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Diffstat (limited to 'contrib/llvm/lib/CodeGen/MachineVerifier.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/MachineVerifier.cpp | 1820 |
1 files changed, 1820 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/MachineVerifier.cpp b/contrib/llvm/lib/CodeGen/MachineVerifier.cpp new file mode 100644 index 0000000..72a6769 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/MachineVerifier.cpp @@ -0,0 +1,1820 @@ +//===-- MachineVerifier.cpp - Machine Code Verifier -----------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Pass to verify generated machine code. The following is checked: +// +// Operand counts: All explicit operands must be present. +// +// Register classes: All physical and virtual register operands must be +// compatible with the register class required by the instruction descriptor. +// +// Register live intervals: Registers must be defined only once, and must be +// defined before use. +// +// The machine code verifier is enabled from LLVMTargetMachine.cpp with the +// command-line option -verify-machineinstrs, or by defining the environment +// variable LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive +// the verifier errors. +//===----------------------------------------------------------------------===// + +#include "llvm/CodeGen/Passes.h" +#include "llvm/ADT/DenseSet.h" +#include "llvm/ADT/DepthFirstIterator.h" +#include "llvm/ADT/SetOperations.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/CodeGen/LiveIntervalAnalysis.h" +#include "llvm/CodeGen/LiveStackAnalysis.h" +#include "llvm/CodeGen/LiveVariables.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineMemOperand.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/IR/BasicBlock.h" +#include "llvm/IR/InlineAsm.h" +#include "llvm/IR/Instructions.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/FileSystem.h" +#include "llvm/Support/Format.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetInstrInfo.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetSubtargetInfo.h" +using namespace llvm; + +namespace { + struct MachineVerifier { + + MachineVerifier(Pass *pass, const char *b) : + PASS(pass), + Banner(b) + {} + + bool runOnMachineFunction(MachineFunction &MF); + + Pass *const PASS; + const char *Banner; + const MachineFunction *MF; + const TargetMachine *TM; + const TargetInstrInfo *TII; + const TargetRegisterInfo *TRI; + const MachineRegisterInfo *MRI; + + unsigned foundErrors; + + typedef SmallVector<unsigned, 16> RegVector; + typedef SmallVector<const uint32_t*, 4> RegMaskVector; + typedef DenseSet<unsigned> RegSet; + typedef DenseMap<unsigned, const MachineInstr*> RegMap; + typedef SmallPtrSet<const MachineBasicBlock*, 8> BlockSet; + + const MachineInstr *FirstTerminator; + BlockSet FunctionBlocks; + + BitVector regsReserved; + RegSet regsLive; + RegVector regsDefined, regsDead, regsKilled; + RegMaskVector regMasks; + RegSet regsLiveInButUnused; + + SlotIndex lastIndex; + + // Add Reg and any sub-registers to RV + void addRegWithSubRegs(RegVector &RV, unsigned Reg) { + RV.push_back(Reg); + if (TargetRegisterInfo::isPhysicalRegister(Reg)) + for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) + RV.push_back(*SubRegs); + } + + struct BBInfo { + // Is this MBB reachable from the MF entry point? + bool reachable; + + // Vregs that must be live in because they are used without being + // defined. Map value is the user. + RegMap vregsLiveIn; + + // Regs killed in MBB. They may be defined again, and will then be in both + // regsKilled and regsLiveOut. + RegSet regsKilled; + + // Regs defined in MBB and live out. Note that vregs passing through may + // be live out without being mentioned here. + RegSet regsLiveOut; + + // Vregs that pass through MBB untouched. This set is disjoint from + // regsKilled and regsLiveOut. + RegSet vregsPassed; + + // Vregs that must pass through MBB because they are needed by a successor + // block. This set is disjoint from regsLiveOut. + RegSet vregsRequired; + + // Set versions of block's predecessor and successor lists. + BlockSet Preds, Succs; + + BBInfo() : reachable(false) {} + + // Add register to vregsPassed if it belongs there. Return true if + // anything changed. + bool addPassed(unsigned Reg) { + if (!TargetRegisterInfo::isVirtualRegister(Reg)) + return false; + if (regsKilled.count(Reg) || regsLiveOut.count(Reg)) + return false; + return vregsPassed.insert(Reg).second; + } + + // Same for a full set. + bool addPassed(const RegSet &RS) { + bool changed = false; + for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I) + if (addPassed(*I)) + changed = true; + return changed; + } + + // Add register to vregsRequired if it belongs there. Return true if + // anything changed. + bool addRequired(unsigned Reg) { + if (!TargetRegisterInfo::isVirtualRegister(Reg)) + return false; + if (regsLiveOut.count(Reg)) + return false; + return vregsRequired.insert(Reg).second; + } + + // Same for a full set. + bool addRequired(const RegSet &RS) { + bool changed = false; + for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I) + if (addRequired(*I)) + changed = true; + return changed; + } + + // Same for a full map. + bool addRequired(const RegMap &RM) { + bool changed = false; + for (RegMap::const_iterator I = RM.begin(), E = RM.end(); I != E; ++I) + if (addRequired(I->first)) + changed = true; + return changed; + } + + // Live-out registers are either in regsLiveOut or vregsPassed. + bool isLiveOut(unsigned Reg) const { + return regsLiveOut.count(Reg) || vregsPassed.count(Reg); + } + }; + + // Extra register info per MBB. + DenseMap<const MachineBasicBlock*, BBInfo> MBBInfoMap; + + bool isReserved(unsigned Reg) { + return Reg < regsReserved.size() && regsReserved.test(Reg); + } + + bool isAllocatable(unsigned Reg) { + return Reg < TRI->getNumRegs() && MRI->isAllocatable(Reg); + } + + // Analysis information if available + LiveVariables *LiveVars; + LiveIntervals *LiveInts; + LiveStacks *LiveStks; + SlotIndexes *Indexes; + + void visitMachineFunctionBefore(); + void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB); + void visitMachineBundleBefore(const MachineInstr *MI); + void visitMachineInstrBefore(const MachineInstr *MI); + void visitMachineOperand(const MachineOperand *MO, unsigned MONum); + void visitMachineInstrAfter(const MachineInstr *MI); + void visitMachineBundleAfter(const MachineInstr *MI); + void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB); + void visitMachineFunctionAfter(); + + void report(const char *msg, const MachineFunction *MF); + void report(const char *msg, const MachineBasicBlock *MBB); + void report(const char *msg, const MachineInstr *MI); + void report(const char *msg, const MachineOperand *MO, unsigned MONum); + void report(const char *msg, const MachineFunction *MF, + const LiveInterval &LI); + void report(const char *msg, const MachineBasicBlock *MBB, + const LiveInterval &LI); + void report(const char *msg, const MachineFunction *MF, + const LiveRange &LR, unsigned Reg, unsigned LaneMask); + void report(const char *msg, const MachineBasicBlock *MBB, + const LiveRange &LR, unsigned Reg, unsigned LaneMask); + + void verifyInlineAsm(const MachineInstr *MI); + + void checkLiveness(const MachineOperand *MO, unsigned MONum); + void markReachable(const MachineBasicBlock *MBB); + void calcRegsPassed(); + void checkPHIOps(const MachineBasicBlock *MBB); + + void calcRegsRequired(); + void verifyLiveVariables(); + void verifyLiveIntervals(); + void verifyLiveInterval(const LiveInterval&); + void verifyLiveRangeValue(const LiveRange&, const VNInfo*, unsigned, + unsigned); + void verifyLiveRangeSegment(const LiveRange&, + const LiveRange::const_iterator I, unsigned, + unsigned); + void verifyLiveRange(const LiveRange&, unsigned, unsigned LaneMask = 0); + + void verifyStackFrame(); + }; + + struct MachineVerifierPass : public MachineFunctionPass { + static char ID; // Pass ID, replacement for typeid + const std::string Banner; + + MachineVerifierPass(const std::string &banner = nullptr) + : MachineFunctionPass(ID), Banner(banner) { + initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry()); + } + + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.setPreservesAll(); + MachineFunctionPass::getAnalysisUsage(AU); + } + + bool runOnMachineFunction(MachineFunction &MF) override { + MF.verify(this, Banner.c_str()); + return false; + } + }; + +} // namespace + +char MachineVerifierPass::ID = 0; +INITIALIZE_PASS(MachineVerifierPass, "machineverifier", + "Verify generated machine code", false, false) + +FunctionPass *llvm::createMachineVerifierPass(const std::string &Banner) { + return new MachineVerifierPass(Banner); +} + +void MachineFunction::verify(Pass *p, const char *Banner) const { + MachineVerifier(p, Banner) + .runOnMachineFunction(const_cast<MachineFunction&>(*this)); +} + +bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) { + foundErrors = 0; + + this->MF = &MF; + TM = &MF.getTarget(); + TII = MF.getSubtarget().getInstrInfo(); + TRI = MF.getSubtarget().getRegisterInfo(); + MRI = &MF.getRegInfo(); + + LiveVars = nullptr; + LiveInts = nullptr; + LiveStks = nullptr; + Indexes = nullptr; + if (PASS) { + LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>(); + // We don't want to verify LiveVariables if LiveIntervals is available. + if (!LiveInts) + LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>(); + LiveStks = PASS->getAnalysisIfAvailable<LiveStacks>(); + Indexes = PASS->getAnalysisIfAvailable<SlotIndexes>(); + } + + visitMachineFunctionBefore(); + for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end(); + MFI!=MFE; ++MFI) { + visitMachineBasicBlockBefore(MFI); + // Keep track of the current bundle header. + const MachineInstr *CurBundle = nullptr; + // Do we expect the next instruction to be part of the same bundle? + bool InBundle = false; + + for (MachineBasicBlock::const_instr_iterator MBBI = MFI->instr_begin(), + MBBE = MFI->instr_end(); MBBI != MBBE; ++MBBI) { + if (MBBI->getParent() != MFI) { + report("Bad instruction parent pointer", MFI); + errs() << "Instruction: " << *MBBI; + continue; + } + + // Check for consistent bundle flags. + if (InBundle && !MBBI->isBundledWithPred()) + report("Missing BundledPred flag, " + "BundledSucc was set on predecessor", MBBI); + if (!InBundle && MBBI->isBundledWithPred()) + report("BundledPred flag is set, " + "but BundledSucc not set on predecessor", MBBI); + + // Is this a bundle header? + if (!MBBI->isInsideBundle()) { + if (CurBundle) + visitMachineBundleAfter(CurBundle); + CurBundle = MBBI; + visitMachineBundleBefore(CurBundle); + } else if (!CurBundle) + report("No bundle header", MBBI); + visitMachineInstrBefore(MBBI); + for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I) { + const MachineInstr &MI = *MBBI; + const MachineOperand &Op = MI.getOperand(I); + if (Op.getParent() != &MI) { + // Make sure to use correct addOperand / RemoveOperand / ChangeTo + // functions when replacing operands of a MachineInstr. + report("Instruction has operand with wrong parent set", &MI); + } + + visitMachineOperand(&Op, I); + } + + visitMachineInstrAfter(MBBI); + + // Was this the last bundled instruction? + InBundle = MBBI->isBundledWithSucc(); + } + if (CurBundle) + visitMachineBundleAfter(CurBundle); + if (InBundle) + report("BundledSucc flag set on last instruction in block", &MFI->back()); + visitMachineBasicBlockAfter(MFI); + } + visitMachineFunctionAfter(); + + if (foundErrors) + report_fatal_error("Found "+Twine(foundErrors)+" machine code errors."); + + // Clean up. + regsLive.clear(); + regsDefined.clear(); + regsDead.clear(); + regsKilled.clear(); + regMasks.clear(); + regsLiveInButUnused.clear(); + MBBInfoMap.clear(); + + return false; // no changes +} + +void MachineVerifier::report(const char *msg, const MachineFunction *MF) { + assert(MF); + errs() << '\n'; + if (!foundErrors++) { + if (Banner) + errs() << "# " << Banner << '\n'; + MF->print(errs(), Indexes); + } + errs() << "*** Bad machine code: " << msg << " ***\n" + << "- function: " << MF->getName() << "\n"; +} + +void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) { + assert(MBB); + report(msg, MBB->getParent()); + errs() << "- basic block: BB#" << MBB->getNumber() + << ' ' << MBB->getName() + << " (" << (const void*)MBB << ')'; + if (Indexes) + errs() << " [" << Indexes->getMBBStartIdx(MBB) + << ';' << Indexes->getMBBEndIdx(MBB) << ')'; + errs() << '\n'; +} + +void MachineVerifier::report(const char *msg, const MachineInstr *MI) { + assert(MI); + report(msg, MI->getParent()); + errs() << "- instruction: "; + if (Indexes && Indexes->hasIndex(MI)) + errs() << Indexes->getInstructionIndex(MI) << '\t'; + MI->print(errs(), TM); +} + +void MachineVerifier::report(const char *msg, + const MachineOperand *MO, unsigned MONum) { + assert(MO); + report(msg, MO->getParent()); + errs() << "- operand " << MONum << ": "; + MO->print(errs(), TRI); + errs() << "\n"; +} + +void MachineVerifier::report(const char *msg, const MachineFunction *MF, + const LiveInterval &LI) { + report(msg, MF); + errs() << "- interval: " << LI << '\n'; +} + +void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB, + const LiveInterval &LI) { + report(msg, MBB); + errs() << "- interval: " << LI << '\n'; +} + +void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB, + const LiveRange &LR, unsigned Reg, + unsigned LaneMask) { + report(msg, MBB); + errs() << "- liverange: " << LR << '\n'; + errs() << "- register: " << PrintReg(Reg, TRI) << '\n'; + if (LaneMask != 0) + errs() << "- lanemask: " << format("%04X\n", LaneMask); +} + +void MachineVerifier::report(const char *msg, const MachineFunction *MF, + const LiveRange &LR, unsigned Reg, + unsigned LaneMask) { + report(msg, MF); + errs() << "- liverange: " << LR << '\n'; + errs() << "- register: " << PrintReg(Reg, TRI) << '\n'; + if (LaneMask != 0) + errs() << "- lanemask: " << format("%04X\n", LaneMask); +} + +void MachineVerifier::markReachable(const MachineBasicBlock *MBB) { + BBInfo &MInfo = MBBInfoMap[MBB]; + if (!MInfo.reachable) { + MInfo.reachable = true; + for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(), + SuE = MBB->succ_end(); SuI != SuE; ++SuI) + markReachable(*SuI); + } +} + +void MachineVerifier::visitMachineFunctionBefore() { + lastIndex = SlotIndex(); + regsReserved = MRI->getReservedRegs(); + + // A sub-register of a reserved register is also reserved + for (int Reg = regsReserved.find_first(); Reg>=0; + Reg = regsReserved.find_next(Reg)) { + for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) { + // FIXME: This should probably be: + // assert(regsReserved.test(*SubRegs) && "Non-reserved sub-register"); + regsReserved.set(*SubRegs); + } + } + + markReachable(&MF->front()); + + // Build a set of the basic blocks in the function. + FunctionBlocks.clear(); + for (const auto &MBB : *MF) { + FunctionBlocks.insert(&MBB); + BBInfo &MInfo = MBBInfoMap[&MBB]; + + MInfo.Preds.insert(MBB.pred_begin(), MBB.pred_end()); + if (MInfo.Preds.size() != MBB.pred_size()) + report("MBB has duplicate entries in its predecessor list.", &MBB); + + MInfo.Succs.insert(MBB.succ_begin(), MBB.succ_end()); + if (MInfo.Succs.size() != MBB.succ_size()) + report("MBB has duplicate entries in its successor list.", &MBB); + } + + // Check that the register use lists are sane. + MRI->verifyUseLists(); + + verifyStackFrame(); +} + +// Does iterator point to a and b as the first two elements? +static bool matchPair(MachineBasicBlock::const_succ_iterator i, + const MachineBasicBlock *a, const MachineBasicBlock *b) { + if (*i == a) + return *++i == b; + if (*i == b) + return *++i == a; + return false; +} + +void +MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) { + FirstTerminator = nullptr; + + if (MRI->isSSA()) { + // If this block has allocatable physical registers live-in, check that + // it is an entry block or landing pad. + for (MachineBasicBlock::livein_iterator LI = MBB->livein_begin(), + LE = MBB->livein_end(); + LI != LE; ++LI) { + unsigned reg = *LI; + if (isAllocatable(reg) && !MBB->isLandingPad() && + MBB != MBB->getParent()->begin()) { + report("MBB has allocable live-in, but isn't entry or landing-pad.", MBB); + } + } + } + + // Count the number of landing pad successors. + SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs; + for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(), + E = MBB->succ_end(); I != E; ++I) { + if ((*I)->isLandingPad()) + LandingPadSuccs.insert(*I); + if (!FunctionBlocks.count(*I)) + report("MBB has successor that isn't part of the function.", MBB); + if (!MBBInfoMap[*I].Preds.count(MBB)) { + report("Inconsistent CFG", MBB); + errs() << "MBB is not in the predecessor list of the successor BB#" + << (*I)->getNumber() << ".\n"; + } + } + + // Check the predecessor list. + for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(), + E = MBB->pred_end(); I != E; ++I) { + if (!FunctionBlocks.count(*I)) + report("MBB has predecessor that isn't part of the function.", MBB); + if (!MBBInfoMap[*I].Succs.count(MBB)) { + report("Inconsistent CFG", MBB); + errs() << "MBB is not in the successor list of the predecessor BB#" + << (*I)->getNumber() << ".\n"; + } + } + + const MCAsmInfo *AsmInfo = TM->getMCAsmInfo(); + const BasicBlock *BB = MBB->getBasicBlock(); + if (LandingPadSuccs.size() > 1 && + !(AsmInfo && + AsmInfo->getExceptionHandlingType() == ExceptionHandling::SjLj && + BB && isa<SwitchInst>(BB->getTerminator()))) + report("MBB has more than one landing pad successor", MBB); + + // Call AnalyzeBranch. If it succeeds, there several more conditions to check. + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; + SmallVector<MachineOperand, 4> Cond; + if (!TII->AnalyzeBranch(*const_cast<MachineBasicBlock *>(MBB), + TBB, FBB, Cond)) { + // Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's + // check whether its answers match up with reality. + if (!TBB && !FBB) { + // Block falls through to its successor. + MachineFunction::const_iterator MBBI = MBB; + ++MBBI; + if (MBBI == MF->end()) { + // It's possible that the block legitimately ends with a noreturn + // call or an unreachable, in which case it won't actually fall + // out the bottom of the function. + } else if (MBB->succ_size() == LandingPadSuccs.size()) { + // It's possible that the block legitimately ends with a noreturn + // call or an unreachable, in which case it won't actuall fall + // out of the block. + } else if (MBB->succ_size() != 1+LandingPadSuccs.size()) { + report("MBB exits via unconditional fall-through but doesn't have " + "exactly one CFG successor!", MBB); + } else if (!MBB->isSuccessor(MBBI)) { + report("MBB exits via unconditional fall-through but its successor " + "differs from its CFG successor!", MBB); + } + if (!MBB->empty() && MBB->back().isBarrier() && + !TII->isPredicated(&MBB->back())) { + report("MBB exits via unconditional fall-through but ends with a " + "barrier instruction!", MBB); + } + if (!Cond.empty()) { + report("MBB exits via unconditional fall-through but has a condition!", + MBB); + } + } else if (TBB && !FBB && Cond.empty()) { + // Block unconditionally branches somewhere. + // If the block has exactly one successor, that happens to be a + // landingpad, accept it as valid control flow. + if (MBB->succ_size() != 1+LandingPadSuccs.size() && + (MBB->succ_size() != 1 || LandingPadSuccs.size() != 1 || + *MBB->succ_begin() != *LandingPadSuccs.begin())) { + report("MBB exits via unconditional branch but doesn't have " + "exactly one CFG successor!", MBB); + } else if (!MBB->isSuccessor(TBB)) { + report("MBB exits via unconditional branch but the CFG " + "successor doesn't match the actual successor!", MBB); + } + if (MBB->empty()) { + report("MBB exits via unconditional branch but doesn't contain " + "any instructions!", MBB); + } else if (!MBB->back().isBarrier()) { + report("MBB exits via unconditional branch but doesn't end with a " + "barrier instruction!", MBB); + } else if (!MBB->back().isTerminator()) { + report("MBB exits via unconditional branch but the branch isn't a " + "terminator instruction!", MBB); + } + } else if (TBB && !FBB && !Cond.empty()) { + // Block conditionally branches somewhere, otherwise falls through. + MachineFunction::const_iterator MBBI = MBB; + ++MBBI; + if (MBBI == MF->end()) { + report("MBB conditionally falls through out of function!", MBB); + } else if (MBB->succ_size() == 1) { + // A conditional branch with only one successor is weird, but allowed. + if (&*MBBI != TBB) + report("MBB exits via conditional branch/fall-through but only has " + "one CFG successor!", MBB); + else if (TBB != *MBB->succ_begin()) + report("MBB exits via conditional branch/fall-through but the CFG " + "successor don't match the actual successor!", MBB); + } else if (MBB->succ_size() != 2) { + report("MBB exits via conditional branch/fall-through but doesn't have " + "exactly two CFG successors!", MBB); + } else if (!matchPair(MBB->succ_begin(), TBB, MBBI)) { + report("MBB exits via conditional branch/fall-through but the CFG " + "successors don't match the actual successors!", MBB); + } + if (MBB->empty()) { + report("MBB exits via conditional branch/fall-through but doesn't " + "contain any instructions!", MBB); + } else if (MBB->back().isBarrier()) { + report("MBB exits via conditional branch/fall-through but ends with a " + "barrier instruction!", MBB); + } else if (!MBB->back().isTerminator()) { + report("MBB exits via conditional branch/fall-through but the branch " + "isn't a terminator instruction!", MBB); + } + } else if (TBB && FBB) { + // Block conditionally branches somewhere, otherwise branches + // somewhere else. + if (MBB->succ_size() == 1) { + // A conditional branch with only one successor is weird, but allowed. + if (FBB != TBB) + report("MBB exits via conditional branch/branch through but only has " + "one CFG successor!", MBB); + else if (TBB != *MBB->succ_begin()) + report("MBB exits via conditional branch/branch through but the CFG " + "successor don't match the actual successor!", MBB); + } else if (MBB->succ_size() != 2) { + report("MBB exits via conditional branch/branch but doesn't have " + "exactly two CFG successors!", MBB); + } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) { + report("MBB exits via conditional branch/branch but the CFG " + "successors don't match the actual successors!", MBB); + } + if (MBB->empty()) { + report("MBB exits via conditional branch/branch but doesn't " + "contain any instructions!", MBB); + } else if (!MBB->back().isBarrier()) { + report("MBB exits via conditional branch/branch but doesn't end with a " + "barrier instruction!", MBB); + } else if (!MBB->back().isTerminator()) { + report("MBB exits via conditional branch/branch but the branch " + "isn't a terminator instruction!", MBB); + } + if (Cond.empty()) { + report("MBB exits via conditinal branch/branch but there's no " + "condition!", MBB); + } + } else { + report("AnalyzeBranch returned invalid data!", MBB); + } + } + + regsLive.clear(); + for (MachineBasicBlock::livein_iterator I = MBB->livein_begin(), + E = MBB->livein_end(); I != E; ++I) { + if (!TargetRegisterInfo::isPhysicalRegister(*I)) { + report("MBB live-in list contains non-physical register", MBB); + continue; + } + for (MCSubRegIterator SubRegs(*I, TRI, /*IncludeSelf=*/true); + SubRegs.isValid(); ++SubRegs) + regsLive.insert(*SubRegs); + } + regsLiveInButUnused = regsLive; + + const MachineFrameInfo *MFI = MF->getFrameInfo(); + assert(MFI && "Function has no frame info"); + BitVector PR = MFI->getPristineRegs(*MF); + for (int I = PR.find_first(); I>0; I = PR.find_next(I)) { + for (MCSubRegIterator SubRegs(I, TRI, /*IncludeSelf=*/true); + SubRegs.isValid(); ++SubRegs) + regsLive.insert(*SubRegs); + } + + regsKilled.clear(); + regsDefined.clear(); + + if (Indexes) + lastIndex = Indexes->getMBBStartIdx(MBB); +} + +// This function gets called for all bundle headers, including normal +// stand-alone unbundled instructions. +void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) { + if (Indexes && Indexes->hasIndex(MI)) { + SlotIndex idx = Indexes->getInstructionIndex(MI); + if (!(idx > lastIndex)) { + report("Instruction index out of order", MI); + errs() << "Last instruction was at " << lastIndex << '\n'; + } + lastIndex = idx; + } + + // Ensure non-terminators don't follow terminators. + // Ignore predicated terminators formed by if conversion. + // FIXME: If conversion shouldn't need to violate this rule. + if (MI->isTerminator() && !TII->isPredicated(MI)) { + if (!FirstTerminator) + FirstTerminator = MI; + } else if (FirstTerminator) { + report("Non-terminator instruction after the first terminator", MI); + errs() << "First terminator was:\t" << *FirstTerminator; + } +} + +// The operands on an INLINEASM instruction must follow a template. +// Verify that the flag operands make sense. +void MachineVerifier::verifyInlineAsm(const MachineInstr *MI) { + // The first two operands on INLINEASM are the asm string and global flags. + if (MI->getNumOperands() < 2) { + report("Too few operands on inline asm", MI); + return; + } + if (!MI->getOperand(0).isSymbol()) + report("Asm string must be an external symbol", MI); + if (!MI->getOperand(1).isImm()) + report("Asm flags must be an immediate", MI); + // Allowed flags are Extra_HasSideEffects = 1, Extra_IsAlignStack = 2, + // Extra_AsmDialect = 4, Extra_MayLoad = 8, and Extra_MayStore = 16. + if (!isUInt<5>(MI->getOperand(1).getImm())) + report("Unknown asm flags", &MI->getOperand(1), 1); + + static_assert(InlineAsm::MIOp_FirstOperand == 2, "Asm format changed"); + + unsigned OpNo = InlineAsm::MIOp_FirstOperand; + unsigned NumOps; + for (unsigned e = MI->getNumOperands(); OpNo < e; OpNo += NumOps) { + const MachineOperand &MO = MI->getOperand(OpNo); + // There may be implicit ops after the fixed operands. + if (!MO.isImm()) + break; + NumOps = 1 + InlineAsm::getNumOperandRegisters(MO.getImm()); + } + + if (OpNo > MI->getNumOperands()) + report("Missing operands in last group", MI); + + // An optional MDNode follows the groups. + if (OpNo < MI->getNumOperands() && MI->getOperand(OpNo).isMetadata()) + ++OpNo; + + // All trailing operands must be implicit registers. + for (unsigned e = MI->getNumOperands(); OpNo < e; ++OpNo) { + const MachineOperand &MO = MI->getOperand(OpNo); + if (!MO.isReg() || !MO.isImplicit()) + report("Expected implicit register after groups", &MO, OpNo); + } +} + +void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) { + const MCInstrDesc &MCID = MI->getDesc(); + if (MI->getNumOperands() < MCID.getNumOperands()) { + report("Too few operands", MI); + errs() << MCID.getNumOperands() << " operands expected, but " + << MI->getNumOperands() << " given.\n"; + } + + // Check the tied operands. + if (MI->isInlineAsm()) + verifyInlineAsm(MI); + + // Check the MachineMemOperands for basic consistency. + for (MachineInstr::mmo_iterator I = MI->memoperands_begin(), + E = MI->memoperands_end(); I != E; ++I) { + if ((*I)->isLoad() && !MI->mayLoad()) + report("Missing mayLoad flag", MI); + if ((*I)->isStore() && !MI->mayStore()) + report("Missing mayStore flag", MI); + } + + // Debug values must not have a slot index. + // Other instructions must have one, unless they are inside a bundle. + if (LiveInts) { + bool mapped = !LiveInts->isNotInMIMap(MI); + if (MI->isDebugValue()) { + if (mapped) + report("Debug instruction has a slot index", MI); + } else if (MI->isInsideBundle()) { + if (mapped) + report("Instruction inside bundle has a slot index", MI); + } else { + if (!mapped) + report("Missing slot index", MI); + } + } + + StringRef ErrorInfo; + if (!TII->verifyInstruction(MI, ErrorInfo)) + report(ErrorInfo.data(), MI); +} + +void +MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) { + const MachineInstr *MI = MO->getParent(); + const MCInstrDesc &MCID = MI->getDesc(); + + // The first MCID.NumDefs operands must be explicit register defines + if (MONum < MCID.getNumDefs()) { + const MCOperandInfo &MCOI = MCID.OpInfo[MONum]; + if (!MO->isReg()) + report("Explicit definition must be a register", MO, MONum); + else if (!MO->isDef() && !MCOI.isOptionalDef()) + report("Explicit definition marked as use", MO, MONum); + else if (MO->isImplicit()) + report("Explicit definition marked as implicit", MO, MONum); + } else if (MONum < MCID.getNumOperands()) { + const MCOperandInfo &MCOI = MCID.OpInfo[MONum]; + // Don't check if it's the last operand in a variadic instruction. See, + // e.g., LDM_RET in the arm back end. + if (MO->isReg() && + !(MI->isVariadic() && MONum == MCID.getNumOperands()-1)) { + if (MO->isDef() && !MCOI.isOptionalDef()) + report("Explicit operand marked as def", MO, MONum); + if (MO->isImplicit()) + report("Explicit operand marked as implicit", MO, MONum); + } + + int TiedTo = MCID.getOperandConstraint(MONum, MCOI::TIED_TO); + if (TiedTo != -1) { + if (!MO->isReg()) + report("Tied use must be a register", MO, MONum); + else if (!MO->isTied()) + report("Operand should be tied", MO, MONum); + else if (unsigned(TiedTo) != MI->findTiedOperandIdx(MONum)) + report("Tied def doesn't match MCInstrDesc", MO, MONum); + } else if (MO->isReg() && MO->isTied()) + report("Explicit operand should not be tied", MO, MONum); + } else { + // ARM adds %reg0 operands to indicate predicates. We'll allow that. + if (MO->isReg() && !MO->isImplicit() && !MI->isVariadic() && MO->getReg()) + report("Extra explicit operand on non-variadic instruction", MO, MONum); + } + + switch (MO->getType()) { + case MachineOperand::MO_Register: { + const unsigned Reg = MO->getReg(); + if (!Reg) + return; + if (MRI->tracksLiveness() && !MI->isDebugValue()) + checkLiveness(MO, MONum); + + // Verify the consistency of tied operands. + if (MO->isTied()) { + unsigned OtherIdx = MI->findTiedOperandIdx(MONum); + const MachineOperand &OtherMO = MI->getOperand(OtherIdx); + if (!OtherMO.isReg()) + report("Must be tied to a register", MO, MONum); + if (!OtherMO.isTied()) + report("Missing tie flags on tied operand", MO, MONum); + if (MI->findTiedOperandIdx(OtherIdx) != MONum) + report("Inconsistent tie links", MO, MONum); + if (MONum < MCID.getNumDefs()) { + if (OtherIdx < MCID.getNumOperands()) { + if (-1 == MCID.getOperandConstraint(OtherIdx, MCOI::TIED_TO)) + report("Explicit def tied to explicit use without tie constraint", + MO, MONum); + } else { + if (!OtherMO.isImplicit()) + report("Explicit def should be tied to implicit use", MO, MONum); + } + } + } + + // Verify two-address constraints after leaving SSA form. + unsigned DefIdx; + if (!MRI->isSSA() && MO->isUse() && + MI->isRegTiedToDefOperand(MONum, &DefIdx) && + Reg != MI->getOperand(DefIdx).getReg()) + report("Two-address instruction operands must be identical", MO, MONum); + + // Check register classes. + if (MONum < MCID.getNumOperands() && !MO->isImplicit()) { + unsigned SubIdx = MO->getSubReg(); + + if (TargetRegisterInfo::isPhysicalRegister(Reg)) { + if (SubIdx) { + report("Illegal subregister index for physical register", MO, MONum); + return; + } + if (const TargetRegisterClass *DRC = + TII->getRegClass(MCID, MONum, TRI, *MF)) { + if (!DRC->contains(Reg)) { + report("Illegal physical register for instruction", MO, MONum); + errs() << TRI->getName(Reg) << " is not a " + << TRI->getRegClassName(DRC) << " register.\n"; + } + } + } else { + // Virtual register. + const TargetRegisterClass *RC = MRI->getRegClass(Reg); + if (SubIdx) { + const TargetRegisterClass *SRC = + TRI->getSubClassWithSubReg(RC, SubIdx); + if (!SRC) { + report("Invalid subregister index for virtual register", MO, MONum); + errs() << "Register class " << TRI->getRegClassName(RC) + << " does not support subreg index " << SubIdx << "\n"; + return; + } + if (RC != SRC) { + report("Invalid register class for subregister index", MO, MONum); + errs() << "Register class " << TRI->getRegClassName(RC) + << " does not fully support subreg index " << SubIdx << "\n"; + return; + } + } + if (const TargetRegisterClass *DRC = + TII->getRegClass(MCID, MONum, TRI, *MF)) { + if (SubIdx) { + const TargetRegisterClass *SuperRC = + TRI->getLargestLegalSuperClass(RC, *MF); + if (!SuperRC) { + report("No largest legal super class exists.", MO, MONum); + return; + } + DRC = TRI->getMatchingSuperRegClass(SuperRC, DRC, SubIdx); + if (!DRC) { + report("No matching super-reg register class.", MO, MONum); + return; + } + } + if (!RC->hasSuperClassEq(DRC)) { + report("Illegal virtual register for instruction", MO, MONum); + errs() << "Expected a " << TRI->getRegClassName(DRC) + << " register, but got a " << TRI->getRegClassName(RC) + << " register\n"; + } + } + } + } + break; + } + + case MachineOperand::MO_RegisterMask: + regMasks.push_back(MO->getRegMask()); + break; + + case MachineOperand::MO_MachineBasicBlock: + if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent())) + report("PHI operand is not in the CFG", MO, MONum); + break; + + case MachineOperand::MO_FrameIndex: + if (LiveStks && LiveStks->hasInterval(MO->getIndex()) && + LiveInts && !LiveInts->isNotInMIMap(MI)) { + LiveInterval &LI = LiveStks->getInterval(MO->getIndex()); + SlotIndex Idx = LiveInts->getInstructionIndex(MI); + if (MI->mayLoad() && !LI.liveAt(Idx.getRegSlot(true))) { + report("Instruction loads from dead spill slot", MO, MONum); + errs() << "Live stack: " << LI << '\n'; + } + if (MI->mayStore() && !LI.liveAt(Idx.getRegSlot())) { + report("Instruction stores to dead spill slot", MO, MONum); + errs() << "Live stack: " << LI << '\n'; + } + } + break; + + default: + break; + } +} + +void MachineVerifier::checkLiveness(const MachineOperand *MO, unsigned MONum) { + const MachineInstr *MI = MO->getParent(); + const unsigned Reg = MO->getReg(); + + // Both use and def operands can read a register. + if (MO->readsReg()) { + regsLiveInButUnused.erase(Reg); + + if (MO->isKill()) + addRegWithSubRegs(regsKilled, Reg); + + // Check that LiveVars knows this kill. + if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg) && + MO->isKill()) { + LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg); + if (std::find(VI.Kills.begin(), VI.Kills.end(), MI) == VI.Kills.end()) + report("Kill missing from LiveVariables", MO, MONum); + } + + // Check LiveInts liveness and kill. + if (LiveInts && !LiveInts->isNotInMIMap(MI)) { + SlotIndex UseIdx = LiveInts->getInstructionIndex(MI); + // Check the cached regunit intervals. + if (TargetRegisterInfo::isPhysicalRegister(Reg) && !isReserved(Reg)) { + for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) { + if (const LiveRange *LR = LiveInts->getCachedRegUnit(*Units)) { + LiveQueryResult LRQ = LR->Query(UseIdx); + if (!LRQ.valueIn()) { + report("No live segment at use", MO, MONum); + errs() << UseIdx << " is not live in " << PrintRegUnit(*Units, TRI) + << ' ' << *LR << '\n'; + } + if (MO->isKill() && !LRQ.isKill()) { + report("Live range continues after kill flag", MO, MONum); + errs() << PrintRegUnit(*Units, TRI) << ' ' << *LR << '\n'; + } + } + } + } + + if (TargetRegisterInfo::isVirtualRegister(Reg)) { + if (LiveInts->hasInterval(Reg)) { + // This is a virtual register interval. + const LiveInterval &LI = LiveInts->getInterval(Reg); + LiveQueryResult LRQ = LI.Query(UseIdx); + if (!LRQ.valueIn()) { + report("No live segment at use", MO, MONum); + errs() << UseIdx << " is not live in " << LI << '\n'; + } + // Check for extra kill flags. + // Note that we allow missing kill flags for now. + if (MO->isKill() && !LRQ.isKill()) { + report("Live range continues after kill flag", MO, MONum); + errs() << "Live range: " << LI << '\n'; + } + } else { + report("Virtual register has no live interval", MO, MONum); + } + } + } + + // Use of a dead register. + if (!regsLive.count(Reg)) { + if (TargetRegisterInfo::isPhysicalRegister(Reg)) { + // Reserved registers may be used even when 'dead'. + bool Bad = !isReserved(Reg); + // We are fine if just any subregister has a defined value. + if (Bad) { + for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); + ++SubRegs) { + if (regsLive.count(*SubRegs)) { + Bad = false; + break; + } + } + } + // If there is an additional implicit-use of a super register we stop + // here. By definition we are fine if the super register is not + // (completely) dead, if the complete super register is dead we will + // get a report for its operand. + if (Bad) { + for (const MachineOperand &MOP : MI->uses()) { + if (!MOP.isReg()) + continue; + if (!MOP.isImplicit()) + continue; + for (MCSubRegIterator SubRegs(MOP.getReg(), TRI); SubRegs.isValid(); + ++SubRegs) { + if (*SubRegs == Reg) { + Bad = false; + break; + } + } + } + } + if (Bad) + report("Using an undefined physical register", MO, MONum); + } else if (MRI->def_empty(Reg)) { + report("Reading virtual register without a def", MO, MONum); + } else { + BBInfo &MInfo = MBBInfoMap[MI->getParent()]; + // We don't know which virtual registers are live in, so only complain + // if vreg was killed in this MBB. Otherwise keep track of vregs that + // must be live in. PHI instructions are handled separately. + if (MInfo.regsKilled.count(Reg)) + report("Using a killed virtual register", MO, MONum); + else if (!MI->isPHI()) + MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI)); + } + } + } + + if (MO->isDef()) { + // Register defined. + // TODO: verify that earlyclobber ops are not used. + if (MO->isDead()) + addRegWithSubRegs(regsDead, Reg); + else + addRegWithSubRegs(regsDefined, Reg); + + // Verify SSA form. + if (MRI->isSSA() && TargetRegisterInfo::isVirtualRegister(Reg) && + std::next(MRI->def_begin(Reg)) != MRI->def_end()) + report("Multiple virtual register defs in SSA form", MO, MONum); + + // Check LiveInts for a live segment, but only for virtual registers. + if (LiveInts && TargetRegisterInfo::isVirtualRegister(Reg) && + !LiveInts->isNotInMIMap(MI)) { + SlotIndex DefIdx = LiveInts->getInstructionIndex(MI); + DefIdx = DefIdx.getRegSlot(MO->isEarlyClobber()); + if (LiveInts->hasInterval(Reg)) { + const LiveInterval &LI = LiveInts->getInterval(Reg); + if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) { + assert(VNI && "NULL valno is not allowed"); + if (VNI->def != DefIdx) { + report("Inconsistent valno->def", MO, MONum); + errs() << "Valno " << VNI->id << " is not defined at " + << DefIdx << " in " << LI << '\n'; + } + } else { + report("No live segment at def", MO, MONum); + errs() << DefIdx << " is not live in " << LI << '\n'; + } + // Check that, if the dead def flag is present, LiveInts agree. + if (MO->isDead()) { + LiveQueryResult LRQ = LI.Query(DefIdx); + if (!LRQ.isDeadDef()) { + report("Live range continues after dead def flag", MO, MONum); + errs() << "Live range: " << LI << '\n'; + } + } + } else { + report("Virtual register has no Live interval", MO, MONum); + } + } + } +} + +void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) { +} + +// This function gets called after visiting all instructions in a bundle. The +// argument points to the bundle header. +// Normal stand-alone instructions are also considered 'bundles', and this +// function is called for all of them. +void MachineVerifier::visitMachineBundleAfter(const MachineInstr *MI) { + BBInfo &MInfo = MBBInfoMap[MI->getParent()]; + set_union(MInfo.regsKilled, regsKilled); + set_subtract(regsLive, regsKilled); regsKilled.clear(); + // Kill any masked registers. + while (!regMasks.empty()) { + const uint32_t *Mask = regMasks.pop_back_val(); + for (RegSet::iterator I = regsLive.begin(), E = regsLive.end(); I != E; ++I) + if (TargetRegisterInfo::isPhysicalRegister(*I) && + MachineOperand::clobbersPhysReg(Mask, *I)) + regsDead.push_back(*I); + } + set_subtract(regsLive, regsDead); regsDead.clear(); + set_union(regsLive, regsDefined); regsDefined.clear(); +} + +void +MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) { + MBBInfoMap[MBB].regsLiveOut = regsLive; + regsLive.clear(); + + if (Indexes) { + SlotIndex stop = Indexes->getMBBEndIdx(MBB); + if (!(stop > lastIndex)) { + report("Block ends before last instruction index", MBB); + errs() << "Block ends at " << stop + << " last instruction was at " << lastIndex << '\n'; + } + lastIndex = stop; + } +} + +// Calculate the largest possible vregsPassed sets. These are the registers that +// can pass through an MBB live, but may not be live every time. It is assumed +// that all vregsPassed sets are empty before the call. +void MachineVerifier::calcRegsPassed() { + // First push live-out regs to successors' vregsPassed. Remember the MBBs that + // have any vregsPassed. + SmallPtrSet<const MachineBasicBlock*, 8> todo; + for (const auto &MBB : *MF) { + BBInfo &MInfo = MBBInfoMap[&MBB]; + if (!MInfo.reachable) + continue; + for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(), + SuE = MBB.succ_end(); SuI != SuE; ++SuI) { + BBInfo &SInfo = MBBInfoMap[*SuI]; + if (SInfo.addPassed(MInfo.regsLiveOut)) + todo.insert(*SuI); + } + } + + // Iteratively push vregsPassed to successors. This will converge to the same + // final state regardless of DenseSet iteration order. + while (!todo.empty()) { + const MachineBasicBlock *MBB = *todo.begin(); + todo.erase(MBB); + BBInfo &MInfo = MBBInfoMap[MBB]; + for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(), + SuE = MBB->succ_end(); SuI != SuE; ++SuI) { + if (*SuI == MBB) + continue; + BBInfo &SInfo = MBBInfoMap[*SuI]; + if (SInfo.addPassed(MInfo.vregsPassed)) + todo.insert(*SuI); + } + } +} + +// Calculate the set of virtual registers that must be passed through each basic +// block in order to satisfy the requirements of successor blocks. This is very +// similar to calcRegsPassed, only backwards. +void MachineVerifier::calcRegsRequired() { + // First push live-in regs to predecessors' vregsRequired. + SmallPtrSet<const MachineBasicBlock*, 8> todo; + for (const auto &MBB : *MF) { + BBInfo &MInfo = MBBInfoMap[&MBB]; + for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(), + PrE = MBB.pred_end(); PrI != PrE; ++PrI) { + BBInfo &PInfo = MBBInfoMap[*PrI]; + if (PInfo.addRequired(MInfo.vregsLiveIn)) + todo.insert(*PrI); + } + } + + // Iteratively push vregsRequired to predecessors. This will converge to the + // same final state regardless of DenseSet iteration order. + while (!todo.empty()) { + const MachineBasicBlock *MBB = *todo.begin(); + todo.erase(MBB); + BBInfo &MInfo = MBBInfoMap[MBB]; + for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(), + PrE = MBB->pred_end(); PrI != PrE; ++PrI) { + if (*PrI == MBB) + continue; + BBInfo &SInfo = MBBInfoMap[*PrI]; + if (SInfo.addRequired(MInfo.vregsRequired)) + todo.insert(*PrI); + } + } +} + +// Check PHI instructions at the beginning of MBB. It is assumed that +// calcRegsPassed has been run so BBInfo::isLiveOut is valid. +void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) { + SmallPtrSet<const MachineBasicBlock*, 8> seen; + for (const auto &BBI : *MBB) { + if (!BBI.isPHI()) + break; + seen.clear(); + + for (unsigned i = 1, e = BBI.getNumOperands(); i != e; i += 2) { + unsigned Reg = BBI.getOperand(i).getReg(); + const MachineBasicBlock *Pre = BBI.getOperand(i + 1).getMBB(); + if (!Pre->isSuccessor(MBB)) + continue; + seen.insert(Pre); + BBInfo &PrInfo = MBBInfoMap[Pre]; + if (PrInfo.reachable && !PrInfo.isLiveOut(Reg)) + report("PHI operand is not live-out from predecessor", + &BBI.getOperand(i), i); + } + + // Did we see all predecessors? + for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(), + PrE = MBB->pred_end(); PrI != PrE; ++PrI) { + if (!seen.count(*PrI)) { + report("Missing PHI operand", &BBI); + errs() << "BB#" << (*PrI)->getNumber() + << " is a predecessor according to the CFG.\n"; + } + } + } +} + +void MachineVerifier::visitMachineFunctionAfter() { + calcRegsPassed(); + + for (const auto &MBB : *MF) { + BBInfo &MInfo = MBBInfoMap[&MBB]; + + // Skip unreachable MBBs. + if (!MInfo.reachable) + continue; + + checkPHIOps(&MBB); + } + + // Now check liveness info if available + calcRegsRequired(); + + // Check for killed virtual registers that should be live out. + for (const auto &MBB : *MF) { + BBInfo &MInfo = MBBInfoMap[&MBB]; + for (RegSet::iterator + I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E; + ++I) + if (MInfo.regsKilled.count(*I)) { + report("Virtual register killed in block, but needed live out.", &MBB); + errs() << "Virtual register " << PrintReg(*I) + << " is used after the block.\n"; + } + } + + if (!MF->empty()) { + BBInfo &MInfo = MBBInfoMap[&MF->front()]; + for (RegSet::iterator + I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E; + ++I) + report("Virtual register def doesn't dominate all uses.", + MRI->getVRegDef(*I)); + } + + if (LiveVars) + verifyLiveVariables(); + if (LiveInts) + verifyLiveIntervals(); +} + +void MachineVerifier::verifyLiveVariables() { + assert(LiveVars && "Don't call verifyLiveVariables without LiveVars"); + for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { + unsigned Reg = TargetRegisterInfo::index2VirtReg(i); + LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg); + for (const auto &MBB : *MF) { + BBInfo &MInfo = MBBInfoMap[&MBB]; + + // Our vregsRequired should be identical to LiveVariables' AliveBlocks + if (MInfo.vregsRequired.count(Reg)) { + if (!VI.AliveBlocks.test(MBB.getNumber())) { + report("LiveVariables: Block missing from AliveBlocks", &MBB); + errs() << "Virtual register " << PrintReg(Reg) + << " must be live through the block.\n"; + } + } else { + if (VI.AliveBlocks.test(MBB.getNumber())) { + report("LiveVariables: Block should not be in AliveBlocks", &MBB); + errs() << "Virtual register " << PrintReg(Reg) + << " is not needed live through the block.\n"; + } + } + } + } +} + +void MachineVerifier::verifyLiveIntervals() { + assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts"); + for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { + unsigned Reg = TargetRegisterInfo::index2VirtReg(i); + + // Spilling and splitting may leave unused registers around. Skip them. + if (MRI->reg_nodbg_empty(Reg)) + continue; + + if (!LiveInts->hasInterval(Reg)) { + report("Missing live interval for virtual register", MF); + errs() << PrintReg(Reg, TRI) << " still has defs or uses\n"; + continue; + } + + const LiveInterval &LI = LiveInts->getInterval(Reg); + assert(Reg == LI.reg && "Invalid reg to interval mapping"); + verifyLiveInterval(LI); + } + + // Verify all the cached regunit intervals. + for (unsigned i = 0, e = TRI->getNumRegUnits(); i != e; ++i) + if (const LiveRange *LR = LiveInts->getCachedRegUnit(i)) + verifyLiveRange(*LR, i); +} + +void MachineVerifier::verifyLiveRangeValue(const LiveRange &LR, + const VNInfo *VNI, unsigned Reg, + unsigned LaneMask) { + if (VNI->isUnused()) + return; + + const VNInfo *DefVNI = LR.getVNInfoAt(VNI->def); + + if (!DefVNI) { + report("Valno not live at def and not marked unused", MF, LR, Reg, + LaneMask); + errs() << "Valno #" << VNI->id << '\n'; + return; + } + + if (DefVNI != VNI) { + report("Live segment at def has different valno", MF, LR, Reg, LaneMask); + errs() << "Valno #" << VNI->id << " is defined at " << VNI->def + << " where valno #" << DefVNI->id << " is live\n"; + return; + } + + const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def); + if (!MBB) { + report("Invalid definition index", MF, LR, Reg, LaneMask); + errs() << "Valno #" << VNI->id << " is defined at " << VNI->def + << " in " << LR << '\n'; + return; + } + + if (VNI->isPHIDef()) { + if (VNI->def != LiveInts->getMBBStartIdx(MBB)) { + report("PHIDef value is not defined at MBB start", MBB, LR, Reg, + LaneMask); + errs() << "Valno #" << VNI->id << " is defined at " << VNI->def + << ", not at the beginning of BB#" << MBB->getNumber() << '\n'; + } + return; + } + + // Non-PHI def. + const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def); + if (!MI) { + report("No instruction at def index", MBB, LR, Reg, LaneMask); + errs() << "Valno #" << VNI->id << " is defined at " << VNI->def << '\n'; + return; + } + + if (Reg != 0) { + bool hasDef = false; + bool isEarlyClobber = false; + for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) { + if (!MOI->isReg() || !MOI->isDef()) + continue; + if (TargetRegisterInfo::isVirtualRegister(Reg)) { + if (MOI->getReg() != Reg) + continue; + } else { + if (!TargetRegisterInfo::isPhysicalRegister(MOI->getReg()) || + !TRI->hasRegUnit(MOI->getReg(), Reg)) + continue; + } + if (LaneMask != 0 && + (TRI->getSubRegIndexLaneMask(MOI->getSubReg()) & LaneMask) == 0) + continue; + hasDef = true; + if (MOI->isEarlyClobber()) + isEarlyClobber = true; + } + + if (!hasDef) { + report("Defining instruction does not modify register", MI); + errs() << "Valno #" << VNI->id << " in " << LR << '\n'; + } + + // Early clobber defs begin at USE slots, but other defs must begin at + // DEF slots. + if (isEarlyClobber) { + if (!VNI->def.isEarlyClobber()) { + report("Early clobber def must be at an early-clobber slot", MBB, LR, + Reg, LaneMask); + errs() << "Valno #" << VNI->id << " is defined at " << VNI->def << '\n'; + } + } else if (!VNI->def.isRegister()) { + report("Non-PHI, non-early clobber def must be at a register slot", + MBB, LR, Reg, LaneMask); + errs() << "Valno #" << VNI->id << " is defined at " << VNI->def << '\n'; + } + } +} + +void MachineVerifier::verifyLiveRangeSegment(const LiveRange &LR, + const LiveRange::const_iterator I, + unsigned Reg, unsigned LaneMask) { + const LiveRange::Segment &S = *I; + const VNInfo *VNI = S.valno; + assert(VNI && "Live segment has no valno"); + + if (VNI->id >= LR.getNumValNums() || VNI != LR.getValNumInfo(VNI->id)) { + report("Foreign valno in live segment", MF, LR, Reg, LaneMask); + errs() << S << " has a bad valno\n"; + } + + if (VNI->isUnused()) { + report("Live segment valno is marked unused", MF, LR, Reg, LaneMask); + errs() << S << '\n'; + } + + const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(S.start); + if (!MBB) { + report("Bad start of live segment, no basic block", MF, LR, Reg, LaneMask); + errs() << S << '\n'; + return; + } + SlotIndex MBBStartIdx = LiveInts->getMBBStartIdx(MBB); + if (S.start != MBBStartIdx && S.start != VNI->def) { + report("Live segment must begin at MBB entry or valno def", MBB, LR, Reg, + LaneMask); + errs() << S << '\n'; + } + + const MachineBasicBlock *EndMBB = + LiveInts->getMBBFromIndex(S.end.getPrevSlot()); + if (!EndMBB) { + report("Bad end of live segment, no basic block", MF, LR, Reg, LaneMask); + errs() << S << '\n'; + return; + } + + // No more checks for live-out segments. + if (S.end == LiveInts->getMBBEndIdx(EndMBB)) + return; + + // RegUnit intervals are allowed dead phis. + if (!TargetRegisterInfo::isVirtualRegister(Reg) && VNI->isPHIDef() && + S.start == VNI->def && S.end == VNI->def.getDeadSlot()) + return; + + // The live segment is ending inside EndMBB + const MachineInstr *MI = + LiveInts->getInstructionFromIndex(S.end.getPrevSlot()); + if (!MI) { + report("Live segment doesn't end at a valid instruction", EndMBB, LR, Reg, + LaneMask); + errs() << S << '\n'; + return; + } + + // The block slot must refer to a basic block boundary. + if (S.end.isBlock()) { + report("Live segment ends at B slot of an instruction", EndMBB, LR, Reg, + LaneMask); + errs() << S << '\n'; + } + + if (S.end.isDead()) { + // Segment ends on the dead slot. + // That means there must be a dead def. + if (!SlotIndex::isSameInstr(S.start, S.end)) { + report("Live segment ending at dead slot spans instructions", EndMBB, LR, + Reg, LaneMask); + errs() << S << '\n'; + } + } + + // A live segment can only end at an early-clobber slot if it is being + // redefined by an early-clobber def. + if (S.end.isEarlyClobber()) { + if (I+1 == LR.end() || (I+1)->start != S.end) { + report("Live segment ending at early clobber slot must be " + "redefined by an EC def in the same instruction", EndMBB, LR, Reg, + LaneMask); + errs() << S << '\n'; + } + } + + // The following checks only apply to virtual registers. Physreg liveness + // is too weird to check. + if (TargetRegisterInfo::isVirtualRegister(Reg)) { + // A live segment can end with either a redefinition, a kill flag on a + // use, or a dead flag on a def. + bool hasRead = false; + bool hasSubRegDef = false; + for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) { + if (!MOI->isReg() || MOI->getReg() != Reg) + continue; + if (LaneMask != 0 && + (LaneMask & TRI->getSubRegIndexLaneMask(MOI->getSubReg())) == 0) + continue; + if (MOI->isDef() && MOI->getSubReg() != 0) + hasSubRegDef = true; + if (MOI->readsReg()) + hasRead = true; + } + if (!S.end.isDead()) { + if (!hasRead) { + // When tracking subregister liveness, the main range must start new + // values on partial register writes, even if there is no read. + if (!MRI->shouldTrackSubRegLiveness(Reg) || LaneMask != 0 || + !hasSubRegDef) { + report("Instruction ending live segment doesn't read the register", + MI); + errs() << S << " in " << LR << '\n'; + } + } + } + } + + // Now check all the basic blocks in this live segment. + MachineFunction::const_iterator MFI = MBB; + // Is this live segment the beginning of a non-PHIDef VN? + if (S.start == VNI->def && !VNI->isPHIDef()) { + // Not live-in to any blocks. + if (MBB == EndMBB) + return; + // Skip this block. + ++MFI; + } + for (;;) { + assert(LiveInts->isLiveInToMBB(LR, MFI)); + // We don't know how to track physregs into a landing pad. + if (!TargetRegisterInfo::isVirtualRegister(Reg) && + MFI->isLandingPad()) { + if (&*MFI == EndMBB) + break; + ++MFI; + continue; + } + + // Is VNI a PHI-def in the current block? + bool IsPHI = VNI->isPHIDef() && + VNI->def == LiveInts->getMBBStartIdx(MFI); + + // Check that VNI is live-out of all predecessors. + for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(), + PE = MFI->pred_end(); PI != PE; ++PI) { + SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI); + const VNInfo *PVNI = LR.getVNInfoBefore(PEnd); + + // All predecessors must have a live-out value. + if (!PVNI) { + report("Register not marked live out of predecessor", *PI, LR, Reg, + LaneMask); + errs() << "Valno #" << VNI->id << " live into BB#" << MFI->getNumber() + << '@' << LiveInts->getMBBStartIdx(MFI) << ", not live before " + << PEnd << '\n'; + continue; + } + + // Only PHI-defs can take different predecessor values. + if (!IsPHI && PVNI != VNI) { + report("Different value live out of predecessor", *PI, LR, Reg, + LaneMask); + errs() << "Valno #" << PVNI->id << " live out of BB#" + << (*PI)->getNumber() << '@' << PEnd + << "\nValno #" << VNI->id << " live into BB#" << MFI->getNumber() + << '@' << LiveInts->getMBBStartIdx(MFI) << '\n'; + } + } + if (&*MFI == EndMBB) + break; + ++MFI; + } +} + +void MachineVerifier::verifyLiveRange(const LiveRange &LR, unsigned Reg, + unsigned LaneMask) { + for (const VNInfo *VNI : LR.valnos) + verifyLiveRangeValue(LR, VNI, Reg, LaneMask); + + for (LiveRange::const_iterator I = LR.begin(), E = LR.end(); I != E; ++I) + verifyLiveRangeSegment(LR, I, Reg, LaneMask); +} + +void MachineVerifier::verifyLiveInterval(const LiveInterval &LI) { + unsigned Reg = LI.reg; + assert(TargetRegisterInfo::isVirtualRegister(Reg)); + verifyLiveRange(LI, Reg); + + unsigned Mask = 0; + unsigned MaxMask = MRI->getMaxLaneMaskForVReg(Reg); + for (const LiveInterval::SubRange &SR : LI.subranges()) { + if ((Mask & SR.LaneMask) != 0) + report("Lane masks of sub ranges overlap in live interval", MF, LI); + if ((SR.LaneMask & ~MaxMask) != 0) + report("Subrange lanemask is invalid", MF, LI); + Mask |= SR.LaneMask; + verifyLiveRange(SR, LI.reg, SR.LaneMask); + if (!LI.covers(SR)) + report("A Subrange is not covered by the main range", MF, LI); + } + + // Check the LI only has one connected component. + ConnectedVNInfoEqClasses ConEQ(*LiveInts); + unsigned NumComp = ConEQ.Classify(&LI); + if (NumComp > 1) { + report("Multiple connected components in live interval", MF, LI); + for (unsigned comp = 0; comp != NumComp; ++comp) { + errs() << comp << ": valnos"; + for (LiveInterval::const_vni_iterator I = LI.vni_begin(), + E = LI.vni_end(); I!=E; ++I) + if (comp == ConEQ.getEqClass(*I)) + errs() << ' ' << (*I)->id; + errs() << '\n'; + } + } +} + +namespace { + // FrameSetup and FrameDestroy can have zero adjustment, so using a single + // integer, we can't tell whether it is a FrameSetup or FrameDestroy if the + // value is zero. + // We use a bool plus an integer to capture the stack state. + struct StackStateOfBB { + StackStateOfBB() : EntryValue(0), ExitValue(0), EntryIsSetup(false), + ExitIsSetup(false) { } + StackStateOfBB(int EntryVal, int ExitVal, bool EntrySetup, bool ExitSetup) : + EntryValue(EntryVal), ExitValue(ExitVal), EntryIsSetup(EntrySetup), + ExitIsSetup(ExitSetup) { } + // Can be negative, which means we are setting up a frame. + int EntryValue; + int ExitValue; + bool EntryIsSetup; + bool ExitIsSetup; + }; +} // namespace + +/// Make sure on every path through the CFG, a FrameSetup <n> is always followed +/// by a FrameDestroy <n>, stack adjustments are identical on all +/// CFG edges to a merge point, and frame is destroyed at end of a return block. +void MachineVerifier::verifyStackFrame() { + unsigned FrameSetupOpcode = TII->getCallFrameSetupOpcode(); + unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode(); + + SmallVector<StackStateOfBB, 8> SPState; + SPState.resize(MF->getNumBlockIDs()); + SmallPtrSet<const MachineBasicBlock*, 8> Reachable; + + // Visit the MBBs in DFS order. + for (df_ext_iterator<const MachineFunction*, + SmallPtrSet<const MachineBasicBlock*, 8> > + DFI = df_ext_begin(MF, Reachable), DFE = df_ext_end(MF, Reachable); + DFI != DFE; ++DFI) { + const MachineBasicBlock *MBB = *DFI; + + StackStateOfBB BBState; + // Check the exit state of the DFS stack predecessor. + if (DFI.getPathLength() >= 2) { + const MachineBasicBlock *StackPred = DFI.getPath(DFI.getPathLength() - 2); + assert(Reachable.count(StackPred) && + "DFS stack predecessor is already visited.\n"); + BBState.EntryValue = SPState[StackPred->getNumber()].ExitValue; + BBState.EntryIsSetup = SPState[StackPred->getNumber()].ExitIsSetup; + BBState.ExitValue = BBState.EntryValue; + BBState.ExitIsSetup = BBState.EntryIsSetup; + } + + // Update stack state by checking contents of MBB. + for (const auto &I : *MBB) { + if (I.getOpcode() == FrameSetupOpcode) { + // The first operand of a FrameOpcode should be i32. + int Size = I.getOperand(0).getImm(); + assert(Size >= 0 && + "Value should be non-negative in FrameSetup and FrameDestroy.\n"); + + if (BBState.ExitIsSetup) + report("FrameSetup is after another FrameSetup", &I); + BBState.ExitValue -= Size; + BBState.ExitIsSetup = true; + } + + if (I.getOpcode() == FrameDestroyOpcode) { + // The first operand of a FrameOpcode should be i32. + int Size = I.getOperand(0).getImm(); + assert(Size >= 0 && + "Value should be non-negative in FrameSetup and FrameDestroy.\n"); + + if (!BBState.ExitIsSetup) + report("FrameDestroy is not after a FrameSetup", &I); + int AbsSPAdj = BBState.ExitValue < 0 ? -BBState.ExitValue : + BBState.ExitValue; + if (BBState.ExitIsSetup && AbsSPAdj != Size) { + report("FrameDestroy <n> is after FrameSetup <m>", &I); + errs() << "FrameDestroy <" << Size << "> is after FrameSetup <" + << AbsSPAdj << ">.\n"; + } + BBState.ExitValue += Size; + BBState.ExitIsSetup = false; + } + } + SPState[MBB->getNumber()] = BBState; + + // Make sure the exit state of any predecessor is consistent with the entry + // state. + for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(), + E = MBB->pred_end(); I != E; ++I) { + if (Reachable.count(*I) && + (SPState[(*I)->getNumber()].ExitValue != BBState.EntryValue || + SPState[(*I)->getNumber()].ExitIsSetup != BBState.EntryIsSetup)) { + report("The exit stack state of a predecessor is inconsistent.", MBB); + errs() << "Predecessor BB#" << (*I)->getNumber() << " has exit state (" + << SPState[(*I)->getNumber()].ExitValue << ", " + << SPState[(*I)->getNumber()].ExitIsSetup + << "), while BB#" << MBB->getNumber() << " has entry state (" + << BBState.EntryValue << ", " << BBState.EntryIsSetup << ").\n"; + } + } + + // Make sure the entry state of any successor is consistent with the exit + // state. + for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(), + E = MBB->succ_end(); I != E; ++I) { + if (Reachable.count(*I) && + (SPState[(*I)->getNumber()].EntryValue != BBState.ExitValue || + SPState[(*I)->getNumber()].EntryIsSetup != BBState.ExitIsSetup)) { + report("The entry stack state of a successor is inconsistent.", MBB); + errs() << "Successor BB#" << (*I)->getNumber() << " has entry state (" + << SPState[(*I)->getNumber()].EntryValue << ", " + << SPState[(*I)->getNumber()].EntryIsSetup + << "), while BB#" << MBB->getNumber() << " has exit state (" + << BBState.ExitValue << ", " << BBState.ExitIsSetup << ").\n"; + } + } + + // Make sure a basic block with return ends with zero stack adjustment. + if (!MBB->empty() && MBB->back().isReturn()) { + if (BBState.ExitIsSetup) + report("A return block ends with a FrameSetup.", MBB); + if (BBState.ExitValue) + report("A return block ends with a nonzero stack adjustment.", MBB); + } + } +} |
