instruction in
431   // the bundle.
432   if (Orig.shouldUpdateCallSiteInfo())
433     copyCallSiteInfo(&Orig, FirstClone);
434   return *FirstClone;
435 }
436 
437 /// Delete the given MachineInstr.
438 ///
439 /// This function also serves as the MachineInstr destructor - the real
440 /// ~MachineInstr() destructor must be empty.
441 void MachineFunction::deleteMachineInstr(MachineInstr *MI) {
442   // Verify that a call site info is at valid state. This assertion should
443   // be triggered during the implementation of support for the
444   // call site info of a new architecture. If the assertion is triggered,
445   // back trace will tell where to insert a call to updateCallSiteInfo().
446   assert((!MI->isCandidateForCallSiteEntry() || !CallSitesInfo.contains(MI)) &&
447          "Call site info was not updated!");
448   // Strip it for parts. The operand array and the MI object itself are
449   // independently recyclable.
450   if (MI->Operands)
451     deallocateOperandArray(MI->CapOperands, MI->Operands);
452   // Don't call ~MachineInstr() which must be trivial anyway because
453   // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
454   // destructors.
455   InstructionRecycler.Deallocate(Allocator, MI);
456 }
457 
458 /// Allocate a new MachineBasicBlock. Use this instead of
459 /// `new MachineBasicBlock'.
460 MachineBasicBlock *
461 MachineFunction::CreateMachineBasicBlock(const BasicBlock *BB,
462                                          std::optional<UniqueBBID> BBID) {
463   MachineBasicBlock *MBB =
464       new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
465           MachineBasicBlock(*this, BB);
466   // Set BBID for `-basic-block=sections=labels` and
467   // `-basic-block-sections=list` to allow robust mapping of profiles to basic
468   // blocks.
469   if (Target.getBBSectionsType() == BasicBlockSection::Labels ||
470       Target.Options.BBAddrMap ||
471       Target.getBBSectionsType() == BasicBlockSection::List)
472     MBB->setBBID(BBID.has_value() ? *BBID : UniqueBBID{NextBBID++, 0});
473   return MBB;
474 }
475 
476 /// Delete the given MachineBasicBlock.
477 void MachineFunction::deleteMachineBasicBlock(MachineBasicBlock *MBB) {
478   assert(MBB->getParent() == this && "MBB parent mismatch!");
479   // Clean up any references to MBB in jump tables before deleting it.
480   if (JumpTableInfo)
481     JumpTableInfo->RemoveMBBFromJumpTables(MBB);
482   MBB->~MachineBasicBlock();
483   BasicBlockRecycler.Deallocate(Allocator, MBB);
484 }
485 
486 MachineMemOperand *MachineFunction::getMachineMemOperand(
487     MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s,
488     Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
489     SyncScope::ID SSID, AtomicOrdering Ordering,
490     AtomicOrdering FailureOrdering) {
491   return new (Allocator)
492       MachineMemOperand(PtrInfo, f, s, base_alignment, AAInfo, Ranges,
493                         SSID, Ordering, FailureOrdering);
494 }
495 
496 MachineMemOperand *MachineFunction::getMachineMemOperand(
497     MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, LLT MemTy,
498     Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,
499     SyncScope::ID SSID, AtomicOrdering Ordering,
500     AtomicOrdering FailureOrdering) {
501   return new (Allocator)
502       MachineMemOperand(PtrInfo, f, MemTy, base_alignment, AAInfo, Ranges, SSID,
503                         Ordering, FailureOrdering);
504 }
505 
506 MachineMemOperand *MachineFunction::getMachineMemOperand(
507     const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, uint64_t Size) {
508   return new (Allocator)
509       MachineMemOperand(PtrInfo, MMO->getFlags(), Size, MMO->getBaseAlign(),
510                         AAMDNodes(), nullptr, MMO->getSyncScopeID(),
511                         MMO->getSuccessOrdering(), MMO->getFailureOrdering());
512 }
513 
514 MachineMemOperand *MachineFunction::getMachineMemOperand(
515     const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, LLT Ty) {
516   return new (Allocator)
517       MachineMemOperand(PtrInfo, MMO->getFlags(), Ty, MMO->getBaseAlign(),
518                         AAMDNodes(), nullptr, MMO->getSyncScopeID(),
519                         MMO->getSuccessOrdering(), MMO->getFailureOrdering());
520 }
521 
522 MachineMemOperand *
523 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
524                                       int64_t Offset, LLT Ty) {
525   const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();
526 
527   // If there is no pointer value, the offset isn't tracked so we need to adjust
528   // the base alignment.
529   Align Alignment = PtrInfo.V.isNull()
530                         ? commonAlignment(MMO->getBaseAlign(), Offset)
531                         : MMO->getBaseAlign();
532 
533   // Do not preserve ranges, since we don't necessarily know what the high bits
534   // are anymore.
535   return new (Allocator) MachineMemOperand(
536       PtrInfo.getWithOffset(Offset), MMO->getFlags(), Ty, Alignment,
537       MMO->getAAInfo(), nullptr, MMO->getSyncScopeID(),
538       MMO->getSuccessOrdering(), MMO->getFailureOrdering());
539 }
540 
541 MachineMemOperand *
542 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
543                                       const AAMDNodes &AAInfo) {
544   MachinePointerInfo MPI = MMO->getValue() ?
545              MachinePointerInfo(MMO->getValue(), MMO->getOffset()) :
546              MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset());
547 
548   return new (Allocator) MachineMemOperand(
549       MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign(), AAInfo,
550       MMO->getRanges(), MMO->getSyncScopeID(), MMO->getSuccessOrdering(),
551       MMO->getFailureOrdering());
552 }
553 
554 MachineMemOperand *
555 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
556                                       MachineMemOperand::Flags Flags) {
557   return new (Allocator) MachineMemOperand(
558       MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign(),
559       MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),
560       MMO->getSuccessOrdering(), MMO->getFailureOrdering());
561 }
562 
563 MachineInstr::ExtraInfo *MachineFunction::createMIExtraInfo(
564     ArrayRef<MachineMemOperand *> MMOs, MCSymbol *PreInstrSymbol,
565     MCSymbol *PostInstrSymbol, MDNode *HeapAllocMarker, MDNode *PCSections,
566     uint32_t CFIType) {
567   return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol,
568                                          PostInstrSymbol, HeapAllocMarker,
569                                          PCSections, CFIType);
570 }
571 
572 const char *MachineFunction::createExternalSymbolName(StringRef Name) {
573   char *Dest = Allocator.Allocate<char>(Name.size() + 1);
574   llvm::copy(Name, Dest);
575   Dest[Name.size()] = 0;
576   return Dest;
577 }
578 
579 uint32_t *MachineFunction::allocateRegMask() {
580   unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs();
581   unsigned Size = MachineOperand::getRegMaskSize(NumRegs);
582   uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
583   memset(Mask, 0, Size * sizeof(Mask[0]));
584   return Mask;
585 }
586 
587 ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) {
588   int* AllocMask = Allocator.Allocate<int>(Mask.size());
589   copy(Mask, AllocMask);
590   return {AllocMask, Mask.size()};
591 }
592 
593 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
594 LLVM_DUMP_METHOD void MachineFunction::dump() const {
595   print(dbgs());
596 }
597 #endif
598 
599 StringRef MachineFunction::getName() const {
600   return getFunction().getName();
601 }
602 
603 void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const {
604   OS << "# Machine code for function " << getName() << ": ";
605   getProperties().print(OS);
606   OS << '\n';
607 
608   // Print Frame Information
609   FrameInfo->print(*this, OS);
610 
611   // Print JumpTable Information
612   if (JumpTableInfo)
613     JumpTableInfo->print(OS);
614 
615   // Print Constant Pool
616   ConstantPool->print(OS);
617 
618   const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();
619 
620   if (RegInfo && !RegInfo->livein_empty()) {
621     OS << "Function Live Ins: ";
622     for (MachineRegisterInfo::livein_iterator
623          I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
624       OS << printReg(I->first, TRI);
625       if (I->second)
626         OS << " in " << printReg(I->second, TRI);
627       if (std::next(I) != E)
628         OS << ", ";
629     }
630     OS << '\n';
631   }
632 
633   ModuleSlotTracker MST(getFunction().getParent());
634   MST.incorporateFunction(getFunction());
635   for (const auto &BB : *this) {
636     OS << '\n';
637     // If we print the whole function, print it at its most verbose level.
638     BB.print(OS, MST, Indexes, /*IsStandalone=*/true);
639   }
640 
641   OS << "\n# End machine code for function " << getName() << ".\n\n";
642 }
643 
644 /// True if this function needs frame moves for debug or exceptions.
645 bool MachineFunction::needsFrameMoves() const {
646   return getMMI().hasDebugInfo() ||
647          getTarget().Options.ForceDwarfFrameSection ||
648          F.needsUnwindTableEntry();
649 }
650 
651 namespace llvm {
652 
653   template<>
654   struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
655     DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
656 
657     static std::string getGraphName(const MachineFunction *F) {
658       return ("CFG for '" + F->getName() + "' function").str();
659     }
660 
661     std::string getNodeLabel(const MachineBasicBlock *Node,
662                              const MachineFunction *Graph) {
663       std::string OutStr;
664       {
665         raw_string_ostream OSS(OutStr);
666 
667         if (isSimple()) {
668           OSS << printMBBReference(*Node);
669           if (const BasicBlock *BB = Node->getBasicBlock())
670             OSS << ": " << BB->getName();
671         } else
672           Node->print(OSS);
673       }
674 
675       if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
676 
677       // Process string output to make it nicer...
678       for (unsigned i = 0; i != OutStr.length(); ++i)
679         if (OutStr[i] == '\n') {                            // Left justify
680           OutStr[i] = '\\';
681           OutStr.insert(OutStr.begin()+i+1, 'l');
682         }
683       return OutStr;
684     }
685   };
686 
687 } // end namespace llvm
688 
689 void MachineFunction::viewCFG() const
690 {
691 #ifndef NDEBUG
692   ViewGraph(this, "mf" + getName());
693 #else
694   errs() << "MachineFunction::viewCFG is only available in debug builds on "
695          << "systems with Graphviz or gv!\n";
696 #endif // NDEBUG
697 }
698 
699 void MachineFunction::viewCFGOnly() const
700 {
701 #ifndef NDEBUG
702   ViewGraph(this, "mf" + getName(), true);
703 #else
704   errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
705          << "systems with Graphviz or gv!\n";
706 #endif // NDEBUG
707 }
708 
709 /// Add the specified physical register as a live-in value and
710 /// create a corresponding virtual register for it.
711 Register MachineFunction::addLiveIn(MCRegister PReg,
712                                     const TargetRegisterClass *RC) {
713   MachineRegisterInfo &MRI = getRegInfo();
714   Register VReg = MRI.getLiveInVirtReg(PReg);
715   if (VReg) {
716     const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
717     (void)VRegRC;
718     // A physical register can be added several times.
719     // Between two calls, the register class of the related virtual register
720     // may have been constrained to match some operation constraints.
721     // In that case, check that the current register class includes the
722     // physical register and is a sub class of the specified RC.
723     assert((VRegRC == RC || (VRegRC->contains(PReg) &&
724                              RC->hasSubClassEq(VRegRC))) &&
725             "Register class mismatch!");
726     return VReg;
727   }
728   VReg = MRI.createVirtualRegister(RC);
729   MRI.addLiveIn(PReg, VReg);
730   return VReg;
731 }
732 
733 /// Return the MCSymbol for the specified non-empty jump table.
734 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
735 /// normal 'L' label is returned.
736 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
737                                         bool isLinkerPrivate) const {
738   const DataLayout &DL = getDataLayout();
739   assert(JumpTableInfo && "No jump tables");
740   assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
741 
742   StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix()
743                                      : DL.getPrivateGlobalPrefix();
744   SmallString<60> Name;
745   raw_svector_ostream(Name)
746     << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
747   return Ctx.getOrCreateSymbol(Name);
748 }
749 
750 /// Return a function-local symbol to represent the PIC base.
751 MCSymbol *MachineFunction::getPICBaseSymbol() const {
752   const DataLayout &DL = getDataLayout();
753   return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
754                                Twine(getFunctionNumber()) + "$pb");
755 }
756 
757 /// \name Exception Handling
758 /// \{
759 
760 LandingPadInfo &
761 MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) {
762   unsigned N = LandingPads.size();
763   for (unsigned i = 0; i < N; ++i) {
764     LandingPadInfo &LP = LandingPads[i];
765     if (LP.LandingPadBlock == LandingPad)
766       return LP;
767   }
768 
769   LandingPads.push_back(LandingPadInfo(LandingPad));
770   return LandingPads[N];
771 }
772 
773 void MachineFunction::addInvoke(MachineBasicBlock *LandingPad,
774                                 MCSymbol *BeginLabel, MCSymbol *EndLabel) {
775   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
776   LP.BeginLabels.push_back(BeginLabel);
777   LP.EndLabels.push_back(EndLabel);
778 }
779 
780 MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) {
781   MCSymbol *LandingPadLabel = Ctx.createTempSymbol();
782   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
783   LP.LandingPadLabel = LandingPadLabel;
784 
785   const Instruction *FirstI = LandingPad->getBasicBlock()->getFirstNonPHI();
786   if (const auto *LPI = dyn_cast<LandingPadInst>(FirstI)) {
787     // If there's no typeid list specified, then "cleanup" is implicit.
788     // Otherwise, id 0 is reserved for the cleanup action.
789     if (LPI->isCleanup() && LPI->getNumClauses() != 0)
790       LP.TypeIds.push_back(0);
791 
792     // FIXME: New EH - Add the clauses in reverse order. This isn't 100%
793     //        correct, but we need to do it this way because of how the DWARF EH
794     //        emitter processes the clauses.
795     for (unsigned I = LPI->getNumClauses(); I != 0; --I) {
796       Value *Val = LPI->getClause(I - 1);
797       if (LPI->isCatch(I - 1)) {
798         LP.TypeIds.push_back(
799             getTypeIDFor(dyn_cast<GlobalValue>(Val->stripPointerCasts())));
800       } else {
801         // Add filters in a list.
802         auto *CVal = cast<Constant>(Val);
803         SmallVector<unsigned, 4> FilterList;
804         for (const Use &U : CVal->operands())
805           FilterList.push_back(
806               getTypeIDFor(cast<GlobalValue>(U->stripPointerCasts())));
807 
808         LP.TypeIds.push_back(getFilterIDFor(FilterList));
809       }
810     }
811 
812   } else if (const auto *CPI = dyn_cast<CatchPadInst>(FirstI)) {
813     for (unsigned I = CPI->arg_size(); I != 0; --I) {
814       auto *TypeInfo =
815           dyn_cast<GlobalValue>(CPI->getArgOperand(I - 1)->stripPointerCasts());
816       LP.TypeIds.push_back(getTypeIDFor(TypeInfo));
817     }
818 
819   } else {
820     assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!");
821   }
822 
823   return LandingPadLabel;
824 }
825 
826 void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,
827                                             ArrayRef<unsigned> Sites) {
828   LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
829 }
830 
831 unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) {
832   for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
833     if (TypeInfos[i] == TI) return i + 1;
834 
835   TypeInfos.push_back(TI);
836   return TypeInfos.size();
837 }
838 
839 int MachineFunction::getFilterIDFor(ArrayRef<unsigned> TyIds) {
840   // If the new filter coincides with the tail of an existing filter, then
841   // re-use the existing filter.  Folding filters more than this requires
842   // re-ordering filters and/or their elements - probably not worth it.
843   for (unsigned i : FilterEnds) {
844     unsigned j = TyIds.size();
845 
846     while (i && j)
847       if (FilterIds[--i] != TyIds[--j])
848         goto try_next;
849 
850     if (!j)
851       // The new filter coincides with range [i, end) of the existing filter.
852       return -(1 + i);
853 
854 try_next:;
855   }
856 
857   // Add the new filter.
858   int FilterID = -(1 + FilterIds.size());
859   FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
860   llvm::append_range(FilterIds, TyIds);
861   FilterEnds.push_back(FilterIds.size());
862   FilterIds.push_back(0); // terminator
863   return FilterID;
864 }
865 
866 MachineFunction::CallSiteInfoMap::iterator
867 MachineFunction::getCallSiteInfo(const MachineInstr *MI) {
868   assert(MI->isCandidateForCallSiteEntry() &&
869          "Call site info refers only to call (MI) candidates");
870 
871   if (!Target.Options.EmitCallSiteInfo)
872     return CallSitesInfo.end();
873   return CallSitesInfo.find(MI);
874 }
875 
876 /// Return the call machine instruction or find a call within bundle.
877 static const MachineInstr *getCallInstr(const MachineInstr *MI) {
878   if (!MI->isBundle())
879     return MI;
880 
881   for (const auto &BMI : make_range(getBundleStart(MI->getIterator()),
882                                     getBundleEnd(MI->getIterator())))
883     if (BMI.isCandidateForCallSiteEntry())
884       return &BMI;
885 
886   llvm_unreachable("Unexpected bundle without a call site candidate");
887 }
888 
889 void MachineFunction::eraseCallSiteInfo(const MachineInstr *MI) {
890   assert(MI->shouldUpdateCallSiteInfo() &&
891          "Call site info refers only to call (MI) candidates or "
892          "candidates inside bundles");
893 
894   const MachineInstr *CallMI = getCallInstr(MI);
895   CallSiteInfoMap::iterator CSIt = getCallSiteInfo(CallMI);
896   if (CSIt == CallSitesInfo.end())
897     return;
898   CallSitesInfo.erase(CSIt);
899 }
900 
901 void MachineFunction::copyCallSiteInfo(const MachineInstr *Old,
902                                        const MachineInstr *New) {
903   assert(Old->shouldUpdateCallSiteInfo() &&
904          "Call site info refers only to call (MI) candidates or "
905          "candidates inside bundles");
906 
907   if (!New->isCandidateForCallSiteEntry())
908     return eraseCallSiteInfo(Old);
909 
910   const MachineInstr *OldCallMI = getCallInstr(Old);
911   CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI);
912   if (CSIt == CallSitesInfo.end())
913     return;
914 
915   CallSiteInfo CSInfo = CSIt->second;
916   CallSitesInfo[New] = CSInfo;
917 }
918 
919 void MachineFunction::moveCallSiteInfo(const MachineInstr *Old,
920                                        const MachineInstr *New) {
921   assert(Old->shouldUpdateCallSiteInfo() &&
922          "Call site info refers only to call (MI) candidates or "
923          "candidates inside bundles");
924 
925   if (!New->isCandidateForCallSiteEntry())
926     return eraseCallSiteInfo(Old);
927 
928   const MachineInstr *OldCallMI = getCallInstr(Old);
929   CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI);
930   if (CSIt == CallSitesInfo.end())
931     return;
932 
933   CallSiteInfo CSInfo = std::move(CSIt->second);
934   CallSitesInfo.erase(CSIt);
935   CallSitesInfo[New] = CSInfo;
936 }
937 
938 void MachineFunction::setDebugInstrNumberingCount(unsigned Num) {
939   DebugInstrNumberingCount = Num;
940 }
941 
942 void MachineFunction::makeDebugValueSubstitution(DebugInstrOperandPair A,
943                                                  DebugInstrOperandPair B,
944                                                  unsigned Subreg) {
945   // Catch any accidental self-loops.
946   assert(A.first != B.first);
947   // Don't allow any substitutions _from_ the memory operand number.
948   assert(A.second != DebugOperandMemNumber);
949 
950   DebugValueSubstitutions.push_back({A, B, Subreg});
951 }
952 
953 void MachineFunction::substituteDebugValuesForInst(const MachineInstr &Old,
954                                                    MachineInstr &New,
955                                                    unsigned MaxOperand) {
956   // If the Old instruction wasn't tracked at all, there is no work to do.
957   unsigned OldInstrNum = Old.peekDebugInstrNum();
958   if (!OldInstrNum)
959     return;
960 
961   // Iterate over all operands looking for defs to create substitutions for.
962   // Avoid creating new instr numbers unless we create a new substitution.
963   // While this has no functional effect, it risks confusing someone reading
964   // MIR output.
965   // Examine all the operands, or the first N specified by the caller.
966   MaxOperand = std::min(MaxOperand, Old.getNumOperands());
967   for (unsigned int I = 0; I < MaxOperand; ++I) {
968     const auto &OldMO = Old.getOperand(I);
969     auto &NewMO = New.getOperand(I);
970     (void)NewMO;
971 
972     if (!OldMO.isReg() || !OldMO.isDef())
973       continue;
974     assert(NewMO.isDef());
975 
976     unsigned NewInstrNum = New.getDebugInstrNum();
977     makeDebugValueSubstitution(std::make_pair(OldInstrNum, I),
978                                std::make_pair(NewInstrNum, I));
979   }
980 }
981 
982 auto MachineFunction::salvageCopySSA(
983     MachineInstr &MI, DenseMap<Register, DebugInstrOperandPair> &DbgPHICache)
984     -> DebugInstrOperandPair {
985   const TargetInstrInfo &TII = *getSubtarget().getInstrInfo();
986 
987   // Check whether this copy-like instruction has already been salvaged into
988   // an operand pair.
989   Register Dest;
990   if (auto CopyDstSrc = TII.isCopyInstr(MI)) {
991     Dest = CopyDstSrc->Destination->getReg();
992   } else {
993     assert(MI.isSubregToReg());
994     Dest = MI.getOperand(0).getReg();
995   }
996 
997   auto CacheIt = DbgPHICache.find(Dest);
998   if (CacheIt != DbgPHICache.end())
999     return CacheIt->second;
1000 
1001   // Calculate the instruction number to use, or install a DBG_PHI.
1002   auto OperandPair = salvageCopySSAImpl(MI);
1003   DbgPHICache.insert({Dest, OperandPair});
1004   return OperandPair;
1005 }
1006 
1007 auto MachineFunction::salvageCopySSAImpl(MachineInstr &MI)
1008     -> DebugInstrOperandPair {
1009   MachineRegisterInfo &MRI = getRegInfo();
1010   const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
1011   const TargetInstrInfo &TII = *getSubtarget().getInstrInfo();
1012 
1013   // Chase the value read by a copy-like instruction back to the instruction
1014   // that ultimately _defines_ that value. This may pass:
1015   //  * Through multiple intermediate copies, including subregister moves /
1016   //    copies,
1017   //  * Copies from physical registers that must then be traced back to the
1018   //    defining instruction,
1019   //  * Or, physical registers may be live-in to (only) the entry block, which
1020   //    requires a DBG_PHI to be created.
1021   // We can pursue this problem in that order: trace back through copies,
1022   // optionally through a physical register, to a defining instruction. We
1023   // should never move from physreg to vreg. As we're still in SSA form, no need
1024   // to worry about partial definitions of registers.
1025 
1026   // Helper lambda to interpret a copy-like instruction. Takes instruction,
1027   // returns the register read and any subregister identifying which part is
1028   // read.
1029   auto GetRegAndSubreg =
1030       [&](const MachineInstr &Cpy) -> std::pair<Register, unsigned> {
1031     Register NewReg, OldReg;
1032     unsigned SubReg;
1033     if (Cpy.isCopy()) {
1034       OldReg = Cpy.getOperand(0).getReg();
1035       NewReg = Cpy.getOperand(1).getReg();
1036       SubReg = Cpy.getOperand(1).getSubReg();
1037     } else if (Cpy.isSubregToReg()) {
1038       OldReg = Cpy.getOperand(0).getReg();
1039       NewReg = Cpy.getOperand(2).getReg();
1040       SubReg = Cpy.getOperand(3).getImm();
1041     } else {
1042       auto CopyDetails = *TII.isCopyInstr(Cpy);
1043       const MachineOperand &Src = *CopyDetails.Source;
1044       const MachineOperand &Dest = *CopyDetails.Destination;
1045       OldReg = Dest.getReg();
1046       NewReg = Src.getReg();
1047       SubReg = Src.getSubReg();
1048     }
1049 
1050     return {NewReg, SubReg};
1051   };
1052 
1053   // First seek either the defining instruction, or a copy from a physreg.
1054   // During search, the current state is the current copy instruction, and which
1055   // register we've read. Accumulate qualifying subregisters into SubregsSeen;
1056   // deal with those later.
1057   auto State = GetRegAndSubreg(MI);
1058   auto CurInst = MI.getIterator();
1059   SmallVector<unsigned, 4> SubregsSeen;
1060   while (true) {
1061     // If we've found a copy from a physreg, first portion of search is over.
1062     if (!State.first.isVirtual())
1063       break;
1064 
1065     // Record any subregister qualifier.
1066     if (State.second)
1067       SubregsSeen.push_back(State.second);
1068 
1069     assert(MRI.hasOneDef(State.first));
1070     MachineInstr &Inst = *MRI.def_begin(State.first)->getParent();
1071     CurInst = Inst.getIterator();
1072 
1073     // Any non-copy instruction is the defining instruction we're seeking.
1074     if (!Inst.isCopyLike() && !TII.isCopyInstr(Inst))
1075       break;
1076     State = GetRegAndSubreg(Inst);
1077   };
1078 
1079   // Helper lambda to apply additional subregister substitutions to a known
1080   // instruction/operand pair. Adds new (fake) substitutions so that we can
1081   // record the subregister. FIXME: this isn't very space efficient if multiple
1082   // values are tracked back through the same copies; cache something later.
1083   auto ApplySubregisters =
1084       [&](DebugInstrOperandPair P) -> DebugInstrOperandPair {
1085     for (unsigned Subreg : reverse(SubregsSeen)) {
1086       // Fetch a new instruction number, not attached to an actual instruction.
1087       unsigned NewInstrNumber = getNewDebugInstrNum();
1088       // Add a substitution from the "new" number to the known one, with a
1089       // qualifying subreg.
1090       makeDebugValueSubstitution({NewInstrNumber, 0}, P, Subreg);
1091       // Return the new number; to find the underlying value, consumers need to
1092       // deal with the qualifying subreg.
1093       P = {NewInstrNumber, 0};
1094     }
1095     return P;
1096   };
1097 
1098   // If we managed to find the defining instruction after COPYs, return an
1099   // instruction / operand pair after adding subregister qualifiers.
1100   if (State.first.isVirtual()) {
1101     // Virtual register def -- we can just look up where this happens.
1102     MachineInstr *Inst = MRI.def_begin(State.first)->getParent();
1103     for (auto &MO : Inst->all_defs()) {
1104       if (MO.getReg() != State.first)
1105         continue;
1106       return ApplySubregisters({Inst->getDebugInstrNum(), MO.getOperandNo()});
1107     }
1108 
1109     llvm_unreachable("Vreg def with no corresponding operand?");
1110   }
1111 
1112   // Our search ended in a copy from a physreg: walk back up the function
1113   // looking for whatever defines the physreg.
1114   assert(CurInst->isCopyLike() || TII.isCopyInstr(*CurInst));
1115   State = GetRegAndSubreg(*CurInst);
1116   Register RegToSeek = State.first;
1117 
1118   auto RMII = CurInst->getReverseIterator();
1119   auto PrevInstrs = make_range(RMII, CurInst->getParent()->instr_rend());
1120   for (auto &ToExamine : PrevInstrs) {
1121     for (auto &MO : ToExamine.all_defs()) {
1122       // Test for operand that defines something aliasing RegToSeek.
1123       if (!TRI.regsOverlap(RegToSeek, MO.getReg()))
1124         continue;
1125 
1126       return ApplySubregisters(
1127           {ToExamine.getDebugInstrNum(), MO.getOperandNo()});
1128     }
1129   }
1130 
1131   MachineBasicBlock &InsertBB = *CurInst->getParent();
1132 
1133   // We reached the start of the block before finding a defining instruction.
1134   // There are numerous scenarios where this can happen:
1135   // * Constant physical registers,
1136   // * Several intrinsics that allow LLVM-IR to read arbitary registers,
1137   // * Arguments in the entry block,
1138   // * Exception handling landing pads.
1139   // Validating all of them is too difficult, so just insert a DBG_PHI reading
1140   // the variable value at this position, rather than checking it makes sense.
1141 
1142   // Create DBG_PHI for specified physreg.
1143   auto Builder = BuildMI(InsertBB, InsertBB.getFirstNonPHI(), DebugLoc(),
1144                          TII.get(TargetOpcode::DBG_PHI));
1145   Builder.addReg(State.first);
1146   unsigned NewNum = getNewDebugInstrNum();
1147   Builder.addImm(NewNum);
1148   return ApplySubregisters({NewNum, 0u});
1149 }
1150 
1151 void MachineFunction::finalizeDebugInstrRefs() {
1152   auto *TII = getSubtarget().getInstrInfo();
1153 
1154   auto MakeUndefDbgValue = [&](MachineInstr &MI) {
1155     const MCInstrDesc &RefII = TII->get(TargetOpcode::DBG_VALUE_LIST);
1156     MI.setDesc(RefII);
1157     MI.setDebugValueUndef();
1158   };
1159 
1160   DenseMap<Register, DebugInstrOperandPair> ArgDbgPHIs;
1161   for (auto &MBB : *this) {
1162     for (auto &MI : MBB) {
1163       if (!MI.isDebugRef())
1164         continue;
1165 
1166       bool IsValidRef = true;
1167 
1168       for (MachineOperand &MO : MI.debug_operands()) {
1169         if (!MO.isReg())
1170           continue;
1171 
1172         Register Reg = MO.getReg();
1173 
1174         // Some vregs can be deleted as redundant in the meantime. Mark those
1175         // as DBG_VALUE $noreg. Additionally, some normal instructions are
1176         // quickly deleted, leaving dangling references to vregs with no def.
1177         if (Reg == 0 || !RegInfo->hasOneDef(Reg)) {
1178           IsValidRef = false;
1179           break;
1180         }
1181 
1182         assert(Reg.isVirtual());
1183         MachineInstr &DefMI = *RegInfo->def_instr_begin(Reg);
1184 
1185         // If we've found a copy-like instruction, follow it back to the
1186         // instruction that defines the source value, see salvageCopySSA docs
1187         // for why this is important.
1188         if (DefMI.isCopyLike() || TII->isCopyInstr(DefMI)) {
1189           auto Result = salvageCopySSA(DefMI, ArgDbgPHIs);
1190           MO.ChangeToDbgInstrRef(Result.first, Result.second);
1191         } else {
1192           // Otherwise, identify the operand number that the VReg refers to.
1193           unsigned OperandIdx = 0;
1194           for (const auto &DefMO : DefMI.operands()) {
1195             if (DefMO.isReg() && DefMO.isDef() && DefMO.getReg() == Reg)
1196               break;
1197             ++OperandIdx;
1198           }
1199           assert(OperandIdx < DefMI.getNumOperands());
1200 
1201           // Morph this instr ref to point at the given instruction and operand.
1202           unsigned ID = DefMI.getDebugInstrNum();
1203           MO.ChangeToDbgInstrRef(ID, OperandIdx);
1204         }
1205       }
1206 
1207       if (!IsValidRef)
1208         MakeUndefDbgValue(MI);
1209     }
1210   }
1211 }
1212 
1213 bool MachineFunction::shouldUseDebugInstrRef() const {
1214   // Disable instr-ref at -O0: it's very slow (in compile time). We can still
1215   // have optimized code inlined into this unoptimized code, however with
1216   // fewer and less aggressive optimizations happening, coverage and accuracy
1217   // should not suffer.
1218   if (getTarget().getOptLevel() == CodeGenOptLevel::None)
1219     return false;
1220 
1221   // Don't use instr-ref if this function is marked optnone.
1222   if (F.hasFnAttribute(Attribute::OptimizeNone))
1223     return false;
1224 
1225   if (llvm::debuginfoShouldUseDebugInstrRef(getTarget().getTargetTriple()))
1226     return true;
1227 
1228   return false;
1229 }
1230 
1231 bool MachineFunction::useDebugInstrRef() const {
1232   return UseDebugInstrRef;
1233 }
1234 
1235 void MachineFunction::setUseDebugInstrRef(bool Use) {
1236   UseDebugInstrRef = Use;
1237 }
1238 
1239 // Use one million as a high / reserved number.
1240 const unsigned MachineFunction::DebugOperandMemNumber = 1000000;
1241 
1242 /// \}
1243 
1244 //===----------------------------------------------------------------------===//
1245 //  MachineJumpTableInfo implementation
1246 //===----------------------------------------------------------------------===//
1247 
1248 /// Return the size of each entry in the jump table.
1249 unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
1250   // The size of a jump table entry is 4 bytes unless the entry is just the
1251   // address of a block, in which case it is the pointer size.
1252   switch (getEntryKind()) {
1253   case MachineJumpTableInfo::EK_BlockAddress:
1254     return TD.getPointerSize();
1255   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
1256   case MachineJumpTableInfo::EK_LabelDifference64:
1257     return 8;
1258   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1259   case MachineJumpTableInfo::EK_LabelDifference32:
1260   case MachineJumpTableInfo::EK_Custom32:
1261     return 4;
1262   case MachineJumpTableInfo::EK_Inline:
1263     return 0;
1264   }
1265   llvm_unreachable("Unknown jump table encoding!");
1266 }
1267 
1268 /// Return the alignment of each entry in the jump table.
1269 unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
1270   // The alignment of a jump table entry is the alignment of int32 unless the
1271   // entry is just the address of a block, in which case it is the pointer
1272   // alignment.
1273   switch (getEntryKind()) {
1274   case MachineJumpTableInfo::EK_BlockAddress:
1275     return TD.getPointerABIAlignment(0).value();
1276   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
1277   case MachineJumpTableInfo::EK_LabelDifference64:
1278     return TD.getABIIntegerTypeAlignment(64).value();
1279   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1280   case MachineJumpTableInfo::EK_LabelDifference32:
1281   case MachineJumpTableInfo::EK_Custom32:
1282     return TD.getABIIntegerTypeAlignment(32).value();
1283   case MachineJumpTableInfo::EK_Inline:
1284     return 1;
1285   }
1286   llvm_unreachable("Unknown jump table encoding!");
1287 }
1288 
1289 /// Create a new jump table entry in the jump table info.
1290 unsigned MachineJumpTableInfo::createJumpTableIndex(
1291                                const std::vector<MachineBasicBlock*> &DestBBs) {
1292   assert(!DestBBs.empty() && "Cannot create an empty jump table!");
1293   JumpTables.push_back(MachineJumpTableEntry(DestBBs));
1294   return JumpTables.size()-1;
1295 }
1296 
1297 /// If Old is the target of any jump tables, update the jump tables to branch
1298 /// to New instead.
1299 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
1300                                                   MachineBasicBlock *New) {
1301   assert(Old != New && "Not making a change?");
1302   bool MadeChange = false;
1303   for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
1304     ReplaceMBBInJumpTable(i, Old, New);
1305   return MadeChange;
1306 }
1307 
1308 /// If MBB is present in any jump tables, remove it.
1309 bool MachineJumpTableInfo::RemoveMBBFromJumpTables(MachineBasicBlock *MBB) {
1310   bool MadeChange = false;
1311   for (MachineJumpTableEntry &JTE : JumpTables) {
1312     auto removeBeginItr = std::remove(JTE.MBBs.begin(), JTE.MBBs.end(), MBB);
1313     MadeChange |= (removeBeginItr != JTE.MBBs.end());
1314     JTE.MBBs.erase(removeBeginItr, JTE.MBBs.end());
1315   }
1316   return MadeChange;
1317 }
1318 
1319 /// If Old is a target of the jump tables, update the jump table to branch to
1320 /// New instead.
1321 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
1322                                                  MachineBasicBlock *Old,
1323                                                  MachineBasicBlock *New) {
1324   assert(Old != New && "Not making a change?");
1325   bool MadeChange = false;
1326   MachineJumpTableEntry &JTE = JumpTables[Idx];
1327   for (MachineBasicBlock *&MBB : JTE.MBBs)
1328     if (MBB == Old) {
1329       MBB = New;
1330       MadeChange = true;
1331     }
1332   return MadeChange;
1333 }
1334 
1335 void MachineJumpTableInfo::print(raw_ostream &OS) const {
1336   if (JumpTables.empty()) return;
1337 
1338   OS << "Jump Tables:\n";
1339 
1340   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
1341     OS << printJumpTableEntryReference(i) << ':';
1342     for (const MachineBasicBlock *MBB : JumpTables[i].MBBs)
1343       OS << ' ' << printMBBReference(*MBB);
1344     if (i != e)
1345       OS << '\n';
1346   }
1347 
1348   OS << '\n';
1349 }
1350 
1351 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1352 LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); }
1353 #endif
1354 
1355 Printable llvm::printJumpTableEntryReference(unsigned Idx) {
1356   return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; });
1357 }
1358 
1359 //===----------------------------------------------------------------------===//
1360 //  MachineConstantPool implementation
1361 //===----------------------------------------------------------------------===//
1362 
1363 void MachineConstantPoolValue::anchor() {}
1364 
1365 unsigned MachineConstantPoolValue::getSizeInBytes(const DataLayout &DL) const {
1366   return DL.getTypeAllocSize(Ty);
1367 }
1368 
1369 unsigned MachineConstantPoolEntry::getSizeInBytes(const DataLayout &DL) const {
1370   if (isMachineConstantPoolEntry())
1371     return Val.MachineCPVal->getSizeInBytes(DL);
1372   return DL.getTypeAllocSize(Val.ConstVal->getType());
1373 }
1374 
1375 bool MachineConstantPoolEntry::needsRelocation() const {
1376   if (isMachineConstantPoolEntry())
1377     return true;
1378   return Val.ConstVal->needsDynamicRelocation();
1379 }
1380 
1381 SectionKind
1382 MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
1383   if (needsRelocation())
1384     return SectionKind::getReadOnlyWithRel();
1385   switch (getSizeInBytes(*DL)) {
1386   case 4:
1387     return SectionKind::getMergeableConst4();
1388   case 8:
1389     return SectionKind::getMergeableConst8();
1390   case 16:
1391     return SectionKind::getMergeableConst16();
1392   case 32:
1393     return SectionKind::getMergeableConst32();
1394   default:
1395     return SectionKind::getReadOnly();
1396   }
1397 }
1398 
1399 MachineConstantPool::~MachineConstantPool() {
1400   // A constant may be a member of both Constants and MachineCPVsSharingEntries,
1401   // so keep track of which we've deleted to avoid double deletions.
1402   DenseSet<MachineConstantPoolValue*> Deleted;
1403   for (const MachineConstantPoolEntry &C : Constants)
1404     if (C.isMachineConstantPoolEntry()) {
1405       Deleted.insert(C.Val.MachineCPVal);
1406       delete C.Val.MachineCPVal;
1407     }
1408   for (MachineConstantPoolValue *CPV : MachineCPVsSharingEntries) {
1409     if (Deleted.count(CPV) == 0)
1410       delete CPV;
1411   }
1412 }
1413 
1414 /// Test whether the given two constants can be allocated the same constant pool
1415 /// entry referenced by \param A.
1416 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
1417                                       const DataLayout &DL) {
1418   // Handle the trivial case quickly.
1419   if (A == B) return true;
1420 
1421   // If they have the same type but weren't the same constant, quickly
1422   // reject them.
1423   if (A->getType() == B->getType()) return false;
1424 
1425   // We can't handle structs or arrays.
1426   if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
1427       isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
1428     return false;
1429 
1430   // For now, only support constants with the same size.
1431   uint64_t StoreSize = DL.getTypeStoreSize(A->getType());
1432   if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128)
1433     return false;
1434 
1435   bool ContainsUndefOrPoisonA = A->containsUndefOrPoisonElement();
1436 
1437   Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
1438 
1439   // Try constant folding a bitcast of both instructions to an integer.  If we
1440   // get two identical ConstantInt's, then we are good to share them.  We use
1441   // the constant folding APIs to do this so that we get the benefit of
1442   // DataLayout.
1443   if (isa<PointerType>(A->getType()))
1444     A = ConstantFoldCastOperand(Instruction::PtrToInt,
1445                                 const_cast<Constant *>(A), IntTy, DL);
1446   else if (A->getType() != IntTy)
1447     A = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(A),
1448                                 IntTy, DL);
1449   if (isa<PointerType>(B->getType()))
1450     B = ConstantFoldCastOperand(Instruction::PtrToInt,
1451                                 const_cast<Constant *>(B), IntTy, DL);
1452   else if (B->getType() != IntTy)
1453     B = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(B),
1454                                 IntTy, DL);
1455 
1456   if (A != B)
1457     return false;
1458 
1459   // Constants only safely match if A doesn't contain undef/poison.
1460   // As we'll be reusing A, it doesn't matter if B contain undef/poison.
1461   // TODO: Handle cases where A and B have the same undef/poison elements.
1462   // TODO: Merge A and B with mismatching undef/poison elements.
1463   return !ContainsUndefOrPoisonA;
1464 }
1465 
1466 /// Create a new entry in the constant pool or return an existing one.
1467 /// User must specify the log2 of the minimum required alignment for the object.
1468 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
1469                                                    Align Alignment) {
1470   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
1471 
1472   // Check to see if we already have this constant.
1473   //
1474   // FIXME, this could be made much more efficient for large constant pools.
1475   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
1476     if (!Constants[i].isMachineConstantPoolEntry() &&
1477         CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) {
1478       if (Constants[i].getAlign() < Alignment)
1479         Constants[i].Alignment = Alignment;
1480       return i;
1481     }
1482 
1483   Constants.push_back(MachineConstantPoolEntry(C, Alignment));
1484   return Constants.size()-1;
1485 }
1486 
1487 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
1488                                                    Align Alignment) {
1489   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
1490 
1491   // Check to see if we already have this constant.
1492   //
1493   // FIXME, this could be made much more efficient for large constant pools.
1494   int Idx = V->getExistingMachineCPValue(this, Alignment);
1495   if (Idx != -1) {
1496     MachineCPVsSharingEntries.insert(V);
1497     return (unsigned)Idx;
1498   }
1499 
1500   Constants.push_back(MachineConstantPoolEntry(V, Alignment));
1501   return Constants.size()-1;
1502 }
1503 
1504 void MachineConstantPool::print(raw_ostream &OS) const {
1505   if (Constants.empty()) return;
1506 
1507   OS << "Constant Pool:\n";
1508   for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1509     OS << "  cp#" << i << ": ";
1510     if (Constants[i].isMachineConstantPoolEntry())
1511       Constants[i].Val.MachineCPVal->print(OS);
1512     else
1513       Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
1514     OS << ", align=" << Constants[i].getAlign().value();
1515     OS << "\n";
1516   }
1517 }
1518 
1519 //===----------------------------------------------------------------------===//
1520 // Template specialization for MachineFunction implementation of
1521 // ProfileSummaryInfo::getEntryCount().
1522 //===----------------------------------------------------------------------===//
1523 template <>
1524 std::optional<Function::ProfileCount>
1525 ProfileSummaryInfo::getEntryCount<llvm::MachineFunction>(
1526     const llvm::MachineFunction *F) const {
1527   return F->getFunction().getEntryCount();
1528 }
1529 
1530 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1531 LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); }
1532 #endif
1533