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 LiveIntervals *LiveInts;
171 SlotIndexes *Indexes;
173 void visitMachineFunctionBefore();
174 void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
175 void visitMachineInstrBefore(const MachineInstr *MI);
176 void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
177 void visitMachineInstrAfter(const MachineInstr *MI);
178 void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB);
179 void visitMachineFunctionAfter();
181 void report(const char *msg, const MachineFunction *MF);
182 void report(const char *msg, const MachineBasicBlock *MBB);
183 void report(const char *msg, const MachineInstr *MI);
184 void report(const char *msg, const MachineOperand *MO, unsigned MONum);
186 void markReachable(const MachineBasicBlock *MBB);
187 void calcRegsPassed();
188 void checkPHIOps(const MachineBasicBlock *MBB);
190 void calcRegsRequired();
191 void verifyLiveVariables();
192 void verifyLiveIntervals();
195 struct MachineVerifierPass : public MachineFunctionPass {
196 static char ID; // Pass ID, replacement for typeid
198 MachineVerifierPass()
199 : MachineFunctionPass(ID) {
200 initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
203 void getAnalysisUsage(AnalysisUsage &AU) const {
204 AU.setPreservesAll();
205 MachineFunctionPass::getAnalysisUsage(AU);
208 bool runOnMachineFunction(MachineFunction &MF) {
216 char MachineVerifierPass::ID = 0;
217 INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
218 "Verify generated machine code", false, false)
220 FunctionPass *llvm::createMachineVerifierPass() {
221 return new MachineVerifierPass();
224 void MachineFunction::verify(Pass *p) const {
225 MachineVerifier(p).runOnMachineFunction(const_cast<MachineFunction&>(*this));
228 bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
229 raw_ostream *OutFile = 0;
231 std::string ErrorInfo;
232 OutFile = new raw_fd_ostream(OutFileName, ErrorInfo,
233 raw_fd_ostream::F_Append);
234 if (!ErrorInfo.empty()) {
235 errs() << "Error opening '" << OutFileName << "': " << ErrorInfo << '\n';
247 TM = &MF.getTarget();
248 TRI = TM->getRegisterInfo();
249 MRI = &MF.getRegInfo();
255 LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>();
256 // We don't want to verify LiveVariables if LiveIntervals is available.
258 LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
259 Indexes = PASS->getAnalysisIfAvailable<SlotIndexes>();
262 visitMachineFunctionBefore();
263 for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
265 visitMachineBasicBlockBefore(MFI);
266 for (MachineBasicBlock::const_iterator MBBI = MFI->begin(),
267 MBBE = MFI->end(); MBBI != MBBE; ++MBBI) {
268 visitMachineInstrBefore(MBBI);
269 for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
270 visitMachineOperand(&MBBI->getOperand(I), I);
271 visitMachineInstrAfter(MBBI);
273 visitMachineBasicBlockAfter(MFI);
275 visitMachineFunctionAfter();
279 else if (foundErrors)
280 report_fatal_error("Found "+Twine(foundErrors)+" machine code errors.");
287 regsLiveInButUnused.clear();
290 return false; // no changes
293 void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
297 MF->print(*OS, Indexes);
298 *OS << "*** Bad machine code: " << msg << " ***\n"
299 << "- function: " << MF->getFunction()->getNameStr() << "\n";
302 void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
304 report(msg, MBB->getParent());
305 *OS << "- basic block: " << MBB->getName()
307 << " (BB#" << MBB->getNumber() << ")";
309 *OS << " [" << Indexes->getMBBStartIdx(MBB)
310 << ';' << Indexes->getMBBEndIdx(MBB) << ')';
314 void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
316 report(msg, MI->getParent());
317 *OS << "- instruction: ";
318 if (Indexes && Indexes->hasIndex(MI))
319 *OS << Indexes->getInstructionIndex(MI) << '\t';
323 void MachineVerifier::report(const char *msg,
324 const MachineOperand *MO, unsigned MONum) {
326 report(msg, MO->getParent());
327 *OS << "- operand " << MONum << ": ";
332 void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
333 BBInfo &MInfo = MBBInfoMap[MBB];
334 if (!MInfo.reachable) {
335 MInfo.reachable = true;
336 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
337 SuE = MBB->succ_end(); SuI != SuE; ++SuI)
342 void MachineVerifier::visitMachineFunctionBefore() {
343 regsReserved = TRI->getReservedRegs(*MF);
345 // A sub-register of a reserved register is also reserved
346 for (int Reg = regsReserved.find_first(); Reg>=0;
347 Reg = regsReserved.find_next(Reg)) {
348 for (const unsigned *Sub = TRI->getSubRegisters(Reg); *Sub; ++Sub) {
349 // FIXME: This should probably be:
350 // assert(regsReserved.test(*Sub) && "Non-reserved sub-register");
351 regsReserved.set(*Sub);
354 markReachable(&MF->front());
357 // Does iterator point to a and b as the first two elements?
358 static bool matchPair(MachineBasicBlock::const_succ_iterator i,
359 const MachineBasicBlock *a, const MachineBasicBlock *b) {
368 MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
369 const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
371 // Count the number of landing pad successors.
372 unsigned LandingPadSuccs = 0;
373 for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
374 E = MBB->succ_end(); I != E; ++I)
375 LandingPadSuccs += (*I)->isLandingPad();
376 if (LandingPadSuccs > 1)
377 report("MBB has more than one landing pad successor", MBB);
379 // Call AnalyzeBranch. If it succeeds, there several more conditions to check.
380 MachineBasicBlock *TBB = 0, *FBB = 0;
381 SmallVector<MachineOperand, 4> Cond;
382 if (!TII->AnalyzeBranch(*const_cast<MachineBasicBlock *>(MBB),
384 // Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's
385 // check whether its answers match up with reality.
387 // Block falls through to its successor.
388 MachineFunction::const_iterator MBBI = MBB;
390 if (MBBI == MF->end()) {
391 // It's possible that the block legitimately ends with a noreturn
392 // call or an unreachable, in which case it won't actually fall
393 // out the bottom of the function.
394 } else if (MBB->succ_size() == LandingPadSuccs) {
395 // It's possible that the block legitimately ends with a noreturn
396 // call or an unreachable, in which case it won't actuall fall
398 } else if (MBB->succ_size() != 1+LandingPadSuccs) {
399 report("MBB exits via unconditional fall-through but doesn't have "
400 "exactly one CFG successor!", MBB);
401 } else if (!MBB->isSuccessor(MBBI)) {
402 report("MBB exits via unconditional fall-through but its successor "
403 "differs from its CFG successor!", MBB);
405 if (!MBB->empty() && MBB->back().getDesc().isBarrier() &&
406 !TII->isPredicated(&MBB->back())) {
407 report("MBB exits via unconditional fall-through but ends with a "
408 "barrier instruction!", MBB);
411 report("MBB exits via unconditional fall-through but has a condition!",
414 } else if (TBB && !FBB && Cond.empty()) {
415 // Block unconditionally branches somewhere.
416 if (MBB->succ_size() != 1+LandingPadSuccs) {
417 report("MBB exits via unconditional branch but doesn't have "
418 "exactly one CFG successor!", MBB);
419 } else if (!MBB->isSuccessor(TBB)) {
420 report("MBB exits via unconditional branch but the CFG "
421 "successor doesn't match the actual successor!", MBB);
424 report("MBB exits via unconditional branch but doesn't contain "
425 "any instructions!", MBB);
426 } else if (!MBB->back().getDesc().isBarrier()) {
427 report("MBB exits via unconditional branch but doesn't end with a "
428 "barrier instruction!", MBB);
429 } else if (!MBB->back().getDesc().isTerminator()) {
430 report("MBB exits via unconditional branch but the branch isn't a "
431 "terminator instruction!", MBB);
433 } else if (TBB && !FBB && !Cond.empty()) {
434 // Block conditionally branches somewhere, otherwise falls through.
435 MachineFunction::const_iterator MBBI = MBB;
437 if (MBBI == MF->end()) {
438 report("MBB conditionally falls through out of function!", MBB);
439 } if (MBB->succ_size() != 2) {
440 report("MBB exits via conditional branch/fall-through but doesn't have "
441 "exactly two CFG successors!", MBB);
442 } else if (!matchPair(MBB->succ_begin(), TBB, MBBI)) {
443 report("MBB exits via conditional branch/fall-through but the CFG "
444 "successors don't match the actual successors!", MBB);
447 report("MBB exits via conditional branch/fall-through but doesn't "
448 "contain any instructions!", MBB);
449 } else if (MBB->back().getDesc().isBarrier()) {
450 report("MBB exits via conditional branch/fall-through but ends with a "
451 "barrier instruction!", MBB);
452 } else if (!MBB->back().getDesc().isTerminator()) {
453 report("MBB exits via conditional branch/fall-through but the branch "
454 "isn't a terminator instruction!", MBB);
456 } else if (TBB && FBB) {
457 // Block conditionally branches somewhere, otherwise branches
459 if (MBB->succ_size() != 2) {
460 report("MBB exits via conditional branch/branch but doesn't have "
461 "exactly two CFG successors!", MBB);
462 } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) {
463 report("MBB exits via conditional branch/branch but the CFG "
464 "successors don't match the actual successors!", MBB);
467 report("MBB exits via conditional branch/branch but doesn't "
468 "contain any instructions!", MBB);
469 } else if (!MBB->back().getDesc().isBarrier()) {
470 report("MBB exits via conditional branch/branch but doesn't end with a "
471 "barrier instruction!", MBB);
472 } else if (!MBB->back().getDesc().isTerminator()) {
473 report("MBB exits via conditional branch/branch but the branch "
474 "isn't a terminator instruction!", MBB);
477 report("MBB exits via conditinal branch/branch but there's no "
481 report("AnalyzeBranch returned invalid data!", MBB);
486 for (MachineBasicBlock::livein_iterator I = MBB->livein_begin(),
487 E = MBB->livein_end(); I != E; ++I) {
488 if (!TargetRegisterInfo::isPhysicalRegister(*I)) {
489 report("MBB live-in list contains non-physical register", MBB);
493 for (const unsigned *R = TRI->getSubRegisters(*I); *R; R++)
496 regsLiveInButUnused = regsLive;
498 const MachineFrameInfo *MFI = MF->getFrameInfo();
499 assert(MFI && "Function has no frame info");
500 BitVector PR = MFI->getPristineRegs(MBB);
501 for (int I = PR.find_first(); I>0; I = PR.find_next(I)) {
503 for (const unsigned *R = TRI->getSubRegisters(I); *R; R++)
511 void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
512 const TargetInstrDesc &TI = MI->getDesc();
513 if (MI->getNumOperands() < TI.getNumOperands()) {
514 report("Too few operands", MI);
515 *OS << TI.getNumOperands() << " operands expected, but "
516 << MI->getNumExplicitOperands() << " given.\n";
519 // Check the MachineMemOperands for basic consistency.
520 for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
521 E = MI->memoperands_end(); I != E; ++I) {
522 if ((*I)->isLoad() && !TI.mayLoad())
523 report("Missing mayLoad flag", MI);
524 if ((*I)->isStore() && !TI.mayStore())
525 report("Missing mayStore flag", MI);
528 // Debug values must not have a slot index.
529 // Other instructions must have one.
531 bool mapped = !LiveInts->isNotInMIMap(MI);
532 if (MI->isDebugValue()) {
534 report("Debug instruction has a slot index", MI);
537 report("Missing slot index", MI);
544 MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
545 const MachineInstr *MI = MO->getParent();
546 const TargetInstrDesc &TI = MI->getDesc();
548 // The first TI.NumDefs operands must be explicit register defines
549 if (MONum < TI.getNumDefs()) {
551 report("Explicit definition must be a register", MO, MONum);
552 else if (!MO->isDef())
553 report("Explicit definition marked as use", MO, MONum);
554 else if (MO->isImplicit())
555 report("Explicit definition marked as implicit", MO, MONum);
556 } else if (MONum < TI.getNumOperands()) {
559 report("Explicit operand marked as def", MO, MONum);
560 if (MO->isImplicit())
561 report("Explicit operand marked as implicit", MO, MONum);
564 // ARM adds %reg0 operands to indicate predicates. We'll allow that.
565 if (MO->isReg() && !MO->isImplicit() && !TI.isVariadic() && MO->getReg())
566 report("Extra explicit operand on non-variadic instruction", MO, MONum);
569 switch (MO->getType()) {
570 case MachineOperand::MO_Register: {
571 const unsigned Reg = MO->getReg();
575 // Check Live Variables.
577 // An <undef> doesn't refer to any register, so just skip it.
578 } else if (MO->isUse()) {
579 regsLiveInButUnused.erase(Reg);
583 if (MI->isRegTiedToDefOperand(MONum, &defIdx)) {
584 // A two-addr use counts as a kill if use and def are the same.
585 unsigned DefReg = MI->getOperand(defIdx).getReg();
588 // ANd in that case an explicit kill flag is not allowed.
590 report("Illegal kill flag on two-address instruction operand",
592 } else if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
593 report("Two-address instruction operands must be identical",
597 isKill = MO->isKill();
600 addRegWithSubRegs(regsKilled, Reg);
602 // Check that LiveVars knows this kill.
603 if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg) &&
605 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
606 if (std::find(VI.Kills.begin(),
607 VI.Kills.end(), MI) == VI.Kills.end())
608 report("Kill missing from LiveVariables", MO, MONum);
611 // Check LiveInts liveness and kill.
612 if (LiveInts && !LiveInts->isNotInMIMap(MI)) {
613 SlotIndex UseIdx = LiveInts->getInstructionIndex(MI).getUseIndex();
614 if (LiveInts->hasInterval(Reg)) {
615 const LiveInterval &LI = LiveInts->getInterval(Reg);
616 if (!LI.liveAt(UseIdx)) {
617 report("No live range at use", MO, MONum);
618 *OS << UseIdx << " is not live in " << LI << '\n';
620 // TODO: Verify isKill == LI.killedAt.
621 } else if (TargetRegisterInfo::isVirtualRegister(Reg)) {
622 report("Virtual register has no Live interval", MO, MONum);
626 // Use of a dead register.
627 if (!regsLive.count(Reg)) {
628 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
629 // Reserved registers may be used even when 'dead'.
630 if (!isReserved(Reg))
631 report("Using an undefined physical register", MO, MONum);
633 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
634 // We don't know which virtual registers are live in, so only complain
635 // if vreg was killed in this MBB. Otherwise keep track of vregs that
636 // must be live in. PHI instructions are handled separately.
637 if (MInfo.regsKilled.count(Reg))
638 report("Using a killed virtual register", MO, MONum);
639 else if (!MI->isPHI())
640 MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI));
646 // TODO: verify that earlyclobber ops are not used.
648 addRegWithSubRegs(regsDead, Reg);
650 addRegWithSubRegs(regsDefined, Reg);
652 // Check LiveInts for a live range, but only for virtual registers.
653 if (LiveInts && TargetRegisterInfo::isVirtualRegister(Reg) &&
654 !LiveInts->isNotInMIMap(MI)) {
655 SlotIndex DefIdx = LiveInts->getInstructionIndex(MI).getDefIndex();
656 if (LiveInts->hasInterval(Reg)) {
657 const LiveInterval &LI = LiveInts->getInterval(Reg);
658 if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) {
659 assert(VNI && "NULL valno is not allowed");
660 if (VNI->def != DefIdx) {
661 report("Inconsistent valno->def", MO, MONum);
662 *OS << "Valno " << VNI->id << " is not defined at "
663 << DefIdx << " in " << LI << '\n';
666 report("No live range at def", MO, MONum);
667 *OS << DefIdx << " is not live in " << LI << '\n';
670 report("Virtual register has no Live interval", MO, MONum);
675 // Check register classes.
676 if (MONum < TI.getNumOperands() && !MO->isImplicit()) {
677 const TargetOperandInfo &TOI = TI.OpInfo[MONum];
678 unsigned SubIdx = MO->getSubReg();
680 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
683 unsigned s = TRI->getSubReg(Reg, SubIdx);
685 report("Invalid subregister index for physical register",
691 if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
692 if (!DRC->contains(sr)) {
693 report("Illegal physical register for instruction", MO, MONum);
694 *OS << TRI->getName(sr) << " is not a "
695 << DRC->getName() << " register.\n";
700 const TargetRegisterClass *RC = MRI->getRegClass(Reg);
702 const TargetRegisterClass *SRC = RC->getSubRegisterRegClass(SubIdx);
704 report("Invalid subregister index for virtual register", MO, MONum);
705 *OS << "Register class " << RC->getName()
706 << " does not support subreg index " << SubIdx << "\n";
711 if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
712 if (RC != DRC && !RC->hasSuperClass(DRC)) {
713 report("Illegal virtual register for instruction", MO, MONum);
714 *OS << "Expected a " << DRC->getName() << " register, but got a "
715 << RC->getName() << " register\n";
723 case MachineOperand::MO_MachineBasicBlock:
724 if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent()))
725 report("PHI operand is not in the CFG", MO, MONum);
733 void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
734 BBInfo &MInfo = MBBInfoMap[MI->getParent()];
735 set_union(MInfo.regsKilled, regsKilled);
736 set_subtract(regsLive, regsKilled); regsKilled.clear();
737 set_subtract(regsLive, regsDead); regsDead.clear();
738 set_union(regsLive, regsDefined); regsDefined.clear();
742 MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
743 MBBInfoMap[MBB].regsLiveOut = regsLive;
747 // Calculate the largest possible vregsPassed sets. These are the registers that
748 // can pass through an MBB live, but may not be live every time. It is assumed
749 // that all vregsPassed sets are empty before the call.
750 void MachineVerifier::calcRegsPassed() {
751 // First push live-out regs to successors' vregsPassed. Remember the MBBs that
752 // have any vregsPassed.
753 DenseSet<const MachineBasicBlock*> todo;
754 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
756 const MachineBasicBlock &MBB(*MFI);
757 BBInfo &MInfo = MBBInfoMap[&MBB];
758 if (!MInfo.reachable)
760 for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
761 SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
762 BBInfo &SInfo = MBBInfoMap[*SuI];
763 if (SInfo.addPassed(MInfo.regsLiveOut))
768 // Iteratively push vregsPassed to successors. This will converge to the same
769 // final state regardless of DenseSet iteration order.
770 while (!todo.empty()) {
771 const MachineBasicBlock *MBB = *todo.begin();
773 BBInfo &MInfo = MBBInfoMap[MBB];
774 for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
775 SuE = MBB->succ_end(); SuI != SuE; ++SuI) {
778 BBInfo &SInfo = MBBInfoMap[*SuI];
779 if (SInfo.addPassed(MInfo.vregsPassed))
785 // Calculate the set of virtual registers that must be passed through each basic
786 // block in order to satisfy the requirements of successor blocks. This is very
787 // similar to calcRegsPassed, only backwards.
788 void MachineVerifier::calcRegsRequired() {
789 // First push live-in regs to predecessors' vregsRequired.
790 DenseSet<const MachineBasicBlock*> todo;
791 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
793 const MachineBasicBlock &MBB(*MFI);
794 BBInfo &MInfo = MBBInfoMap[&MBB];
795 for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(),
796 PrE = MBB.pred_end(); PrI != PrE; ++PrI) {
797 BBInfo &PInfo = MBBInfoMap[*PrI];
798 if (PInfo.addRequired(MInfo.vregsLiveIn))
803 // Iteratively push vregsRequired to predecessors. This will converge to the
804 // same final state regardless of DenseSet iteration order.
805 while (!todo.empty()) {
806 const MachineBasicBlock *MBB = *todo.begin();
808 BBInfo &MInfo = MBBInfoMap[MBB];
809 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
810 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
813 BBInfo &SInfo = MBBInfoMap[*PrI];
814 if (SInfo.addRequired(MInfo.vregsRequired))
820 // Check PHI instructions at the beginning of MBB. It is assumed that
821 // calcRegsPassed has been run so BBInfo::isLiveOut is valid.
822 void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
823 for (MachineBasicBlock::const_iterator BBI = MBB->begin(), BBE = MBB->end();
824 BBI != BBE && BBI->isPHI(); ++BBI) {
825 DenseSet<const MachineBasicBlock*> seen;
827 for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2) {
828 unsigned Reg = BBI->getOperand(i).getReg();
829 const MachineBasicBlock *Pre = BBI->getOperand(i + 1).getMBB();
830 if (!Pre->isSuccessor(MBB))
833 BBInfo &PrInfo = MBBInfoMap[Pre];
834 if (PrInfo.reachable && !PrInfo.isLiveOut(Reg))
835 report("PHI operand is not live-out from predecessor",
836 &BBI->getOperand(i), i);
839 // Did we see all predecessors?
840 for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
841 PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
842 if (!seen.count(*PrI)) {
843 report("Missing PHI operand", BBI);
844 *OS << "BB#" << (*PrI)->getNumber()
845 << " is a predecessor according to the CFG.\n";
851 void MachineVerifier::visitMachineFunctionAfter() {
854 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
856 BBInfo &MInfo = MBBInfoMap[MFI];
858 // Skip unreachable MBBs.
859 if (!MInfo.reachable)
865 // Now check liveness info if available
866 if (LiveVars || LiveInts)
869 verifyLiveVariables();
871 verifyLiveIntervals();
874 void MachineVerifier::verifyLiveVariables() {
875 assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
876 for (unsigned Reg = TargetRegisterInfo::FirstVirtualRegister,
877 RegE = MRI->getLastVirtReg()-1; Reg != RegE; ++Reg) {
878 LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
879 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
881 BBInfo &MInfo = MBBInfoMap[MFI];
883 // Our vregsRequired should be identical to LiveVariables' AliveBlocks
884 if (MInfo.vregsRequired.count(Reg)) {
885 if (!VI.AliveBlocks.test(MFI->getNumber())) {
886 report("LiveVariables: Block missing from AliveBlocks", MFI);
887 *OS << "Virtual register %reg" << Reg
888 << " must be live through the block.\n";
891 if (VI.AliveBlocks.test(MFI->getNumber())) {
892 report("LiveVariables: Block should not be in AliveBlocks", MFI);
893 *OS << "Virtual register %reg" << Reg
894 << " is not needed live through the block.\n";
901 void MachineVerifier::verifyLiveIntervals() {
902 assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts");
903 for (LiveIntervals::const_iterator LVI = LiveInts->begin(),
904 LVE = LiveInts->end(); LVI != LVE; ++LVI) {
905 const LiveInterval &LI = *LVI->second;
907 // Spilling and splitting may leave unused registers around. Skip them.
908 if (MRI->use_empty(LI.reg))
911 // Physical registers have much weirdness going on, mostly from coalescing.
912 // We should probably fix it, but for now just ignore them.
913 if (TargetRegisterInfo::isPhysicalRegister(LI.reg))
916 assert(LVI->first == LI.reg && "Invalid reg to interval mapping");
918 for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
921 const VNInfo *DefVNI = LI.getVNInfoAt(VNI->def);
924 if (!VNI->isUnused()) {
925 report("Valno not live at def and not marked unused", MF);
926 *OS << "Valno #" << VNI->id << " in " << LI << '\n';
935 report("Live range at def has different valno", MF);
936 *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
937 << " where valno #" << DefVNI->id << " is live in " << LI << '\n';
941 const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def);
943 report("Invalid definition index", MF);
944 *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
945 << " in " << LI << '\n';
949 if (VNI->isPHIDef()) {
950 if (VNI->def != LiveInts->getMBBStartIdx(MBB)) {
951 report("PHIDef value is not defined at MBB start", MF);
952 *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
953 << ", not at the beginning of BB#" << MBB->getNumber()
954 << " in " << LI << '\n';
958 if (!VNI->def.isDef()) {
959 report("Non-PHI def must be at a DEF slot", MF);
960 *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
961 << " in " << LI << '\n';
963 const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
965 report("No instruction at def index", MF);
966 *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
967 << " in " << LI << '\n';
968 } else if (!MI->modifiesRegister(LI.reg, TRI)) {
969 report("Defining instruction does not modify register", MI);
970 *OS << "Valno #" << VNI->id << " in " << LI << '\n';
975 for (LiveInterval::const_iterator I = LI.begin(), E = LI.end(); I!=E; ++I) {
976 const VNInfo *VNI = I->valno;
977 assert(VNI && "Live range has no valno");
979 if (VNI->id >= LI.getNumValNums() || VNI != LI.getValNumInfo(VNI->id)) {
980 report("Foreign valno in live range", MF);
982 *OS << " has a valno not in " << LI << '\n';
985 if (VNI->isUnused()) {
986 report("Live range valno is marked unused", MF);
988 *OS << " in " << LI << '\n';
991 const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(I->start);
993 report("Bad start of live segment, no basic block", MF);
995 *OS << " in " << LI << '\n';
998 SlotIndex MBBStartIdx = LiveInts->getMBBStartIdx(MBB);
999 if (I->start != MBBStartIdx && I->start != VNI->def) {
1000 report("Live segment must begin at MBB entry or valno def", MBB);
1002 *OS << " in " << LI << '\n' << "Basic block starts at "
1003 << MBBStartIdx << '\n';
1006 const MachineBasicBlock *EndMBB =
1007 LiveInts->getMBBFromIndex(I->end.getPrevSlot());
1009 report("Bad end of live segment, no basic block", MF);
1011 *OS << " in " << LI << '\n';
1014 if (I->end != LiveInts->getMBBEndIdx(EndMBB)) {
1015 // The live segment is ending inside EndMBB
1016 const MachineInstr *MI =
1017 LiveInts->getInstructionFromIndex(I->end.getPrevSlot());
1019 report("Live segment doesn't end at a valid instruction", EndMBB);
1021 *OS << " in " << LI << '\n' << "Basic block starts at "
1022 << MBBStartIdx << '\n';
1023 } else if (TargetRegisterInfo::isVirtualRegister(LI.reg) &&
1024 !MI->readsVirtualRegister(LI.reg)) {
1025 // FIXME: Should we require a kill flag?
1026 report("Instruction killing live segment doesn't read register", MI);
1028 *OS << " in " << LI << '\n';
1032 // Now check all the basic blocks in this live segment.
1033 MachineFunction::const_iterator MFI = MBB;
1034 // Is LI live-in to MBB and not a PHIDef?
1035 if (I->start == VNI->def) {
1036 // Not live-in to any blocks.
1043 assert(LiveInts->isLiveInToMBB(LI, MFI));
1044 // We don't know how to track physregs into a landing pad.
1045 if (TargetRegisterInfo::isPhysicalRegister(LI.reg) &&
1046 MFI->isLandingPad()) {
1047 if (&*MFI == EndMBB)
1052 // Check that VNI is live-out of all predecessors.
1053 for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(),
1054 PE = MFI->pred_end(); PI != PE; ++PI) {
1055 SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI).getPrevSlot();
1056 const VNInfo *PVNI = LI.getVNInfoAt(PEnd);
1058 report("Register not marked live out of predecessor", *PI);
1059 *OS << "Valno #" << VNI->id << " live into BB#" << MFI->getNumber()
1060 << '@' << LiveInts->getMBBStartIdx(MFI) << ", not live at "
1061 << PEnd << " in " << LI << '\n';
1062 } else if (PVNI != VNI) {
1063 report("Different value live out of predecessor", *PI);
1064 *OS << "Valno #" << PVNI->id << " live out of BB#"
1065 << (*PI)->getNumber() << '@' << PEnd
1066 << "\nValno #" << VNI->id << " live into BB#" << MFI->getNumber()
1067 << '@' << LiveInts->getMBBStartIdx(MFI) << " in " << LI << '\n';
1070 if (&*MFI == EndMBB)
1076 // Check the LI only has one connected component.
1077 if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
1078 ConnectedVNInfoEqClasses ConEQ(*LiveInts);
1079 unsigned NumComp = ConEQ.Classify(&LI);
1081 report("Multiple connected components in live interval", MF);
1082 *OS << NumComp << " components in " << LI << '\n';