1 //===-- MachineVerifier.cpp - Machine Code Verifier -----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Pass to verify generated machine code. The following is checked:
11 //
12 // Operand counts: All explicit operands must be present.
13 //
14 // Register classes: All physical and virtual register operands must be
15 // compatible with the register class required by the instruction descriptor.
16 //
17 // Register live intervals: Registers must be defined only once, and must be
18 // defined before use.
19 //
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 //===----------------------------------------------------------------------===//
25
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"
51 using namespace llvm;
52
53 namespace {
54 struct MachineVerifier {
55
MachineVerifier__anon480184f30111::MachineVerifier56 MachineVerifier(Pass *pass, const char *b) :
57 PASS(pass),
58 Banner(b)
59 {}
60
61 bool runOnMachineFunction(MachineFunction &MF);
62
63 Pass *const PASS;
64 const char *Banner;
65 const MachineFunction *MF;
66 const TargetMachine *TM;
67 const TargetInstrInfo *TII;
68 const TargetRegisterInfo *TRI;
69 const MachineRegisterInfo *MRI;
70
71 unsigned foundErrors;
72
73 typedef SmallVector<unsigned, 16> RegVector;
74 typedef SmallVector<const uint32_t*, 4> RegMaskVector;
75 typedef DenseSet<unsigned> RegSet;
76 typedef DenseMap<unsigned, const MachineInstr*> RegMap;
77 typedef SmallPtrSet<const MachineBasicBlock*, 8> BlockSet;
78
79 const MachineInstr *FirstTerminator;
80 BlockSet FunctionBlocks;
81
82 BitVector regsReserved;
83 RegSet regsLive;
84 RegVector regsDefined, regsDead, regsKilled;
85 RegMaskVector regMasks;
86 RegSet regsLiveInButUnused;
87
88 SlotIndex lastIndex;
89
90 // Add Reg and any sub-registers to RV
addRegWithSubRegs__anon480184f30111::MachineVerifier91 void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
92 RV.push_back(Reg);
93 if (TargetRegisterInfo::isPhysicalRegister(Reg))
94 for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
95 RV.push_back(*SubRegs);
96 }
97
98 struct BBInfo {
99 // Is this MBB reachable from the MF entry point?
100 bool reachable;
101
102 // Vregs that must be live in because they are used without being
103 // defined. Map value is the user.
104 RegMap vregsLiveIn;
105
106 // Regs killed in MBB. They may be defined again, and will then be in both
107 // regsKilled and regsLiveOut.
108 RegSet regsKilled;
109
110 // Regs defined in MBB and live out. Note that vregs passing through may
111 // be live out without being mentioned here.
112 RegSet regsLiveOut;
113
114 // Vregs that pass through MBB untouched. This set is disjoint from
115 // regsKilled and regsLiveOut.
116 RegSet vregsPassed;
117
118 // Vregs that must pass through MBB because they are needed by a successor
119 // block. This set is disjoint from regsLiveOut.
120 RegSet vregsRequired;
121
122 // Set versions of block's predecessor and successor lists.
123 BlockSet Preds, Succs;
124
BBInfo__anon480184f30111::MachineVerifier::BBInfo125 BBInfo() : reachable(false) {}
126
127 // Add register to vregsPassed if it belongs there. Return true if
128 // anything changed.
addPassed__anon480184f30111::MachineVerifier::BBInfo129 bool addPassed(unsigned Reg) {
130 if (!TargetRegisterInfo::isVirtualRegister(Reg))
131 return false;
132 if (regsKilled.count(Reg) || regsLiveOut.count(Reg))
133 return false;
134 return vregsPassed.insert(Reg).second;
135 }
136
137 // Same for a full set.
addPassed__anon480184f30111::MachineVerifier::BBInfo138 bool addPassed(const RegSet &RS) {
139 bool changed = false;
140 for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
141 if (addPassed(*I))
142 changed = true;
143 return changed;
144 }
145
146 // Add register to vregsRequired if it belongs there. Return true if
147 // anything changed.
addRequired__anon480184f30111::MachineVerifier::BBInfo148 bool addRequired(unsigned Reg) {
149 if (!TargetRegisterInfo::isVirtualRegister(Reg))
150 return false;
151 if (regsLiveOut.count(Reg))
152 return false;
153 return vregsRequired.insert(Reg).second;
154 }
155
156 // Same for a full set.
addRequired__anon480184f30111::MachineVerifier::BBInfo157 bool addRequired(const RegSet &RS) {
158 bool changed = false;
159 for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
160 if (addRequired(*I))
161 changed = true;
162 return changed;
163 }
164
165 // Same for a full map.
addRequired__anon480184f30111::MachineVerifier::BBInfo166 bool addRequired(const RegMap &RM) {
167 bool changed = false;
168 for (RegMap::const_iterator I = RM.begin(), E = RM.end(); I != E; ++I)
169 if (addRequired(I->first))
170 changed = true;
171 return changed;
172 }
173
174 // Live-out registers are either in regsLiveOut or vregsPassed.
isLiveOut__anon480184f30111::MachineVerifier::BBInfo175 bool isLiveOut(unsigned Reg) const {
176 return regsLiveOut.count(Reg) || vregsPassed.count(Reg);
177 }
178 };
179
180 // Extra register info per MBB.
181 DenseMap<const MachineBasicBlock*, BBInfo> MBBInfoMap;
182
isReserved__anon480184f30111::MachineVerifier183 bool isReserved(unsigned Reg) {
184 return Reg < regsReserved.size() && regsReserved.test(Reg);
185 }
186
isAllocatable__anon480184f30111::MachineVerifier187 bool isAllocatable(unsigned Reg) {
188 return Reg < TRI->getNumRegs() && MRI->isAllocatable(Reg);
189 }
190
191 // Analysis information if available
192 LiveVariables *LiveVars;
193 LiveIntervals *LiveInts;
194 LiveStacks *LiveStks;
195 SlotIndexes *Indexes;
196
197 void visitMachineFunctionBefore();
198 void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
199 void visitMachineBundleBefore(const MachineInstr *MI);
200 void visitMachineInstrBefore(const MachineInstr *MI);
201 void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
202 void visitMachineInstrAfter(const MachineInstr *MI);
203 void visitMachineBundleAfter(const MachineInstr *MI);
204 void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB);
205 void visitMachineFunctionAfter();
206
report__anon480184f30111::MachineVerifier207 template <typename T> void report(const char *msg, ilist_iterator<T> I) {
208 report(msg, &*I);
209 }
210 void report(const char *msg, const MachineFunction *MF);
211 void report(const char *msg, const MachineBasicBlock *MBB);
212 void report(const char *msg, const MachineInstr *MI);
213 void report(const char *msg, const MachineOperand *MO, unsigned MONum);
214
215 void report_context(const LiveInterval &LI) const;
216 void report_context(const LiveRange &LR, unsigned Reg,
217 LaneBitmask LaneMask) const;
218 void report_context(const LiveRange::Segment &S) const;
219 void report_context(const VNInfo &VNI) const;
220
221 void verifyInlineAsm(const MachineInstr *MI);
222
223 void checkLiveness(const MachineOperand *MO, unsigned MONum);
224 void markReachable(const MachineBasicBlock *MBB);
225 void calcRegsPassed();
226 void checkPHIOps(const MachineBasicBlock *MBB);
227
228 void calcRegsRequired();
229 void verifyLiveVariables();
230 void verifyLiveIntervals();
231 void verifyLiveInterval(const LiveInterval&);
232 void verifyLiveRangeValue(const LiveRange&, const VNInfo*, unsigned,
233 unsigned);
234 void verifyLiveRangeSegment(const LiveRange&,
235 const LiveRange::const_iterator I, unsigned,
236 unsigned);
237 void verifyLiveRange(const LiveRange&, unsigned, LaneBitmask LaneMask = 0);
238
239 void verifyStackFrame();
240
241 void verifySlotIndexes() const;
242 };
243
244 struct MachineVerifierPass : public MachineFunctionPass {
245 static char ID; // Pass ID, replacement for typeid
246 const std::string Banner;
247
MachineVerifierPass__anon480184f30111::MachineVerifierPass248 MachineVerifierPass(const std::string &banner = nullptr)
249 : MachineFunctionPass(ID), Banner(banner) {
250 initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
251 }
252
getAnalysisUsage__anon480184f30111::MachineVerifierPass253 void getAnalysisUsage(AnalysisUsage &AU) const override {
254 AU.setPreservesAll();
255 MachineFunctionPass::getAnalysisUsage(AU);
256 }
257
runOnMachineFunction__anon480184f30111::MachineVerifierPass258 bool runOnMachineFunction(MachineFunction &MF) override {
259 MF.verify(this, Banner.c_str());
260 return false;
261 }
262 };
263
264 }
265
266 char MachineVerifierPass::ID = 0;
267 INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
268 "Verify generated machine code", false, false)
269
createMachineVerifierPass(const std::string & Banner)270 FunctionPass *llvm::createMachineVerifierPass(const std::string &Banner) {
271 return new MachineVerifierPass(Banner);
272 }
273
verify(Pass * p,const char * Banner) const274 void MachineFunction::verify(Pass *p, const char *Banner) const {
275 MachineVerifier(p, Banner)
276 .runOnMachineFunction(const_cast<MachineFunction&>(*this));
277 }
278
verifySlotIndexes() const279 void MachineVerifier::verifySlotIndexes() const {
280 if (Indexes == nullptr)
281 return;
282
283 // Ensure the IdxMBB list is sorted by slot indexes.
284 SlotIndex Last;
285 for (SlotIndexes::MBBIndexIterator I = Indexes->MBBIndexBegin(),
286 E = Indexes->MBBIndexEnd(); I != E; ++I) {
287 assert(!Last.isValid() || I->first > Last);
288 Last = I->first;
289 }
290 }
291
runOnMachineFunction(MachineFunction & MF)292 bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
293 foundErrors = 0;
294
295 this->MF = &MF;
296 TM = &MF.getTarget();
297 TII = MF.getSubtarget().getInstrInfo();
298 TRI = MF.getSubtarget().getRegisterInfo();
299 MRI = &MF.getRegInfo();
300
301 LiveVars = nullptr;
302 LiveInts = nullptr;
303 LiveStks = nullptr;
304 Indexes = nullptr;
305 if (PASS) {
306 LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>();
307 // We don't want to verify LiveVariables if LiveIntervals is available.
308 if (!LiveInts)
309 LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
310 LiveStks = PASS->getAnalysisIfAvailable<LiveStacks>();
311 Indexes = PASS->getAnalysisIfAvailable<SlotIndexes>();
312 }
313
314 verifySlotIndexes();
315
316 visitMachineFunctionBefore();
317 for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
318 MFI!=MFE; ++MFI) {
319 visitMachineBasicBlockBefore(&*MFI);
320 // Keep track of the current bundle header.
321 const MachineInstr *CurBundle = nullptr;
322 // Do we expect the next instruction to be part of the same bundle?
323 bool InBundle = false;
324
325 for (MachineBasicBlock::const_instr_iterator MBBI = MFI->instr_begin(),
326 MBBE = MFI->instr_end(); MBBI != MBBE; ++MBBI) {
327 if (MBBI->getParent() != &*MFI) {
328 report("Bad instruction parent pointer", MFI);
329 errs() << "Instruction: " << *MBBI;
330 continue;
331 }
332
333 // Check for consistent bundle flags.
334 if (InBundle && !MBBI->isBundledWithPred())
335 report("Missing BundledPred flag, "
336 "BundledSucc was set on predecessor",
337 &*MBBI);
338 if (!InBundle && MBBI->isBundledWithPred())
339 report("BundledPred flag is set, "
340 "but BundledSucc not set on predecessor",
341 &*MBBI);
342
343 // Is this a bundle header?
344 if (!MBBI->isInsideBundle()) {
345 if (CurBundle)
346 visitMachineBundleAfter(CurBundle);
347 CurBundle = &*MBBI;
348 visitMachineBundleBefore(CurBundle);
349 } else if (!CurBundle)
350 report("No bundle header", MBBI);
351 visitMachineInstrBefore(&*MBBI);
352 for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I) {
353 const MachineInstr &MI = *MBBI;
354 const MachineOperand &Op = MI.getOperand(I);
355 if (Op.getParent() != &MI) {
356 // Make sure to use correct addOperand / RemoveOperand / ChangeTo
357 // functions when replacing operands of a MachineInstr.
358 report("Instruction has operand with wrong parent set", &MI);
359 }
360
361 visitMachineOperand(&Op, I);
362 }
363
364 visitMachineInstrAfter(&*MBBI);
365
366 // Was this the last bundled instruction?
367 InBundle = MBBI->isBundledWithSucc();
368 }
369 if (CurBundle)
370 visitMachineBundleAfter(CurBundle);
371 if (InBundle)
372 report("BundledSucc flag set on last instruction in block", &MFI->back());
373 visitMachineBasicBlockAfter(&*MFI);
374 }
375 visitMachineFunctionAfter();
376
377 if (foundErrors)
378 report_fatal_error("Found "+Twine(foundErrors)+" machine code errors.");
379
380 // Clean up.
381 regsLive.clear();
382 regsDefined.clear();
383 regsDead.clear();
384 regsKilled.clear();
385 regMasks.clear();
386 regsLiveInButUnused.clear();
387 MBBInfoMap.clear();
388
389 return false; // no changes
390 }
391
report(const char * msg,const MachineFunction * MF)392 void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
393 assert(MF);
394 errs() << '\n';
395 if (!foundErrors++) {
396 if (Banner)
397 errs() << "# " << Banner << '\n';
398 if (LiveInts != nullptr)
399 LiveInts->print(errs());
400 else
401 MF->print(errs(), Indexes);
402 }
403 errs() << "*** Bad machine code: " << msg << " ***\n"
404 << "- function: " << MF->getName() << "\n";
405 }
406
report(const char * msg,const MachineBasicBlock * MBB)407 void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
408 assert(MBB);
409 report(msg, MBB->getParent());
410 errs() << "- basic block: BB#" << MBB->getNumber()
411 << ' ' << MBB->getName()
412 << " (" << (const void*)MBB << ')';
413 if (Indexes)
414 errs() << " [" << Indexes->getMBBStartIdx(MBB)
415 << ';' << Indexes->getMBBEndIdx(MBB) << ')';
416 errs() << '\n';
417 }
418
report(const char * msg,const MachineInstr * MI)419 void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
420 assert(MI);
421 report(msg, MI->getParent());
422 errs() << "- instruction: ";
423 if (Indexes && Indexes->hasIndex(MI))
424 errs() << Indexes->getInstructionIndex(MI) << '\t';
425 MI->print(errs(), /*SkipOpers=*/true);
426 errs() << '\n';
427 }
428
report(const char * msg,const MachineOperand * MO,unsigned MONum)429 void MachineVerifier::report(const char *msg,
430 const MachineOperand *MO, unsigned MONum) {
431 assert(MO);
432 report(msg, MO->getParent());
433 errs() << "- operand " << MONum << ": ";
434 MO->print(errs(), TRI);
435 errs() << "\n";
436 }
437
report_context(const LiveInterval & LI) const438 void MachineVerifier::report_context(const LiveInterval &LI) const {
439 errs() << "- interval: " << LI << '\n';
440 }
441
report_context(const LiveRange & LR,unsigned Reg,LaneBitmask LaneMask) const442 void MachineVerifier::report_context(const LiveRange &LR, unsigned Reg,
443 LaneBitmask LaneMask) const {
444 errs() << "- register: " << PrintReg(Reg, TRI) << '\n';
445 if (LaneMask != 0)
446 errs() << "- lanemask: " << PrintLaneMask(LaneMask) << '\n';
447 errs() << "- liverange: " << LR << '\n';
448 }
449
report_context(const LiveRange::Segment & S) const450 void MachineVerifier::report_context(const LiveRange::Segment &S) const {
451 errs() << "- segment: " << S << '\n';
452 }
453
report_context(const VNInfo & VNI) const454 void MachineVerifier::report_context(const VNInfo &VNI) const {
455 errs() << "- ValNo: " << VNI.id << " (def " << VNI.def << ")\n";
456 }
457
markReachable(const MachineBasicBlock * MBB)458 void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
459 BBInfo &MInfo = MBBInfoMap[MBB];
460 if (!MInfo.reachable) {
461 MInfo.reachable = true;
462 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
463 SuE = MBB->succ_end(); SuI != SuE; ++SuI)
464 markReachable(*SuI);
465 }
466 }
467
visitMachineFunctionBefore()468 void MachineVerifier::visitMachineFunctionBefore() {
469 lastIndex = SlotIndex();
470 regsReserved = MRI->getReservedRegs();
471
472 // A sub-register of a reserved register is also reserved
473 for (int Reg = regsReserved.find_first(); Reg>=0;
474 Reg = regsReserved.find_next(Reg)) {
475 for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
476 // FIXME: This should probably be:
477 // assert(regsReserved.test(*SubRegs) && "Non-reserved sub-register");
478 regsReserved.set(*SubRegs);
479 }
480 }
481
482 markReachable(&MF->front());
483
484 // Build a set of the basic blocks in the function.
485 FunctionBlocks.clear();
486 for (const auto &MBB : *MF) {
487 FunctionBlocks.insert(&MBB);
488 BBInfo &MInfo = MBBInfoMap[&MBB];
489
490 MInfo.Preds.insert(MBB.pred_begin(), MBB.pred_end());
491 if (MInfo.Preds.size() != MBB.pred_size())
492 report("MBB has duplicate entries in its predecessor list.", &MBB);
493
494 MInfo.Succs.insert(MBB.succ_begin(), MBB.succ_end());
495 if (MInfo.Succs.size() != MBB.succ_size())
496 report("MBB has duplicate entries in its successor list.", &MBB);
497 }
498
499 // Check that the register use lists are sane.
500 MRI->verifyUseLists();
501
502 verifyStackFrame();
503 }
504
505 // Does iterator point to a and b as the first two elements?
matchPair(MachineBasicBlock::const_succ_iterator i,const MachineBasicBlock * a,const MachineBasicBlock * b)506 static bool matchPair(MachineBasicBlock::const_succ_iterator i,
507 const MachineBasicBlock *a, const MachineBasicBlock *b) {
508 if (*i == a)
509 return *++i == b;
510 if (*i == b)
511 return *++i == a;
512 return false;
513 }
514
515 void
visitMachineBasicBlockBefore(const MachineBasicBlock * MBB)516 MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
517 FirstTerminator = nullptr;
518
519 if (MRI->isSSA()) {
520 // If this block has allocatable physical registers live-in, check that
521 // it is an entry block or landing pad.
522 for (const auto &LI : MBB->liveins()) {
523 if (isAllocatable(LI.PhysReg) && !MBB->isEHPad() &&
524 MBB != MBB->getParent()->begin()) {
525 report("MBB has allocable live-in, but isn't entry or landing-pad.", MBB);
526 }
527 }
528 }
529
530 // Count the number of landing pad successors.
531 SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs;
532 for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
533 E = MBB->succ_end(); I != E; ++I) {
534 if ((*I)->isEHPad())
535 LandingPadSuccs.insert(*I);
536 if (!FunctionBlocks.count(*I))
537 report("MBB has successor that isn't part of the function.", MBB);
538 if (!MBBInfoMap[*I].Preds.count(MBB)) {
539 report("Inconsistent CFG", MBB);
540 errs() << "MBB is not in the predecessor list of the successor BB#"
541 << (*I)->getNumber() << ".\n";
542 }
543 }
544
545 // Check the predecessor list.
546 for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(),
547 E = MBB->pred_end(); I != E; ++I) {
548 if (!FunctionBlocks.count(*I))
549 report("MBB has predecessor that isn't part of the function.", MBB);
550 if (!MBBInfoMap[*I].Succs.count(MBB)) {
551 report("Inconsistent CFG", MBB);
552 errs() << "MBB is not in the successor list of the predecessor BB#"
553 << (*I)->getNumber() << ".\n";
554 }
555 }
556
557 const MCAsmInfo *AsmInfo = TM->getMCAsmInfo();
558 const BasicBlock *BB = MBB->getBasicBlock();
559 const Function *Fn = MF->getFunction();
560 if (LandingPadSuccs.size() > 1 &&
561 !(AsmInfo &&
562 AsmInfo->getExceptionHandlingType() == ExceptionHandling::SjLj &&
563 BB && isa<SwitchInst>(BB->getTerminator())) &&
564 !isFuncletEHPersonality(classifyEHPersonality(Fn->getPersonalityFn())))
565 report("MBB has more than one landing pad successor", MBB);
566
567 // Call AnalyzeBranch. If it succeeds, there several more conditions to check.
568 MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
569 SmallVector<MachineOperand, 4> Cond;
570 if (!TII->AnalyzeBranch(*const_cast<MachineBasicBlock *>(MBB),
571 TBB, FBB, Cond)) {
572 // Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's
573 // check whether its answers match up with reality.
574 if (!TBB && !FBB) {
575 // Block falls through to its successor.
576 MachineFunction::const_iterator MBBI = MBB->getIterator();
577 ++MBBI;
578 if (MBBI == MF->end()) {
579 // It's possible that the block legitimately ends with a noreturn
580 // call or an unreachable, in which case it won't actually fall
581 // out the bottom of the function.
582 } else if (MBB->succ_size() == LandingPadSuccs.size()) {
583 // It's possible that the block legitimately ends with a noreturn
584 // call or an unreachable, in which case it won't actuall fall
585 // out of the block.
586 } else if (MBB->succ_size() != 1+LandingPadSuccs.size()) {
587 report("MBB exits via unconditional fall-through but doesn't have "
588 "exactly one CFG successor!", MBB);
589 } else if (!MBB->isSuccessor(&*MBBI)) {
590 report("MBB exits via unconditional fall-through but its successor "
591 "differs from its CFG successor!", MBB);
592 }
593 if (!MBB->empty() && MBB->back().isBarrier() &&
594 !TII->isPredicated(&MBB->back())) {
595 report("MBB exits via unconditional fall-through but ends with a "
596 "barrier instruction!", MBB);
597 }
598 if (!Cond.empty()) {
599 report("MBB exits via unconditional fall-through but has a condition!",
600 MBB);
601 }
602 } else if (TBB && !FBB && Cond.empty()) {
603 // Block unconditionally branches somewhere.
604 // If the block has exactly one successor, that happens to be a
605 // landingpad, accept it as valid control flow.
606 if (MBB->succ_size() != 1+LandingPadSuccs.size() &&
607 (MBB->succ_size() != 1 || LandingPadSuccs.size() != 1 ||
608 *MBB->succ_begin() != *LandingPadSuccs.begin())) {
609 report("MBB exits via unconditional branch but doesn't have "
610 "exactly one CFG successor!", MBB);
611 } else if (!MBB->isSuccessor(TBB)) {
612 report("MBB exits via unconditional branch but the CFG "
613 "successor doesn't match the actual successor!", MBB);
614 }
615 if (MBB->empty()) {
616 report("MBB exits via unconditional branch but doesn't contain "
617 "any instructions!", MBB);
618 } else if (!MBB->back().isBarrier()) {
619 report("MBB exits via unconditional branch but doesn't end with a "
620 "barrier instruction!", MBB);
621 } else if (!MBB->back().isTerminator()) {
622 report("MBB exits via unconditional branch but the branch isn't a "
623 "terminator instruction!", MBB);
624 }
625 } else if (TBB && !FBB && !Cond.empty()) {
626 // Block conditionally branches somewhere, otherwise falls through.
627 MachineFunction::const_iterator MBBI = MBB->getIterator();
628 ++MBBI;
629 if (MBBI == MF->end()) {
630 report("MBB conditionally falls through out of function!", MBB);
631 } else if (MBB->succ_size() == 1) {
632 // A conditional branch with only one successor is weird, but allowed.
633 if (&*MBBI != TBB)
634 report("MBB exits via conditional branch/fall-through but only has "
635 "one CFG successor!", MBB);
636 else if (TBB != *MBB->succ_begin())
637 report("MBB exits via conditional branch/fall-through but the CFG "
638 "successor don't match the actual successor!", MBB);
639 } else if (MBB->succ_size() != 2) {
640 report("MBB exits via conditional branch/fall-through but doesn't have "
641 "exactly two CFG successors!", MBB);
642 } else if (!matchPair(MBB->succ_begin(), TBB, &*MBBI)) {
643 report("MBB exits via conditional branch/fall-through but the CFG "
644 "successors don't match the actual successors!", MBB);
645 }
646 if (MBB->empty()) {
647 report("MBB exits via conditional branch/fall-through but doesn't "
648 "contain any instructions!", MBB);
649 } else if (MBB->back().isBarrier()) {
650 report("MBB exits via conditional branch/fall-through but ends with a "
651 "barrier instruction!", MBB);
652 } else if (!MBB->back().isTerminator()) {
653 report("MBB exits via conditional branch/fall-through but the branch "
654 "isn't a terminator instruction!", MBB);
655 }
656 } else if (TBB && FBB) {
657 // Block conditionally branches somewhere, otherwise branches
658 // somewhere else.
659 if (MBB->succ_size() == 1) {
660 // A conditional branch with only one successor is weird, but allowed.
661 if (FBB != TBB)
662 report("MBB exits via conditional branch/branch through but only has "
663 "one CFG successor!", MBB);
664 else if (TBB != *MBB->succ_begin())
665 report("MBB exits via conditional branch/branch through but the CFG "
666 "successor don't match the actual successor!", MBB);
667 } else if (MBB->succ_size() != 2) {
668 report("MBB exits via conditional branch/branch but doesn't have "
669 "exactly two CFG successors!", MBB);
670 } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) {
671 report("MBB exits via conditional branch/branch but the CFG "
672 "successors don't match the actual successors!", MBB);
673 }
674 if (MBB->empty()) {
675 report("MBB exits via conditional branch/branch but doesn't "
676 "contain any instructions!", MBB);
677 } else if (!MBB->back().isBarrier()) {
678 report("MBB exits via conditional branch/branch but doesn't end with a "
679 "barrier instruction!", MBB);
680 } else if (!MBB->back().isTerminator()) {
681 report("MBB exits via conditional branch/branch but the branch "
682 "isn't a terminator instruction!", MBB);
683 }
684 if (Cond.empty()) {
685 report("MBB exits via conditinal branch/branch but there's no "
686 "condition!", MBB);
687 }
688 } else {
689 report("AnalyzeBranch returned invalid data!", MBB);
690 }
691 }
692
693 regsLive.clear();
694 for (const auto &LI : MBB->liveins()) {
695 if (!TargetRegisterInfo::isPhysicalRegister(LI.PhysReg)) {
696 report("MBB live-in list contains non-physical register", MBB);
697 continue;
698 }
699 for (MCSubRegIterator SubRegs(LI.PhysReg, TRI, /*IncludeSelf=*/true);
700 SubRegs.isValid(); ++SubRegs)
701 regsLive.insert(*SubRegs);
702 }
703 regsLiveInButUnused = regsLive;
704
705 const MachineFrameInfo *MFI = MF->getFrameInfo();
706 assert(MFI && "Function has no frame info");
707 BitVector PR = MFI->getPristineRegs(*MF);
708 for (int I = PR.find_first(); I>0; I = PR.find_next(I)) {
709 for (MCSubRegIterator SubRegs(I, TRI, /*IncludeSelf=*/true);
710 SubRegs.isValid(); ++SubRegs)
711 regsLive.insert(*SubRegs);
712 }
713
714 regsKilled.clear();
715 regsDefined.clear();
716
717 if (Indexes)
718 lastIndex = Indexes->getMBBStartIdx(MBB);
719 }
720
721 // This function gets called for all bundle headers, including normal
722 // stand-alone unbundled instructions.
visitMachineBundleBefore(const MachineInstr * MI)723 void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
724 if (Indexes && Indexes->hasIndex(MI)) {
725 SlotIndex idx = Indexes->getInstructionIndex(MI);
726 if (!(idx > lastIndex)) {
727 report("Instruction index out of order", MI);
728 errs() << "Last instruction was at " << lastIndex << '\n';
729 }
730 lastIndex = idx;
731 }
732
733 // Ensure non-terminators don't follow terminators.
734 // Ignore predicated terminators formed by if conversion.
735 // FIXME: If conversion shouldn't need to violate this rule.
736 if (MI->isTerminator() && !TII->isPredicated(MI)) {
737 if (!FirstTerminator)
738 FirstTerminator = MI;
739 } else if (FirstTerminator) {
740 report("Non-terminator instruction after the first terminator", MI);
741 errs() << "First terminator was:\t" << *FirstTerminator;
742 }
743 }
744
745 // The operands on an INLINEASM instruction must follow a template.
746 // Verify that the flag operands make sense.
verifyInlineAsm(const MachineInstr * MI)747 void MachineVerifier::verifyInlineAsm(const MachineInstr *MI) {
748 // The first two operands on INLINEASM are the asm string and global flags.
749 if (MI->getNumOperands() < 2) {
750 report("Too few operands on inline asm", MI);
751 return;
752 }
753 if (!MI->getOperand(0).isSymbol())
754 report("Asm string must be an external symbol", MI);
755 if (!MI->getOperand(1).isImm())
756 report("Asm flags must be an immediate", MI);
757 // Allowed flags are Extra_HasSideEffects = 1, Extra_IsAlignStack = 2,
758 // Extra_AsmDialect = 4, Extra_MayLoad = 8, and Extra_MayStore = 16.
759 if (!isUInt<5>(MI->getOperand(1).getImm()))
760 report("Unknown asm flags", &MI->getOperand(1), 1);
761
762 static_assert(InlineAsm::MIOp_FirstOperand == 2, "Asm format changed");
763
764 unsigned OpNo = InlineAsm::MIOp_FirstOperand;
765 unsigned NumOps;
766 for (unsigned e = MI->getNumOperands(); OpNo < e; OpNo += NumOps) {
767 const MachineOperand &MO = MI->getOperand(OpNo);
768 // There may be implicit ops after the fixed operands.
769 if (!MO.isImm())
770 break;
771 NumOps = 1 + InlineAsm::getNumOperandRegisters(MO.getImm());
772 }
773
774 if (OpNo > MI->getNumOperands())
775 report("Missing operands in last group", MI);
776
777 // An optional MDNode follows the groups.
778 if (OpNo < MI->getNumOperands() && MI->getOperand(OpNo).isMetadata())
779 ++OpNo;
780
781 // All trailing operands must be implicit registers.
782 for (unsigned e = MI->getNumOperands(); OpNo < e; ++OpNo) {
783 const MachineOperand &MO = MI->getOperand(OpNo);
784 if (!MO.isReg() || !MO.isImplicit())
785 report("Expected implicit register after groups", &MO, OpNo);
786 }
787 }
788
visitMachineInstrBefore(const MachineInstr * MI)789 void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
790 const MCInstrDesc &MCID = MI->getDesc();
791 if (MI->getNumOperands() < MCID.getNumOperands()) {
792 report("Too few operands", MI);
793 errs() << MCID.getNumOperands() << " operands expected, but "
794 << MI->getNumOperands() << " given.\n";
795 }
796
797 // Check the tied operands.
798 if (MI->isInlineAsm())
799 verifyInlineAsm(MI);
800
801 // Check the MachineMemOperands for basic consistency.
802 for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
803 E = MI->memoperands_end(); I != E; ++I) {
804 if ((*I)->isLoad() && !MI->mayLoad())
805 report("Missing mayLoad flag", MI);
806 if ((*I)->isStore() && !MI->mayStore())
807 report("Missing mayStore flag", MI);
808 }
809
810 // Debug values must not have a slot index.
811 // Other instructions must have one, unless they are inside a bundle.
812 if (LiveInts) {
813 bool mapped = !LiveInts->isNotInMIMap(MI);
814 if (MI->isDebugValue()) {
815 if (mapped)
816 report("Debug instruction has a slot index", MI);
817 } else if (MI->isInsideBundle()) {
818 if (mapped)
819 report("Instruction inside bundle has a slot index", MI);
820 } else {
821 if (!mapped)
822 report("Missing slot index", MI);
823 }
824 }
825
826 StringRef ErrorInfo;
827 if (!TII->verifyInstruction(MI, ErrorInfo))
828 report(ErrorInfo.data(), MI);
829 }
830
831 void
visitMachineOperand(const MachineOperand * MO,unsigned MONum)832 MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
833 const MachineInstr *MI = MO->getParent();
834 const MCInstrDesc &MCID = MI->getDesc();
835 unsigned NumDefs = MCID.getNumDefs();
836 if (MCID.getOpcode() == TargetOpcode::PATCHPOINT)
837 NumDefs = (MONum == 0 && MO->isReg()) ? NumDefs : 0;
838
839 // The first MCID.NumDefs operands must be explicit register defines
840 if (MONum < NumDefs) {
841 const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
842 if (!MO->isReg())
843 report("Explicit definition must be a register", MO, MONum);
844 else if (!MO->isDef() && !MCOI.isOptionalDef())
845 report("Explicit definition marked as use", MO, MONum);
846 else if (MO->isImplicit())
847 report("Explicit definition marked as implicit", MO, MONum);
848 } else if (MONum < MCID.getNumOperands()) {
849 const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
850 // Don't check if it's the last operand in a variadic instruction. See,
851 // e.g., LDM_RET in the arm back end.
852 if (MO->isReg() &&
853 !(MI->isVariadic() && MONum == MCID.getNumOperands()-1)) {
854 if (MO->isDef() && !MCOI.isOptionalDef())
855 report("Explicit operand marked as def", MO, MONum);
856 if (MO->isImplicit())
857 report("Explicit operand marked as implicit", MO, MONum);
858 }
859
860 int TiedTo = MCID.getOperandConstraint(MONum, MCOI::TIED_TO);
861 if (TiedTo != -1) {
862 if (!MO->isReg())
863 report("Tied use must be a register", MO, MONum);
864 else if (!MO->isTied())
865 report("Operand should be tied", MO, MONum);
866 else if (unsigned(TiedTo) != MI->findTiedOperandIdx(MONum))
867 report("Tied def doesn't match MCInstrDesc", MO, MONum);
868 } else if (MO->isReg() && MO->isTied())
869 report("Explicit operand should not be tied", MO, MONum);
870 } else {
871 // ARM adds %reg0 operands to indicate predicates. We'll allow that.
872 if (MO->isReg() && !MO->isImplicit() && !MI->isVariadic() && MO->getReg())
873 report("Extra explicit operand on non-variadic instruction", MO, MONum);
874 }
875
876 switch (MO->getType()) {
877 case MachineOperand::MO_Register: {
878 const unsigned Reg = MO->getReg();
879 if (!Reg)
880 return;
881 if (MRI->tracksLiveness() && !MI->isDebugValue())
882 checkLiveness(MO, MONum);
883
884 // Verify the consistency of tied operands.
885 if (MO->isTied()) {
886 unsigned OtherIdx = MI->findTiedOperandIdx(MONum);
887 const MachineOperand &OtherMO = MI->getOperand(OtherIdx);
888 if (!OtherMO.isReg())
889 report("Must be tied to a register", MO, MONum);
890 if (!OtherMO.isTied())
891 report("Missing tie flags on tied operand", MO, MONum);
892 if (MI->findTiedOperandIdx(OtherIdx) != MONum)
893 report("Inconsistent tie links", MO, MONum);
894 if (MONum < MCID.getNumDefs()) {
895 if (OtherIdx < MCID.getNumOperands()) {
896 if (-1 == MCID.getOperandConstraint(OtherIdx, MCOI::TIED_TO))
897 report("Explicit def tied to explicit use without tie constraint",
898 MO, MONum);
899 } else {
900 if (!OtherMO.isImplicit())
901 report("Explicit def should be tied to implicit use", MO, MONum);
902 }
903 }
904 }
905
906 // Verify two-address constraints after leaving SSA form.
907 unsigned DefIdx;
908 if (!MRI->isSSA() && MO->isUse() &&
909 MI->isRegTiedToDefOperand(MONum, &DefIdx) &&
910 Reg != MI->getOperand(DefIdx).getReg())
911 report("Two-address instruction operands must be identical", MO, MONum);
912
913 // Check register classes.
914 if (MONum < MCID.getNumOperands() && !MO->isImplicit()) {
915 unsigned SubIdx = MO->getSubReg();
916
917 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
918 if (SubIdx) {
919 report("Illegal subregister index for physical register", MO, MONum);
920 return;
921 }
922 if (const TargetRegisterClass *DRC =
923 TII->getRegClass(MCID, MONum, TRI, *MF)) {
924 if (!DRC->contains(Reg)) {
925 report("Illegal physical register for instruction", MO, MONum);
926 errs() << TRI->getName(Reg) << " is not a "
927 << TRI->getRegClassName(DRC) << " register.\n";
928 }
929 }
930 } else {
931 // Virtual register.
932 const TargetRegisterClass *RC = MRI->getRegClass(Reg);
933 if (SubIdx) {
934 const TargetRegisterClass *SRC =
935 TRI->getSubClassWithSubReg(RC, SubIdx);
936 if (!SRC) {
937 report("Invalid subregister index for virtual register", MO, MONum);
938 errs() << "Register class " << TRI->getRegClassName(RC)
939 << " does not support subreg index " << SubIdx << "\n";
940 return;
941 }
942 if (RC != SRC) {
943 report("Invalid register class for subregister index", MO, MONum);
944 errs() << "Register class " << TRI->getRegClassName(RC)
945 << " does not fully support subreg index " << SubIdx << "\n";
946 return;
947 }
948 }
949 if (const TargetRegisterClass *DRC =
950 TII->getRegClass(MCID, MONum, TRI, *MF)) {
951 if (SubIdx) {
952 const TargetRegisterClass *SuperRC =
953 TRI->getLargestLegalSuperClass(RC, *MF);
954 if (!SuperRC) {
955 report("No largest legal super class exists.", MO, MONum);
956 return;
957 }
958 DRC = TRI->getMatchingSuperRegClass(SuperRC, DRC, SubIdx);
959 if (!DRC) {
960 report("No matching super-reg register class.", MO, MONum);
961 return;
962 }
963 }
964 if (!RC->hasSuperClassEq(DRC)) {
965 report("Illegal virtual register for instruction", MO, MONum);
966 errs() << "Expected a " << TRI->getRegClassName(DRC)
967 << " register, but got a " << TRI->getRegClassName(RC)
968 << " register\n";
969 }
970 }
971 }
972 }
973 break;
974 }
975
976 case MachineOperand::MO_RegisterMask:
977 regMasks.push_back(MO->getRegMask());
978 break;
979
980 case MachineOperand::MO_MachineBasicBlock:
981 if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent()))
982 report("PHI operand is not in the CFG", MO, MONum);
983 break;
984
985 case MachineOperand::MO_FrameIndex:
986 if (LiveStks && LiveStks->hasInterval(MO->getIndex()) &&
987 LiveInts && !LiveInts->isNotInMIMap(MI)) {
988 int FI = MO->getIndex();
989 LiveInterval &LI = LiveStks->getInterval(FI);
990 SlotIndex Idx = LiveInts->getInstructionIndex(MI);
991
992 bool stores = MI->mayStore();
993 bool loads = MI->mayLoad();
994 // For a memory-to-memory move, we need to check if the frame
995 // index is used for storing or loading, by inspecting the
996 // memory operands.
997 if (stores && loads) {
998 for (auto *MMO : MI->memoperands()) {
999 const PseudoSourceValue *PSV = MMO->getPseudoValue();
1000 if (PSV == nullptr) continue;
1001 const FixedStackPseudoSourceValue *Value =
1002 dyn_cast<FixedStackPseudoSourceValue>(PSV);
1003 if (Value == nullptr) continue;
1004 if (Value->getFrameIndex() != FI) continue;
1005
1006 if (MMO->isStore())
1007 loads = false;
1008 else
1009 stores = false;
1010 break;
1011 }
1012 if (loads == stores)
1013 report("Missing fixed stack memoperand.", MI);
1014 }
1015 if (loads && !LI.liveAt(Idx.getRegSlot(true))) {
1016 report("Instruction loads from dead spill slot", MO, MONum);
1017 errs() << "Live stack: " << LI << '\n';
1018 }
1019 if (stores && !LI.liveAt(Idx.getRegSlot())) {
1020 report("Instruction stores to dead spill slot", MO, MONum);
1021 errs() << "Live stack: " << LI << '\n';
1022 }
1023 }
1024 break;
1025
1026 default:
1027 break;
1028 }
1029 }
1030
checkLiveness(const MachineOperand * MO,unsigned MONum)1031 void MachineVerifier::checkLiveness(const MachineOperand *MO, unsigned MONum) {
1032 const MachineInstr *MI = MO->getParent();
1033 const unsigned Reg = MO->getReg();
1034
1035 // Both use and def operands can read a register.
1036 if (MO->readsReg()) {
1037 regsLiveInButUnused.erase(Reg);
1038
1039 if (MO->isKill())
1040 addRegWithSubRegs(regsKilled, Reg);
1041
1042 // Check that LiveVars knows this kill.
1043 if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg) &&
1044 MO->isKill()) {
1045 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
1046 if (std::find(VI.Kills.begin(), VI.Kills.end(), MI) == VI.Kills.end())
1047 report("Kill missing from LiveVariables", MO, MONum);
1048 }
1049
1050 // Check LiveInts liveness and kill.
1051 if (LiveInts && !LiveInts->isNotInMIMap(MI)) {
1052 SlotIndex UseIdx = LiveInts->getInstructionIndex(MI);
1053 // Check the cached regunit intervals.
1054 if (TargetRegisterInfo::isPhysicalRegister(Reg) && !isReserved(Reg)) {
1055 for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
1056 if (const LiveRange *LR = LiveInts->getCachedRegUnit(*Units)) {
1057 LiveQueryResult LRQ = LR->Query(UseIdx);
1058 if (!LRQ.valueIn()) {
1059 report("No live segment at use", MO, MONum);
1060 errs() << UseIdx << " is not live in " << PrintRegUnit(*Units, TRI)
1061 << ' ' << *LR << '\n';
1062 }
1063 if (MO->isKill() && !LRQ.isKill()) {
1064 report("Live range continues after kill flag", MO, MONum);
1065 errs() << PrintRegUnit(*Units, TRI) << ' ' << *LR << '\n';
1066 }
1067 }
1068 }
1069 }
1070
1071 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1072 if (LiveInts->hasInterval(Reg)) {
1073 // This is a virtual register interval.
1074 const LiveInterval &LI = LiveInts->getInterval(Reg);
1075 LiveQueryResult LRQ = LI.Query(UseIdx);
1076 if (!LRQ.valueIn()) {
1077 report("No live segment at use", MO, MONum);
1078 errs() << UseIdx << " is not live in " << LI << '\n';
1079 }
1080 // Check for extra kill flags.
1081 // Note that we allow missing kill flags for now.
1082 if (MO->isKill() && !LRQ.isKill()) {
1083 report("Live range continues after kill flag", MO, MONum);
1084 errs() << "Live range: " << LI << '\n';
1085 }
1086 } else {
1087 report("Virtual register has no live interval", MO, MONum);
1088 }
1089 }
1090 }
1091
1092 // Use of a dead register.
1093 if (!regsLive.count(Reg)) {
1094 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
1095 // Reserved registers may be used even when 'dead'.
1096 bool Bad = !isReserved(Reg);
1097 // We are fine if just any subregister has a defined value.
1098 if (Bad) {
1099 for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid();
1100 ++SubRegs) {
1101 if (regsLive.count(*SubRegs)) {
1102 Bad = false;
1103 break;
1104 }
1105 }
1106 }
1107 // If there is an additional implicit-use of a super register we stop
1108 // here. By definition we are fine if the super register is not
1109 // (completely) dead, if the complete super register is dead we will
1110 // get a report for its operand.
1111 if (Bad) {
1112 for (const MachineOperand &MOP : MI->uses()) {
1113 if (!MOP.isReg())
1114 continue;
1115 if (!MOP.isImplicit())
1116 continue;
1117 for (MCSubRegIterator SubRegs(MOP.getReg(), TRI); SubRegs.isValid();
1118 ++SubRegs) {
1119 if (*SubRegs == Reg) {
1120 Bad = false;
1121 break;
1122 }
1123 }
1124 }
1125 }
1126 if (Bad)
1127 report("Using an undefined physical register", MO, MONum);
1128 } else if (MRI->def_empty(Reg)) {
1129 report("Reading virtual register without a def", MO, MONum);
1130 } else {
1131 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
1132 // We don't know which virtual registers are live in, so only complain
1133 // if vreg was killed in this MBB. Otherwise keep track of vregs that
1134 // must be live in. PHI instructions are handled separately.
1135 if (MInfo.regsKilled.count(Reg))
1136 report("Using a killed virtual register", MO, MONum);
1137 else if (!MI->isPHI())
1138 MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI));
1139 }
1140 }
1141 }
1142
1143 if (MO->isDef()) {
1144 // Register defined.
1145 // TODO: verify that earlyclobber ops are not used.
1146 if (MO->isDead())
1147 addRegWithSubRegs(regsDead, Reg);
1148 else
1149 addRegWithSubRegs(regsDefined, Reg);
1150
1151 // Verify SSA form.
1152 if (MRI->isSSA() && TargetRegisterInfo::isVirtualRegister(Reg) &&
1153 std::next(MRI->def_begin(Reg)) != MRI->def_end())
1154 report("Multiple virtual register defs in SSA form", MO, MONum);
1155
1156 // Check LiveInts for a live segment, but only for virtual registers.
1157 if (LiveInts && TargetRegisterInfo::isVirtualRegister(Reg) &&
1158 !LiveInts->isNotInMIMap(MI)) {
1159 SlotIndex DefIdx = LiveInts->getInstructionIndex(MI);
1160 DefIdx = DefIdx.getRegSlot(MO->isEarlyClobber());
1161 if (LiveInts->hasInterval(Reg)) {
1162 const LiveInterval &LI = LiveInts->getInterval(Reg);
1163 if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) {
1164 assert(VNI && "NULL valno is not allowed");
1165 if (VNI->def != DefIdx) {
1166 report("Inconsistent valno->def", MO, MONum);
1167 errs() << "Valno " << VNI->id << " is not defined at "
1168 << DefIdx << " in " << LI << '\n';
1169 }
1170 } else {
1171 report("No live segment at def", MO, MONum);
1172 errs() << DefIdx << " is not live in " << LI << '\n';
1173 }
1174 // Check that, if the dead def flag is present, LiveInts agree.
1175 if (MO->isDead()) {
1176 LiveQueryResult LRQ = LI.Query(DefIdx);
1177 if (!LRQ.isDeadDef()) {
1178 report("Live range continues after dead def flag", MO, MONum);
1179 errs() << "Live range: " << LI << '\n';
1180 }
1181 }
1182 } else {
1183 report("Virtual register has no Live interval", MO, MONum);
1184 }
1185 }
1186 }
1187 }
1188
visitMachineInstrAfter(const MachineInstr * MI)1189 void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
1190 }
1191
1192 // This function gets called after visiting all instructions in a bundle. The
1193 // argument points to the bundle header.
1194 // Normal stand-alone instructions are also considered 'bundles', and this
1195 // function is called for all of them.
visitMachineBundleAfter(const MachineInstr * MI)1196 void MachineVerifier::visitMachineBundleAfter(const MachineInstr *MI) {
1197 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
1198 set_union(MInfo.regsKilled, regsKilled);
1199 set_subtract(regsLive, regsKilled); regsKilled.clear();
1200 // Kill any masked registers.
1201 while (!regMasks.empty()) {
1202 const uint32_t *Mask = regMasks.pop_back_val();
1203 for (RegSet::iterator I = regsLive.begin(), E = regsLive.end(); I != E; ++I)
1204 if (TargetRegisterInfo::isPhysicalRegister(*I) &&
1205 MachineOperand::clobbersPhysReg(Mask, *I))
1206 regsDead.push_back(*I);
1207 }
1208 set_subtract(regsLive, regsDead); regsDead.clear();
1209 set_union(regsLive, regsDefined); regsDefined.clear();
1210 }
1211
1212 void
visitMachineBasicBlockAfter(const MachineBasicBlock * MBB)1213 MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
1214 MBBInfoMap[MBB].regsLiveOut = regsLive;
1215 regsLive.clear();
1216
1217 if (Indexes) {
1218 SlotIndex stop = Indexes->getMBBEndIdx(MBB);
1219 if (!(stop > lastIndex)) {
1220 report("Block ends before last instruction index", MBB);
1221 errs() << "Block ends at " << stop
1222 << " last instruction was at " << lastIndex << '\n';
1223 }
1224 lastIndex = stop;
1225 }
1226 }
1227
1228 // Calculate the largest possible vregsPassed sets. These are the registers that
1229 // can pass through an MBB live, but may not be live every time. It is assumed
1230 // that all vregsPassed sets are empty before the call.
calcRegsPassed()1231 void MachineVerifier::calcRegsPassed() {
1232 // First push live-out regs to successors' vregsPassed. Remember the MBBs that
1233 // have any vregsPassed.
1234 SmallPtrSet<const MachineBasicBlock*, 8> todo;
1235 for (const auto &MBB : *MF) {
1236 BBInfo &MInfo = MBBInfoMap[&MBB];
1237 if (!MInfo.reachable)
1238 continue;
1239 for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
1240 SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
1241 BBInfo &SInfo = MBBInfoMap[*SuI];
1242 if (SInfo.addPassed(MInfo.regsLiveOut))
1243 todo.insert(*SuI);
1244 }
1245 }
1246
1247 // Iteratively push vregsPassed to successors. This will converge to the same
1248 // final state regardless of DenseSet iteration order.
1249 while (!todo.empty()) {
1250 const MachineBasicBlock *MBB = *todo.begin();
1251 todo.erase(MBB);
1252 BBInfo &MInfo = MBBInfoMap[MBB];
1253 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
1254 SuE = MBB->succ_end(); SuI != SuE; ++SuI) {
1255 if (*SuI == MBB)
1256 continue;
1257 BBInfo &SInfo = MBBInfoMap[*SuI];
1258 if (SInfo.addPassed(MInfo.vregsPassed))
1259 todo.insert(*SuI);
1260 }
1261 }
1262 }
1263
1264 // Calculate the set of virtual registers that must be passed through each basic
1265 // block in order to satisfy the requirements of successor blocks. This is very
1266 // similar to calcRegsPassed, only backwards.
calcRegsRequired()1267 void MachineVerifier::calcRegsRequired() {
1268 // First push live-in regs to predecessors' vregsRequired.
1269 SmallPtrSet<const MachineBasicBlock*, 8> todo;
1270 for (const auto &MBB : *MF) {
1271 BBInfo &MInfo = MBBInfoMap[&MBB];
1272 for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(),
1273 PrE = MBB.pred_end(); PrI != PrE; ++PrI) {
1274 BBInfo &PInfo = MBBInfoMap[*PrI];
1275 if (PInfo.addRequired(MInfo.vregsLiveIn))
1276 todo.insert(*PrI);
1277 }
1278 }
1279
1280 // Iteratively push vregsRequired to predecessors. This will converge to the
1281 // same final state regardless of DenseSet iteration order.
1282 while (!todo.empty()) {
1283 const MachineBasicBlock *MBB = *todo.begin();
1284 todo.erase(MBB);
1285 BBInfo &MInfo = MBBInfoMap[MBB];
1286 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
1287 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
1288 if (*PrI == MBB)
1289 continue;
1290 BBInfo &SInfo = MBBInfoMap[*PrI];
1291 if (SInfo.addRequired(MInfo.vregsRequired))
1292 todo.insert(*PrI);
1293 }
1294 }
1295 }
1296
1297 // Check PHI instructions at the beginning of MBB. It is assumed that
1298 // calcRegsPassed has been run so BBInfo::isLiveOut is valid.
checkPHIOps(const MachineBasicBlock * MBB)1299 void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
1300 SmallPtrSet<const MachineBasicBlock*, 8> seen;
1301 for (const auto &BBI : *MBB) {
1302 if (!BBI.isPHI())
1303 break;
1304 seen.clear();
1305
1306 for (unsigned i = 1, e = BBI.getNumOperands(); i != e; i += 2) {
1307 unsigned Reg = BBI.getOperand(i).getReg();
1308 const MachineBasicBlock *Pre = BBI.getOperand(i + 1).getMBB();
1309 if (!Pre->isSuccessor(MBB))
1310 continue;
1311 seen.insert(Pre);
1312 BBInfo &PrInfo = MBBInfoMap[Pre];
1313 if (PrInfo.reachable && !PrInfo.isLiveOut(Reg))
1314 report("PHI operand is not live-out from predecessor",
1315 &BBI.getOperand(i), i);
1316 }
1317
1318 // Did we see all predecessors?
1319 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
1320 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
1321 if (!seen.count(*PrI)) {
1322 report("Missing PHI operand", &BBI);
1323 errs() << "BB#" << (*PrI)->getNumber()
1324 << " is a predecessor according to the CFG.\n";
1325 }
1326 }
1327 }
1328 }
1329
visitMachineFunctionAfter()1330 void MachineVerifier::visitMachineFunctionAfter() {
1331 calcRegsPassed();
1332
1333 for (const auto &MBB : *MF) {
1334 BBInfo &MInfo = MBBInfoMap[&MBB];
1335
1336 // Skip unreachable MBBs.
1337 if (!MInfo.reachable)
1338 continue;
1339
1340 checkPHIOps(&MBB);
1341 }
1342
1343 // Now check liveness info if available
1344 calcRegsRequired();
1345
1346 // Check for killed virtual registers that should be live out.
1347 for (const auto &MBB : *MF) {
1348 BBInfo &MInfo = MBBInfoMap[&MBB];
1349 for (RegSet::iterator
1350 I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E;
1351 ++I)
1352 if (MInfo.regsKilled.count(*I)) {
1353 report("Virtual register killed in block, but needed live out.", &MBB);
1354 errs() << "Virtual register " << PrintReg(*I)
1355 << " is used after the block.\n";
1356 }
1357 }
1358
1359 if (!MF->empty()) {
1360 BBInfo &MInfo = MBBInfoMap[&MF->front()];
1361 for (RegSet::iterator
1362 I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E;
1363 ++I)
1364 report("Virtual register def doesn't dominate all uses.",
1365 MRI->getVRegDef(*I));
1366 }
1367
1368 if (LiveVars)
1369 verifyLiveVariables();
1370 if (LiveInts)
1371 verifyLiveIntervals();
1372 }
1373
verifyLiveVariables()1374 void MachineVerifier::verifyLiveVariables() {
1375 assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
1376 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
1377 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
1378 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
1379 for (const auto &MBB : *MF) {
1380 BBInfo &MInfo = MBBInfoMap[&MBB];
1381
1382 // Our vregsRequired should be identical to LiveVariables' AliveBlocks
1383 if (MInfo.vregsRequired.count(Reg)) {
1384 if (!VI.AliveBlocks.test(MBB.getNumber())) {
1385 report("LiveVariables: Block missing from AliveBlocks", &MBB);
1386 errs() << "Virtual register " << PrintReg(Reg)
1387 << " must be live through the block.\n";
1388 }
1389 } else {
1390 if (VI.AliveBlocks.test(MBB.getNumber())) {
1391 report("LiveVariables: Block should not be in AliveBlocks", &MBB);
1392 errs() << "Virtual register " << PrintReg(Reg)
1393 << " is not needed live through the block.\n";
1394 }
1395 }
1396 }
1397 }
1398 }
1399
verifyLiveIntervals()1400 void MachineVerifier::verifyLiveIntervals() {
1401 assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts");
1402 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
1403 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
1404
1405 // Spilling and splitting may leave unused registers around. Skip them.
1406 if (MRI->reg_nodbg_empty(Reg))
1407 continue;
1408
1409 if (!LiveInts->hasInterval(Reg)) {
1410 report("Missing live interval for virtual register", MF);
1411 errs() << PrintReg(Reg, TRI) << " still has defs or uses\n";
1412 continue;
1413 }
1414
1415 const LiveInterval &LI = LiveInts->getInterval(Reg);
1416 assert(Reg == LI.reg && "Invalid reg to interval mapping");
1417 verifyLiveInterval(LI);
1418 }
1419
1420 // Verify all the cached regunit intervals.
1421 for (unsigned i = 0, e = TRI->getNumRegUnits(); i != e; ++i)
1422 if (const LiveRange *LR = LiveInts->getCachedRegUnit(i))
1423 verifyLiveRange(*LR, i);
1424 }
1425
verifyLiveRangeValue(const LiveRange & LR,const VNInfo * VNI,unsigned Reg,LaneBitmask LaneMask)1426 void MachineVerifier::verifyLiveRangeValue(const LiveRange &LR,
1427 const VNInfo *VNI, unsigned Reg,
1428 LaneBitmask LaneMask) {
1429 if (VNI->isUnused())
1430 return;
1431
1432 const VNInfo *DefVNI = LR.getVNInfoAt(VNI->def);
1433
1434 if (!DefVNI) {
1435 report("Value not live at VNInfo def and not marked unused", MF);
1436 report_context(LR, Reg, LaneMask);
1437 report_context(*VNI);
1438 return;
1439 }
1440
1441 if (DefVNI != VNI) {
1442 report("Live segment at def has different VNInfo", MF);
1443 report_context(LR, Reg, LaneMask);
1444 report_context(*VNI);
1445 return;
1446 }
1447
1448 const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def);
1449 if (!MBB) {
1450 report("Invalid VNInfo definition index", MF);
1451 report_context(LR, Reg, LaneMask);
1452 report_context(*VNI);
1453 return;
1454 }
1455
1456 if (VNI->isPHIDef()) {
1457 if (VNI->def != LiveInts->getMBBStartIdx(MBB)) {
1458 report("PHIDef VNInfo is not defined at MBB start", MBB);
1459 report_context(LR, Reg, LaneMask);
1460 report_context(*VNI);
1461 }
1462 return;
1463 }
1464
1465 // Non-PHI def.
1466 const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
1467 if (!MI) {
1468 report("No instruction at VNInfo def index", MBB);
1469 report_context(LR, Reg, LaneMask);
1470 report_context(*VNI);
1471 return;
1472 }
1473
1474 if (Reg != 0) {
1475 bool hasDef = false;
1476 bool isEarlyClobber = false;
1477 for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) {
1478 if (!MOI->isReg() || !MOI->isDef())
1479 continue;
1480 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1481 if (MOI->getReg() != Reg)
1482 continue;
1483 } else {
1484 if (!TargetRegisterInfo::isPhysicalRegister(MOI->getReg()) ||
1485 !TRI->hasRegUnit(MOI->getReg(), Reg))
1486 continue;
1487 }
1488 if (LaneMask != 0 &&
1489 (TRI->getSubRegIndexLaneMask(MOI->getSubReg()) & LaneMask) == 0)
1490 continue;
1491 hasDef = true;
1492 if (MOI->isEarlyClobber())
1493 isEarlyClobber = true;
1494 }
1495
1496 if (!hasDef) {
1497 report("Defining instruction does not modify register", MI);
1498 report_context(LR, Reg, LaneMask);
1499 report_context(*VNI);
1500 }
1501
1502 // Early clobber defs begin at USE slots, but other defs must begin at
1503 // DEF slots.
1504 if (isEarlyClobber) {
1505 if (!VNI->def.isEarlyClobber()) {
1506 report("Early clobber def must be at an early-clobber slot", MBB);
1507 report_context(LR, Reg, LaneMask);
1508 report_context(*VNI);
1509 }
1510 } else if (!VNI->def.isRegister()) {
1511 report("Non-PHI, non-early clobber def must be at a register slot", MBB);
1512 report_context(LR, Reg, LaneMask);
1513 report_context(*VNI);
1514 }
1515 }
1516 }
1517
verifyLiveRangeSegment(const LiveRange & LR,const LiveRange::const_iterator I,unsigned Reg,LaneBitmask LaneMask)1518 void MachineVerifier::verifyLiveRangeSegment(const LiveRange &LR,
1519 const LiveRange::const_iterator I,
1520 unsigned Reg, LaneBitmask LaneMask)
1521 {
1522 const LiveRange::Segment &S = *I;
1523 const VNInfo *VNI = S.valno;
1524 assert(VNI && "Live segment has no valno");
1525
1526 if (VNI->id >= LR.getNumValNums() || VNI != LR.getValNumInfo(VNI->id)) {
1527 report("Foreign valno in live segment", MF);
1528 report_context(LR, Reg, LaneMask);
1529 report_context(S);
1530 report_context(*VNI);
1531 }
1532
1533 if (VNI->isUnused()) {
1534 report("Live segment valno is marked unused", MF);
1535 report_context(LR, Reg, LaneMask);
1536 report_context(S);
1537 }
1538
1539 const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(S.start);
1540 if (!MBB) {
1541 report("Bad start of live segment, no basic block", MF);
1542 report_context(LR, Reg, LaneMask);
1543 report_context(S);
1544 return;
1545 }
1546 SlotIndex MBBStartIdx = LiveInts->getMBBStartIdx(MBB);
1547 if (S.start != MBBStartIdx && S.start != VNI->def) {
1548 report("Live segment must begin at MBB entry or valno def", MBB);
1549 report_context(LR, Reg, LaneMask);
1550 report_context(S);
1551 }
1552
1553 const MachineBasicBlock *EndMBB =
1554 LiveInts->getMBBFromIndex(S.end.getPrevSlot());
1555 if (!EndMBB) {
1556 report("Bad end of live segment, no basic block", MF);
1557 report_context(LR, Reg, LaneMask);
1558 report_context(S);
1559 return;
1560 }
1561
1562 // No more checks for live-out segments.
1563 if (S.end == LiveInts->getMBBEndIdx(EndMBB))
1564 return;
1565
1566 // RegUnit intervals are allowed dead phis.
1567 if (!TargetRegisterInfo::isVirtualRegister(Reg) && VNI->isPHIDef() &&
1568 S.start == VNI->def && S.end == VNI->def.getDeadSlot())
1569 return;
1570
1571 // The live segment is ending inside EndMBB
1572 const MachineInstr *MI =
1573 LiveInts->getInstructionFromIndex(S.end.getPrevSlot());
1574 if (!MI) {
1575 report("Live segment doesn't end at a valid instruction", EndMBB);
1576 report_context(LR, Reg, LaneMask);
1577 report_context(S);
1578 return;
1579 }
1580
1581 // The block slot must refer to a basic block boundary.
1582 if (S.end.isBlock()) {
1583 report("Live segment ends at B slot of an instruction", EndMBB);
1584 report_context(LR, Reg, LaneMask);
1585 report_context(S);
1586 }
1587
1588 if (S.end.isDead()) {
1589 // Segment ends on the dead slot.
1590 // That means there must be a dead def.
1591 if (!SlotIndex::isSameInstr(S.start, S.end)) {
1592 report("Live segment ending at dead slot spans instructions", EndMBB);
1593 report_context(LR, Reg, LaneMask);
1594 report_context(S);
1595 }
1596 }
1597
1598 // A live segment can only end at an early-clobber slot if it is being
1599 // redefined by an early-clobber def.
1600 if (S.end.isEarlyClobber()) {
1601 if (I+1 == LR.end() || (I+1)->start != S.end) {
1602 report("Live segment ending at early clobber slot must be "
1603 "redefined by an EC def in the same instruction", EndMBB);
1604 report_context(LR, Reg, LaneMask);
1605 report_context(S);
1606 }
1607 }
1608
1609 // The following checks only apply to virtual registers. Physreg liveness
1610 // is too weird to check.
1611 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1612 // A live segment can end with either a redefinition, a kill flag on a
1613 // use, or a dead flag on a def.
1614 bool hasRead = false;
1615 bool hasSubRegDef = false;
1616 for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) {
1617 if (!MOI->isReg() || MOI->getReg() != Reg)
1618 continue;
1619 if (LaneMask != 0 &&
1620 (LaneMask & TRI->getSubRegIndexLaneMask(MOI->getSubReg())) == 0)
1621 continue;
1622 if (MOI->isDef() && MOI->getSubReg() != 0)
1623 hasSubRegDef = true;
1624 if (MOI->readsReg())
1625 hasRead = true;
1626 }
1627 if (!S.end.isDead()) {
1628 if (!hasRead) {
1629 // When tracking subregister liveness, the main range must start new
1630 // values on partial register writes, even if there is no read.
1631 if (!MRI->shouldTrackSubRegLiveness(Reg) || LaneMask != 0 ||
1632 !hasSubRegDef) {
1633 report("Instruction ending live segment doesn't read the register",
1634 MI);
1635 report_context(LR, Reg, LaneMask);
1636 report_context(S);
1637 }
1638 }
1639 }
1640 }
1641
1642 // Now check all the basic blocks in this live segment.
1643 MachineFunction::const_iterator MFI = MBB->getIterator();
1644 // Is this live segment the beginning of a non-PHIDef VN?
1645 if (S.start == VNI->def && !VNI->isPHIDef()) {
1646 // Not live-in to any blocks.
1647 if (MBB == EndMBB)
1648 return;
1649 // Skip this block.
1650 ++MFI;
1651 }
1652 for (;;) {
1653 assert(LiveInts->isLiveInToMBB(LR, &*MFI));
1654 // We don't know how to track physregs into a landing pad.
1655 if (!TargetRegisterInfo::isVirtualRegister(Reg) &&
1656 MFI->isEHPad()) {
1657 if (&*MFI == EndMBB)
1658 break;
1659 ++MFI;
1660 continue;
1661 }
1662
1663 // Is VNI a PHI-def in the current block?
1664 bool IsPHI = VNI->isPHIDef() &&
1665 VNI->def == LiveInts->getMBBStartIdx(&*MFI);
1666
1667 // Check that VNI is live-out of all predecessors.
1668 for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(),
1669 PE = MFI->pred_end(); PI != PE; ++PI) {
1670 SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI);
1671 const VNInfo *PVNI = LR.getVNInfoBefore(PEnd);
1672
1673 // All predecessors must have a live-out value.
1674 if (!PVNI) {
1675 report("Register not marked live out of predecessor", *PI);
1676 report_context(LR, Reg, LaneMask);
1677 report_context(*VNI);
1678 errs() << " live into BB#" << MFI->getNumber()
1679 << '@' << LiveInts->getMBBStartIdx(&*MFI) << ", not live before "
1680 << PEnd << '\n';
1681 continue;
1682 }
1683
1684 // Only PHI-defs can take different predecessor values.
1685 if (!IsPHI && PVNI != VNI) {
1686 report("Different value live out of predecessor", *PI);
1687 report_context(LR, Reg, LaneMask);
1688 errs() << "Valno #" << PVNI->id << " live out of BB#"
1689 << (*PI)->getNumber() << '@' << PEnd << "\nValno #" << VNI->id
1690 << " live into BB#" << MFI->getNumber() << '@'
1691 << LiveInts->getMBBStartIdx(&*MFI) << '\n';
1692 }
1693 }
1694 if (&*MFI == EndMBB)
1695 break;
1696 ++MFI;
1697 }
1698 }
1699
verifyLiveRange(const LiveRange & LR,unsigned Reg,LaneBitmask LaneMask)1700 void MachineVerifier::verifyLiveRange(const LiveRange &LR, unsigned Reg,
1701 LaneBitmask LaneMask) {
1702 for (const VNInfo *VNI : LR.valnos)
1703 verifyLiveRangeValue(LR, VNI, Reg, LaneMask);
1704
1705 for (LiveRange::const_iterator I = LR.begin(), E = LR.end(); I != E; ++I)
1706 verifyLiveRangeSegment(LR, I, Reg, LaneMask);
1707 }
1708
verifyLiveInterval(const LiveInterval & LI)1709 void MachineVerifier::verifyLiveInterval(const LiveInterval &LI) {
1710 unsigned Reg = LI.reg;
1711 assert(TargetRegisterInfo::isVirtualRegister(Reg));
1712 verifyLiveRange(LI, Reg);
1713
1714 LaneBitmask Mask = 0;
1715 LaneBitmask MaxMask = MRI->getMaxLaneMaskForVReg(Reg);
1716 for (const LiveInterval::SubRange &SR : LI.subranges()) {
1717 if ((Mask & SR.LaneMask) != 0) {
1718 report("Lane masks of sub ranges overlap in live interval", MF);
1719 report_context(LI);
1720 }
1721 if ((SR.LaneMask & ~MaxMask) != 0) {
1722 report("Subrange lanemask is invalid", MF);
1723 report_context(LI);
1724 }
1725 if (SR.empty()) {
1726 report("Subrange must not be empty", MF);
1727 report_context(SR, LI.reg, SR.LaneMask);
1728 }
1729 Mask |= SR.LaneMask;
1730 verifyLiveRange(SR, LI.reg, SR.LaneMask);
1731 if (!LI.covers(SR)) {
1732 report("A Subrange is not covered by the main range", MF);
1733 report_context(LI);
1734 }
1735 }
1736
1737 // Check the LI only has one connected component.
1738 ConnectedVNInfoEqClasses ConEQ(*LiveInts);
1739 unsigned NumComp = ConEQ.Classify(&LI);
1740 if (NumComp > 1) {
1741 report("Multiple connected components in live interval", MF);
1742 report_context(LI);
1743 for (unsigned comp = 0; comp != NumComp; ++comp) {
1744 errs() << comp << ": valnos";
1745 for (LiveInterval::const_vni_iterator I = LI.vni_begin(),
1746 E = LI.vni_end(); I!=E; ++I)
1747 if (comp == ConEQ.getEqClass(*I))
1748 errs() << ' ' << (*I)->id;
1749 errs() << '\n';
1750 }
1751 }
1752 }
1753
1754 namespace {
1755 // FrameSetup and FrameDestroy can have zero adjustment, so using a single
1756 // integer, we can't tell whether it is a FrameSetup or FrameDestroy if the
1757 // value is zero.
1758 // We use a bool plus an integer to capture the stack state.
1759 struct StackStateOfBB {
StackStateOfBB__anon480184f30211::StackStateOfBB1760 StackStateOfBB() : EntryValue(0), ExitValue(0), EntryIsSetup(false),
1761 ExitIsSetup(false) { }
StackStateOfBB__anon480184f30211::StackStateOfBB1762 StackStateOfBB(int EntryVal, int ExitVal, bool EntrySetup, bool ExitSetup) :
1763 EntryValue(EntryVal), ExitValue(ExitVal), EntryIsSetup(EntrySetup),
1764 ExitIsSetup(ExitSetup) { }
1765 // Can be negative, which means we are setting up a frame.
1766 int EntryValue;
1767 int ExitValue;
1768 bool EntryIsSetup;
1769 bool ExitIsSetup;
1770 };
1771 }
1772
1773 /// Make sure on every path through the CFG, a FrameSetup <n> is always followed
1774 /// by a FrameDestroy <n>, stack adjustments are identical on all
1775 /// CFG edges to a merge point, and frame is destroyed at end of a return block.
verifyStackFrame()1776 void MachineVerifier::verifyStackFrame() {
1777 unsigned FrameSetupOpcode = TII->getCallFrameSetupOpcode();
1778 unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode();
1779
1780 SmallVector<StackStateOfBB, 8> SPState;
1781 SPState.resize(MF->getNumBlockIDs());
1782 SmallPtrSet<const MachineBasicBlock*, 8> Reachable;
1783
1784 // Visit the MBBs in DFS order.
1785 for (df_ext_iterator<const MachineFunction*,
1786 SmallPtrSet<const MachineBasicBlock*, 8> >
1787 DFI = df_ext_begin(MF, Reachable), DFE = df_ext_end(MF, Reachable);
1788 DFI != DFE; ++DFI) {
1789 const MachineBasicBlock *MBB = *DFI;
1790
1791 StackStateOfBB BBState;
1792 // Check the exit state of the DFS stack predecessor.
1793 if (DFI.getPathLength() >= 2) {
1794 const MachineBasicBlock *StackPred = DFI.getPath(DFI.getPathLength() - 2);
1795 assert(Reachable.count(StackPred) &&
1796 "DFS stack predecessor is already visited.\n");
1797 BBState.EntryValue = SPState[StackPred->getNumber()].ExitValue;
1798 BBState.EntryIsSetup = SPState[StackPred->getNumber()].ExitIsSetup;
1799 BBState.ExitValue = BBState.EntryValue;
1800 BBState.ExitIsSetup = BBState.EntryIsSetup;
1801 }
1802
1803 // Update stack state by checking contents of MBB.
1804 for (const auto &I : *MBB) {
1805 if (I.getOpcode() == FrameSetupOpcode) {
1806 // The first operand of a FrameOpcode should be i32.
1807 int Size = I.getOperand(0).getImm();
1808 assert(Size >= 0 &&
1809 "Value should be non-negative in FrameSetup and FrameDestroy.\n");
1810
1811 if (BBState.ExitIsSetup)
1812 report("FrameSetup is after another FrameSetup", &I);
1813 BBState.ExitValue -= Size;
1814 BBState.ExitIsSetup = true;
1815 }
1816
1817 if (I.getOpcode() == FrameDestroyOpcode) {
1818 // The first operand of a FrameOpcode should be i32.
1819 int Size = I.getOperand(0).getImm();
1820 assert(Size >= 0 &&
1821 "Value should be non-negative in FrameSetup and FrameDestroy.\n");
1822
1823 if (!BBState.ExitIsSetup)
1824 report("FrameDestroy is not after a FrameSetup", &I);
1825 int AbsSPAdj = BBState.ExitValue < 0 ? -BBState.ExitValue :
1826 BBState.ExitValue;
1827 if (BBState.ExitIsSetup && AbsSPAdj != Size) {
1828 report("FrameDestroy <n> is after FrameSetup <m>", &I);
1829 errs() << "FrameDestroy <" << Size << "> is after FrameSetup <"
1830 << AbsSPAdj << ">.\n";
1831 }
1832 BBState.ExitValue += Size;
1833 BBState.ExitIsSetup = false;
1834 }
1835 }
1836 SPState[MBB->getNumber()] = BBState;
1837
1838 // Make sure the exit state of any predecessor is consistent with the entry
1839 // state.
1840 for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(),
1841 E = MBB->pred_end(); I != E; ++I) {
1842 if (Reachable.count(*I) &&
1843 (SPState[(*I)->getNumber()].ExitValue != BBState.EntryValue ||
1844 SPState[(*I)->getNumber()].ExitIsSetup != BBState.EntryIsSetup)) {
1845 report("The exit stack state of a predecessor is inconsistent.", MBB);
1846 errs() << "Predecessor BB#" << (*I)->getNumber() << " has exit state ("
1847 << SPState[(*I)->getNumber()].ExitValue << ", "
1848 << SPState[(*I)->getNumber()].ExitIsSetup
1849 << "), while BB#" << MBB->getNumber() << " has entry state ("
1850 << BBState.EntryValue << ", " << BBState.EntryIsSetup << ").\n";
1851 }
1852 }
1853
1854 // Make sure the entry state of any successor is consistent with the exit
1855 // state.
1856 for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
1857 E = MBB->succ_end(); I != E; ++I) {
1858 if (Reachable.count(*I) &&
1859 (SPState[(*I)->getNumber()].EntryValue != BBState.ExitValue ||
1860 SPState[(*I)->getNumber()].EntryIsSetup != BBState.ExitIsSetup)) {
1861 report("The entry stack state of a successor is inconsistent.", MBB);
1862 errs() << "Successor BB#" << (*I)->getNumber() << " has entry state ("
1863 << SPState[(*I)->getNumber()].EntryValue << ", "
1864 << SPState[(*I)->getNumber()].EntryIsSetup
1865 << "), while BB#" << MBB->getNumber() << " has exit state ("
1866 << BBState.ExitValue << ", " << BBState.ExitIsSetup << ").\n";
1867 }
1868 }
1869
1870 // Make sure a basic block with return ends with zero stack adjustment.
1871 if (!MBB->empty() && MBB->back().isReturn()) {
1872 if (BBState.ExitIsSetup)
1873 report("A return block ends with a FrameSetup.", MBB);
1874 if (BBState.ExitValue)
1875 report("A return block ends with a nonzero stack adjustment.", MBB);
1876 }
1877 }
1878 }
1879