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
81using namespace llvm;
82
83#define DEBUG_TYPE "codegen"
84
85static 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(Val: 0), cl::Hidden);
90
91static 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
112void setUnsafeStackSize(const Function &F, MachineFrameInfo &FrameInfo) {
113 if (!F.hasFnAttribute(Attribute::SafeStack))
114 return;
115
116 auto *Existing =
117 dyn_cast_or_null<MDTuple>(Val: F.getMetadata(KindID: 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(I: 0)) {
124 if (N.equalsStr(Str: MetadataName)) {
125 if (auto &Op = Existing->getOperand(I: 1)) {
126 auto Val = mdconst::extract<ConstantInt>(MD: Op)->getZExtValue();
127 FrameInfo.setUnsafeStackSize(Val);
128 }
129 }
130 }
131}
132
133// Pin the vtable to this file.
134void MachineFunction::Delegate::anchor() {}
135
136void 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(Prop: static_cast<Property>(I));
142 Separator = ", ";
143 }
144}
145
146//===----------------------------------------------------------------------===//
147// MachineFunction implementation
148//===----------------------------------------------------------------------===//
149
150// Out-of-line virtual method.
151MachineFunctionInfo::~MachineFunctionInfo() = default;
152
153void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
154 MBB->getParent()->deleteMachineBasicBlock(MBB);
155}
156
157static 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
164MachineFunction::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
172void MachineFunction::handleInsertion(MachineInstr &MI) {
173 if (TheDelegate)
174 TheDelegate->MF_HandleInsertion(MI);
175}
176
177void MachineFunction::handleRemoval(MachineInstr &MI) {
178 if (TheDelegate)
179 TheDelegate->MF_HandleRemoval(MI);
180}
181
182void MachineFunction::handleChangeDesc(MachineInstr &MI,
183 const MCInstrDesc &TID) {
184 if (TheDelegate)
185 TheDelegate->MF_HandleChangeDesc(MI, TID);
186}
187
188void 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(Kind: "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&: *FrameInfo);
209
210 if (F.hasFnAttribute(Attribute::StackAlignment))
211 FrameInfo->ensureMaxAlignment(Alignment: *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(a: Alignment,
220 b: 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(KindID: LLVMContext::MD_func_sanitize) ||
227 F.getMetadata(KindID: LLVMContext::MD_kcfi_type))
228 Alignment = std::max(a: Alignment, b: Align(4));
229
230 if (AlignAllFunctions)
231 Alignment = Align(1ULL << AlignAllFunctions);
232
233 JumpTableInfo = nullptr;
234
235 if (isFuncletEHPersonality(Pers: classifyEHPersonality(
236 Pers: F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
237 WinEHInfo = new (Allocator) WinEHFuncInfo();
238 }
239
240 if (isScopedEHPersonality(Pers: classifyEHPersonality(
241 Pers: 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>(args: getTarget());
250}
251
252void MachineFunction::initTargetMachineFunctionInfo(
253 const TargetSubtargetInfo &STI) {
254 assert(!MFInfo && "MachineFunctionInfo already set");
255 MFInfo = Target.createMachineFunctionInfo(Allocator, F, STI: &STI);
256}
257
258MachineFunction::~MachineFunction() {
259 clear();
260}
261
262void 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(where: 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(Ptr: RegInfo);
280 }
281 if (MFInfo) {
282 MFInfo->~MachineFunctionInfo();
283 Allocator.Deallocate(Ptr: MFInfo);
284 }
285
286 FrameInfo->~MachineFrameInfo();
287 Allocator.Deallocate(Ptr: FrameInfo);
288
289 ConstantPool->~MachineConstantPool();
290 Allocator.Deallocate(Ptr: ConstantPool);
291
292 if (JumpTableInfo) {
293 JumpTableInfo->~MachineJumpTableInfo();
294 Allocator.Deallocate(Ptr: JumpTableInfo);
295 }
296
297 if (WinEHInfo) {
298 WinEHInfo->~WinEHFuncInfo();
299 Allocator.Deallocate(Ptr: WinEHInfo);
300 }
301
302 if (WasmEHInfo) {
303 WasmEHInfo->~WasmEHFuncInfo();
304 Allocator.Deallocate(Ptr: WasmEHInfo);
305 }
306}
307
308const 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.
314MachineJumpTableInfo *MachineFunction::
315getOrCreateJumpTableInfo(unsigned EntryKind) {
316 if (JumpTableInfo) return JumpTableInfo;
317
318 JumpTableInfo = new (Allocator)
319 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
320 return JumpTableInfo;
321}
322
323DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const {
324 return F.getDenormalMode(FPType);
325}
326
327/// Should we be emitting segmented stack stuff for the function
328bool MachineFunction::shouldSplitStack() const {
329 return getFunction().hasFnAttribute(Kind: "split-stack");
330}
331
332[[nodiscard]] unsigned
333MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {
334 FrameInstructions.push_back(x: 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.
342void 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(x: 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(new_size: 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.
382void MachineFunction::assignBeginEndSections() {
383 front().setIsBeginSection();
384 auto CurrentSectionID = front().getSectionID();
385 for (auto MBBI = std::next(x: begin()), E = end(); MBBI != E; ++MBBI) {
386 if (MBBI->getSectionID() == CurrentSectionID)
387 continue;
388 MBBI->setIsBeginSection();
389 std::prev(x: MBBI)->setIsEndSection();
390 CurrentSectionID = MBBI->getSectionID();
391 }
392 back().setIsEndSection();
393}
394
395/// Allocate a new MachineInstr. Use this instead of `new MachineInstr'.
396MachineInstr *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.
405MachineInstr *
406MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
407 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
408 MachineInstr(*this, *Orig);
409}
410
411MachineInstr &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(Orig: &*I);
418 MBB.insert(I: InsertBefore, MI: 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(Old: &Orig, New: 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.
441void 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(Cap: MI->CapOperands, Array: 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, Element: MI);
456}
457
458/// Allocate a new MachineBasicBlock. Use this instead of
459/// `new MachineBasicBlock'.
460MachineBasicBlock *
461MachineFunction::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{.BaseID: NextBBID++, .CloneID: 0});
473 return MBB;
474}
475
476/// Delete the given MachineBasicBlock.
477void 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, Element: MBB);
484}
485
486MachineMemOperand *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
496MachineMemOperand *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
506MachineMemOperand *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
514MachineMemOperand *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
522MachineMemOperand *
523MachineFunction::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(A: 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(O: Offset), MMO->getFlags(), Ty, Alignment,
537 MMO->getAAInfo(), nullptr, MMO->getSyncScopeID(),
538 MMO->getSuccessOrdering(), MMO->getFailureOrdering());
539}
540
541MachineMemOperand *
542MachineFunction::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
554MachineMemOperand *
555MachineFunction::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
563MachineInstr::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
572const char *MachineFunction::createExternalSymbolName(StringRef Name) {
573 char *Dest = Allocator.Allocate<char>(Num: Name.size() + 1);
574 llvm::copy(Range&: Name, Out: Dest);
575 Dest[Name.size()] = 0;
576 return Dest;
577}
578
579uint32_t *MachineFunction::allocateRegMask() {
580 unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs();
581 unsigned Size = MachineOperand::getRegMaskSize(NumRegs);
582 uint32_t *Mask = Allocator.Allocate<uint32_t>(Num: Size);
583 memset(s: Mask, c: 0, n: Size * sizeof(Mask[0]));
584 return Mask;
585}
586
587ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) {
588 int* AllocMask = Allocator.Allocate<int>(Num: Mask.size());
589 copy(Range&: Mask, Out: AllocMask);
590 return {AllocMask, Mask.size()};
591}
592
593#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
594LLVM_DUMP_METHOD void MachineFunction::dump() const {
595 print(OS&: dbgs());
596}
597#endif
598
599StringRef MachineFunction::getName() const {
600 return getFunction().getName();
601}
602
603void 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(MF: *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(Reg: I->first, TRI);
625 if (I->second)
626 OS << " in " << printReg(Reg: I->second, TRI);
627 if (std::next(x: I) != E)
628 OS << ", ";
629 }
630 OS << '\n';
631 }
632
633 ModuleSlotTracker MST(getFunction().getParent());
634 MST.incorporateFunction(F: 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.
645bool MachineFunction::needsFrameMoves() const {
646 return getMMI().hasDebugInfo() ||
647 getTarget().Options.ForceDwarfFrameSection ||
648 F.needsUnwindTableEntry();
649}
650
651namespace 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(MBB: *Node);
669 if (const BasicBlock *BB = Node->getBasicBlock())
670 OSS << ": " << BB->getName();
671 } else
672 Node->print(OS&: OSS);
673 }
674
675 if (OutStr[0] == '\n') OutStr.erase(position: 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(p: OutStr.begin()+i+1, c: 'l');
682 }
683 return OutStr;
684 }
685 };
686
687} // end namespace llvm
688
689void MachineFunction::viewCFG() const
690{
691#ifndef NDEBUG
692 ViewGraph(G: this, Name: "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
699void MachineFunction::viewCFGOnly() const
700{
701#ifndef NDEBUG
702 ViewGraph(G: this, Name: "mf" + getName(), ShortNames: 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.
711Register 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(Reg: 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(RegClass: RC);
729 MRI.addLiveIn(Reg: PReg, vreg: 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.
736MCSymbol *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.
751MCSymbol *MachineFunction::getPICBaseSymbol() const {
752 const DataLayout &DL = getDataLayout();
753 return Ctx.getOrCreateSymbol(Name: Twine(DL.getPrivateGlobalPrefix()) +
754 Twine(getFunctionNumber()) + "$pb");
755}
756
757/// \name Exception Handling
758/// \{
759
760LandingPadInfo &
761MachineFunction::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(x: LandingPadInfo(LandingPad));
770 return LandingPads[N];
771}
772
773void MachineFunction::addInvoke(MachineBasicBlock *LandingPad,
774 MCSymbol *BeginLabel, MCSymbol *EndLabel) {
775 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
776 LP.BeginLabels.push_back(Elt: BeginLabel);
777 LP.EndLabels.push_back(Elt: EndLabel);
778}
779
780MCSymbol *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>(Val: 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(x: 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(Idx: I - 1);
797 if (LPI->isCatch(Idx: I - 1)) {
798 LP.TypeIds.push_back(
799 x: getTypeIDFor(TI: dyn_cast<GlobalValue>(Val: 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 Elt: getTypeIDFor(TI: cast<GlobalValue>(Val: U->stripPointerCasts())));
807
808 LP.TypeIds.push_back(x: getFilterIDFor(TyIds: FilterList));
809 }
810 }
811
812 } else if (const auto *CPI = dyn_cast<CatchPadInst>(Val: FirstI)) {
813 for (unsigned I = CPI->arg_size(); I != 0; --I) {
814 auto *TypeInfo =
815 dyn_cast<GlobalValue>(Val: CPI->getArgOperand(i: I - 1)->stripPointerCasts());
816 LP.TypeIds.push_back(x: getTypeIDFor(TI: TypeInfo));
817 }
818
819 } else {
820 assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!");
821 }
822
823 return LandingPadLabel;
824}
825
826void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,
827 ArrayRef<unsigned> Sites) {
828 LPadToCallSiteMap[Sym].append(in_start: Sites.begin(), in_end: Sites.end());
829}
830
831unsigned 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(x: TI);
836 return TypeInfos.size();
837}
838
839int 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
854try_next:;
855 }
856
857 // Add the new filter.
858 int FilterID = -(1 + FilterIds.size());
859 FilterIds.reserve(n: FilterIds.size() + TyIds.size() + 1);
860 llvm::append_range(C&: FilterIds, R&: TyIds);
861 FilterEnds.push_back(x: FilterIds.size());
862 FilterIds.push_back(x: 0); // terminator
863 return FilterID;
864}
865
866MachineFunction::CallSiteInfoMap::iterator
867MachineFunction::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(Val: MI);
874}
875
876/// Return the call machine instruction or find a call within bundle.
877static const MachineInstr *getCallInstr(const MachineInstr *MI) {
878 if (!MI->isBundle())
879 return MI;
880
881 for (const auto &BMI : make_range(x: getBundleStart(I: MI->getIterator()),
882 y: getBundleEnd(I: MI->getIterator())))
883 if (BMI.isCandidateForCallSiteEntry())
884 return &BMI;
885
886 llvm_unreachable("Unexpected bundle without a call site candidate");
887}
888
889void 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(MI: CallMI);
896 if (CSIt == CallSitesInfo.end())
897 return;
898 CallSitesInfo.erase(I: CSIt);
899}
900
901void 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(MI: Old);
909
910 const MachineInstr *OldCallMI = getCallInstr(MI: Old);
911 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(MI: OldCallMI);
912 if (CSIt == CallSitesInfo.end())
913 return;
914
915 CallSiteInfo CSInfo = CSIt->second;
916 CallSitesInfo[New] = CSInfo;
917}
918
919void 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(MI: Old);
927
928 const MachineInstr *OldCallMI = getCallInstr(MI: Old);
929 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(MI: OldCallMI);
930 if (CSIt == CallSitesInfo.end())
931 return;
932
933 CallSiteInfo CSInfo = std::move(CSIt->second);
934 CallSitesInfo.erase(I: CSIt);
935 CallSitesInfo[New] = CSInfo;
936}
937
938void MachineFunction::setDebugInstrNumberingCount(unsigned Num) {
939 DebugInstrNumberingCount = Num;
940}
941
942void 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(Elt: {A, B, Subreg});
951}
952
953void 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(a: MaxOperand, b: Old.getNumOperands());
967 for (unsigned int I = 0; I < MaxOperand; ++I) {
968 const auto &OldMO = Old.getOperand(i: I);
969 auto &NewMO = New.getOperand(i: 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(A: std::make_pair(x&: OldInstrNum, y&: I),
978 B: std::make_pair(x&: NewInstrNum, y&: I));
979 }
980}
981
982auto 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(i: 0).getReg();
995 }
996
997 auto CacheIt = DbgPHICache.find(Val: 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(KV: {Dest, OperandPair});
1004 return OperandPair;
1005}
1006
1007auto 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(i: 0).getReg();
1035 NewReg = Cpy.getOperand(i: 1).getReg();
1036 SubReg = Cpy.getOperand(i: 1).getSubReg();
1037 } else if (Cpy.isSubregToReg()) {
1038 OldReg = Cpy.getOperand(i: 0).getReg();
1039 NewReg = Cpy.getOperand(i: 2).getReg();
1040 SubReg = Cpy.getOperand(i: 3).getImm();
1041 } else {
1042 auto CopyDetails = *TII.isCopyInstr(MI: 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(Elt: State.second);
1068
1069 assert(MRI.hasOneDef(State.first));
1070 MachineInstr &Inst = *MRI.def_begin(RegNo: 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(MI: 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(C&: 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(A: {NewInstrNumber, 0}, B: 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(RegNo: 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(x: RMII, y: 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(RegA: RegToSeek, RegB: 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(BB&: InsertBB, I: InsertBB.getFirstNonPHI(), MIMD: DebugLoc(),
1144 MCID: TII.get(Opcode: TargetOpcode::DBG_PHI));
1145 Builder.addReg(RegNo: State.first);
1146 unsigned NewNum = getNewDebugInstrNum();
1147 Builder.addImm(Val: NewNum);
1148 return ApplySubregisters({NewNum, 0u});
1149}
1150
1151void MachineFunction::finalizeDebugInstrRefs() {
1152 auto *TII = getSubtarget().getInstrInfo();
1153
1154 auto MakeUndefDbgValue = [&](MachineInstr &MI) {
1155 const MCInstrDesc &RefII = TII->get(Opcode: 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(RegNo: Reg)) {
1178 IsValidRef = false;
1179 break;
1180 }
1181
1182 assert(Reg.isVirtual());
1183 MachineInstr &DefMI = *RegInfo->def_instr_begin(RegNo: 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(MI: DefMI)) {
1189 auto Result = salvageCopySSA(MI&: DefMI, DbgPHICache&: ArgDbgPHIs);
1190 MO.ChangeToDbgInstrRef(InstrIdx: Result.first, OpIdx: 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(InstrIdx: ID, OpIdx: OperandIdx);
1204 }
1205 }
1206
1207 if (!IsValidRef)
1208 MakeUndefDbgValue(MI);
1209 }
1210 }
1211}
1212
1213bool 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(T: getTarget().getTargetTriple()))
1226 return true;
1227
1228 return false;
1229}
1230
1231bool MachineFunction::useDebugInstrRef() const {
1232 return UseDebugInstrRef;
1233}
1234
1235void MachineFunction::setUseDebugInstrRef(bool Use) {
1236 UseDebugInstrRef = Use;
1237}
1238
1239// Use one million as a high / reserved number.
1240const unsigned MachineFunction::DebugOperandMemNumber = 1000000;
1241
1242/// \}
1243
1244//===----------------------------------------------------------------------===//
1245// MachineJumpTableInfo implementation
1246//===----------------------------------------------------------------------===//
1247
1248/// Return the size of each entry in the jump table.
1249unsigned 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.
1269unsigned 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(AS: 0).value();
1276 case MachineJumpTableInfo::EK_GPRel64BlockAddress:
1277 case MachineJumpTableInfo::EK_LabelDifference64:
1278 return TD.getABIIntegerTypeAlignment(BitWidth: 64).value();
1279 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1280 case MachineJumpTableInfo::EK_LabelDifference32:
1281 case MachineJumpTableInfo::EK_Custom32:
1282 return TD.getABIIntegerTypeAlignment(BitWidth: 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.
1290unsigned MachineJumpTableInfo::createJumpTableIndex(
1291 const std::vector<MachineBasicBlock*> &DestBBs) {
1292 assert(!DestBBs.empty() && "Cannot create an empty jump table!");
1293 JumpTables.push_back(x: 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.
1299bool 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(Idx: i, Old, New);
1305 return MadeChange;
1306}
1307
1308/// If MBB is present in any jump tables, remove it.
1309bool MachineJumpTableInfo::RemoveMBBFromJumpTables(MachineBasicBlock *MBB) {
1310 bool MadeChange = false;
1311 for (MachineJumpTableEntry &JTE : JumpTables) {
1312 auto removeBeginItr = std::remove(first: JTE.MBBs.begin(), last: JTE.MBBs.end(), value: MBB);
1313 MadeChange |= (removeBeginItr != JTE.MBBs.end());
1314 JTE.MBBs.erase(first: removeBeginItr, last: 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.
1321bool 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
1335void 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(Idx: i) << ':';
1342 for (const MachineBasicBlock *MBB : JumpTables[i].MBBs)
1343 OS << ' ' << printMBBReference(MBB: *MBB);
1344 if (i != e)
1345 OS << '\n';
1346 }
1347
1348 OS << '\n';
1349}
1350
1351#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1352LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(OS&: dbgs()); }
1353#endif
1354
1355Printable llvm::printJumpTableEntryReference(unsigned Idx) {
1356 return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; });
1357}
1358
1359//===----------------------------------------------------------------------===//
1360// MachineConstantPool implementation
1361//===----------------------------------------------------------------------===//
1362
1363void MachineConstantPoolValue::anchor() {}
1364
1365unsigned MachineConstantPoolValue::getSizeInBytes(const DataLayout &DL) const {
1366 return DL.getTypeAllocSize(Ty);
1367}
1368
1369unsigned MachineConstantPoolEntry::getSizeInBytes(const DataLayout &DL) const {
1370 if (isMachineConstantPoolEntry())
1371 return Val.MachineCPVal->getSizeInBytes(DL);
1372 return DL.getTypeAllocSize(Ty: Val.ConstVal->getType());
1373}
1374
1375bool MachineConstantPoolEntry::needsRelocation() const {
1376 if (isMachineConstantPoolEntry())
1377 return true;
1378 return Val.ConstVal->needsDynamicRelocation();
1379}
1380
1381SectionKind
1382MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
1383 if (needsRelocation())
1384 return SectionKind::getReadOnlyWithRel();
1385 switch (getSizeInBytes(DL: *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
1399MachineConstantPool::~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(V: C.Val.MachineCPVal);
1406 delete C.Val.MachineCPVal;
1407 }
1408 for (MachineConstantPoolValue *CPV : MachineCPVsSharingEntries) {
1409 if (Deleted.count(V: 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.
1416static 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>(Val: A->getType()) || isa<ArrayType>(Val: A->getType()) ||
1427 isa<StructType>(Val: B->getType()) || isa<ArrayType>(Val: B->getType()))
1428 return false;
1429
1430 // For now, only support constants with the same size.
1431 uint64_t StoreSize = DL.getTypeStoreSize(Ty: A->getType());
1432 if (StoreSize != DL.getTypeStoreSize(Ty: B->getType()) || StoreSize > 128)
1433 return false;
1434
1435 bool ContainsUndefOrPoisonA = A->containsUndefOrPoisonElement();
1436
1437 Type *IntTy = IntegerType::get(C&: A->getContext(), NumBits: 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>(Val: A->getType()))
1444 A = ConstantFoldCastOperand(Opcode: Instruction::PtrToInt,
1445 C: const_cast<Constant *>(A), DestTy: IntTy, DL);
1446 else if (A->getType() != IntTy)
1447 A = ConstantFoldCastOperand(Opcode: Instruction::BitCast, C: const_cast<Constant *>(A),
1448 DestTy: IntTy, DL);
1449 if (isa<PointerType>(Val: B->getType()))
1450 B = ConstantFoldCastOperand(Opcode: Instruction::PtrToInt,
1451 C: const_cast<Constant *>(B), DestTy: IntTy, DL);
1452 else if (B->getType() != IntTy)
1453 B = ConstantFoldCastOperand(Opcode: Instruction::BitCast, C: const_cast<Constant *>(B),
1454 DestTy: 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.
1468unsigned 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(A: Constants[i].Val.ConstVal, B: C, DL)) {
1478 if (Constants[i].getAlign() < Alignment)
1479 Constants[i].Alignment = Alignment;
1480 return i;
1481 }
1482
1483 Constants.push_back(x: MachineConstantPoolEntry(C, Alignment));
1484 return Constants.size()-1;
1485}
1486
1487unsigned 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(CP: this, Alignment);
1495 if (Idx != -1) {
1496 MachineCPVsSharingEntries.insert(V);
1497 return (unsigned)Idx;
1498 }
1499
1500 Constants.push_back(x: MachineConstantPoolEntry(V, Alignment));
1501 return Constants.size()-1;
1502}
1503
1504void 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(O&: OS);
1512 else
1513 Constants[i].Val.ConstVal->printAsOperand(O&: 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//===----------------------------------------------------------------------===//
1523template <>
1524std::optional<Function::ProfileCount>
1525ProfileSummaryInfo::getEntryCount<llvm::MachineFunction>(
1526 const llvm::MachineFunction *F) const {
1527 return F->getFunction().getEntryCount();
1528}
1529
1530#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1531LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(OS&: dbgs()); }
1532#endif
1533

source code of llvm/lib/CodeGen/MachineFunction.cpp