1 //===-- MachineVerifier.cpp - Machine Code Verifier -----------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Pass to verify generated machine code. The following is checked:
12 // Operand counts: All explicit operands must be present.
14 // Register classes: All physical and virtual register operands must be
15 // compatible with the register class required by the instruction descriptor.
17 // Register live intervals: Registers must be defined only once, and must be
18 // defined before use.
20 // The machine code verifier is enabled from LLVMTargetMachine.cpp with the
21 // command-line option -verify-machineinstrs, or by defining the environment
22 // variable LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive
23 // the verifier errors.
24 //===----------------------------------------------------------------------===//
26 #include "llvm/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 const 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();
191 void verifyLiveIntervals();
194 struct MachineVerifierPass : public MachineFunctionPass {
195 static char ID; // Pass ID, replacement for typeid
197 MachineVerifierPass()
198 : MachineFunctionPass(ID) {
199 initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
202 void getAnalysisUsage(AnalysisUsage &AU) const {
203 AU.setPreservesAll();
204 MachineFunctionPass::getAnalysisUsage(AU);
207 bool runOnMachineFunction(MachineFunction &MF) {
215 char MachineVerifierPass::ID = 0;
216 INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
217 "Verify generated machine code", false, false)
219 FunctionPass *llvm::createMachineVerifierPass() {
220 return new MachineVerifierPass();
223 void MachineFunction::verify(Pass *p) const {
224 MachineVerifier(p).runOnMachineFunction(const_cast<MachineFunction&>(*this));
227 bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
228 raw_ostream *OutFile = 0;
230 std::string ErrorInfo;
231 OutFile = new raw_fd_ostream(OutFileName, ErrorInfo,
232 raw_fd_ostream::F_Append);
233 if (!ErrorInfo.empty()) {
234 errs() << "Error opening '" << OutFileName << "': " << ErrorInfo << '\n';
246 TM = &MF.getTarget();
247 TRI = TM->getRegisterInfo();
248 MRI = &MF.getRegInfo();
253 LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>();
254 // We don't want to verify LiveVariables if LiveIntervals is available.
256 LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
259 visitMachineFunctionBefore();
260 for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
262 visitMachineBasicBlockBefore(MFI);
263 for (MachineBasicBlock::const_iterator MBBI = MFI->begin(),
264 MBBE = MFI->end(); MBBI != MBBE; ++MBBI) {
265 visitMachineInstrBefore(MBBI);
266 for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
267 visitMachineOperand(&MBBI->getOperand(I), I);
268 visitMachineInstrAfter(MBBI);
270 visitMachineBasicBlockAfter(MFI);
272 visitMachineFunctionAfter();
276 else if (foundErrors)
277 report_fatal_error("Found "+Twine(foundErrors)+" machine code errors.");
284 regsLiveInButUnused.clear();
287 return false; // no changes
290 void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
295 *OS << "*** Bad machine code: " << msg << " ***\n"
296 << "- function: " << MF->getFunction()->getNameStr() << "\n";
299 void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
301 report(msg, MBB->getParent());
302 *OS << "- basic block: " << MBB->getName()
304 << " (BB#" << MBB->getNumber() << ")\n";
307 void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
309 report(msg, MI->getParent());
310 *OS << "- instruction: ";
314 void MachineVerifier::report(const char *msg,
315 const MachineOperand *MO, unsigned MONum) {
317 report(msg, MO->getParent());
318 *OS << "- operand " << MONum << ": ";
323 void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
324 BBInfo &MInfo = MBBInfoMap[MBB];
325 if (!MInfo.reachable) {
326 MInfo.reachable = true;
327 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
328 SuE = MBB->succ_end(); SuI != SuE; ++SuI)
333 void MachineVerifier::visitMachineFunctionBefore() {
334 regsReserved = TRI->getReservedRegs(*MF);
336 // A sub-register of a reserved register is also reserved
337 for (int Reg = regsReserved.find_first(); Reg>=0;
338 Reg = regsReserved.find_next(Reg)) {
339 for (const unsigned *Sub = TRI->getSubRegisters(Reg); *Sub; ++Sub) {
340 // FIXME: This should probably be:
341 // assert(regsReserved.test(*Sub) && "Non-reserved sub-register");
342 regsReserved.set(*Sub);
345 markReachable(&MF->front());
348 // Does iterator point to a and b as the first two elements?
349 static bool matchPair(MachineBasicBlock::const_succ_iterator i,
350 const MachineBasicBlock *a, const MachineBasicBlock *b) {
359 MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
360 const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
362 // Call AnalyzeBranch. If it succeeds, there several more conditions to check.
363 MachineBasicBlock *TBB = 0, *FBB = 0;
364 SmallVector<MachineOperand, 4> Cond;
365 if (!TII->AnalyzeBranch(*const_cast<MachineBasicBlock *>(MBB),
367 // Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's
368 // check whether its answers match up with reality.
370 // Block falls through to its successor.
371 MachineFunction::const_iterator MBBI = MBB;
373 if (MBBI == MF->end()) {
374 // It's possible that the block legitimately ends with a noreturn
375 // call or an unreachable, in which case it won't actually fall
376 // out the bottom of the function.
377 } else if (MBB->succ_empty()) {
378 // It's possible that the block legitimately ends with a noreturn
379 // call or an unreachable, in which case it won't actuall fall
381 } else if (MBB->succ_size() != 1) {
382 report("MBB exits via unconditional fall-through but doesn't have "
383 "exactly one CFG successor!", MBB);
384 } else if (MBB->succ_begin()[0] != MBBI) {
385 report("MBB exits via unconditional fall-through but its successor "
386 "differs from its CFG successor!", MBB);
388 if (!MBB->empty() && MBB->back().getDesc().isBarrier() &&
389 !TII->isPredicated(&MBB->back())) {
390 report("MBB exits via unconditional fall-through but ends with a "
391 "barrier instruction!", MBB);
394 report("MBB exits via unconditional fall-through but has a condition!",
397 } else if (TBB && !FBB && Cond.empty()) {
398 // Block unconditionally branches somewhere.
399 if (MBB->succ_size() != 1) {
400 report("MBB exits via unconditional branch but doesn't have "
401 "exactly one CFG successor!", MBB);
402 } else if (MBB->succ_begin()[0] != TBB) {
403 report("MBB exits via unconditional branch but the CFG "
404 "successor doesn't match the actual successor!", MBB);
407 report("MBB exits via unconditional branch but doesn't contain "
408 "any instructions!", MBB);
409 } else if (!MBB->back().getDesc().isBarrier()) {
410 report("MBB exits via unconditional branch but doesn't end with a "
411 "barrier instruction!", MBB);
412 } else if (!MBB->back().getDesc().isTerminator()) {
413 report("MBB exits via unconditional branch but the branch isn't a "
414 "terminator instruction!", MBB);
416 } else if (TBB && !FBB && !Cond.empty()) {
417 // Block conditionally branches somewhere, otherwise falls through.
418 MachineFunction::const_iterator MBBI = MBB;
420 if (MBBI == MF->end()) {
421 report("MBB conditionally falls through out of function!", MBB);
422 } if (MBB->succ_size() != 2) {
423 report("MBB exits via conditional branch/fall-through but doesn't have "
424 "exactly two CFG successors!", MBB);
425 } else if (!matchPair(MBB->succ_begin(), TBB, MBBI)) {
426 report("MBB exits via conditional branch/fall-through but the CFG "
427 "successors don't match the actual successors!", MBB);
430 report("MBB exits via conditional branch/fall-through but doesn't "
431 "contain any instructions!", MBB);
432 } else if (MBB->back().getDesc().isBarrier()) {
433 report("MBB exits via conditional branch/fall-through but ends with a "
434 "barrier instruction!", MBB);
435 } else if (!MBB->back().getDesc().isTerminator()) {
436 report("MBB exits via conditional branch/fall-through but the branch "
437 "isn't a terminator instruction!", MBB);
439 } else if (TBB && FBB) {
440 // Block conditionally branches somewhere, otherwise branches
442 if (MBB->succ_size() != 2) {
443 report("MBB exits via conditional branch/branch but doesn't have "
444 "exactly two CFG successors!", MBB);
445 } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) {
446 report("MBB exits via conditional branch/branch but the CFG "
447 "successors don't match the actual successors!", MBB);
450 report("MBB exits via conditional branch/branch but doesn't "
451 "contain any instructions!", MBB);
452 } else if (!MBB->back().getDesc().isBarrier()) {
453 report("MBB exits via conditional branch/branch but doesn't end with a "
454 "barrier instruction!", MBB);
455 } else if (!MBB->back().getDesc().isTerminator()) {
456 report("MBB exits via conditional branch/branch but the branch "
457 "isn't a terminator instruction!", MBB);
460 report("MBB exits via conditinal branch/branch but there's no "
464 report("AnalyzeBranch returned invalid data!", MBB);
469 for (MachineBasicBlock::livein_iterator I = MBB->livein_begin(),
470 E = MBB->livein_end(); I != E; ++I) {
471 if (!TargetRegisterInfo::isPhysicalRegister(*I)) {
472 report("MBB live-in list contains non-physical register", MBB);
476 for (const unsigned *R = TRI->getSubRegisters(*I); *R; R++)
479 regsLiveInButUnused = regsLive;
481 const MachineFrameInfo *MFI = MF->getFrameInfo();
482 assert(MFI && "Function has no frame info");
483 BitVector PR = MFI->getPristineRegs(MBB);
484 for (int I = PR.find_first(); I>0; I = PR.find_next(I)) {
486 for (const unsigned *R = TRI->getSubRegisters(I); *R; R++)
494 void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
495 const TargetInstrDesc &TI = MI->getDesc();
496 if (MI->getNumOperands() < TI.getNumOperands()) {
497 report("Too few operands", MI);
498 *OS << TI.getNumOperands() << " operands expected, but "
499 << MI->getNumExplicitOperands() << " given.\n";
502 // Check the MachineMemOperands for basic consistency.
503 for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
504 E = MI->memoperands_end(); I != E; ++I) {
505 if ((*I)->isLoad() && !TI.mayLoad())
506 report("Missing mayLoad flag", MI);
507 if ((*I)->isStore() && !TI.mayStore())
508 report("Missing mayStore flag", MI);
511 // Debug values must not have a slot index.
512 // Other instructions must have one.
514 bool mapped = !LiveInts->isNotInMIMap(MI);
515 if (MI->isDebugValue()) {
517 report("Debug instruction has a slot index", MI);
520 report("Missing slot index", MI);
527 MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
528 const MachineInstr *MI = MO->getParent();
529 const TargetInstrDesc &TI = MI->getDesc();
531 // The first TI.NumDefs operands must be explicit register defines
532 if (MONum < TI.getNumDefs()) {
534 report("Explicit definition must be a register", MO, MONum);
535 else if (!MO->isDef())
536 report("Explicit definition marked as use", MO, MONum);
537 else if (MO->isImplicit())
538 report("Explicit definition marked as implicit", MO, MONum);
539 } else if (MONum < TI.getNumOperands()) {
542 report("Explicit operand marked as def", MO, MONum);
543 if (MO->isImplicit())
544 report("Explicit operand marked as implicit", MO, MONum);
547 // ARM adds %reg0 operands to indicate predicates. We'll allow that.
548 if (MO->isReg() && !MO->isImplicit() && !TI.isVariadic() && MO->getReg())
549 report("Extra explicit operand on non-variadic instruction", MO, MONum);
552 switch (MO->getType()) {
553 case MachineOperand::MO_Register: {
554 const unsigned Reg = MO->getReg();
558 // Check Live Variables.
560 // An <undef> doesn't refer to any register, so just skip it.
561 } else if (MO->isUse()) {
562 regsLiveInButUnused.erase(Reg);
566 if (MI->isRegTiedToDefOperand(MONum, &defIdx)) {
567 // A two-addr use counts as a kill if use and def are the same.
568 unsigned DefReg = MI->getOperand(defIdx).getReg();
571 // ANd in that case an explicit kill flag is not allowed.
573 report("Illegal kill flag on two-address instruction operand",
575 } else if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
576 report("Two-address instruction operands must be identical",
580 isKill = MO->isKill();
583 addRegWithSubRegs(regsKilled, Reg);
585 // Check that LiveVars knows this kill.
586 if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg) &&
588 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
589 if (std::find(VI.Kills.begin(),
590 VI.Kills.end(), MI) == VI.Kills.end())
591 report("Kill missing from LiveVariables", MO, MONum);
594 // Check LiveInts liveness and kill.
595 if (LiveInts && !LiveInts->isNotInMIMap(MI)) {
596 SlotIndex UseIdx = LiveInts->getInstructionIndex(MI).getUseIndex();
597 if (LiveInts->hasInterval(Reg)) {
598 const LiveInterval &LI = LiveInts->getInterval(Reg);
599 if (!LI.liveAt(UseIdx)) {
600 report("No live range at use", MO, MONum);
601 *OS << UseIdx << " is not live in " << LI << '\n';
603 // TODO: Verify isKill == LI.killedAt.
604 } else if (TargetRegisterInfo::isVirtualRegister(Reg)) {
605 report("Virtual register has no Live interval", MO, MONum);
609 // Use of a dead register.
610 if (!regsLive.count(Reg)) {
611 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
612 // Reserved registers may be used even when 'dead'.
613 if (!isReserved(Reg))
614 report("Using an undefined physical register", MO, MONum);
616 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
617 // We don't know which virtual registers are live in, so only complain
618 // if vreg was killed in this MBB. Otherwise keep track of vregs that
619 // must be live in. PHI instructions are handled separately.
620 if (MInfo.regsKilled.count(Reg))
621 report("Using a killed virtual register", MO, MONum);
622 else if (!MI->isPHI())
623 MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI));
629 // TODO: verify that earlyclobber ops are not used.
631 addRegWithSubRegs(regsDead, Reg);
633 addRegWithSubRegs(regsDefined, Reg);
635 // Check LiveInts for a live range, but only for virtual registers.
636 if (LiveInts && TargetRegisterInfo::isVirtualRegister(Reg) &&
637 !LiveInts->isNotInMIMap(MI)) {
638 SlotIndex DefIdx = LiveInts->getInstructionIndex(MI).getDefIndex();
639 if (LiveInts->hasInterval(Reg)) {
640 const LiveInterval &LI = LiveInts->getInterval(Reg);
641 if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) {
642 assert(VNI && "NULL valno is not allowed");
643 if (VNI->def != DefIdx) {
644 report("Inconsistent valno->def", MO, MONum);
645 *OS << "Valno " << VNI->id << " is not defined at "
646 << DefIdx << " in " << LI << '\n';
649 report("No live range at def", MO, MONum);
650 *OS << DefIdx << " is not live in " << LI << '\n';
653 report("Virtual register has no Live interval", MO, MONum);
658 // Check register classes.
659 if (MONum < TI.getNumOperands() && !MO->isImplicit()) {
660 const TargetOperandInfo &TOI = TI.OpInfo[MONum];
661 unsigned SubIdx = MO->getSubReg();
663 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
666 unsigned s = TRI->getSubReg(Reg, SubIdx);
668 report("Invalid subregister index for physical register",
674 if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
675 if (!DRC->contains(sr)) {
676 report("Illegal physical register for instruction", MO, MONum);
677 *OS << TRI->getName(sr) << " is not a "
678 << DRC->getName() << " register.\n";
683 const TargetRegisterClass *RC = MRI->getRegClass(Reg);
685 const TargetRegisterClass *SRC = RC->getSubRegisterRegClass(SubIdx);
687 report("Invalid subregister index for virtual register", MO, MONum);
688 *OS << "Register class " << RC->getName()
689 << " does not support subreg index " << SubIdx << "\n";
694 if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
695 if (RC != DRC && !RC->hasSuperClass(DRC)) {
696 report("Illegal virtual register for instruction", MO, MONum);
697 *OS << "Expected a " << DRC->getName() << " register, but got a "
698 << RC->getName() << " register\n";
706 case MachineOperand::MO_MachineBasicBlock:
707 if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent()))
708 report("PHI operand is not in the CFG", MO, MONum);
716 void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
717 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
718 set_union(MInfo.regsKilled, regsKilled);
719 set_subtract(regsLive, regsKilled); regsKilled.clear();
720 set_subtract(regsLive, regsDead); regsDead.clear();
721 set_union(regsLive, regsDefined); regsDefined.clear();
725 MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
726 MBBInfoMap[MBB].regsLiveOut = regsLive;
730 // Calculate the largest possible vregsPassed sets. These are the registers that
731 // can pass through an MBB live, but may not be live every time. It is assumed
732 // that all vregsPassed sets are empty before the call.
733 void MachineVerifier::calcRegsPassed() {
734 // First push live-out regs to successors' vregsPassed. Remember the MBBs that
735 // have any vregsPassed.
736 DenseSet<const MachineBasicBlock*> todo;
737 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
739 const MachineBasicBlock &MBB(*MFI);
740 BBInfo &MInfo = MBBInfoMap[&MBB];
741 if (!MInfo.reachable)
743 for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
744 SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
745 BBInfo &SInfo = MBBInfoMap[*SuI];
746 if (SInfo.addPassed(MInfo.regsLiveOut))
751 // Iteratively push vregsPassed to successors. This will converge to the same
752 // final state regardless of DenseSet iteration order.
753 while (!todo.empty()) {
754 const MachineBasicBlock *MBB = *todo.begin();
756 BBInfo &MInfo = MBBInfoMap[MBB];
757 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
758 SuE = MBB->succ_end(); SuI != SuE; ++SuI) {
761 BBInfo &SInfo = MBBInfoMap[*SuI];
762 if (SInfo.addPassed(MInfo.vregsPassed))
768 // Calculate the set of virtual registers that must be passed through each basic
769 // block in order to satisfy the requirements of successor blocks. This is very
770 // similar to calcRegsPassed, only backwards.
771 void MachineVerifier::calcRegsRequired() {
772 // First push live-in regs to predecessors' vregsRequired.
773 DenseSet<const MachineBasicBlock*> todo;
774 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
776 const MachineBasicBlock &MBB(*MFI);
777 BBInfo &MInfo = MBBInfoMap[&MBB];
778 for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(),
779 PrE = MBB.pred_end(); PrI != PrE; ++PrI) {
780 BBInfo &PInfo = MBBInfoMap[*PrI];
781 if (PInfo.addRequired(MInfo.vregsLiveIn))
786 // Iteratively push vregsRequired to predecessors. This will converge to the
787 // same final state regardless of DenseSet iteration order.
788 while (!todo.empty()) {
789 const MachineBasicBlock *MBB = *todo.begin();
791 BBInfo &MInfo = MBBInfoMap[MBB];
792 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
793 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
796 BBInfo &SInfo = MBBInfoMap[*PrI];
797 if (SInfo.addRequired(MInfo.vregsRequired))
803 // Check PHI instructions at the beginning of MBB. It is assumed that
804 // calcRegsPassed has been run so BBInfo::isLiveOut is valid.
805 void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
806 for (MachineBasicBlock::const_iterator BBI = MBB->begin(), BBE = MBB->end();
807 BBI != BBE && BBI->isPHI(); ++BBI) {
808 DenseSet<const MachineBasicBlock*> seen;
810 for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2) {
811 unsigned Reg = BBI->getOperand(i).getReg();
812 const MachineBasicBlock *Pre = BBI->getOperand(i + 1).getMBB();
813 if (!Pre->isSuccessor(MBB))
816 BBInfo &PrInfo = MBBInfoMap[Pre];
817 if (PrInfo.reachable && !PrInfo.isLiveOut(Reg))
818 report("PHI operand is not live-out from predecessor",
819 &BBI->getOperand(i), i);
822 // Did we see all predecessors?
823 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
824 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
825 if (!seen.count(*PrI)) {
826 report("Missing PHI operand", BBI);
827 *OS << "BB#" << (*PrI)->getNumber()
828 << " is a predecessor according to the CFG.\n";
834 void MachineVerifier::visitMachineFunctionAfter() {
837 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
839 BBInfo &MInfo = MBBInfoMap[MFI];
841 // Skip unreachable MBBs.
842 if (!MInfo.reachable)
848 // Now check liveness info if available
849 if (LiveVars || LiveInts)
852 verifyLiveVariables();
854 verifyLiveIntervals();
857 void MachineVerifier::verifyLiveVariables() {
858 assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
859 for (unsigned Reg = TargetRegisterInfo::FirstVirtualRegister,
860 RegE = MRI->getLastVirtReg()-1; Reg != RegE; ++Reg) {
861 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
862 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
864 BBInfo &MInfo = MBBInfoMap[MFI];
866 // Our vregsRequired should be identical to LiveVariables' AliveBlocks
867 if (MInfo.vregsRequired.count(Reg)) {
868 if (!VI.AliveBlocks.test(MFI->getNumber())) {
869 report("LiveVariables: Block missing from AliveBlocks", MFI);
870 *OS << "Virtual register %reg" << Reg
871 << " must be live through the block.\n";
874 if (VI.AliveBlocks.test(MFI->getNumber())) {
875 report("LiveVariables: Block should not be in AliveBlocks", MFI);
876 *OS << "Virtual register %reg" << Reg
877 << " is not needed live through the block.\n";
884 void MachineVerifier::verifyLiveIntervals() {
885 assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts");
886 for (LiveIntervals::const_iterator LVI = LiveInts->begin(),
887 LVE = LiveInts->end(); LVI != LVE; ++LVI) {
888 const LiveInterval &LI = *LVI->second;
890 // Spilling and splitting may leave unused registers around. Skip them.
891 if (MRI->use_empty(LI.reg))
894 assert(LVI->first == LI.reg && "Invalid reg to interval mapping");
896 for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
899 const VNInfo *DefVNI = LI.getVNInfoAt(VNI->def);
902 if (!VNI->isUnused()) {
903 report("Valno not live at def and not marked unused", MF);
904 *OS << "Valno #" << VNI->id << " in " << LI << '\n';
913 report("Live range at def has different valno", MF);
914 *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
915 << " where valno #" << DefVNI->id << " is live.\n";
920 for (LiveInterval::const_iterator I = LI.begin(), E = LI.end(); I!=E; ++I) {
921 const VNInfo *VNI = I->valno;
922 assert(VNI && "Live range has no valno");
924 if (VNI->id >= LI.getNumValNums() || VNI != LI.getValNumInfo(VNI->id)) {
925 report("Foreign valno in live range", MF);
927 *OS << " has a valno not in " << LI << '\n';
930 if (VNI->isUnused()) {
931 report("Live range valno is marked unused", MF);
933 *OS << " in " << LI << '\n';