1 //===-- MachineVerifier.cpp - Machine Code Verifier -------------*- C++ -*-===//
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/Function.h"
27 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
28 #include "llvm/CodeGen/LiveVariables.h"
29 #include "llvm/CodeGen/MachineFunctionPass.h"
30 #include "llvm/CodeGen/MachineFrameInfo.h"
31 #include "llvm/CodeGen/MachineMemOperand.h"
32 #include "llvm/CodeGen/MachineRegisterInfo.h"
33 #include "llvm/CodeGen/Passes.h"
34 #include "llvm/Target/TargetMachine.h"
35 #include "llvm/Target/TargetRegisterInfo.h"
36 #include "llvm/Target/TargetInstrInfo.h"
37 #include "llvm/ADT/DenseSet.h"
38 #include "llvm/ADT/SetOperations.h"
39 #include "llvm/ADT/SmallVector.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/raw_ostream.h"
46 struct MachineVerifier {
48 MachineVerifier(Pass *pass) :
50 OutFileName(getenv("LLVM_VERIFY_MACHINEINSTRS"))
53 bool runOnMachineFunction(MachineFunction &MF);
56 const char *const OutFileName;
58 const MachineFunction *MF;
59 const TargetMachine *TM;
60 const TargetRegisterInfo *TRI;
61 const MachineRegisterInfo *MRI;
65 typedef SmallVector<unsigned, 16> RegVector;
66 typedef DenseSet<unsigned> RegSet;
67 typedef DenseMap<unsigned, const MachineInstr*> RegMap;
69 BitVector regsReserved;
71 RegVector regsDefined, regsDead, regsKilled;
72 RegSet regsLiveInButUnused;
74 // Add Reg and any sub-registers to RV
75 void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
77 if (TargetRegisterInfo::isPhysicalRegister(Reg))
78 for (const unsigned *R = TRI->getSubRegisters(Reg); *R; R++)
83 // Is this MBB reachable from the MF entry point?
86 // Vregs that must be live in because they are used without being
87 // defined. Map value is the user.
90 // Regs killed in MBB. They may be defined again, and will then be in both
91 // regsKilled and regsLiveOut.
94 // Regs defined in MBB and live out. Note that vregs passing through may
95 // be live out without being mentioned here.
98 // Vregs that pass through MBB untouched. This set is disjoint from
99 // regsKilled and regsLiveOut.
102 // Vregs that must pass through MBB because they are needed by a successor
103 // block. This set is disjoint from regsLiveOut.
104 RegSet vregsRequired;
106 BBInfo() : reachable(false) {}
108 // Add register to vregsPassed if it belongs there. Return true if
110 bool addPassed(unsigned Reg) {
111 if (!TargetRegisterInfo::isVirtualRegister(Reg))
113 if (regsKilled.count(Reg) || regsLiveOut.count(Reg))
115 return vregsPassed.insert(Reg).second;
118 // Same for a full set.
119 bool addPassed(const RegSet &RS) {
120 bool changed = false;
121 for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
127 // Add register to vregsRequired if it belongs there. Return true if
129 bool addRequired(unsigned Reg) {
130 if (!TargetRegisterInfo::isVirtualRegister(Reg))
132 if (regsLiveOut.count(Reg))
134 return vregsRequired.insert(Reg).second;
137 // Same for a full set.
138 bool addRequired(const RegSet &RS) {
139 bool changed = false;
140 for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
146 // Same for a full map.
147 bool addRequired(const RegMap &RM) {
148 bool changed = false;
149 for (RegMap::const_iterator I = RM.begin(), E = RM.end(); I != E; ++I)
150 if (addRequired(I->first))
155 // Live-out registers are either in regsLiveOut or vregsPassed.
156 bool isLiveOut(unsigned Reg) const {
157 return regsLiveOut.count(Reg) || vregsPassed.count(Reg);
161 // Extra register info per MBB.
162 DenseMap<const MachineBasicBlock*, BBInfo> MBBInfoMap;
164 bool isReserved(unsigned Reg) {
165 return Reg < regsReserved.size() && regsReserved.test(Reg);
168 // Analysis information if available
169 LiveVariables *LiveVars;
170 LiveIntervals *LiveInts;
172 void visitMachineFunctionBefore();
173 void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
174 void visitMachineInstrBefore(const MachineInstr *MI);
175 void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
176 void visitMachineInstrAfter(const MachineInstr *MI);
177 void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB);
178 void visitMachineFunctionAfter();
180 void report(const char *msg, const MachineFunction *MF);
181 void report(const char *msg, const MachineBasicBlock *MBB);
182 void report(const char *msg, const MachineInstr *MI);
183 void report(const char *msg, const MachineOperand *MO, unsigned MONum);
185 void markReachable(const MachineBasicBlock *MBB);
186 void calcRegsPassed();
187 void checkPHIOps(const MachineBasicBlock *MBB);
189 void calcRegsRequired();
190 void verifyLiveVariables();
193 struct MachineVerifierPass : public MachineFunctionPass {
194 static char ID; // Pass ID, replacement for typeid
196 MachineVerifierPass()
197 : MachineFunctionPass(ID) {}
199 void getAnalysisUsage(AnalysisUsage &AU) const {
200 AU.setPreservesAll();
201 MachineFunctionPass::getAnalysisUsage(AU);
204 bool runOnMachineFunction(MachineFunction &MF) {
212 char MachineVerifierPass::ID = 0;
213 static RegisterPass<MachineVerifierPass>
214 MachineVer("machineverifier", "Verify generated machine code");
215 static const PassInfo *const MachineVerifyID = &MachineVer;
217 FunctionPass *llvm::createMachineVerifierPass() {
218 return new MachineVerifierPass();
221 void MachineFunction::verify(Pass *p) const {
222 MachineVerifier(p).runOnMachineFunction(const_cast<MachineFunction&>(*this));
225 bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
226 raw_ostream *OutFile = 0;
228 std::string ErrorInfo;
229 OutFile = new raw_fd_ostream(OutFileName, ErrorInfo,
230 raw_fd_ostream::F_Append);
231 if (!ErrorInfo.empty()) {
232 errs() << "Error opening '" << OutFileName << "': " << ErrorInfo << '\n';
244 TM = &MF.getTarget();
245 TRI = TM->getRegisterInfo();
246 MRI = &MF.getRegInfo();
249 LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
250 LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>();
256 visitMachineFunctionBefore();
257 for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
259 visitMachineBasicBlockBefore(MFI);
260 for (MachineBasicBlock::const_iterator MBBI = MFI->begin(),
261 MBBE = MFI->end(); MBBI != MBBE; ++MBBI) {
262 visitMachineInstrBefore(MBBI);
263 for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
264 visitMachineOperand(&MBBI->getOperand(I), I);
265 visitMachineInstrAfter(MBBI);
267 visitMachineBasicBlockAfter(MFI);
269 visitMachineFunctionAfter();
273 else if (foundErrors)
274 report_fatal_error("Found "+Twine(foundErrors)+" machine code errors.");
281 regsLiveInButUnused.clear();
284 return false; // no changes
287 void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
292 *OS << "*** Bad machine code: " << msg << " ***\n"
293 << "- function: " << MF->getFunction()->getNameStr() << "\n";
296 void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
298 report(msg, MBB->getParent());
299 *OS << "- basic block: " << MBB->getName()
301 << " (BB#" << MBB->getNumber() << ")\n";
304 void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
306 report(msg, MI->getParent());
307 *OS << "- instruction: ";
311 void MachineVerifier::report(const char *msg,
312 const MachineOperand *MO, unsigned MONum) {
314 report(msg, MO->getParent());
315 *OS << "- operand " << MONum << ": ";
320 void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
321 BBInfo &MInfo = MBBInfoMap[MBB];
322 if (!MInfo.reachable) {
323 MInfo.reachable = true;
324 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
325 SuE = MBB->succ_end(); SuI != SuE; ++SuI)
330 void MachineVerifier::visitMachineFunctionBefore() {
331 regsReserved = TRI->getReservedRegs(*MF);
333 // A sub-register of a reserved register is also reserved
334 for (int Reg = regsReserved.find_first(); Reg>=0;
335 Reg = regsReserved.find_next(Reg)) {
336 for (const unsigned *Sub = TRI->getSubRegisters(Reg); *Sub; ++Sub) {
337 // FIXME: This should probably be:
338 // assert(regsReserved.test(*Sub) && "Non-reserved sub-register");
339 regsReserved.set(*Sub);
342 markReachable(&MF->front());
345 // Does iterator point to a and b as the first two elements?
346 static bool matchPair(MachineBasicBlock::const_succ_iterator i,
347 const MachineBasicBlock *a, const MachineBasicBlock *b) {
356 MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
357 const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
359 // Call AnalyzeBranch. If it succeeds, there several more conditions to check.
360 MachineBasicBlock *TBB = 0, *FBB = 0;
361 SmallVector<MachineOperand, 4> Cond;
362 if (!TII->AnalyzeBranch(*const_cast<MachineBasicBlock *>(MBB),
364 // Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's
365 // check whether its answers match up with reality.
367 // Block falls through to its successor.
368 MachineFunction::const_iterator MBBI = MBB;
370 if (MBBI == MF->end()) {
371 // It's possible that the block legitimately ends with a noreturn
372 // call or an unreachable, in which case it won't actually fall
373 // out the bottom of the function.
374 } else if (MBB->succ_empty()) {
375 // It's possible that the block legitimately ends with a noreturn
376 // call or an unreachable, in which case it won't actuall fall
378 } else if (MBB->succ_size() != 1) {
379 report("MBB exits via unconditional fall-through but doesn't have "
380 "exactly one CFG successor!", MBB);
381 } else if (MBB->succ_begin()[0] != MBBI) {
382 report("MBB exits via unconditional fall-through but its successor "
383 "differs from its CFG successor!", MBB);
385 if (!MBB->empty() && MBB->back().getDesc().isBarrier() &&
386 !TII->isPredicated(&MBB->back())) {
387 report("MBB exits via unconditional fall-through but ends with a "
388 "barrier instruction!", MBB);
391 report("MBB exits via unconditional fall-through but has a condition!",
394 } else if (TBB && !FBB && Cond.empty()) {
395 // Block unconditionally branches somewhere.
396 if (MBB->succ_size() != 1) {
397 report("MBB exits via unconditional branch but doesn't have "
398 "exactly one CFG successor!", MBB);
399 } else if (MBB->succ_begin()[0] != TBB) {
400 report("MBB exits via unconditional branch but the CFG "
401 "successor doesn't match the actual successor!", MBB);
404 report("MBB exits via unconditional branch but doesn't contain "
405 "any instructions!", MBB);
406 } else if (!MBB->back().getDesc().isBarrier()) {
407 report("MBB exits via unconditional branch but doesn't end with a "
408 "barrier instruction!", MBB);
409 } else if (!MBB->back().getDesc().isTerminator()) {
410 report("MBB exits via unconditional branch but the branch isn't a "
411 "terminator instruction!", MBB);
413 } else if (TBB && !FBB && !Cond.empty()) {
414 // Block conditionally branches somewhere, otherwise falls through.
415 MachineFunction::const_iterator MBBI = MBB;
417 if (MBBI == MF->end()) {
418 report("MBB conditionally falls through out of function!", MBB);
419 } if (MBB->succ_size() != 2) {
420 report("MBB exits via conditional branch/fall-through but doesn't have "
421 "exactly two CFG successors!", MBB);
422 } else if (!matchPair(MBB->succ_begin(), TBB, MBBI)) {
423 report("MBB exits via conditional branch/fall-through but the CFG "
424 "successors don't match the actual successors!", MBB);
427 report("MBB exits via conditional branch/fall-through but doesn't "
428 "contain any instructions!", MBB);
429 } else if (MBB->back().getDesc().isBarrier()) {
430 report("MBB exits via conditional branch/fall-through but ends with a "
431 "barrier instruction!", MBB);
432 } else if (!MBB->back().getDesc().isTerminator()) {
433 report("MBB exits via conditional branch/fall-through but the branch "
434 "isn't a terminator instruction!", MBB);
436 } else if (TBB && FBB) {
437 // Block conditionally branches somewhere, otherwise branches
439 if (MBB->succ_size() != 2) {
440 report("MBB exits via conditional branch/branch but doesn't have "
441 "exactly two CFG successors!", MBB);
442 } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) {
443 report("MBB exits via conditional branch/branch but the CFG "
444 "successors don't match the actual successors!", MBB);
447 report("MBB exits via conditional branch/branch but doesn't "
448 "contain any instructions!", MBB);
449 } else if (!MBB->back().getDesc().isBarrier()) {
450 report("MBB exits via conditional branch/branch but doesn't end with a "
451 "barrier instruction!", MBB);
452 } else if (!MBB->back().getDesc().isTerminator()) {
453 report("MBB exits via conditional branch/branch but the branch "
454 "isn't a terminator instruction!", MBB);
457 report("MBB exits via conditinal branch/branch but there's no "
461 report("AnalyzeBranch returned invalid data!", MBB);
466 for (MachineBasicBlock::livein_iterator I = MBB->livein_begin(),
467 E = MBB->livein_end(); I != E; ++I) {
468 if (!TargetRegisterInfo::isPhysicalRegister(*I)) {
469 report("MBB live-in list contains non-physical register", MBB);
473 for (const unsigned *R = TRI->getSubRegisters(*I); *R; R++)
476 regsLiveInButUnused = regsLive;
478 const MachineFrameInfo *MFI = MF->getFrameInfo();
479 assert(MFI && "Function has no frame info");
480 BitVector PR = MFI->getPristineRegs(MBB);
481 for (int I = PR.find_first(); I>0; I = PR.find_next(I)) {
483 for (const unsigned *R = TRI->getSubRegisters(I); *R; R++)
491 void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
492 const TargetInstrDesc &TI = MI->getDesc();
493 if (MI->getNumOperands() < TI.getNumOperands()) {
494 report("Too few operands", MI);
495 *OS << TI.getNumOperands() << " operands expected, but "
496 << MI->getNumExplicitOperands() << " given.\n";
499 // Check the MachineMemOperands for basic consistency.
500 for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
501 E = MI->memoperands_end(); I != E; ++I) {
502 if ((*I)->isLoad() && !TI.mayLoad())
503 report("Missing mayLoad flag", MI);
504 if ((*I)->isStore() && !TI.mayStore())
505 report("Missing mayStore flag", MI);
508 // Debug values must not have a slot index.
509 // Other instructions must have one.
511 bool mapped = !LiveInts->isNotInMIMap(MI);
512 if (MI->isDebugValue()) {
514 report("Debug instruction has a slot index", MI);
517 report("Missing slot index", MI);
524 MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
525 const MachineInstr *MI = MO->getParent();
526 const TargetInstrDesc &TI = MI->getDesc();
528 // The first TI.NumDefs operands must be explicit register defines
529 if (MONum < TI.getNumDefs()) {
531 report("Explicit definition must be a register", MO, MONum);
532 else if (!MO->isDef())
533 report("Explicit definition marked as use", MO, MONum);
534 else if (MO->isImplicit())
535 report("Explicit definition marked as implicit", MO, MONum);
536 } else if (MONum < TI.getNumOperands()) {
539 report("Explicit operand marked as def", MO, MONum);
540 if (MO->isImplicit())
541 report("Explicit operand marked as implicit", MO, MONum);
544 // ARM adds %reg0 operands to indicate predicates. We'll allow that.
545 if (MO->isReg() && !MO->isImplicit() && !TI.isVariadic() && MO->getReg())
546 report("Extra explicit operand on non-variadic instruction", MO, MONum);
549 switch (MO->getType()) {
550 case MachineOperand::MO_Register: {
551 const unsigned Reg = MO->getReg();
555 // Check Live Variables.
557 // An <undef> doesn't refer to any register, so just skip it.
558 } else if (MO->isUse()) {
559 regsLiveInButUnused.erase(Reg);
563 if (MI->isRegTiedToDefOperand(MONum, &defIdx)) {
564 // A two-addr use counts as a kill if use and def are the same.
565 unsigned DefReg = MI->getOperand(defIdx).getReg();
568 // ANd in that case an explicit kill flag is not allowed.
570 report("Illegal kill flag on two-address instruction operand",
572 } else if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
573 report("Two-address instruction operands must be identical",
577 isKill = MO->isKill();
580 addRegWithSubRegs(regsKilled, Reg);
582 // Check that LiveVars knows this kill
583 if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg)) {
584 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
585 if (std::find(VI.Kills.begin(),
586 VI.Kills.end(), MI) == VI.Kills.end())
587 report("Kill missing from LiveVariables", MO, MONum);
591 // Check LiveInts liveness and kill.
592 if (LiveInts && !LiveInts->isNotInMIMap(MI)) {
593 SlotIndex UseIdx = LiveInts->getInstructionIndex(MI).getUseIndex();
594 if (LiveInts->hasInterval(Reg)) {
595 const LiveInterval &LI = LiveInts->getInterval(Reg);
596 if (!LI.liveAt(UseIdx)) {
597 report("No live range at use", MO, MONum);
598 *OS << UseIdx << " is not live in " << LI << '\n';
600 // TODO: Verify isKill == LI.killedAt.
601 } else if (TargetRegisterInfo::isVirtualRegister(Reg)) {
602 report("Virtual register has no Live interval", MO, MONum);
606 // Use of a dead register.
607 if (!regsLive.count(Reg)) {
608 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
609 // Reserved registers may be used even when 'dead'.
610 if (!isReserved(Reg))
611 report("Using an undefined physical register", MO, MONum);
613 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
614 // We don't know which virtual registers are live in, so only complain
615 // if vreg was killed in this MBB. Otherwise keep track of vregs that
616 // must be live in. PHI instructions are handled separately.
617 if (MInfo.regsKilled.count(Reg))
618 report("Using a killed virtual register", MO, MONum);
619 else if (!MI->isPHI())
620 MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI));
626 // TODO: verify that earlyclobber ops are not used.
628 addRegWithSubRegs(regsDead, Reg);
630 addRegWithSubRegs(regsDefined, Reg);
632 // Check LiveInts for a live range.
633 if (LiveInts && !LiveInts->isNotInMIMap(MI)) {
634 SlotIndex DefIdx = LiveInts->getInstructionIndex(MI).getDefIndex();
635 if (LiveInts->hasInterval(Reg)) {
636 const LiveInterval &LI = LiveInts->getInterval(Reg);
637 if (const LiveRange *LR = LI.getLiveRangeContaining(DefIdx)) {
638 assert(LR->valno && "NULL valno is not allowed");
639 if (LR->valno->def != DefIdx) {
640 report("Inconsistent valno->def", MO, MONum);
641 *OS << "Valno " << LR->valno->id << " is not defined at "
642 << DefIdx << " in " << LI << '\n';
644 if (LR->start != DefIdx) {
645 report("Live range doesn't start at def", MO, MONum);
647 *OS << " should start at " << DefIdx << " in " << LI << '\n';
650 report("No live range at def", MO, MONum);
651 *OS << DefIdx << " is not live in " << LI << '\n';
653 } else if (TargetRegisterInfo::isVirtualRegister(Reg)) {
654 report("Virtual register has no Live interval", MO, MONum);
659 // Check register classes.
660 if (MONum < TI.getNumOperands() && !MO->isImplicit()) {
661 const TargetOperandInfo &TOI = TI.OpInfo[MONum];
662 unsigned SubIdx = MO->getSubReg();
664 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
667 unsigned s = TRI->getSubReg(Reg, SubIdx);
669 report("Invalid subregister index for physical register",
675 if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
676 if (!DRC->contains(sr)) {
677 report("Illegal physical register for instruction", MO, MONum);
678 *OS << TRI->getName(sr) << " is not a "
679 << DRC->getName() << " register.\n";
684 const TargetRegisterClass *RC = MRI->getRegClass(Reg);
686 const TargetRegisterClass *SRC = RC->getSubRegisterRegClass(SubIdx);
688 report("Invalid subregister index for virtual register", MO, MONum);
689 *OS << "Register class " << RC->getName()
690 << " does not support subreg index " << SubIdx << "\n";
695 if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
696 if (RC != DRC && !RC->hasSuperClass(DRC)) {
697 report("Illegal virtual register for instruction", MO, MONum);
698 *OS << "Expected a " << DRC->getName() << " register, but got a "
699 << RC->getName() << " register\n";
707 case MachineOperand::MO_MachineBasicBlock:
708 if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent()))
709 report("PHI operand is not in the CFG", MO, MONum);
717 void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
718 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
719 set_union(MInfo.regsKilled, regsKilled);
720 set_subtract(regsLive, regsKilled); regsKilled.clear();
721 set_subtract(regsLive, regsDead); regsDead.clear();
722 set_union(regsLive, regsDefined); regsDefined.clear();
726 MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
727 MBBInfoMap[MBB].regsLiveOut = regsLive;
731 // Calculate the largest possible vregsPassed sets. These are the registers that
732 // can pass through an MBB live, but may not be live every time. It is assumed
733 // that all vregsPassed sets are empty before the call.
734 void MachineVerifier::calcRegsPassed() {
735 // First push live-out regs to successors' vregsPassed. Remember the MBBs that
736 // have any vregsPassed.
737 DenseSet<const MachineBasicBlock*> todo;
738 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
740 const MachineBasicBlock &MBB(*MFI);
741 BBInfo &MInfo = MBBInfoMap[&MBB];
742 if (!MInfo.reachable)
744 for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
745 SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
746 BBInfo &SInfo = MBBInfoMap[*SuI];
747 if (SInfo.addPassed(MInfo.regsLiveOut))
752 // Iteratively push vregsPassed to successors. This will converge to the same
753 // final state regardless of DenseSet iteration order.
754 while (!todo.empty()) {
755 const MachineBasicBlock *MBB = *todo.begin();
757 BBInfo &MInfo = MBBInfoMap[MBB];
758 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
759 SuE = MBB->succ_end(); SuI != SuE; ++SuI) {
762 BBInfo &SInfo = MBBInfoMap[*SuI];
763 if (SInfo.addPassed(MInfo.vregsPassed))
769 // Calculate the set of virtual registers that must be passed through each basic
770 // block in order to satisfy the requirements of successor blocks. This is very
771 // similar to calcRegsPassed, only backwards.
772 void MachineVerifier::calcRegsRequired() {
773 // First push live-in regs to predecessors' vregsRequired.
774 DenseSet<const MachineBasicBlock*> todo;
775 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
777 const MachineBasicBlock &MBB(*MFI);
778 BBInfo &MInfo = MBBInfoMap[&MBB];
779 for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(),
780 PrE = MBB.pred_end(); PrI != PrE; ++PrI) {
781 BBInfo &PInfo = MBBInfoMap[*PrI];
782 if (PInfo.addRequired(MInfo.vregsLiveIn))
787 // Iteratively push vregsRequired to predecessors. This will converge to the
788 // same final state regardless of DenseSet iteration order.
789 while (!todo.empty()) {
790 const MachineBasicBlock *MBB = *todo.begin();
792 BBInfo &MInfo = MBBInfoMap[MBB];
793 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
794 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
797 BBInfo &SInfo = MBBInfoMap[*PrI];
798 if (SInfo.addRequired(MInfo.vregsRequired))
804 // Check PHI instructions at the beginning of MBB. It is assumed that
805 // calcRegsPassed has been run so BBInfo::isLiveOut is valid.
806 void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
807 for (MachineBasicBlock::const_iterator BBI = MBB->begin(), BBE = MBB->end();
808 BBI != BBE && BBI->isPHI(); ++BBI) {
809 DenseSet<const MachineBasicBlock*> seen;
811 for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2) {
812 unsigned Reg = BBI->getOperand(i).getReg();
813 const MachineBasicBlock *Pre = BBI->getOperand(i + 1).getMBB();
814 if (!Pre->isSuccessor(MBB))
817 BBInfo &PrInfo = MBBInfoMap[Pre];
818 if (PrInfo.reachable && !PrInfo.isLiveOut(Reg))
819 report("PHI operand is not live-out from predecessor",
820 &BBI->getOperand(i), i);
823 // Did we see all predecessors?
824 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
825 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
826 if (!seen.count(*PrI)) {
827 report("Missing PHI operand", BBI);
828 *OS << "BB#" << (*PrI)->getNumber()
829 << " is a predecessor according to the CFG.\n";
835 void MachineVerifier::visitMachineFunctionAfter() {
838 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
840 BBInfo &MInfo = MBBInfoMap[MFI];
842 // Skip unreachable MBBs.
843 if (!MInfo.reachable)
849 // Now check LiveVariables info if available
852 verifyLiveVariables();
856 void MachineVerifier::verifyLiveVariables() {
857 assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
858 for (unsigned Reg = TargetRegisterInfo::FirstVirtualRegister,
859 RegE = MRI->getLastVirtReg()-1; Reg != RegE; ++Reg) {
860 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
861 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
863 BBInfo &MInfo = MBBInfoMap[MFI];
865 // Our vregsRequired should be identical to LiveVariables' AliveBlocks
866 if (MInfo.vregsRequired.count(Reg)) {
867 if (!VI.AliveBlocks.test(MFI->getNumber())) {
868 report("LiveVariables: Block missing from AliveBlocks", MFI);
869 *OS << "Virtual register %reg" << Reg
870 << " must be live through the block.\n";
873 if (VI.AliveBlocks.test(MFI->getNumber())) {
874 report("LiveVariables: Block should not be in AliveBlocks", MFI);
875 *OS << "Virtual register %reg" << Reg
876 << " is not needed live through the block.\n";