1 //===-- MachineVerifier.cpp - Machine Code Verifier -----------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Pass to verify generated machine code. The following is checked:
12 // Operand counts: All explicit operands must be present.
14 // Register classes: All physical and virtual register operands must be
15 // compatible with the register class required by the instruction descriptor.
17 // Register live intervals: Registers must be defined only once, and must be
18 // defined before use.
20 // The machine code verifier is enabled from LLVMTargetMachine.cpp with the
21 // command-line option -verify-machineinstrs, or by defining the environment
22 // variable LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive
23 // the verifier errors.
24 //===----------------------------------------------------------------------===//
26 #include "llvm/CodeGen/Passes.h"
27 #include "llvm/ADT/DenseSet.h"
28 #include "llvm/ADT/DepthFirstIterator.h"
29 #include "llvm/ADT/SetOperations.h"
30 #include "llvm/ADT/SmallVector.h"
31 #include "llvm/Analysis/EHPersonalities.h"
32 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
33 #include "llvm/CodeGen/LiveStackAnalysis.h"
34 #include "llvm/CodeGen/LiveVariables.h"
35 #include "llvm/CodeGen/MachineFrameInfo.h"
36 #include "llvm/CodeGen/MachineFunctionPass.h"
37 #include "llvm/CodeGen/MachineMemOperand.h"
38 #include "llvm/CodeGen/MachineRegisterInfo.h"
39 #include "llvm/IR/BasicBlock.h"
40 #include "llvm/IR/InlineAsm.h"
41 #include "llvm/IR/Instructions.h"
42 #include "llvm/MC/MCAsmInfo.h"
43 #include "llvm/Support/Debug.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/FileSystem.h"
46 #include "llvm/Support/raw_ostream.h"
47 #include "llvm/Target/TargetInstrInfo.h"
48 #include "llvm/Target/TargetMachine.h"
49 #include "llvm/Target/TargetRegisterInfo.h"
50 #include "llvm/Target/TargetSubtargetInfo.h"
54 struct MachineVerifier {
56 MachineVerifier(Pass *pass, const char *b) :
61 unsigned verify(MachineFunction &MF);
65 const MachineFunction *MF;
66 const TargetMachine *TM;
67 const TargetInstrInfo *TII;
68 const TargetRegisterInfo *TRI;
69 const MachineRegisterInfo *MRI;
73 // Avoid querying the MachineFunctionProperties for each operand.
74 bool isFunctionRegBankSelected;
75 bool isFunctionSelected;
77 typedef SmallVector<unsigned, 16> RegVector;
78 typedef SmallVector<const uint32_t*, 4> RegMaskVector;
79 typedef DenseSet<unsigned> RegSet;
80 typedef DenseMap<unsigned, const MachineInstr*> RegMap;
81 typedef SmallPtrSet<const MachineBasicBlock*, 8> BlockSet;
83 const MachineInstr *FirstTerminator;
84 BlockSet FunctionBlocks;
86 BitVector regsReserved;
88 RegVector regsDefined, regsDead, regsKilled;
89 RegMaskVector regMasks;
90 RegSet regsLiveInButUnused;
94 // Add Reg and any sub-registers to RV
95 void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
97 if (TargetRegisterInfo::isPhysicalRegister(Reg))
98 for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
99 RV.push_back(*SubRegs);
103 // Is this MBB reachable from the MF entry point?
106 // Vregs that must be live in because they are used without being
107 // defined. Map value is the user.
110 // Regs killed in MBB. They may be defined again, and will then be in both
111 // regsKilled and regsLiveOut.
114 // Regs defined in MBB and live out. Note that vregs passing through may
115 // be live out without being mentioned here.
118 // Vregs that pass through MBB untouched. This set is disjoint from
119 // regsKilled and regsLiveOut.
122 // Vregs that must pass through MBB because they are needed by a successor
123 // block. This set is disjoint from regsLiveOut.
124 RegSet vregsRequired;
126 // Set versions of block's predecessor and successor lists.
127 BlockSet Preds, Succs;
129 BBInfo() : reachable(false) {}
131 // Add register to vregsPassed if it belongs there. Return true if
133 bool addPassed(unsigned Reg) {
134 if (!TargetRegisterInfo::isVirtualRegister(Reg))
136 if (regsKilled.count(Reg) || regsLiveOut.count(Reg))
138 return vregsPassed.insert(Reg).second;
141 // Same for a full set.
142 bool addPassed(const RegSet &RS) {
143 bool changed = false;
144 for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
150 // Add register to vregsRequired if it belongs there. Return true if
152 bool addRequired(unsigned Reg) {
153 if (!TargetRegisterInfo::isVirtualRegister(Reg))
155 if (regsLiveOut.count(Reg))
157 return vregsRequired.insert(Reg).second;
160 // Same for a full set.
161 bool addRequired(const RegSet &RS) {
162 bool changed = false;
163 for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
169 // Same for a full map.
170 bool addRequired(const RegMap &RM) {
171 bool changed = false;
172 for (RegMap::const_iterator I = RM.begin(), E = RM.end(); I != E; ++I)
173 if (addRequired(I->first))
178 // Live-out registers are either in regsLiveOut or vregsPassed.
179 bool isLiveOut(unsigned Reg) const {
180 return regsLiveOut.count(Reg) || vregsPassed.count(Reg);
184 // Extra register info per MBB.
185 DenseMap<const MachineBasicBlock*, BBInfo> MBBInfoMap;
187 bool isReserved(unsigned Reg) {
188 return Reg < regsReserved.size() && regsReserved.test(Reg);
191 bool isAllocatable(unsigned Reg) {
192 return Reg < TRI->getNumRegs() && MRI->isAllocatable(Reg);
195 // Analysis information if available
196 LiveVariables *LiveVars;
197 LiveIntervals *LiveInts;
198 LiveStacks *LiveStks;
199 SlotIndexes *Indexes;
201 void visitMachineFunctionBefore();
202 void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
203 void visitMachineBundleBefore(const MachineInstr *MI);
204 void visitMachineInstrBefore(const MachineInstr *MI);
205 void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
206 void visitMachineInstrAfter(const MachineInstr *MI);
207 void visitMachineBundleAfter(const MachineInstr *MI);
208 void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB);
209 void visitMachineFunctionAfter();
211 void report(const char *msg, const MachineFunction *MF);
212 void report(const char *msg, const MachineBasicBlock *MBB);
213 void report(const char *msg, const MachineInstr *MI);
214 void report(const char *msg, const MachineOperand *MO, unsigned MONum);
216 void report_context(const LiveInterval &LI) const;
217 void report_context(const LiveRange &LR, unsigned VRegUnit,
218 LaneBitmask LaneMask) const;
219 void report_context(const LiveRange::Segment &S) const;
220 void report_context(const VNInfo &VNI) const;
221 void report_context(SlotIndex Pos) const;
222 void report_context_liverange(const LiveRange &LR) const;
223 void report_context_lanemask(LaneBitmask LaneMask) const;
224 void report_context_vreg(unsigned VReg) const;
225 void report_context_vreg_regunit(unsigned VRegOrRegUnit) const;
227 void verifyInlineAsm(const MachineInstr *MI);
229 void checkLiveness(const MachineOperand *MO, unsigned MONum);
230 void checkLivenessAtUse(const MachineOperand *MO, unsigned MONum,
231 SlotIndex UseIdx, const LiveRange &LR, unsigned Reg,
232 LaneBitmask LaneMask = LaneBitmask::getNone());
233 void checkLivenessAtDef(const MachineOperand *MO, unsigned MONum,
234 SlotIndex DefIdx, const LiveRange &LR, unsigned Reg,
235 LaneBitmask LaneMask = LaneBitmask::getNone());
237 void markReachable(const MachineBasicBlock *MBB);
238 void calcRegsPassed();
239 void checkPHIOps(const MachineBasicBlock *MBB);
241 void calcRegsRequired();
242 void verifyLiveVariables();
243 void verifyLiveIntervals();
244 void verifyLiveInterval(const LiveInterval&);
245 void verifyLiveRangeValue(const LiveRange&, const VNInfo*, unsigned,
247 void verifyLiveRangeSegment(const LiveRange&,
248 const LiveRange::const_iterator I, unsigned,
250 void verifyLiveRange(const LiveRange&, unsigned,
251 LaneBitmask LaneMask = LaneBitmask::getNone());
253 void verifyStackFrame();
255 void verifySlotIndexes() const;
256 void verifyProperties(const MachineFunction &MF);
259 struct MachineVerifierPass : public MachineFunctionPass {
260 static char ID; // Pass ID, replacement for typeid
261 const std::string Banner;
263 MachineVerifierPass(std::string banner = std::string())
264 : MachineFunctionPass(ID), Banner(std::move(banner)) {
265 initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
268 void getAnalysisUsage(AnalysisUsage &AU) const override {
269 AU.setPreservesAll();
270 MachineFunctionPass::getAnalysisUsage(AU);
273 bool runOnMachineFunction(MachineFunction &MF) override {
274 unsigned FoundErrors = MachineVerifier(this, Banner.c_str()).verify(MF);
276 report_fatal_error("Found "+Twine(FoundErrors)+" machine code errors.");
283 char MachineVerifierPass::ID = 0;
284 INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
285 "Verify generated machine code", false, false)
287 FunctionPass *llvm::createMachineVerifierPass(const std::string &Banner) {
288 return new MachineVerifierPass(Banner);
291 bool MachineFunction::verify(Pass *p, const char *Banner, bool AbortOnErrors)
293 MachineFunction &MF = const_cast<MachineFunction&>(*this);
294 unsigned FoundErrors = MachineVerifier(p, Banner).verify(MF);
295 if (AbortOnErrors && FoundErrors)
296 report_fatal_error("Found "+Twine(FoundErrors)+" machine code errors.");
297 return FoundErrors == 0;
300 void MachineVerifier::verifySlotIndexes() const {
301 if (Indexes == nullptr)
304 // Ensure the IdxMBB list is sorted by slot indexes.
306 for (SlotIndexes::MBBIndexIterator I = Indexes->MBBIndexBegin(),
307 E = Indexes->MBBIndexEnd(); I != E; ++I) {
308 assert(!Last.isValid() || I->first > Last);
313 void MachineVerifier::verifyProperties(const MachineFunction &MF) {
314 // If a pass has introduced virtual registers without clearing the
315 // NoVRegs property (or set it without allocating the vregs)
316 // then report an error.
317 if (MF.getProperties().hasProperty(
318 MachineFunctionProperties::Property::NoVRegs) &&
319 MRI->getNumVirtRegs())
320 report("Function has NoVRegs property but there are VReg operands", &MF);
323 unsigned MachineVerifier::verify(MachineFunction &MF) {
327 TM = &MF.getTarget();
328 TII = MF.getSubtarget().getInstrInfo();
329 TRI = MF.getSubtarget().getRegisterInfo();
330 MRI = &MF.getRegInfo();
332 isFunctionRegBankSelected = MF.getProperties().hasProperty(
333 MachineFunctionProperties::Property::RegBankSelected);
334 isFunctionSelected = MF.getProperties().hasProperty(
335 MachineFunctionProperties::Property::Selected);
342 LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>();
343 // We don't want to verify LiveVariables if LiveIntervals is available.
345 LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
346 LiveStks = PASS->getAnalysisIfAvailable<LiveStacks>();
347 Indexes = PASS->getAnalysisIfAvailable<SlotIndexes>();
352 verifyProperties(MF);
354 visitMachineFunctionBefore();
355 for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
357 visitMachineBasicBlockBefore(&*MFI);
358 // Keep track of the current bundle header.
359 const MachineInstr *CurBundle = nullptr;
360 // Do we expect the next instruction to be part of the same bundle?
361 bool InBundle = false;
363 for (MachineBasicBlock::const_instr_iterator MBBI = MFI->instr_begin(),
364 MBBE = MFI->instr_end(); MBBI != MBBE; ++MBBI) {
365 if (MBBI->getParent() != &*MFI) {
366 report("Bad instruction parent pointer", &*MFI);
367 errs() << "Instruction: " << *MBBI;
371 // Check for consistent bundle flags.
372 if (InBundle && !MBBI->isBundledWithPred())
373 report("Missing BundledPred flag, "
374 "BundledSucc was set on predecessor",
376 if (!InBundle && MBBI->isBundledWithPred())
377 report("BundledPred flag is set, "
378 "but BundledSucc not set on predecessor",
381 // Is this a bundle header?
382 if (!MBBI->isInsideBundle()) {
384 visitMachineBundleAfter(CurBundle);
386 visitMachineBundleBefore(CurBundle);
387 } else if (!CurBundle)
388 report("No bundle header", &*MBBI);
389 visitMachineInstrBefore(&*MBBI);
390 for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I) {
391 const MachineInstr &MI = *MBBI;
392 const MachineOperand &Op = MI.getOperand(I);
393 if (Op.getParent() != &MI) {
394 // Make sure to use correct addOperand / RemoveOperand / ChangeTo
395 // functions when replacing operands of a MachineInstr.
396 report("Instruction has operand with wrong parent set", &MI);
399 visitMachineOperand(&Op, I);
402 visitMachineInstrAfter(&*MBBI);
404 // Was this the last bundled instruction?
405 InBundle = MBBI->isBundledWithSucc();
408 visitMachineBundleAfter(CurBundle);
410 report("BundledSucc flag set on last instruction in block", &MFI->back());
411 visitMachineBasicBlockAfter(&*MFI);
413 visitMachineFunctionAfter();
421 regsLiveInButUnused.clear();
427 void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
430 if (!foundErrors++) {
432 errs() << "# " << Banner << '\n';
433 if (LiveInts != nullptr)
434 LiveInts->print(errs());
436 MF->print(errs(), Indexes);
438 errs() << "*** Bad machine code: " << msg << " ***\n"
439 << "- function: " << MF->getName() << "\n";
442 void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
444 report(msg, MBB->getParent());
445 errs() << "- basic block: BB#" << MBB->getNumber()
446 << ' ' << MBB->getName()
447 << " (" << (const void*)MBB << ')';
449 errs() << " [" << Indexes->getMBBStartIdx(MBB)
450 << ';' << Indexes->getMBBEndIdx(MBB) << ')';
454 void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
456 report(msg, MI->getParent());
457 errs() << "- instruction: ";
458 if (Indexes && Indexes->hasIndex(*MI))
459 errs() << Indexes->getInstructionIndex(*MI) << '\t';
460 MI->print(errs(), /*SkipOpers=*/true);
464 void MachineVerifier::report(const char *msg,
465 const MachineOperand *MO, unsigned MONum) {
467 report(msg, MO->getParent());
468 errs() << "- operand " << MONum << ": ";
469 MO->print(errs(), TRI);
473 void MachineVerifier::report_context(SlotIndex Pos) const {
474 errs() << "- at: " << Pos << '\n';
477 void MachineVerifier::report_context(const LiveInterval &LI) const {
478 errs() << "- interval: " << LI << '\n';
481 void MachineVerifier::report_context(const LiveRange &LR, unsigned VRegUnit,
482 LaneBitmask LaneMask) const {
483 report_context_liverange(LR);
484 report_context_vreg_regunit(VRegUnit);
486 report_context_lanemask(LaneMask);
489 void MachineVerifier::report_context(const LiveRange::Segment &S) const {
490 errs() << "- segment: " << S << '\n';
493 void MachineVerifier::report_context(const VNInfo &VNI) const {
494 errs() << "- ValNo: " << VNI.id << " (def " << VNI.def << ")\n";
497 void MachineVerifier::report_context_liverange(const LiveRange &LR) const {
498 errs() << "- liverange: " << LR << '\n';
501 void MachineVerifier::report_context_vreg(unsigned VReg) const {
502 errs() << "- v. register: " << PrintReg(VReg, TRI) << '\n';
505 void MachineVerifier::report_context_vreg_regunit(unsigned VRegOrUnit) const {
506 if (TargetRegisterInfo::isVirtualRegister(VRegOrUnit)) {
507 report_context_vreg(VRegOrUnit);
509 errs() << "- regunit: " << PrintRegUnit(VRegOrUnit, TRI) << '\n';
513 void MachineVerifier::report_context_lanemask(LaneBitmask LaneMask) const {
514 errs() << "- lanemask: " << PrintLaneMask(LaneMask) << '\n';
517 void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
518 BBInfo &MInfo = MBBInfoMap[MBB];
519 if (!MInfo.reachable) {
520 MInfo.reachable = true;
521 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
522 SuE = MBB->succ_end(); SuI != SuE; ++SuI)
527 void MachineVerifier::visitMachineFunctionBefore() {
528 lastIndex = SlotIndex();
529 regsReserved = MRI->getReservedRegs();
532 markReachable(&MF->front());
534 // Build a set of the basic blocks in the function.
535 FunctionBlocks.clear();
536 for (const auto &MBB : *MF) {
537 FunctionBlocks.insert(&MBB);
538 BBInfo &MInfo = MBBInfoMap[&MBB];
540 MInfo.Preds.insert(MBB.pred_begin(), MBB.pred_end());
541 if (MInfo.Preds.size() != MBB.pred_size())
542 report("MBB has duplicate entries in its predecessor list.", &MBB);
544 MInfo.Succs.insert(MBB.succ_begin(), MBB.succ_end());
545 if (MInfo.Succs.size() != MBB.succ_size())
546 report("MBB has duplicate entries in its successor list.", &MBB);
549 // Check that the register use lists are sane.
550 MRI->verifyUseLists();
556 // Does iterator point to a and b as the first two elements?
557 static bool matchPair(MachineBasicBlock::const_succ_iterator i,
558 const MachineBasicBlock *a, const MachineBasicBlock *b) {
567 MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
568 FirstTerminator = nullptr;
570 if (!MF->getProperties().hasProperty(
571 MachineFunctionProperties::Property::NoPHIs) && MRI->tracksLiveness()) {
572 // If this block has allocatable physical registers live-in, check that
573 // it is an entry block or landing pad.
574 for (const auto &LI : MBB->liveins()) {
575 if (isAllocatable(LI.PhysReg) && !MBB->isEHPad() &&
576 MBB->getIterator() != MBB->getParent()->begin()) {
577 report("MBB has allocatable live-in, but isn't entry or landing-pad.", MBB);
582 // Count the number of landing pad successors.
583 SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs;
584 for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
585 E = MBB->succ_end(); I != E; ++I) {
587 LandingPadSuccs.insert(*I);
588 if (!FunctionBlocks.count(*I))
589 report("MBB has successor that isn't part of the function.", MBB);
590 if (!MBBInfoMap[*I].Preds.count(MBB)) {
591 report("Inconsistent CFG", MBB);
592 errs() << "MBB is not in the predecessor list of the successor BB#"
593 << (*I)->getNumber() << ".\n";
597 // Check the predecessor list.
598 for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(),
599 E = MBB->pred_end(); I != E; ++I) {
600 if (!FunctionBlocks.count(*I))
601 report("MBB has predecessor that isn't part of the function.", MBB);
602 if (!MBBInfoMap[*I].Succs.count(MBB)) {
603 report("Inconsistent CFG", MBB);
604 errs() << "MBB is not in the successor list of the predecessor BB#"
605 << (*I)->getNumber() << ".\n";
609 const MCAsmInfo *AsmInfo = TM->getMCAsmInfo();
610 const BasicBlock *BB = MBB->getBasicBlock();
611 const Function *Fn = MF->getFunction();
612 if (LandingPadSuccs.size() > 1 &&
614 AsmInfo->getExceptionHandlingType() == ExceptionHandling::SjLj &&
615 BB && isa<SwitchInst>(BB->getTerminator())) &&
616 !isFuncletEHPersonality(classifyEHPersonality(Fn->getPersonalityFn())))
617 report("MBB has more than one landing pad successor", MBB);
619 // Call AnalyzeBranch. If it succeeds, there several more conditions to check.
620 MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
621 SmallVector<MachineOperand, 4> Cond;
622 if (!TII->analyzeBranch(*const_cast<MachineBasicBlock *>(MBB), TBB, FBB,
624 // Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's
625 // check whether its answers match up with reality.
627 // Block falls through to its successor.
628 MachineFunction::const_iterator MBBI = MBB->getIterator();
630 if (MBBI == MF->end()) {
631 // It's possible that the block legitimately ends with a noreturn
632 // call or an unreachable, in which case it won't actually fall
633 // out the bottom of the function.
634 } else if (MBB->succ_size() == LandingPadSuccs.size()) {
635 // It's possible that the block legitimately ends with a noreturn
636 // call or an unreachable, in which case it won't actuall fall
638 } else if (MBB->succ_size() != 1+LandingPadSuccs.size()) {
639 report("MBB exits via unconditional fall-through but doesn't have "
640 "exactly one CFG successor!", MBB);
641 } else if (!MBB->isSuccessor(&*MBBI)) {
642 report("MBB exits via unconditional fall-through but its successor "
643 "differs from its CFG successor!", MBB);
645 if (!MBB->empty() && MBB->back().isBarrier() &&
646 !TII->isPredicated(MBB->back())) {
647 report("MBB exits via unconditional fall-through but ends with a "
648 "barrier instruction!", MBB);
651 report("MBB exits via unconditional fall-through but has a condition!",
654 } else if (TBB && !FBB && Cond.empty()) {
655 // Block unconditionally branches somewhere.
656 // If the block has exactly one successor, that happens to be a
657 // landingpad, accept it as valid control flow.
658 if (MBB->succ_size() != 1+LandingPadSuccs.size() &&
659 (MBB->succ_size() != 1 || LandingPadSuccs.size() != 1 ||
660 *MBB->succ_begin() != *LandingPadSuccs.begin())) {
661 report("MBB exits via unconditional branch but doesn't have "
662 "exactly one CFG successor!", MBB);
663 } else if (!MBB->isSuccessor(TBB)) {
664 report("MBB exits via unconditional branch but the CFG "
665 "successor doesn't match the actual successor!", MBB);
668 report("MBB exits via unconditional branch but doesn't contain "
669 "any instructions!", MBB);
670 } else if (!MBB->back().isBarrier()) {
671 report("MBB exits via unconditional branch but doesn't end with a "
672 "barrier instruction!", MBB);
673 } else if (!MBB->back().isTerminator()) {
674 report("MBB exits via unconditional branch but the branch isn't a "
675 "terminator instruction!", MBB);
677 } else if (TBB && !FBB && !Cond.empty()) {
678 // Block conditionally branches somewhere, otherwise falls through.
679 MachineFunction::const_iterator MBBI = MBB->getIterator();
681 if (MBBI == MF->end()) {
682 report("MBB conditionally falls through out of function!", MBB);
683 } else if (MBB->succ_size() == 1) {
684 // A conditional branch with only one successor is weird, but allowed.
686 report("MBB exits via conditional branch/fall-through but only has "
687 "one CFG successor!", MBB);
688 else if (TBB != *MBB->succ_begin())
689 report("MBB exits via conditional branch/fall-through but the CFG "
690 "successor don't match the actual successor!", MBB);
691 } else if (MBB->succ_size() != 2) {
692 report("MBB exits via conditional branch/fall-through but doesn't have "
693 "exactly two CFG successors!", MBB);
694 } else if (!matchPair(MBB->succ_begin(), TBB, &*MBBI)) {
695 report("MBB exits via conditional branch/fall-through but the CFG "
696 "successors don't match the actual successors!", MBB);
699 report("MBB exits via conditional branch/fall-through but doesn't "
700 "contain any instructions!", MBB);
701 } else if (MBB->back().isBarrier()) {
702 report("MBB exits via conditional branch/fall-through but ends with a "
703 "barrier instruction!", MBB);
704 } else if (!MBB->back().isTerminator()) {
705 report("MBB exits via conditional branch/fall-through but the branch "
706 "isn't a terminator instruction!", MBB);
708 } else if (TBB && FBB) {
709 // Block conditionally branches somewhere, otherwise branches
711 if (MBB->succ_size() == 1) {
712 // A conditional branch with only one successor is weird, but allowed.
714 report("MBB exits via conditional branch/branch through but only has "
715 "one CFG successor!", MBB);
716 else if (TBB != *MBB->succ_begin())
717 report("MBB exits via conditional branch/branch through but the CFG "
718 "successor don't match the actual successor!", MBB);
719 } else if (MBB->succ_size() != 2) {
720 report("MBB exits via conditional branch/branch but doesn't have "
721 "exactly two CFG successors!", MBB);
722 } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) {
723 report("MBB exits via conditional branch/branch but the CFG "
724 "successors don't match the actual successors!", MBB);
727 report("MBB exits via conditional branch/branch but doesn't "
728 "contain any instructions!", MBB);
729 } else if (!MBB->back().isBarrier()) {
730 report("MBB exits via conditional branch/branch but doesn't end with a "
731 "barrier instruction!", MBB);
732 } else if (!MBB->back().isTerminator()) {
733 report("MBB exits via conditional branch/branch but the branch "
734 "isn't a terminator instruction!", MBB);
737 report("MBB exits via conditinal branch/branch but there's no "
741 report("AnalyzeBranch returned invalid data!", MBB);
746 if (MRI->tracksLiveness()) {
747 for (const auto &LI : MBB->liveins()) {
748 if (!TargetRegisterInfo::isPhysicalRegister(LI.PhysReg)) {
749 report("MBB live-in list contains non-physical register", MBB);
752 for (MCSubRegIterator SubRegs(LI.PhysReg, TRI, /*IncludeSelf=*/true);
753 SubRegs.isValid(); ++SubRegs)
754 regsLive.insert(*SubRegs);
757 regsLiveInButUnused = regsLive;
759 const MachineFrameInfo &MFI = MF->getFrameInfo();
760 BitVector PR = MFI.getPristineRegs(*MF);
761 for (int I = PR.find_first(); I>0; I = PR.find_next(I)) {
762 for (MCSubRegIterator SubRegs(I, TRI, /*IncludeSelf=*/true);
763 SubRegs.isValid(); ++SubRegs)
764 regsLive.insert(*SubRegs);
771 lastIndex = Indexes->getMBBStartIdx(MBB);
774 // This function gets called for all bundle headers, including normal
775 // stand-alone unbundled instructions.
776 void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
777 if (Indexes && Indexes->hasIndex(*MI)) {
778 SlotIndex idx = Indexes->getInstructionIndex(*MI);
779 if (!(idx > lastIndex)) {
780 report("Instruction index out of order", MI);
781 errs() << "Last instruction was at " << lastIndex << '\n';
786 // Ensure non-terminators don't follow terminators.
787 // Ignore predicated terminators formed by if conversion.
788 // FIXME: If conversion shouldn't need to violate this rule.
789 if (MI->isTerminator() && !TII->isPredicated(*MI)) {
790 if (!FirstTerminator)
791 FirstTerminator = MI;
792 } else if (FirstTerminator) {
793 report("Non-terminator instruction after the first terminator", MI);
794 errs() << "First terminator was:\t" << *FirstTerminator;
798 // The operands on an INLINEASM instruction must follow a template.
799 // Verify that the flag operands make sense.
800 void MachineVerifier::verifyInlineAsm(const MachineInstr *MI) {
801 // The first two operands on INLINEASM are the asm string and global flags.
802 if (MI->getNumOperands() < 2) {
803 report("Too few operands on inline asm", MI);
806 if (!MI->getOperand(0).isSymbol())
807 report("Asm string must be an external symbol", MI);
808 if (!MI->getOperand(1).isImm())
809 report("Asm flags must be an immediate", MI);
810 // Allowed flags are Extra_HasSideEffects = 1, Extra_IsAlignStack = 2,
811 // Extra_AsmDialect = 4, Extra_MayLoad = 8, and Extra_MayStore = 16,
812 // and Extra_IsConvergent = 32.
813 if (!isUInt<6>(MI->getOperand(1).getImm()))
814 report("Unknown asm flags", &MI->getOperand(1), 1);
816 static_assert(InlineAsm::MIOp_FirstOperand == 2, "Asm format changed");
818 unsigned OpNo = InlineAsm::MIOp_FirstOperand;
820 for (unsigned e = MI->getNumOperands(); OpNo < e; OpNo += NumOps) {
821 const MachineOperand &MO = MI->getOperand(OpNo);
822 // There may be implicit ops after the fixed operands.
825 NumOps = 1 + InlineAsm::getNumOperandRegisters(MO.getImm());
828 if (OpNo > MI->getNumOperands())
829 report("Missing operands in last group", MI);
831 // An optional MDNode follows the groups.
832 if (OpNo < MI->getNumOperands() && MI->getOperand(OpNo).isMetadata())
835 // All trailing operands must be implicit registers.
836 for (unsigned e = MI->getNumOperands(); OpNo < e; ++OpNo) {
837 const MachineOperand &MO = MI->getOperand(OpNo);
838 if (!MO.isReg() || !MO.isImplicit())
839 report("Expected implicit register after groups", &MO, OpNo);
843 void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
844 const MCInstrDesc &MCID = MI->getDesc();
845 if (MI->getNumOperands() < MCID.getNumOperands()) {
846 report("Too few operands", MI);
847 errs() << MCID.getNumOperands() << " operands expected, but "
848 << MI->getNumOperands() << " given.\n";
851 if (MI->isPHI() && MF->getProperties().hasProperty(
852 MachineFunctionProperties::Property::NoPHIs))
853 report("Found PHI instruction with NoPHIs property set", MI);
855 // Check the tied operands.
856 if (MI->isInlineAsm())
859 // Check the MachineMemOperands for basic consistency.
860 for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
861 E = MI->memoperands_end(); I != E; ++I) {
862 if ((*I)->isLoad() && !MI->mayLoad())
863 report("Missing mayLoad flag", MI);
864 if ((*I)->isStore() && !MI->mayStore())
865 report("Missing mayStore flag", MI);
868 // Debug values must not have a slot index.
869 // Other instructions must have one, unless they are inside a bundle.
871 bool mapped = !LiveInts->isNotInMIMap(*MI);
872 if (MI->isDebugValue()) {
874 report("Debug instruction has a slot index", MI);
875 } else if (MI->isInsideBundle()) {
877 report("Instruction inside bundle has a slot index", MI);
880 report("Missing slot index", MI);
885 if (isPreISelGenericOpcode(MCID.getOpcode())) {
886 if (isFunctionSelected)
887 report("Unexpected generic instruction in a Selected function", MI);
889 // Generic instructions specify equality constraints between some
890 // of their operands. Make sure these are consistent.
891 SmallVector<LLT, 4> Types;
892 for (unsigned i = 0; i < MCID.getNumOperands(); ++i) {
893 if (!MCID.OpInfo[i].isGenericType())
895 size_t TypeIdx = MCID.OpInfo[i].getGenericTypeIndex();
896 Types.resize(std::max(TypeIdx + 1, Types.size()));
898 LLT OpTy = MRI->getType(MI->getOperand(i).getReg());
899 if (Types[TypeIdx].isValid() && Types[TypeIdx] != OpTy)
900 report("type mismatch in generic instruction", MI);
901 Types[TypeIdx] = OpTy;
905 // Generic opcodes must not have physical register operands.
906 if (isPreISelGenericOpcode(MCID.getOpcode())) {
907 for (auto &Op : MI->operands()) {
908 if (Op.isReg() && TargetRegisterInfo::isPhysicalRegister(Op.getReg()))
909 report("Generic instruction cannot have physical register", MI);
913 // Generic loads and stores must have a single MachineMemOperand
914 // describing that access.
915 if ((MI->getOpcode() == TargetOpcode::G_LOAD ||
916 MI->getOpcode() == TargetOpcode::G_STORE) &&
917 !MI->hasOneMemOperand())
918 report("Generic instruction accessing memory must have one mem operand",
922 if (!TII->verifyInstruction(*MI, ErrorInfo))
923 report(ErrorInfo.data(), MI);
927 MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
928 const MachineInstr *MI = MO->getParent();
929 const MCInstrDesc &MCID = MI->getDesc();
930 unsigned NumDefs = MCID.getNumDefs();
931 if (MCID.getOpcode() == TargetOpcode::PATCHPOINT)
932 NumDefs = (MONum == 0 && MO->isReg()) ? NumDefs : 0;
934 // The first MCID.NumDefs operands must be explicit register defines
935 if (MONum < NumDefs) {
936 const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
938 report("Explicit definition must be a register", MO, MONum);
939 else if (!MO->isDef() && !MCOI.isOptionalDef())
940 report("Explicit definition marked as use", MO, MONum);
941 else if (MO->isImplicit())
942 report("Explicit definition marked as implicit", MO, MONum);
943 } else if (MONum < MCID.getNumOperands()) {
944 const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
945 // Don't check if it's the last operand in a variadic instruction. See,
946 // e.g., LDM_RET in the arm back end.
948 !(MI->isVariadic() && MONum == MCID.getNumOperands()-1)) {
949 if (MO->isDef() && !MCOI.isOptionalDef())
950 report("Explicit operand marked as def", MO, MONum);
951 if (MO->isImplicit())
952 report("Explicit operand marked as implicit", MO, MONum);
955 int TiedTo = MCID.getOperandConstraint(MONum, MCOI::TIED_TO);
958 report("Tied use must be a register", MO, MONum);
959 else if (!MO->isTied())
960 report("Operand should be tied", MO, MONum);
961 else if (unsigned(TiedTo) != MI->findTiedOperandIdx(MONum))
962 report("Tied def doesn't match MCInstrDesc", MO, MONum);
963 } else if (MO->isReg() && MO->isTied())
964 report("Explicit operand should not be tied", MO, MONum);
966 // ARM adds %reg0 operands to indicate predicates. We'll allow that.
967 if (MO->isReg() && !MO->isImplicit() && !MI->isVariadic() && MO->getReg())
968 report("Extra explicit operand on non-variadic instruction", MO, MONum);
971 switch (MO->getType()) {
972 case MachineOperand::MO_Register: {
973 const unsigned Reg = MO->getReg();
976 if (MRI->tracksLiveness() && !MI->isDebugValue())
977 checkLiveness(MO, MONum);
979 // Verify the consistency of tied operands.
981 unsigned OtherIdx = MI->findTiedOperandIdx(MONum);
982 const MachineOperand &OtherMO = MI->getOperand(OtherIdx);
983 if (!OtherMO.isReg())
984 report("Must be tied to a register", MO, MONum);
985 if (!OtherMO.isTied())
986 report("Missing tie flags on tied operand", MO, MONum);
987 if (MI->findTiedOperandIdx(OtherIdx) != MONum)
988 report("Inconsistent tie links", MO, MONum);
989 if (MONum < MCID.getNumDefs()) {
990 if (OtherIdx < MCID.getNumOperands()) {
991 if (-1 == MCID.getOperandConstraint(OtherIdx, MCOI::TIED_TO))
992 report("Explicit def tied to explicit use without tie constraint",
995 if (!OtherMO.isImplicit())
996 report("Explicit def should be tied to implicit use", MO, MONum);
1001 // Verify two-address constraints after leaving SSA form.
1003 if (!MRI->isSSA() && MO->isUse() &&
1004 MI->isRegTiedToDefOperand(MONum, &DefIdx) &&
1005 Reg != MI->getOperand(DefIdx).getReg())
1006 report("Two-address instruction operands must be identical", MO, MONum);
1008 // Check register classes.
1009 if (MONum < MCID.getNumOperands() && !MO->isImplicit()) {
1010 unsigned SubIdx = MO->getSubReg();
1012 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
1014 report("Illegal subregister index for physical register", MO, MONum);
1017 if (const TargetRegisterClass *DRC =
1018 TII->getRegClass(MCID, MONum, TRI, *MF)) {
1019 if (!DRC->contains(Reg)) {
1020 report("Illegal physical register for instruction", MO, MONum);
1021 errs() << TRI->getName(Reg) << " is not a "
1022 << TRI->getRegClassName(DRC) << " register.\n";
1026 // Virtual register.
1027 const TargetRegisterClass *RC = MRI->getRegClassOrNull(Reg);
1029 // This is a generic virtual register.
1031 // If we're post-Select, we can't have gvregs anymore.
1032 if (isFunctionSelected) {
1033 report("Generic virtual register invalid in a Selected function",
1038 // The gvreg must have a type and it must not have a SubIdx.
1039 LLT Ty = MRI->getType(Reg);
1040 if (!Ty.isValid()) {
1041 report("Generic virtual register must have a valid type", MO,
1046 const RegisterBank *RegBank = MRI->getRegBankOrNull(Reg);
1048 // If we're post-RegBankSelect, the gvreg must have a bank.
1049 if (!RegBank && isFunctionRegBankSelected) {
1050 report("Generic virtual register must have a bank in a "
1051 "RegBankSelected function",
1056 // Make sure the register fits into its register bank if any.
1057 if (RegBank && Ty.isValid() &&
1058 RegBank->getSize() < Ty.getSizeInBits()) {
1059 report("Register bank is too small for virtual register", MO,
1061 errs() << "Register bank " << RegBank->getName() << " too small("
1062 << RegBank->getSize() << ") to fit " << Ty.getSizeInBits()
1067 report("Generic virtual register does not subregister index", MO,
1072 // If this is a target specific instruction and this operand
1073 // has register class constraint, the virtual register must
1075 if (!isPreISelGenericOpcode(MCID.getOpcode()) &&
1076 TII->getRegClass(MCID, MONum, TRI, *MF)) {
1077 report("Virtual register does not match instruction constraint", MO,
1079 errs() << "Expect register class "
1080 << TRI->getRegClassName(
1081 TII->getRegClass(MCID, MONum, TRI, *MF))
1082 << " but got nothing\n";
1089 const TargetRegisterClass *SRC =
1090 TRI->getSubClassWithSubReg(RC, SubIdx);
1092 report("Invalid subregister index for virtual register", MO, MONum);
1093 errs() << "Register class " << TRI->getRegClassName(RC)
1094 << " does not support subreg index " << SubIdx << "\n";
1098 report("Invalid register class for subregister index", MO, MONum);
1099 errs() << "Register class " << TRI->getRegClassName(RC)
1100 << " does not fully support subreg index " << SubIdx << "\n";
1104 if (const TargetRegisterClass *DRC =
1105 TII->getRegClass(MCID, MONum, TRI, *MF)) {
1107 const TargetRegisterClass *SuperRC =
1108 TRI->getLargestLegalSuperClass(RC, *MF);
1110 report("No largest legal super class exists.", MO, MONum);
1113 DRC = TRI->getMatchingSuperRegClass(SuperRC, DRC, SubIdx);
1115 report("No matching super-reg register class.", MO, MONum);
1119 if (!RC->hasSuperClassEq(DRC)) {
1120 report("Illegal virtual register for instruction", MO, MONum);
1121 errs() << "Expected a " << TRI->getRegClassName(DRC)
1122 << " register, but got a " << TRI->getRegClassName(RC)
1131 case MachineOperand::MO_RegisterMask:
1132 regMasks.push_back(MO->getRegMask());
1135 case MachineOperand::MO_MachineBasicBlock:
1136 if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent()))
1137 report("PHI operand is not in the CFG", MO, MONum);
1140 case MachineOperand::MO_FrameIndex:
1141 if (LiveStks && LiveStks->hasInterval(MO->getIndex()) &&
1142 LiveInts && !LiveInts->isNotInMIMap(*MI)) {
1143 int FI = MO->getIndex();
1144 LiveInterval &LI = LiveStks->getInterval(FI);
1145 SlotIndex Idx = LiveInts->getInstructionIndex(*MI);
1147 bool stores = MI->mayStore();
1148 bool loads = MI->mayLoad();
1149 // For a memory-to-memory move, we need to check if the frame
1150 // index is used for storing or loading, by inspecting the
1152 if (stores && loads) {
1153 for (auto *MMO : MI->memoperands()) {
1154 const PseudoSourceValue *PSV = MMO->getPseudoValue();
1155 if (PSV == nullptr) continue;
1156 const FixedStackPseudoSourceValue *Value =
1157 dyn_cast<FixedStackPseudoSourceValue>(PSV);
1158 if (Value == nullptr) continue;
1159 if (Value->getFrameIndex() != FI) continue;
1167 if (loads == stores)
1168 report("Missing fixed stack memoperand.", MI);
1170 if (loads && !LI.liveAt(Idx.getRegSlot(true))) {
1171 report("Instruction loads from dead spill slot", MO, MONum);
1172 errs() << "Live stack: " << LI << '\n';
1174 if (stores && !LI.liveAt(Idx.getRegSlot())) {
1175 report("Instruction stores to dead spill slot", MO, MONum);
1176 errs() << "Live stack: " << LI << '\n';
1186 void MachineVerifier::checkLivenessAtUse(const MachineOperand *MO,
1187 unsigned MONum, SlotIndex UseIdx, const LiveRange &LR, unsigned VRegOrUnit,
1188 LaneBitmask LaneMask) {
1189 LiveQueryResult LRQ = LR.Query(UseIdx);
1190 // Check if we have a segment at the use, note however that we only need one
1191 // live subregister range, the others may be dead.
1192 if (!LRQ.valueIn() && LaneMask.none()) {
1193 report("No live segment at use", MO, MONum);
1194 report_context_liverange(LR);
1195 report_context_vreg_regunit(VRegOrUnit);
1196 report_context(UseIdx);
1198 if (MO->isKill() && !LRQ.isKill()) {
1199 report("Live range continues after kill flag", MO, MONum);
1200 report_context_liverange(LR);
1201 report_context_vreg_regunit(VRegOrUnit);
1203 report_context_lanemask(LaneMask);
1204 report_context(UseIdx);
1208 void MachineVerifier::checkLivenessAtDef(const MachineOperand *MO,
1209 unsigned MONum, SlotIndex DefIdx, const LiveRange &LR, unsigned VRegOrUnit,
1210 LaneBitmask LaneMask) {
1211 if (const VNInfo *VNI = LR.getVNInfoAt(DefIdx)) {
1212 assert(VNI && "NULL valno is not allowed");
1213 if (VNI->def != DefIdx) {
1214 report("Inconsistent valno->def", MO, MONum);
1215 report_context_liverange(LR);
1216 report_context_vreg_regunit(VRegOrUnit);
1218 report_context_lanemask(LaneMask);
1219 report_context(*VNI);
1220 report_context(DefIdx);
1223 report("No live segment at def", MO, MONum);
1224 report_context_liverange(LR);
1225 report_context_vreg_regunit(VRegOrUnit);
1227 report_context_lanemask(LaneMask);
1228 report_context(DefIdx);
1230 // Check that, if the dead def flag is present, LiveInts agree.
1232 LiveQueryResult LRQ = LR.Query(DefIdx);
1233 if (!LRQ.isDeadDef()) {
1234 // In case of physregs we can have a non-dead definition on another
1236 bool otherDef = false;
1237 if (!TargetRegisterInfo::isVirtualRegister(VRegOrUnit)) {
1238 const MachineInstr &MI = *MO->getParent();
1239 for (const MachineOperand &MO : MI.operands()) {
1240 if (!MO.isReg() || !MO.isDef() || MO.isDead())
1242 unsigned Reg = MO.getReg();
1243 for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
1244 if (*Units == VRegOrUnit) {
1253 report("Live range continues after dead def flag", MO, MONum);
1254 report_context_liverange(LR);
1255 report_context_vreg_regunit(VRegOrUnit);
1257 report_context_lanemask(LaneMask);
1263 void MachineVerifier::checkLiveness(const MachineOperand *MO, unsigned MONum) {
1264 const MachineInstr *MI = MO->getParent();
1265 const unsigned Reg = MO->getReg();
1267 // Both use and def operands can read a register.
1268 if (MO->readsReg()) {
1269 regsLiveInButUnused.erase(Reg);
1272 addRegWithSubRegs(regsKilled, Reg);
1274 // Check that LiveVars knows this kill.
1275 if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg) &&
1277 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
1278 if (!is_contained(VI.Kills, MI))
1279 report("Kill missing from LiveVariables", MO, MONum);
1282 // Check LiveInts liveness and kill.
1283 if (LiveInts && !LiveInts->isNotInMIMap(*MI)) {
1284 SlotIndex UseIdx = LiveInts->getInstructionIndex(*MI);
1285 // Check the cached regunit intervals.
1286 if (TargetRegisterInfo::isPhysicalRegister(Reg) && !isReserved(Reg)) {
1287 for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
1288 if (const LiveRange *LR = LiveInts->getCachedRegUnit(*Units))
1289 checkLivenessAtUse(MO, MONum, UseIdx, *LR, *Units);
1293 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1294 if (LiveInts->hasInterval(Reg)) {
1295 // This is a virtual register interval.
1296 const LiveInterval &LI = LiveInts->getInterval(Reg);
1297 checkLivenessAtUse(MO, MONum, UseIdx, LI, Reg);
1299 if (LI.hasSubRanges() && !MO->isDef()) {
1300 unsigned SubRegIdx = MO->getSubReg();
1301 LaneBitmask MOMask = SubRegIdx != 0
1302 ? TRI->getSubRegIndexLaneMask(SubRegIdx)
1303 : MRI->getMaxLaneMaskForVReg(Reg);
1304 LaneBitmask LiveInMask;
1305 for (const LiveInterval::SubRange &SR : LI.subranges()) {
1306 if ((MOMask & SR.LaneMask).none())
1308 checkLivenessAtUse(MO, MONum, UseIdx, SR, Reg, SR.LaneMask);
1309 LiveQueryResult LRQ = SR.Query(UseIdx);
1311 LiveInMask |= SR.LaneMask;
1313 // At least parts of the register has to be live at the use.
1314 if ((LiveInMask & MOMask).none()) {
1315 report("No live subrange at use", MO, MONum);
1317 report_context(UseIdx);
1321 report("Virtual register has no live interval", MO, MONum);
1326 // Use of a dead register.
1327 if (!regsLive.count(Reg)) {
1328 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
1329 // Reserved registers may be used even when 'dead'.
1330 bool Bad = !isReserved(Reg);
1331 // We are fine if just any subregister has a defined value.
1333 for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid();
1335 if (regsLive.count(*SubRegs)) {
1341 // If there is an additional implicit-use of a super register we stop
1342 // here. By definition we are fine if the super register is not
1343 // (completely) dead, if the complete super register is dead we will
1344 // get a report for its operand.
1346 for (const MachineOperand &MOP : MI->uses()) {
1349 if (!MOP.isImplicit())
1351 for (MCSubRegIterator SubRegs(MOP.getReg(), TRI); SubRegs.isValid();
1353 if (*SubRegs == Reg) {
1361 report("Using an undefined physical register", MO, MONum);
1362 } else if (MRI->def_empty(Reg)) {
1363 report("Reading virtual register without a def", MO, MONum);
1365 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
1366 // We don't know which virtual registers are live in, so only complain
1367 // if vreg was killed in this MBB. Otherwise keep track of vregs that
1368 // must be live in. PHI instructions are handled separately.
1369 if (MInfo.regsKilled.count(Reg))
1370 report("Using a killed virtual register", MO, MONum);
1371 else if (!MI->isPHI())
1372 MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI));
1378 // Register defined.
1379 // TODO: verify that earlyclobber ops are not used.
1381 addRegWithSubRegs(regsDead, Reg);
1383 addRegWithSubRegs(regsDefined, Reg);
1386 if (MRI->isSSA() && TargetRegisterInfo::isVirtualRegister(Reg) &&
1387 std::next(MRI->def_begin(Reg)) != MRI->def_end())
1388 report("Multiple virtual register defs in SSA form", MO, MONum);
1390 // Check LiveInts for a live segment, but only for virtual registers.
1391 if (LiveInts && !LiveInts->isNotInMIMap(*MI)) {
1392 SlotIndex DefIdx = LiveInts->getInstructionIndex(*MI);
1393 DefIdx = DefIdx.getRegSlot(MO->isEarlyClobber());
1395 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1396 if (LiveInts->hasInterval(Reg)) {
1397 const LiveInterval &LI = LiveInts->getInterval(Reg);
1398 checkLivenessAtDef(MO, MONum, DefIdx, LI, Reg);
1400 if (LI.hasSubRanges()) {
1401 unsigned SubRegIdx = MO->getSubReg();
1402 LaneBitmask MOMask = SubRegIdx != 0
1403 ? TRI->getSubRegIndexLaneMask(SubRegIdx)
1404 : MRI->getMaxLaneMaskForVReg(Reg);
1405 for (const LiveInterval::SubRange &SR : LI.subranges()) {
1406 if ((SR.LaneMask & MOMask).none())
1408 checkLivenessAtDef(MO, MONum, DefIdx, SR, Reg, SR.LaneMask);
1412 report("Virtual register has no Live interval", MO, MONum);
1419 void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
1422 // This function gets called after visiting all instructions in a bundle. The
1423 // argument points to the bundle header.
1424 // Normal stand-alone instructions are also considered 'bundles', and this
1425 // function is called for all of them.
1426 void MachineVerifier::visitMachineBundleAfter(const MachineInstr *MI) {
1427 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
1428 set_union(MInfo.regsKilled, regsKilled);
1429 set_subtract(regsLive, regsKilled); regsKilled.clear();
1430 // Kill any masked registers.
1431 while (!regMasks.empty()) {
1432 const uint32_t *Mask = regMasks.pop_back_val();
1433 for (RegSet::iterator I = regsLive.begin(), E = regsLive.end(); I != E; ++I)
1434 if (TargetRegisterInfo::isPhysicalRegister(*I) &&
1435 MachineOperand::clobbersPhysReg(Mask, *I))
1436 regsDead.push_back(*I);
1438 set_subtract(regsLive, regsDead); regsDead.clear();
1439 set_union(regsLive, regsDefined); regsDefined.clear();
1443 MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
1444 MBBInfoMap[MBB].regsLiveOut = regsLive;
1448 SlotIndex stop = Indexes->getMBBEndIdx(MBB);
1449 if (!(stop > lastIndex)) {
1450 report("Block ends before last instruction index", MBB);
1451 errs() << "Block ends at " << stop
1452 << " last instruction was at " << lastIndex << '\n';
1458 // Calculate the largest possible vregsPassed sets. These are the registers that
1459 // can pass through an MBB live, but may not be live every time. It is assumed
1460 // that all vregsPassed sets are empty before the call.
1461 void MachineVerifier::calcRegsPassed() {
1462 // First push live-out regs to successors' vregsPassed. Remember the MBBs that
1463 // have any vregsPassed.
1464 SmallPtrSet<const MachineBasicBlock*, 8> todo;
1465 for (const auto &MBB : *MF) {
1466 BBInfo &MInfo = MBBInfoMap[&MBB];
1467 if (!MInfo.reachable)
1469 for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
1470 SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
1471 BBInfo &SInfo = MBBInfoMap[*SuI];
1472 if (SInfo.addPassed(MInfo.regsLiveOut))
1477 // Iteratively push vregsPassed to successors. This will converge to the same
1478 // final state regardless of DenseSet iteration order.
1479 while (!todo.empty()) {
1480 const MachineBasicBlock *MBB = *todo.begin();
1482 BBInfo &MInfo = MBBInfoMap[MBB];
1483 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
1484 SuE = MBB->succ_end(); SuI != SuE; ++SuI) {
1487 BBInfo &SInfo = MBBInfoMap[*SuI];
1488 if (SInfo.addPassed(MInfo.vregsPassed))
1494 // Calculate the set of virtual registers that must be passed through each basic
1495 // block in order to satisfy the requirements of successor blocks. This is very
1496 // similar to calcRegsPassed, only backwards.
1497 void MachineVerifier::calcRegsRequired() {
1498 // First push live-in regs to predecessors' vregsRequired.
1499 SmallPtrSet<const MachineBasicBlock*, 8> todo;
1500 for (const auto &MBB : *MF) {
1501 BBInfo &MInfo = MBBInfoMap[&MBB];
1502 for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(),
1503 PrE = MBB.pred_end(); PrI != PrE; ++PrI) {
1504 BBInfo &PInfo = MBBInfoMap[*PrI];
1505 if (PInfo.addRequired(MInfo.vregsLiveIn))
1510 // Iteratively push vregsRequired to predecessors. This will converge to the
1511 // same final state regardless of DenseSet iteration order.
1512 while (!todo.empty()) {
1513 const MachineBasicBlock *MBB = *todo.begin();
1515 BBInfo &MInfo = MBBInfoMap[MBB];
1516 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
1517 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
1520 BBInfo &SInfo = MBBInfoMap[*PrI];
1521 if (SInfo.addRequired(MInfo.vregsRequired))
1527 // Check PHI instructions at the beginning of MBB. It is assumed that
1528 // calcRegsPassed has been run so BBInfo::isLiveOut is valid.
1529 void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
1530 SmallPtrSet<const MachineBasicBlock*, 8> seen;
1531 for (const auto &BBI : *MBB) {
1536 for (unsigned i = 1, e = BBI.getNumOperands(); i != e; i += 2) {
1537 unsigned Reg = BBI.getOperand(i).getReg();
1538 const MachineBasicBlock *Pre = BBI.getOperand(i + 1).getMBB();
1539 if (!Pre->isSuccessor(MBB))
1542 BBInfo &PrInfo = MBBInfoMap[Pre];
1543 if (PrInfo.reachable && !PrInfo.isLiveOut(Reg))
1544 report("PHI operand is not live-out from predecessor",
1545 &BBI.getOperand(i), i);
1548 // Did we see all predecessors?
1549 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
1550 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
1551 if (!seen.count(*PrI)) {
1552 report("Missing PHI operand", &BBI);
1553 errs() << "BB#" << (*PrI)->getNumber()
1554 << " is a predecessor according to the CFG.\n";
1560 void MachineVerifier::visitMachineFunctionAfter() {
1563 for (const auto &MBB : *MF) {
1564 BBInfo &MInfo = MBBInfoMap[&MBB];
1566 // Skip unreachable MBBs.
1567 if (!MInfo.reachable)
1573 // Now check liveness info if available
1576 // Check for killed virtual registers that should be live out.
1577 for (const auto &MBB : *MF) {
1578 BBInfo &MInfo = MBBInfoMap[&MBB];
1579 for (RegSet::iterator
1580 I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E;
1582 if (MInfo.regsKilled.count(*I)) {
1583 report("Virtual register killed in block, but needed live out.", &MBB);
1584 errs() << "Virtual register " << PrintReg(*I)
1585 << " is used after the block.\n";
1590 BBInfo &MInfo = MBBInfoMap[&MF->front()];
1591 for (RegSet::iterator
1592 I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E;
1594 report("Virtual register defs don't dominate all uses.", MF);
1595 report_context_vreg(*I);
1600 verifyLiveVariables();
1602 verifyLiveIntervals();
1605 void MachineVerifier::verifyLiveVariables() {
1606 assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
1607 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
1608 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
1609 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
1610 for (const auto &MBB : *MF) {
1611 BBInfo &MInfo = MBBInfoMap[&MBB];
1613 // Our vregsRequired should be identical to LiveVariables' AliveBlocks
1614 if (MInfo.vregsRequired.count(Reg)) {
1615 if (!VI.AliveBlocks.test(MBB.getNumber())) {
1616 report("LiveVariables: Block missing from AliveBlocks", &MBB);
1617 errs() << "Virtual register " << PrintReg(Reg)
1618 << " must be live through the block.\n";
1621 if (VI.AliveBlocks.test(MBB.getNumber())) {
1622 report("LiveVariables: Block should not be in AliveBlocks", &MBB);
1623 errs() << "Virtual register " << PrintReg(Reg)
1624 << " is not needed live through the block.\n";
1631 void MachineVerifier::verifyLiveIntervals() {
1632 assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts");
1633 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
1634 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
1636 // Spilling and splitting may leave unused registers around. Skip them.
1637 if (MRI->reg_nodbg_empty(Reg))
1640 if (!LiveInts->hasInterval(Reg)) {
1641 report("Missing live interval for virtual register", MF);
1642 errs() << PrintReg(Reg, TRI) << " still has defs or uses\n";
1646 const LiveInterval &LI = LiveInts->getInterval(Reg);
1647 assert(Reg == LI.reg && "Invalid reg to interval mapping");
1648 verifyLiveInterval(LI);
1651 // Verify all the cached regunit intervals.
1652 for (unsigned i = 0, e = TRI->getNumRegUnits(); i != e; ++i)
1653 if (const LiveRange *LR = LiveInts->getCachedRegUnit(i))
1654 verifyLiveRange(*LR, i);
1657 void MachineVerifier::verifyLiveRangeValue(const LiveRange &LR,
1658 const VNInfo *VNI, unsigned Reg,
1659 LaneBitmask LaneMask) {
1660 if (VNI->isUnused())
1663 const VNInfo *DefVNI = LR.getVNInfoAt(VNI->def);
1666 report("Value not live at VNInfo def and not marked unused", MF);
1667 report_context(LR, Reg, LaneMask);
1668 report_context(*VNI);
1672 if (DefVNI != VNI) {
1673 report("Live segment at def has different VNInfo", MF);
1674 report_context(LR, Reg, LaneMask);
1675 report_context(*VNI);
1679 const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def);
1681 report("Invalid VNInfo definition index", MF);
1682 report_context(LR, Reg, LaneMask);
1683 report_context(*VNI);
1687 if (VNI->isPHIDef()) {
1688 if (VNI->def != LiveInts->getMBBStartIdx(MBB)) {
1689 report("PHIDef VNInfo is not defined at MBB start", MBB);
1690 report_context(LR, Reg, LaneMask);
1691 report_context(*VNI);
1697 const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
1699 report("No instruction at VNInfo def index", MBB);
1700 report_context(LR, Reg, LaneMask);
1701 report_context(*VNI);
1706 bool hasDef = false;
1707 bool isEarlyClobber = false;
1708 for (ConstMIBundleOperands MOI(*MI); MOI.isValid(); ++MOI) {
1709 if (!MOI->isReg() || !MOI->isDef())
1711 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1712 if (MOI->getReg() != Reg)
1715 if (!TargetRegisterInfo::isPhysicalRegister(MOI->getReg()) ||
1716 !TRI->hasRegUnit(MOI->getReg(), Reg))
1719 if (LaneMask.any() &&
1720 (TRI->getSubRegIndexLaneMask(MOI->getSubReg()) & LaneMask).none())
1723 if (MOI->isEarlyClobber())
1724 isEarlyClobber = true;
1728 report("Defining instruction does not modify register", MI);
1729 report_context(LR, Reg, LaneMask);
1730 report_context(*VNI);
1733 // Early clobber defs begin at USE slots, but other defs must begin at
1735 if (isEarlyClobber) {
1736 if (!VNI->def.isEarlyClobber()) {
1737 report("Early clobber def must be at an early-clobber slot", MBB);
1738 report_context(LR, Reg, LaneMask);
1739 report_context(*VNI);
1741 } else if (!VNI->def.isRegister()) {
1742 report("Non-PHI, non-early clobber def must be at a register slot", MBB);
1743 report_context(LR, Reg, LaneMask);
1744 report_context(*VNI);
1749 void MachineVerifier::verifyLiveRangeSegment(const LiveRange &LR,
1750 const LiveRange::const_iterator I,
1751 unsigned Reg, LaneBitmask LaneMask)
1753 const LiveRange::Segment &S = *I;
1754 const VNInfo *VNI = S.valno;
1755 assert(VNI && "Live segment has no valno");
1757 if (VNI->id >= LR.getNumValNums() || VNI != LR.getValNumInfo(VNI->id)) {
1758 report("Foreign valno in live segment", MF);
1759 report_context(LR, Reg, LaneMask);
1761 report_context(*VNI);
1764 if (VNI->isUnused()) {
1765 report("Live segment valno is marked unused", MF);
1766 report_context(LR, Reg, LaneMask);
1770 const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(S.start);
1772 report("Bad start of live segment, no basic block", MF);
1773 report_context(LR, Reg, LaneMask);
1777 SlotIndex MBBStartIdx = LiveInts->getMBBStartIdx(MBB);
1778 if (S.start != MBBStartIdx && S.start != VNI->def) {
1779 report("Live segment must begin at MBB entry or valno def", MBB);
1780 report_context(LR, Reg, LaneMask);
1784 const MachineBasicBlock *EndMBB =
1785 LiveInts->getMBBFromIndex(S.end.getPrevSlot());
1787 report("Bad end of live segment, no basic block", MF);
1788 report_context(LR, Reg, LaneMask);
1793 // No more checks for live-out segments.
1794 if (S.end == LiveInts->getMBBEndIdx(EndMBB))
1797 // RegUnit intervals are allowed dead phis.
1798 if (!TargetRegisterInfo::isVirtualRegister(Reg) && VNI->isPHIDef() &&
1799 S.start == VNI->def && S.end == VNI->def.getDeadSlot())
1802 // The live segment is ending inside EndMBB
1803 const MachineInstr *MI =
1804 LiveInts->getInstructionFromIndex(S.end.getPrevSlot());
1806 report("Live segment doesn't end at a valid instruction", EndMBB);
1807 report_context(LR, Reg, LaneMask);
1812 // The block slot must refer to a basic block boundary.
1813 if (S.end.isBlock()) {
1814 report("Live segment ends at B slot of an instruction", EndMBB);
1815 report_context(LR, Reg, LaneMask);
1819 if (S.end.isDead()) {
1820 // Segment ends on the dead slot.
1821 // That means there must be a dead def.
1822 if (!SlotIndex::isSameInstr(S.start, S.end)) {
1823 report("Live segment ending at dead slot spans instructions", EndMBB);
1824 report_context(LR, Reg, LaneMask);
1829 // A live segment can only end at an early-clobber slot if it is being
1830 // redefined by an early-clobber def.
1831 if (S.end.isEarlyClobber()) {
1832 if (I+1 == LR.end() || (I+1)->start != S.end) {
1833 report("Live segment ending at early clobber slot must be "
1834 "redefined by an EC def in the same instruction", EndMBB);
1835 report_context(LR, Reg, LaneMask);
1840 // The following checks only apply to virtual registers. Physreg liveness
1841 // is too weird to check.
1842 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1843 // A live segment can end with either a redefinition, a kill flag on a
1844 // use, or a dead flag on a def.
1845 bool hasRead = false;
1846 bool hasSubRegDef = false;
1847 bool hasDeadDef = false;
1848 for (ConstMIBundleOperands MOI(*MI); MOI.isValid(); ++MOI) {
1849 if (!MOI->isReg() || MOI->getReg() != Reg)
1851 unsigned Sub = MOI->getSubReg();
1852 LaneBitmask SLM = Sub != 0 ? TRI->getSubRegIndexLaneMask(Sub)
1853 : LaneBitmask::getAll();
1856 hasSubRegDef = true;
1857 // An operand vreg0:sub0<def> reads vreg0:sub1..n. Invert the lane
1858 // mask for subregister defs. Read-undef defs will be handled by
1865 if (LaneMask.any() && (LaneMask & SLM).none())
1867 if (MOI->readsReg())
1870 if (S.end.isDead()) {
1871 // Make sure that the corresponding machine operand for a "dead" live
1872 // range has the dead flag. We cannot perform this check for subregister
1873 // liveranges as partially dead values are allowed.
1874 if (LaneMask.none() && !hasDeadDef) {
1875 report("Instruction ending live segment on dead slot has no dead flag",
1877 report_context(LR, Reg, LaneMask);
1882 // When tracking subregister liveness, the main range must start new
1883 // values on partial register writes, even if there is no read.
1884 if (!MRI->shouldTrackSubRegLiveness(Reg) || LaneMask.any() ||
1886 report("Instruction ending live segment doesn't read the register",
1888 report_context(LR, Reg, LaneMask);
1895 // Now check all the basic blocks in this live segment.
1896 MachineFunction::const_iterator MFI = MBB->getIterator();
1897 // Is this live segment the beginning of a non-PHIDef VN?
1898 if (S.start == VNI->def && !VNI->isPHIDef()) {
1899 // Not live-in to any blocks.
1906 assert(LiveInts->isLiveInToMBB(LR, &*MFI));
1907 // We don't know how to track physregs into a landing pad.
1908 if (!TargetRegisterInfo::isVirtualRegister(Reg) &&
1910 if (&*MFI == EndMBB)
1916 // Is VNI a PHI-def in the current block?
1917 bool IsPHI = VNI->isPHIDef() &&
1918 VNI->def == LiveInts->getMBBStartIdx(&*MFI);
1920 // Check that VNI is live-out of all predecessors.
1921 for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(),
1922 PE = MFI->pred_end(); PI != PE; ++PI) {
1923 SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI);
1924 const VNInfo *PVNI = LR.getVNInfoBefore(PEnd);
1926 // All predecessors must have a live-out value if this is not a
1927 // subregister liverange.
1928 if (!PVNI && LaneMask.none()) {
1929 report("Register not marked live out of predecessor", *PI);
1930 report_context(LR, Reg, LaneMask);
1931 report_context(*VNI);
1932 errs() << " live into BB#" << MFI->getNumber()
1933 << '@' << LiveInts->getMBBStartIdx(&*MFI) << ", not live before "
1938 // Only PHI-defs can take different predecessor values.
1939 if (!IsPHI && PVNI != VNI) {
1940 report("Different value live out of predecessor", *PI);
1941 report_context(LR, Reg, LaneMask);
1942 errs() << "Valno #" << PVNI->id << " live out of BB#"
1943 << (*PI)->getNumber() << '@' << PEnd << "\nValno #" << VNI->id
1944 << " live into BB#" << MFI->getNumber() << '@'
1945 << LiveInts->getMBBStartIdx(&*MFI) << '\n';
1948 if (&*MFI == EndMBB)
1954 void MachineVerifier::verifyLiveRange(const LiveRange &LR, unsigned Reg,
1955 LaneBitmask LaneMask) {
1956 for (const VNInfo *VNI : LR.valnos)
1957 verifyLiveRangeValue(LR, VNI, Reg, LaneMask);
1959 for (LiveRange::const_iterator I = LR.begin(), E = LR.end(); I != E; ++I)
1960 verifyLiveRangeSegment(LR, I, Reg, LaneMask);
1963 void MachineVerifier::verifyLiveInterval(const LiveInterval &LI) {
1964 unsigned Reg = LI.reg;
1965 assert(TargetRegisterInfo::isVirtualRegister(Reg));
1966 verifyLiveRange(LI, Reg);
1969 LaneBitmask MaxMask = MRI->getMaxLaneMaskForVReg(Reg);
1970 for (const LiveInterval::SubRange &SR : LI.subranges()) {
1971 if ((Mask & SR.LaneMask).any()) {
1972 report("Lane masks of sub ranges overlap in live interval", MF);
1975 if ((SR.LaneMask & ~MaxMask).any()) {
1976 report("Subrange lanemask is invalid", MF);
1980 report("Subrange must not be empty", MF);
1981 report_context(SR, LI.reg, SR.LaneMask);
1983 Mask |= SR.LaneMask;
1984 verifyLiveRange(SR, LI.reg, SR.LaneMask);
1985 if (!LI.covers(SR)) {
1986 report("A Subrange is not covered by the main range", MF);
1991 // Check the LI only has one connected component.
1992 ConnectedVNInfoEqClasses ConEQ(*LiveInts);
1993 unsigned NumComp = ConEQ.Classify(LI);
1995 report("Multiple connected components in live interval", MF);
1997 for (unsigned comp = 0; comp != NumComp; ++comp) {
1998 errs() << comp << ": valnos";
1999 for (LiveInterval::const_vni_iterator I = LI.vni_begin(),
2000 E = LI.vni_end(); I!=E; ++I)
2001 if (comp == ConEQ.getEqClass(*I))
2002 errs() << ' ' << (*I)->id;
2009 // FrameSetup and FrameDestroy can have zero adjustment, so using a single
2010 // integer, we can't tell whether it is a FrameSetup or FrameDestroy if the
2012 // We use a bool plus an integer to capture the stack state.
2013 struct StackStateOfBB {
2014 StackStateOfBB() : EntryValue(0), ExitValue(0), EntryIsSetup(false),
2015 ExitIsSetup(false) { }
2016 StackStateOfBB(int EntryVal, int ExitVal, bool EntrySetup, bool ExitSetup) :
2017 EntryValue(EntryVal), ExitValue(ExitVal), EntryIsSetup(EntrySetup),
2018 ExitIsSetup(ExitSetup) { }
2019 // Can be negative, which means we are setting up a frame.
2027 /// Make sure on every path through the CFG, a FrameSetup <n> is always followed
2028 /// by a FrameDestroy <n>, stack adjustments are identical on all
2029 /// CFG edges to a merge point, and frame is destroyed at end of a return block.
2030 void MachineVerifier::verifyStackFrame() {
2031 unsigned FrameSetupOpcode = TII->getCallFrameSetupOpcode();
2032 unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode();
2033 if (FrameSetupOpcode == ~0u && FrameDestroyOpcode == ~0u)
2036 SmallVector<StackStateOfBB, 8> SPState;
2037 SPState.resize(MF->getNumBlockIDs());
2038 df_iterator_default_set<const MachineBasicBlock*> Reachable;
2040 // Visit the MBBs in DFS order.
2041 for (df_ext_iterator<const MachineFunction*,
2042 df_iterator_default_set<const MachineBasicBlock*> >
2043 DFI = df_ext_begin(MF, Reachable), DFE = df_ext_end(MF, Reachable);
2044 DFI != DFE; ++DFI) {
2045 const MachineBasicBlock *MBB = *DFI;
2047 StackStateOfBB BBState;
2048 // Check the exit state of the DFS stack predecessor.
2049 if (DFI.getPathLength() >= 2) {
2050 const MachineBasicBlock *StackPred = DFI.getPath(DFI.getPathLength() - 2);
2051 assert(Reachable.count(StackPred) &&
2052 "DFS stack predecessor is already visited.\n");
2053 BBState.EntryValue = SPState[StackPred->getNumber()].ExitValue;
2054 BBState.EntryIsSetup = SPState[StackPred->getNumber()].ExitIsSetup;
2055 BBState.ExitValue = BBState.EntryValue;
2056 BBState.ExitIsSetup = BBState.EntryIsSetup;
2059 // Update stack state by checking contents of MBB.
2060 for (const auto &I : *MBB) {
2061 if (I.getOpcode() == FrameSetupOpcode) {
2062 if (BBState.ExitIsSetup)
2063 report("FrameSetup is after another FrameSetup", &I);
2064 BBState.ExitValue -= TII->getFrameSize(I);
2065 BBState.ExitIsSetup = true;
2068 if (I.getOpcode() == FrameDestroyOpcode) {
2069 int Size = TII->getFrameSize(I);
2070 if (!BBState.ExitIsSetup)
2071 report("FrameDestroy is not after a FrameSetup", &I);
2072 int AbsSPAdj = BBState.ExitValue < 0 ? -BBState.ExitValue :
2074 if (BBState.ExitIsSetup && AbsSPAdj != Size) {
2075 report("FrameDestroy <n> is after FrameSetup <m>", &I);
2076 errs() << "FrameDestroy <" << Size << "> is after FrameSetup <"
2077 << AbsSPAdj << ">.\n";
2079 BBState.ExitValue += Size;
2080 BBState.ExitIsSetup = false;
2083 SPState[MBB->getNumber()] = BBState;
2085 // Make sure the exit state of any predecessor is consistent with the entry
2087 for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(),
2088 E = MBB->pred_end(); I != E; ++I) {
2089 if (Reachable.count(*I) &&
2090 (SPState[(*I)->getNumber()].ExitValue != BBState.EntryValue ||
2091 SPState[(*I)->getNumber()].ExitIsSetup != BBState.EntryIsSetup)) {
2092 report("The exit stack state of a predecessor is inconsistent.", MBB);
2093 errs() << "Predecessor BB#" << (*I)->getNumber() << " has exit state ("
2094 << SPState[(*I)->getNumber()].ExitValue << ", "
2095 << SPState[(*I)->getNumber()].ExitIsSetup
2096 << "), while BB#" << MBB->getNumber() << " has entry state ("
2097 << BBState.EntryValue << ", " << BBState.EntryIsSetup << ").\n";
2101 // Make sure the entry state of any successor is consistent with the exit
2103 for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
2104 E = MBB->succ_end(); I != E; ++I) {
2105 if (Reachable.count(*I) &&
2106 (SPState[(*I)->getNumber()].EntryValue != BBState.ExitValue ||
2107 SPState[(*I)->getNumber()].EntryIsSetup != BBState.ExitIsSetup)) {
2108 report("The entry stack state of a successor is inconsistent.", MBB);
2109 errs() << "Successor BB#" << (*I)->getNumber() << " has entry state ("
2110 << SPState[(*I)->getNumber()].EntryValue << ", "
2111 << SPState[(*I)->getNumber()].EntryIsSetup
2112 << "), while BB#" << MBB->getNumber() << " has exit state ("
2113 << BBState.ExitValue << ", " << BBState.ExitIsSetup << ").\n";
2117 // Make sure a basic block with return ends with zero stack adjustment.
2118 if (!MBB->empty() && MBB->back().isReturn()) {
2119 if (BBState.ExitIsSetup)
2120 report("A return block ends with a FrameSetup.", MBB);
2121 if (BBState.ExitValue)
2122 report("A return block ends with a nonzero stack adjustment.", MBB);