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llvm-project/llvm/lib/CodeGen/MachineVerifier.cpp

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//===- MachineVerifier.cpp - Machine Code Verifier ------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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 with the command-line option
// -verify-machineinstrs.
//===----------------------------------------------------------------------===//
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/CodeGen/GlobalISel/RegisterBank.h"
#include "llvm/CodeGen/LiveInterval.h"
#include "llvm/CodeGen/LiveIntervalCalc.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/LiveStacks.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBundle.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/SlotIndexes.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Instructions.h"
#include "llvm/InitializePasses.h"
#include "llvm/MC/LaneBitmask.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LowLevelTypeImpl.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <iterator>
#include <string>
#include <utility>
using namespace llvm;
namespace {
struct MachineVerifier {
MachineVerifier(Pass *pass, const char *b) : PASS(pass), Banner(b) {}
unsigned verify(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;
// Avoid querying the MachineFunctionProperties for each operand.
bool isFunctionRegBankSelected;
bool isFunctionSelected;
using RegVector = SmallVector<unsigned, 16>;
using RegMaskVector = SmallVector<const uint32_t *, 4>;
using RegSet = DenseSet<unsigned>;
using RegMap = DenseMap<unsigned, const MachineInstr *>;
using BlockSet = SmallPtrSet<const MachineBasicBlock *, 8>;
const MachineInstr *FirstNonPHI;
const MachineInstr *FirstTerminator;
BlockSet FunctionBlocks;
BitVector regsReserved;
RegSet regsLive;
RegVector regsDefined, regsDead, regsKilled;
RegMaskVector regMasks;
SlotIndex lastIndex;
// Add Reg and any sub-registers to RV
void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
RV.push_back(Reg);
if (Register::isPhysicalRegister(Reg))
for (const MCPhysReg &SubReg : TRI->subregs(Reg))
RV.push_back(SubReg);
}
struct BBInfo {
// Is this MBB reachable from the MF entry point?
bool reachable = false;
// 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() = default;
// Add register to vregsRequired if it belongs there. Return true if
// anything changed.
bool addRequired(unsigned Reg) {
if (!Register::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 (unsigned Reg : RS)
Changed |= addRequired(Reg);
return Changed;
}
// Same for a full map.
bool addRequired(const RegMap &RM) {
bool Changed = false;
for (const auto &I : RM)
Changed |= addRequired(I.first);
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) const {
return Reg < TRI->getNumRegs() && TRI->isInAllocatableClass(Reg) &&
!regsReserved.test(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);
bool verifyVectorElementMatch(LLT Ty0, LLT Ty1, const MachineInstr *MI);
void verifyPreISelGenericInstruction(const MachineInstr *MI);
void visitMachineInstrBefore(const MachineInstr *MI);
void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
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,
LLT MOVRegType = LLT{});
void report_context(const LiveInterval &LI) const;
void report_context(const LiveRange &LR, unsigned VRegUnit,
LaneBitmask LaneMask) const;
void report_context(const LiveRange::Segment &S) const;
void report_context(const VNInfo &VNI) const;
void report_context(SlotIndex Pos) const;
void report_context(MCPhysReg PhysReg) const;
void report_context_liverange(const LiveRange &LR) const;
void report_context_lanemask(LaneBitmask LaneMask) const;
void report_context_vreg(unsigned VReg) const;
void report_context_vreg_regunit(unsigned VRegOrUnit) const;
void verifyInlineAsm(const MachineInstr *MI);
void checkLiveness(const MachineOperand *MO, unsigned MONum);
void checkLivenessAtUse(const MachineOperand *MO, unsigned MONum,
SlotIndex UseIdx, const LiveRange &LR, unsigned VRegOrUnit,
LaneBitmask LaneMask = LaneBitmask::getNone());
void checkLivenessAtDef(const MachineOperand *MO, unsigned MONum,
SlotIndex DefIdx, const LiveRange &LR, unsigned VRegOrUnit,
bool SubRangeCheck = false,
LaneBitmask LaneMask = LaneBitmask::getNone());
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,
LaneBitmask);
void verifyLiveRangeSegment(const LiveRange&,
const LiveRange::const_iterator I, unsigned,
LaneBitmask);
void verifyLiveRange(const LiveRange&, unsigned,
LaneBitmask LaneMask = LaneBitmask::getNone());
void verifyStackFrame();
void verifySlotIndexes() const;
void verifyProperties(const MachineFunction &MF);
};
struct MachineVerifierPass : public MachineFunctionPass {
static char ID; // Pass ID, replacement for typeid
const std::string Banner;
MachineVerifierPass(std::string banner = std::string())
: MachineFunctionPass(ID), Banner(std::move(banner)) {
initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool runOnMachineFunction(MachineFunction &MF) override {
unsigned FoundErrors = MachineVerifier(this, Banner.c_str()).verify(MF);
if (FoundErrors)
report_fatal_error("Found "+Twine(FoundErrors)+" machine code errors.");
return false;
}
};
} // end anonymous 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);
}
bool MachineFunction::verify(Pass *p, const char *Banner, bool AbortOnErrors)
const {
MachineFunction &MF = const_cast<MachineFunction&>(*this);
unsigned FoundErrors = MachineVerifier(p, Banner).verify(MF);
if (AbortOnErrors && FoundErrors)
report_fatal_error("Found "+Twine(FoundErrors)+" machine code errors.");
return FoundErrors == 0;
}
void MachineVerifier::verifySlotIndexes() const {
if (Indexes == nullptr)
return;
// Ensure the IdxMBB list is sorted by slot indexes.
SlotIndex Last;
for (SlotIndexes::MBBIndexIterator I = Indexes->MBBIndexBegin(),
E = Indexes->MBBIndexEnd(); I != E; ++I) {
assert(!Last.isValid() || I->first > Last);
Last = I->first;
}
}
void MachineVerifier::verifyProperties(const MachineFunction &MF) {
// If a pass has introduced virtual registers without clearing the
// NoVRegs property (or set it without allocating the vregs)
// then report an error.
if (MF.getProperties().hasProperty(
MachineFunctionProperties::Property::NoVRegs) &&
MRI->getNumVirtRegs())
report("Function has NoVRegs property but there are VReg operands", &MF);
}
unsigned MachineVerifier::verify(MachineFunction &MF) {
foundErrors = 0;
this->MF = &MF;
TM = &MF.getTarget();
TII = MF.getSubtarget().getInstrInfo();
TRI = MF.getSubtarget().getRegisterInfo();
MRI = &MF.getRegInfo();
const bool isFunctionFailedISel = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::FailedISel);
// If we're mid-GlobalISel and we already triggered the fallback path then
// it's expected that the MIR is somewhat broken but that's ok since we'll
// reset it and clear the FailedISel attribute in ResetMachineFunctions.
if (isFunctionFailedISel)
return foundErrors;
isFunctionRegBankSelected = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::RegBankSelected);
isFunctionSelected = MF.getProperties().hasProperty(
MachineFunctionProperties::Property::Selected);
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>();
}
verifySlotIndexes();
verifyProperties(MF);
visitMachineFunctionBefore();
for (const MachineBasicBlock &MBB : MF) {
visitMachineBasicBlockBefore(&MBB);
// 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 (const MachineInstr &MI : MBB.instrs()) {
if (MI.getParent() != &MBB) {
report("Bad instruction parent pointer", &MBB);
errs() << "Instruction: " << MI;
continue;
}
// Check for consistent bundle flags.
if (InBundle && !MI.isBundledWithPred())
report("Missing BundledPred flag, "
"BundledSucc was set on predecessor",
&MI);
if (!InBundle && MI.isBundledWithPred())
report("BundledPred flag is set, "
"but BundledSucc not set on predecessor",
&MI);
// Is this a bundle header?
if (!MI.isInsideBundle()) {
if (CurBundle)
visitMachineBundleAfter(CurBundle);
CurBundle = &MI;
visitMachineBundleBefore(CurBundle);
} else if (!CurBundle)
report("No bundle header", &MI);
visitMachineInstrBefore(&MI);
for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
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);
}
// Was this the last bundled instruction?
InBundle = MI.isBundledWithSucc();
}
if (CurBundle)
visitMachineBundleAfter(CurBundle);
if (InBundle)
report("BundledSucc flag set on last instruction in block", &MBB.back());
visitMachineBasicBlockAfter(&MBB);
}
visitMachineFunctionAfter();
// Clean up.
regsLive.clear();
regsDefined.clear();
regsDead.clear();
regsKilled.clear();
regMasks.clear();
MBBInfoMap.clear();
return foundErrors;
}
void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
assert(MF);
errs() << '\n';
if (!foundErrors++) {
if (Banner)
errs() << "# " << Banner << '\n';
if (LiveInts != nullptr)
LiveInts->print(errs());
else
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: " << printMBBReference(*MBB) << ' '
<< 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(), /*SkipOpers=*/true);
}
void MachineVerifier::report(const char *msg, const MachineOperand *MO,
unsigned MONum, LLT MOVRegType) {
assert(MO);
report(msg, MO->getParent());
errs() << "- operand " << MONum << ": ";
MO->print(errs(), MOVRegType, TRI);
errs() << "\n";
}
void MachineVerifier::report_context(SlotIndex Pos) const {
errs() << "- at: " << Pos << '\n';
}
void MachineVerifier::report_context(const LiveInterval &LI) const {
errs() << "- interval: " << LI << '\n';
}
void MachineVerifier::report_context(const LiveRange &LR, unsigned VRegUnit,
LaneBitmask LaneMask) const {
report_context_liverange(LR);
report_context_vreg_regunit(VRegUnit);
if (LaneMask.any())
report_context_lanemask(LaneMask);
}
void MachineVerifier::report_context(const LiveRange::Segment &S) const {
errs() << "- segment: " << S << '\n';
}
void MachineVerifier::report_context(const VNInfo &VNI) const {
errs() << "- ValNo: " << VNI.id << " (def " << VNI.def << ")\n";
}
void MachineVerifier::report_context_liverange(const LiveRange &LR) const {
errs() << "- liverange: " << LR << '\n';
}
void MachineVerifier::report_context(MCPhysReg PReg) const {
errs() << "- p. register: " << printReg(PReg, TRI) << '\n';
}
void MachineVerifier::report_context_vreg(unsigned VReg) const {
errs() << "- v. register: " << printReg(VReg, TRI) << '\n';
}
void MachineVerifier::report_context_vreg_regunit(unsigned VRegOrUnit) const {
if (Register::isVirtualRegister(VRegOrUnit)) {
report_context_vreg(VRegOrUnit);
} else {
errs() << "- regunit: " << printRegUnit(VRegOrUnit, TRI) << '\n';
}
}
void MachineVerifier::report_context_lanemask(LaneBitmask LaneMask) const {
errs() << "- lanemask: " << PrintLaneMask(LaneMask) << '\n';
}
void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
BBInfo &MInfo = MBBInfoMap[MBB];
if (!MInfo.reachable) {
MInfo.reachable = true;
for (const MachineBasicBlock *Succ : MBB->successors())
markReachable(Succ);
}
}
void MachineVerifier::visitMachineFunctionBefore() {
lastIndex = SlotIndex();
regsReserved = MRI->reservedRegsFrozen() ? MRI->getReservedRegs()
: TRI->getReservedRegs(*MF);
if (!MF->empty())
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();
if (!MF->empty())
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;
FirstNonPHI = nullptr;
if (!MF->getProperties().hasProperty(
MachineFunctionProperties::Property::NoPHIs) && MRI->tracksLiveness()) {
// If this block has allocatable physical registers live-in, check that
// it is an entry block or landing pad.
for (const auto &LI : MBB->liveins()) {
if (isAllocatable(LI.PhysReg) && !MBB->isEHPad() &&
!MBB->isInlineAsmBrDefaultTarget() &&
MBB->getIterator() != MBB->getParent()->begin()) {
report("MBB has allocatable live-in, but isn't entry or landing-pad.", MBB);
report_context(LI.PhysReg);
}
}
}
// Count the number of landing pad successors.
SmallPtrSet<const MachineBasicBlock*, 4> LandingPadSuccs;
for (const auto *succ : MBB->successors()) {
if (succ->isEHPad())
LandingPadSuccs.insert(succ);
if (!FunctionBlocks.count(succ))
report("MBB has successor that isn't part of the function.", MBB);
if (!MBBInfoMap[succ].Preds.count(MBB)) {
report("Inconsistent CFG", MBB);
errs() << "MBB is not in the predecessor list of the successor "
<< printMBBReference(*succ) << ".\n";
}
}
// Count the number of INLINEASM_BR indirect target successors.
SmallPtrSet<const MachineBasicBlock*, 4> IndirectTargetSuccs;
for (const auto *succ : MBB->successors()) {
if (MBB->isInlineAsmBrIndirectTarget(succ))
IndirectTargetSuccs.insert(succ);
if (!FunctionBlocks.count(succ))
report("MBB has successor that isn't part of the function.", MBB);
if (!MBBInfoMap[succ].Preds.count(MBB)) {
report("Inconsistent CFG", MBB);
errs() << "MBB is not in the predecessor list of the successor "
<< printMBBReference(*succ) << ".\n";
}
}
// Check the predecessor list.
for (const MachineBasicBlock *Pred : MBB->predecessors()) {
if (!FunctionBlocks.count(Pred))
report("MBB has predecessor that isn't part of the function.", MBB);
if (!MBBInfoMap[Pred].Succs.count(MBB)) {
report("Inconsistent CFG", MBB);
errs() << "MBB is not in the successor list of the predecessor "
<< printMBBReference(*Pred) << ".\n";
}
}
const MCAsmInfo *AsmInfo = TM->getMCAsmInfo();
const BasicBlock *BB = MBB->getBasicBlock();
const Function &F = MF->getFunction();
if (LandingPadSuccs.size() > 1 &&
!(AsmInfo &&
AsmInfo->getExceptionHandlingType() == ExceptionHandling::SjLj &&
BB && isa<SwitchInst>(BB->getTerminator())) &&
!isScopedEHPersonality(classifyEHPersonality(F.getPersonalityFn())))
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 = std::next(MBB->getIterator());
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() ||
MBB->succ_size() == IndirectTargetSuccs.size()) {
// It's possible that the block legitimately ends with a noreturn
// call or an unreachable, in which case it won't actually fall
// out of the block.
} else if ((LandingPadSuccs.size() &&
MBB->succ_size() != 1 + LandingPadSuccs.size()) ||
(IndirectTargetSuccs.size() &&
MBB->succ_size() != 1 + IndirectTargetSuccs.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()) &&
MBB->succ_size() != 1 + IndirectTargetSuccs.size() &&
(MBB->succ_size() != 1 || IndirectTargetSuccs.size() != 1 ||
*MBB->succ_begin() != *IndirectTargetSuccs.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 = std::next(MBB->getIterator());
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 conditional branch/branch but there's no "
"condition!", MBB);
}
} else {
report("analyzeBranch returned invalid data!", MBB);
}
}
regsLive.clear();
if (MRI->tracksLiveness()) {
for (const auto &LI : MBB->liveins()) {
if (!Register::isPhysicalRegister(LI.PhysReg)) {
report("MBB live-in list contains non-physical register", MBB);
continue;
}
for (const MCPhysReg &SubReg : TRI->subregs_inclusive(LI.PhysReg))
regsLive.insert(SubReg);
}
}
const MachineFrameInfo &MFI = MF->getFrameInfo();
BitVector PR = MFI.getPristineRegs(*MF);
for (unsigned I : PR.set_bits()) {
for (const MCPhysReg &SubReg : TRI->subregs_inclusive(I))
regsLive.insert(SubReg);
}
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,
// and Extra_IsConvergent = 32.
if (!isUInt<6>(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);
}
}
/// Check that types are consistent when two operands need to have the same
/// number of vector elements.
/// \return true if the types are valid.
bool MachineVerifier::verifyVectorElementMatch(LLT Ty0, LLT Ty1,
const MachineInstr *MI) {
if (Ty0.isVector() != Ty1.isVector()) {
report("operand types must be all-vector or all-scalar", MI);
// Generally we try to report as many issues as possible at once, but in
// this case it's not clear what should we be comparing the size of the
// scalar with: the size of the whole vector or its lane. Instead of
// making an arbitrary choice and emitting not so helpful message, let's
// avoid the extra noise and stop here.
return false;
}
if (Ty0.isVector() && Ty0.getNumElements() != Ty1.getNumElements()) {
report("operand types must preserve number of vector elements", MI);
return false;
}
return true;
}
void MachineVerifier::verifyPreISelGenericInstruction(const MachineInstr *MI) {
if (isFunctionSelected)
report("Unexpected generic instruction in a Selected function", MI);
const MCInstrDesc &MCID = MI->getDesc();
unsigned NumOps = MI->getNumOperands();
// Check types.
SmallVector<LLT, 4> Types;
for (unsigned I = 0, E = std::min(MCID.getNumOperands(), NumOps);
I != E; ++I) {
if (!MCID.OpInfo[I].isGenericType())
continue;
// Generic instructions specify type equality constraints between some of
// their operands. Make sure these are consistent.
size_t TypeIdx = MCID.OpInfo[I].getGenericTypeIndex();
Types.resize(std::max(TypeIdx + 1, Types.size()));
const MachineOperand *MO = &MI->getOperand(I);
if (!MO->isReg()) {
report("generic instruction must use register operands", MI);
continue;
}
LLT OpTy = MRI->getType(MO->getReg());
// Don't report a type mismatch if there is no actual mismatch, only a
// type missing, to reduce noise:
if (OpTy.isValid()) {
// Only the first valid type for a type index will be printed: don't
// overwrite it later so it's always clear which type was expected:
if (!Types[TypeIdx].isValid())
Types[TypeIdx] = OpTy;
else if (Types[TypeIdx] != OpTy)
report("Type mismatch in generic instruction", MO, I, OpTy);
} else {
// Generic instructions must have types attached to their operands.
report("Generic instruction is missing a virtual register type", MO, I);
}
}
// Generic opcodes must not have physical register operands.
for (unsigned I = 0; I < MI->getNumOperands(); ++I) {
const MachineOperand *MO = &MI->getOperand(I);
if (MO->isReg() && Register::isPhysicalRegister(MO->getReg()))
report("Generic instruction cannot have physical register", MO, I);
}
// Avoid out of bounds in checks below. This was already reported earlier.
if (MI->getNumOperands() < MCID.getNumOperands())
return;
StringRef ErrorInfo;
if (!TII->verifyInstruction(*MI, ErrorInfo))
report(ErrorInfo.data(), MI);
// Verify properties of various specific instruction types
switch (MI->getOpcode()) {
case TargetOpcode::G_CONSTANT:
case TargetOpcode::G_FCONSTANT: {
if (MI->getNumOperands() < MCID.getNumOperands())
break;
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
if (DstTy.isVector())
report("Instruction cannot use a vector result type", MI);
if (MI->getOpcode() == TargetOpcode::G_CONSTANT) {
if (!MI->getOperand(1).isCImm()) {
report("G_CONSTANT operand must be cimm", MI);
break;
}
const ConstantInt *CI = MI->getOperand(1).getCImm();
if (CI->getBitWidth() != DstTy.getSizeInBits())
report("inconsistent constant size", MI);
} else {
if (!MI->getOperand(1).isFPImm()) {
report("G_FCONSTANT operand must be fpimm", MI);
break;
}
const ConstantFP *CF = MI->getOperand(1).getFPImm();
if (APFloat::getSizeInBits(CF->getValueAPF().getSemantics()) !=
DstTy.getSizeInBits()) {
report("inconsistent constant size", MI);
}
}
break;
}
case TargetOpcode::G_LOAD:
case TargetOpcode::G_STORE:
case TargetOpcode::G_ZEXTLOAD:
case TargetOpcode::G_SEXTLOAD: {
LLT ValTy = MRI->getType(MI->getOperand(0).getReg());
LLT PtrTy = MRI->getType(MI->getOperand(1).getReg());
if (!PtrTy.isPointer())
report("Generic memory instruction must access a pointer", MI);
// Generic loads and stores must have a single MachineMemOperand
// describing that access.
if (!MI->hasOneMemOperand()) {
report("Generic instruction accessing memory must have one mem operand",
MI);
} else {
const MachineMemOperand &MMO = **MI->memoperands_begin();
if (MI->getOpcode() == TargetOpcode::G_ZEXTLOAD ||
MI->getOpcode() == TargetOpcode::G_SEXTLOAD) {
if (MMO.getSizeInBits() >= ValTy.getSizeInBits())
report("Generic extload must have a narrower memory type", MI);
} else if (MI->getOpcode() == TargetOpcode::G_LOAD) {
if (MMO.getSize() > ValTy.getSizeInBytes())
report("load memory size cannot exceed result size", MI);
} else if (MI->getOpcode() == TargetOpcode::G_STORE) {
if (ValTy.getSizeInBytes() < MMO.getSize())
report("store memory size cannot exceed value size", MI);
}
}
break;
}
case TargetOpcode::G_PHI: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
if (!DstTy.isValid() ||
!std::all_of(MI->operands_begin() + 1, MI->operands_end(),
[this, &DstTy](const MachineOperand &MO) {
if (!MO.isReg())
return true;
LLT Ty = MRI->getType(MO.getReg());
if (!Ty.isValid() || (Ty != DstTy))
return false;
return true;
}))
report("Generic Instruction G_PHI has operands with incompatible/missing "
"types",
MI);
break;
}
case TargetOpcode::G_BITCAST: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
if (!DstTy.isValid() || !SrcTy.isValid())
break;
if (SrcTy.isPointer() != DstTy.isPointer())
report("bitcast cannot convert between pointers and other types", MI);
if (SrcTy.getSizeInBits() != DstTy.getSizeInBits())
report("bitcast sizes must match", MI);
break;
}
case TargetOpcode::G_INTTOPTR:
case TargetOpcode::G_PTRTOINT:
case TargetOpcode::G_ADDRSPACE_CAST: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
if (!DstTy.isValid() || !SrcTy.isValid())
break;
verifyVectorElementMatch(DstTy, SrcTy, MI);
DstTy = DstTy.getScalarType();
SrcTy = SrcTy.getScalarType();
if (MI->getOpcode() == TargetOpcode::G_INTTOPTR) {
if (!DstTy.isPointer())
report("inttoptr result type must be a pointer", MI);
if (SrcTy.isPointer())
report("inttoptr source type must not be a pointer", MI);
} else if (MI->getOpcode() == TargetOpcode::G_PTRTOINT) {
if (!SrcTy.isPointer())
report("ptrtoint source type must be a pointer", MI);
if (DstTy.isPointer())
report("ptrtoint result type must not be a pointer", MI);
} else {
assert(MI->getOpcode() == TargetOpcode::G_ADDRSPACE_CAST);
if (!SrcTy.isPointer() || !DstTy.isPointer())
report("addrspacecast types must be pointers", MI);
else {
if (SrcTy.getAddressSpace() == DstTy.getAddressSpace())
report("addrspacecast must convert different address spaces", MI);
}
}
break;
}
case TargetOpcode::G_PTR_ADD: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT PtrTy = MRI->getType(MI->getOperand(1).getReg());
LLT OffsetTy = MRI->getType(MI->getOperand(2).getReg());
if (!DstTy.isValid() || !PtrTy.isValid() || !OffsetTy.isValid())
break;
if (!PtrTy.getScalarType().isPointer())
report("gep first operand must be a pointer", MI);
if (OffsetTy.getScalarType().isPointer())
report("gep offset operand must not be a pointer", MI);
// TODO: Is the offset allowed to be a scalar with a vector?
break;
}
case TargetOpcode::G_PTRMASK: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
LLT MaskTy = MRI->getType(MI->getOperand(2).getReg());
if (!DstTy.isValid() || !SrcTy.isValid() || !MaskTy.isValid())
break;
if (!DstTy.getScalarType().isPointer())
report("ptrmask result type must be a pointer", MI);
if (!MaskTy.getScalarType().isScalar())
report("ptrmask mask type must be an integer", MI);
verifyVectorElementMatch(DstTy, MaskTy, MI);
break;
}
case TargetOpcode::G_SEXT:
case TargetOpcode::G_ZEXT:
case TargetOpcode::G_ANYEXT:
case TargetOpcode::G_TRUNC:
case TargetOpcode::G_FPEXT:
case TargetOpcode::G_FPTRUNC: {
// Number of operands and presense of types is already checked (and
// reported in case of any issues), so no need to report them again. As
// we're trying to report as many issues as possible at once, however, the
// instructions aren't guaranteed to have the right number of operands or
// types attached to them at this point
assert(MCID.getNumOperands() == 2 && "Expected 2 operands G_*{EXT,TRUNC}");
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
if (!DstTy.isValid() || !SrcTy.isValid())
break;
LLT DstElTy = DstTy.getScalarType();
LLT SrcElTy = SrcTy.getScalarType();
if (DstElTy.isPointer() || SrcElTy.isPointer())
report("Generic extend/truncate can not operate on pointers", MI);
verifyVectorElementMatch(DstTy, SrcTy, MI);
unsigned DstSize = DstElTy.getSizeInBits();
unsigned SrcSize = SrcElTy.getSizeInBits();
switch (MI->getOpcode()) {
default:
if (DstSize <= SrcSize)
report("Generic extend has destination type no larger than source", MI);
break;
case TargetOpcode::G_TRUNC:
case TargetOpcode::G_FPTRUNC:
if (DstSize >= SrcSize)
report("Generic truncate has destination type no smaller than source",
MI);
break;
}
break;
}
case TargetOpcode::G_SELECT: {
LLT SelTy = MRI->getType(MI->getOperand(0).getReg());
LLT CondTy = MRI->getType(MI->getOperand(1).getReg());
if (!SelTy.isValid() || !CondTy.isValid())
break;
// Scalar condition select on a vector is valid.
if (CondTy.isVector())
verifyVectorElementMatch(SelTy, CondTy, MI);
break;
}
case TargetOpcode::G_MERGE_VALUES: {
// G_MERGE_VALUES should only be used to merge scalars into a larger scalar,
// e.g. s2N = MERGE sN, sN
// Merging multiple scalars into a vector is not allowed, should use
// G_BUILD_VECTOR for that.
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
if (DstTy.isVector() || SrcTy.isVector())
report("G_MERGE_VALUES cannot operate on vectors", MI);
const unsigned NumOps = MI->getNumOperands();
if (DstTy.getSizeInBits() != SrcTy.getSizeInBits() * (NumOps - 1))
report("G_MERGE_VALUES result size is inconsistent", MI);
for (unsigned I = 2; I != NumOps; ++I) {
if (MRI->getType(MI->getOperand(I).getReg()) != SrcTy)
report("G_MERGE_VALUES source types do not match", MI);
}
break;
}
case TargetOpcode::G_UNMERGE_VALUES: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(MI->getNumOperands()-1).getReg());
// For now G_UNMERGE can split vectors.
for (unsigned i = 0; i < MI->getNumOperands()-1; ++i) {
if (MRI->getType(MI->getOperand(i).getReg()) != DstTy)
report("G_UNMERGE_VALUES destination types do not match", MI);
}
if (SrcTy.getSizeInBits() !=
(DstTy.getSizeInBits() * (MI->getNumOperands() - 1))) {
report("G_UNMERGE_VALUES source operand does not cover dest operands",
MI);
}
break;
}
case TargetOpcode::G_BUILD_VECTOR: {
// Source types must be scalars, dest type a vector. Total size of scalars
// must match the dest vector size.
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcEltTy = MRI->getType(MI->getOperand(1).getReg());
if (!DstTy.isVector() || SrcEltTy.isVector()) {
report("G_BUILD_VECTOR must produce a vector from scalar operands", MI);
break;
}
if (DstTy.getElementType() != SrcEltTy)
report("G_BUILD_VECTOR result element type must match source type", MI);
if (DstTy.getNumElements() != MI->getNumOperands() - 1)
report("G_BUILD_VECTOR must have an operand for each elemement", MI);
for (unsigned i = 2; i < MI->getNumOperands(); ++i) {
if (MRI->getType(MI->getOperand(1).getReg()) !=
MRI->getType(MI->getOperand(i).getReg()))
report("G_BUILD_VECTOR source operand types are not homogeneous", MI);
}
break;
}
case TargetOpcode::G_BUILD_VECTOR_TRUNC: {
// Source types must be scalars, dest type a vector. Scalar types must be
// larger than the dest vector elt type, as this is a truncating operation.
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcEltTy = MRI->getType(MI->getOperand(1).getReg());
if (!DstTy.isVector() || SrcEltTy.isVector())
report("G_BUILD_VECTOR_TRUNC must produce a vector from scalar operands",
MI);
for (unsigned i = 2; i < MI->getNumOperands(); ++i) {
if (MRI->getType(MI->getOperand(1).getReg()) !=
MRI->getType(MI->getOperand(i).getReg()))
report("G_BUILD_VECTOR_TRUNC source operand types are not homogeneous",
MI);
}
if (SrcEltTy.getSizeInBits() <= DstTy.getElementType().getSizeInBits())
report("G_BUILD_VECTOR_TRUNC source operand types are not larger than "
"dest elt type",
MI);
break;
}
case TargetOpcode::G_CONCAT_VECTORS: {
// Source types should be vectors, and total size should match the dest
// vector size.
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
if (!DstTy.isVector() || !SrcTy.isVector())
report("G_CONCAT_VECTOR requires vector source and destination operands",
MI);
for (unsigned i = 2; i < MI->getNumOperands(); ++i) {
if (MRI->getType(MI->getOperand(1).getReg()) !=
MRI->getType(MI->getOperand(i).getReg()))
report("G_CONCAT_VECTOR source operand types are not homogeneous", MI);
}
if (DstTy.getNumElements() !=
SrcTy.getNumElements() * (MI->getNumOperands() - 1))
report("G_CONCAT_VECTOR num dest and source elements should match", MI);
break;
}
case TargetOpcode::G_ICMP:
case TargetOpcode::G_FCMP: {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(2).getReg());
if ((DstTy.isVector() != SrcTy.isVector()) ||
(DstTy.isVector() && DstTy.getNumElements() != SrcTy.getNumElements()))
report("Generic vector icmp/fcmp must preserve number of lanes", MI);
break;
}
case TargetOpcode::G_EXTRACT: {
const MachineOperand &SrcOp = MI->getOperand(1);
if (!SrcOp.isReg()) {
report("extract source must be a register", MI);
break;
}
const MachineOperand &OffsetOp = MI->getOperand(2);
if (!OffsetOp.isImm()) {
report("extract offset must be a constant", MI);
break;
}
unsigned DstSize = MRI->getType(MI->getOperand(0).getReg()).getSizeInBits();
unsigned SrcSize = MRI->getType(SrcOp.getReg()).getSizeInBits();
if (SrcSize == DstSize)
report("extract source must be larger than result", MI);
if (DstSize + OffsetOp.getImm() > SrcSize)
report("extract reads past end of register", MI);
break;
}
case TargetOpcode::G_INSERT: {
const MachineOperand &SrcOp = MI->getOperand(2);
if (!SrcOp.isReg()) {
report("insert source must be a register", MI);
break;
}
const MachineOperand &OffsetOp = MI->getOperand(3);
if (!OffsetOp.isImm()) {
report("insert offset must be a constant", MI);
break;
}
unsigned DstSize = MRI->getType(MI->getOperand(0).getReg()).getSizeInBits();
unsigned SrcSize = MRI->getType(SrcOp.getReg()).getSizeInBits();
if (DstSize <= SrcSize)
report("inserted size must be smaller than total register", MI);
if (SrcSize + OffsetOp.getImm() > DstSize)
report("insert writes past end of register", MI);
break;
}
case TargetOpcode::G_JUMP_TABLE: {
if (!MI->getOperand(1).isJTI())
report("G_JUMP_TABLE source operand must be a jump table index", MI);
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
if (!DstTy.isPointer())
report("G_JUMP_TABLE dest operand must have a pointer type", MI);
break;
}
case TargetOpcode::G_BRJT: {
if (!MRI->getType(MI->getOperand(0).getReg()).isPointer())
report("G_BRJT src operand 0 must be a pointer type", MI);
if (!MI->getOperand(1).isJTI())
report("G_BRJT src operand 1 must be a jump table index", MI);
const auto &IdxOp = MI->getOperand(2);
if (!IdxOp.isReg() || MRI->getType(IdxOp.getReg()).isPointer())
report("G_BRJT src operand 2 must be a scalar reg type", MI);
break;
}
case TargetOpcode::G_INTRINSIC:
case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS: {
// TODO: Should verify number of def and use operands, but the current
// interface requires passing in IR types for mangling.
const MachineOperand &IntrIDOp = MI->getOperand(MI->getNumExplicitDefs());
if (!IntrIDOp.isIntrinsicID()) {
report("G_INTRINSIC first src operand must be an intrinsic ID", MI);
break;
}
bool NoSideEffects = MI->getOpcode() == TargetOpcode::G_INTRINSIC;
unsigned IntrID = IntrIDOp.getIntrinsicID();
if (IntrID != 0 && IntrID < Intrinsic::num_intrinsics) {
AttributeList Attrs
= Intrinsic::getAttributes(MF->getFunction().getContext(),
static_cast<Intrinsic::ID>(IntrID));
bool DeclHasSideEffects = !Attrs.hasFnAttribute(Attribute::ReadNone);
if (NoSideEffects && DeclHasSideEffects) {
report("G_INTRINSIC used with intrinsic that accesses memory", MI);
break;
}
if (!NoSideEffects && !DeclHasSideEffects) {
report("G_INTRINSIC_W_SIDE_EFFECTS used with readnone intrinsic", MI);
break;
}
}
switch (IntrID) {
case Intrinsic::memcpy:
if (MI->getNumOperands() != 5)
report("Expected memcpy intrinsic to have 5 operands", MI);
break;
case Intrinsic::memmove:
if (MI->getNumOperands() != 5)
report("Expected memmove intrinsic to have 5 operands", MI);
break;
case Intrinsic::memset:
if (MI->getNumOperands() != 5)
report("Expected memset intrinsic to have 5 operands", MI);
break;
}
break;
}
case TargetOpcode::G_SEXT_INREG: {
if (!MI->getOperand(2).isImm()) {
report("G_SEXT_INREG expects an immediate operand #2", MI);
break;
}
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
verifyVectorElementMatch(DstTy, SrcTy, MI);
int64_t Imm = MI->getOperand(2).getImm();
if (Imm <= 0)
report("G_SEXT_INREG size must be >= 1", MI);
if (Imm >= SrcTy.getScalarSizeInBits())
report("G_SEXT_INREG size must be less than source bit width", MI);
break;
}
case TargetOpcode::G_SHUFFLE_VECTOR: {
const MachineOperand &MaskOp = MI->getOperand(3);
if (!MaskOp.isShuffleMask()) {
report("Incorrect mask operand type for G_SHUFFLE_VECTOR", MI);
break;
}
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT Src0Ty = MRI->getType(MI->getOperand(1).getReg());
LLT Src1Ty = MRI->getType(MI->getOperand(2).getReg());
if (Src0Ty != Src1Ty)
report("Source operands must be the same type", MI);
if (Src0Ty.getScalarType() != DstTy.getScalarType())
report("G_SHUFFLE_VECTOR cannot change element type", MI);
// Don't check that all operands are vector because scalars are used in
// place of 1 element vectors.
int SrcNumElts = Src0Ty.isVector() ? Src0Ty.getNumElements() : 1;
int DstNumElts = DstTy.isVector() ? DstTy.getNumElements() : 1;
ArrayRef<int> MaskIdxes = MaskOp.getShuffleMask();
if (static_cast<int>(MaskIdxes.size()) != DstNumElts)
report("Wrong result type for shufflemask", MI);
for (int Idx : MaskIdxes) {
if (Idx < 0)
continue;
if (Idx >= 2 * SrcNumElts)
report("Out of bounds shuffle index", MI);
}
break;
}
case TargetOpcode::G_DYN_STACKALLOC: {
const MachineOperand &DstOp = MI->getOperand(0);
const MachineOperand &AllocOp = MI->getOperand(1);
const MachineOperand &AlignOp = MI->getOperand(2);
if (!DstOp.isReg() || !MRI->getType(DstOp.getReg()).isPointer()) {
report("dst operand 0 must be a pointer type", MI);
break;
}
if (!AllocOp.isReg() || !MRI->getType(AllocOp.getReg()).isScalar()) {
report("src operand 1 must be a scalar reg type", MI);
break;
}
if (!AlignOp.isImm()) {
report("src operand 2 must be an immediate type", MI);
break;
}
break;
}
default:
break;
}
}
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";
}
if (MI->isPHI()) {
if (MF->getProperties().hasProperty(
MachineFunctionProperties::Property::NoPHIs))
report("Found PHI instruction with NoPHIs property set", MI);
if (FirstNonPHI)
report("Found PHI instruction after non-PHI", MI);
} else if (FirstNonPHI == nullptr)
FirstNonPHI = MI;
// Check the tied operands.
if (MI->isInlineAsm())
verifyInlineAsm(MI);
// A fully-formed DBG_VALUE must have a location. Ignore partially formed
// DBG_VALUEs: these are convenient to use in tests, but should never get
// generated.
if (MI->isDebugValue() && MI->getNumOperands() == 4)
if (!MI->getDebugLoc())
report("Missing DebugLoc for debug instruction", MI);
// Check the MachineMemOperands for basic consistency.
for (MachineMemOperand *Op : MI->memoperands()) {
if (Op->isLoad() && !MI->mayLoad())
report("Missing mayLoad flag", MI);
if (Op->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->isDebugInstr()) {
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);
}
}
if (isPreISelGenericOpcode(MCID.getOpcode())) {
verifyPreISelGenericInstruction(MI);
return;
}
StringRef ErrorInfo;
if (!TII->verifyInstruction(*MI, ErrorInfo))
report(ErrorInfo.data(), MI);
// Verify properties of various specific instruction types
switch (MI->getOpcode()) {
case TargetOpcode::COPY: {
if (foundErrors)
break;
const MachineOperand &DstOp = MI->getOperand(0);
const MachineOperand &SrcOp = MI->getOperand(1);
LLT DstTy = MRI->getType(DstOp.getReg());
LLT SrcTy = MRI->getType(SrcOp.getReg());
if (SrcTy.isValid() && DstTy.isValid()) {
// If both types are valid, check that the types are the same.
if (SrcTy != DstTy) {
report("Copy Instruction is illegal with mismatching types", MI);
errs() << "Def = " << DstTy << ", Src = " << SrcTy << "\n";
}
}
if (SrcTy.isValid() || DstTy.isValid()) {
// If one of them have valid types, let's just check they have the same
// size.
unsigned SrcSize = TRI->getRegSizeInBits(SrcOp.getReg(), *MRI);
unsigned DstSize = TRI->getRegSizeInBits(DstOp.getReg(), *MRI);
assert(SrcSize && "Expecting size here");
assert(DstSize && "Expecting size here");
if (SrcSize != DstSize)
if (!DstOp.getSubReg() && !SrcOp.getSubReg()) {
report("Copy Instruction is illegal with mismatching sizes", MI);
errs() << "Def Size = " << DstSize << ", Src Size = " << SrcSize
<< "\n";
}
}
break;
}
case TargetOpcode::STATEPOINT: {
StatepointOpers SO(MI);
if (!MI->getOperand(SO.getIDPos()).isImm() ||
!MI->getOperand(SO.getNBytesPos()).isImm() ||
!MI->getOperand(SO.getNCallArgsPos()).isImm()) {
report("meta operands to STATEPOINT not constant!", MI);
break;
}
auto VerifyStackMapConstant = [&](unsigned Offset) {
if (!MI->getOperand(Offset - 1).isImm() ||
MI->getOperand(Offset - 1).getImm() != StackMaps::ConstantOp ||
!MI->getOperand(Offset).isImm())
report("stack map constant to STATEPOINT not well formed!", MI);
};
VerifyStackMapConstant(SO.getCCIdx());
VerifyStackMapConstant(SO.getFlagsIdx());
VerifyStackMapConstant(SO.getNumDeoptArgsIdx());
// TODO: verify we have properly encoded deopt arguments
} break;
}
}
void
MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const MCInstrDesc &MCID = MI->getDesc();
unsigned NumDefs = MCID.getNumDefs();
if (MCID.getOpcode() == TargetOpcode::PATCHPOINT)
NumDefs = (MONum == 0 && MO->isReg()) ? NumDefs : 0;
// The first MCID.NumDefs operands must be explicit register defines
if (MONum < NumDefs) {
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. Check non-variadic operands only.
bool IsOptional = MI->isVariadic() && MONum == MCID.getNumOperands() - 1;
if (!IsOptional) {
if (MO->isReg()) {
if (MO->isDef() && !MCOI.isOptionalDef() && !MCID.variadicOpsAreDefs())
report("Explicit operand marked as def", MO, MONum);
if (MO->isImplicit())
report("Explicit operand marked as implicit", MO, MONum);
}
// Check that an instruction has register operands only as expected.
if (MCOI.OperandType == MCOI::OPERAND_REGISTER &&
!MO->isReg() && !MO->isFI())
report("Expected a register operand.", MO, MONum);
if ((MCOI.OperandType == MCOI::OPERAND_IMMEDIATE ||
MCOI.OperandType == MCOI::OPERAND_PCREL) && MO->isReg())
report("Expected a non-register operand.", 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 (Register::isPhysicalRegister(MO->getReg())) {
const MachineOperand &MOTied = MI->getOperand(TiedTo);
if (!MOTied.isReg())
report("Tied counterpart must be a register", &MOTied, TiedTo);
else if (Register::isPhysicalRegister(MOTied.getReg()) &&
MO->getReg() != MOTied.getReg())
report("Tied physical registers must match.", &MOTied, TiedTo);
}
} 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 Register 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.
unsigned SubIdx = MO->getSubReg();
if (Register::isPhysicalRegister(Reg)) {
if (SubIdx) {
report("Illegal subregister index for physical register", MO, MONum);
return;
}
if (MONum < MCID.getNumOperands()) {
if (const TargetRegisterClass *DRC =
TII->getRegClass(MCID, MONum, TRI, *MF)) {
if (!DRC->contains(Reg)) {
report("Illegal physical register for instruction", MO, MONum);
errs() << printReg(Reg, TRI) << " is not a "
<< TRI->getRegClassName(DRC) << " register.\n";
}
}
}
if (MO->isRenamable()) {
if (MRI->isReserved(Reg)) {
report("isRenamable set on reserved register", MO, MONum);
return;
}
}
if (MI->isDebugValue() && MO->isUse() && !MO->isDebug()) {
report("Use-reg is not IsDebug in a DBG_VALUE", MO, MONum);
return;
}
} else {
// Virtual register.
const TargetRegisterClass *RC = MRI->getRegClassOrNull(Reg);
if (!RC) {
// This is a generic virtual register.
// If we're post-Select, we can't have gvregs anymore.
if (isFunctionSelected) {
report("Generic virtual register invalid in a Selected function",
MO, MONum);
return;
}
// The gvreg must have a type and it must not have a SubIdx.
LLT Ty = MRI->getType(Reg);
if (!Ty.isValid()) {
report("Generic virtual register must have a valid type", MO,
MONum);
return;
}
const RegisterBank *RegBank = MRI->getRegBankOrNull(Reg);
// If we're post-RegBankSelect, the gvreg must have a bank.
if (!RegBank && isFunctionRegBankSelected) {
report("Generic virtual register must have a bank in a "
"RegBankSelected function",
MO, MONum);
return;
}
// Make sure the register fits into its register bank if any.
if (RegBank && Ty.isValid() &&
RegBank->getSize() < Ty.getSizeInBits()) {
report("Register bank is too small for virtual register", MO,
MONum);
errs() << "Register bank " << RegBank->getName() << " too small("
<< RegBank->getSize() << ") to fit " << Ty.getSizeInBits()
<< "-bits\n";
return;
}
if (SubIdx) {
report("Generic virtual register does not allow subregister index", MO,
MONum);
return;
}
// If this is a target specific instruction and this operand
// has register class constraint, the virtual register must
// comply to it.
if (!isPreISelGenericOpcode(MCID.getOpcode()) &&
MONum < MCID.getNumOperands() &&
TII->getRegClass(MCID, MONum, TRI, *MF)) {
report("Virtual register does not match instruction constraint", MO,
MONum);
errs() << "Expect register class "
<< TRI->getRegClassName(
TII->getRegClass(MCID, MONum, TRI, *MF))
<< " but got nothing\n";
return;
}
break;
}
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 (MONum < MCID.getNumOperands()) {
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)) {
int FI = MO->getIndex();
LiveInterval &LI = LiveStks->getInterval(FI);
SlotIndex Idx = LiveInts->getInstructionIndex(*MI);
bool stores = MI->mayStore();
bool loads = MI->mayLoad();
// For a memory-to-memory move, we need to check if the frame
// index is used for storing or loading, by inspecting the
// memory operands.
if (stores && loads) {
for (auto *MMO : MI->memoperands()) {
const PseudoSourceValue *PSV = MMO->getPseudoValue();
if (PSV == nullptr) continue;
const FixedStackPseudoSourceValue *Value =
dyn_cast<FixedStackPseudoSourceValue>(PSV);
if (Value == nullptr) continue;
if (Value->getFrameIndex() != FI) continue;
if (MMO->isStore())
loads = false;
else
stores = false;
break;
}
if (loads == stores)
report("Missing fixed stack memoperand.", MI);
}
if (loads && !LI.liveAt(Idx.getRegSlot(true))) {
report("Instruction loads from dead spill slot", MO, MONum);
errs() << "Live stack: " << LI << '\n';
}
if (stores && !LI.liveAt(Idx.getRegSlot())) {
report("Instruction stores to dead spill slot", MO, MONum);
errs() << "Live stack: " << LI << '\n';
}
}
break;
default:
break;
}
}
void MachineVerifier::checkLivenessAtUse(const MachineOperand *MO,
unsigned MONum, SlotIndex UseIdx, const LiveRange &LR, unsigned VRegOrUnit,
LaneBitmask LaneMask) {
LiveQueryResult LRQ = LR.Query(UseIdx);
// Check if we have a segment at the use, note however that we only need one
// live subregister range, the others may be dead.
if (!LRQ.valueIn() && LaneMask.none()) {
report("No live segment at use", MO, MONum);
report_context_liverange(LR);
report_context_vreg_regunit(VRegOrUnit);
report_context(UseIdx);
}
if (MO->isKill() && !LRQ.isKill()) {
report("Live range continues after kill flag", MO, MONum);
report_context_liverange(LR);
report_context_vreg_regunit(VRegOrUnit);
if (LaneMask.any())
report_context_lanemask(LaneMask);
report_context(UseIdx);
}
}
void MachineVerifier::checkLivenessAtDef(const MachineOperand *MO,
unsigned MONum, SlotIndex DefIdx, const LiveRange &LR, unsigned VRegOrUnit,
bool SubRangeCheck, LaneBitmask LaneMask) {
if (const VNInfo *VNI = LR.getVNInfoAt(DefIdx)) {
assert(VNI && "NULL valno is not allowed");
if (VNI->def != DefIdx) {
report("Inconsistent valno->def", MO, MONum);
report_context_liverange(LR);
report_context_vreg_regunit(VRegOrUnit);
if (LaneMask.any())
report_context_lanemask(LaneMask);
report_context(*VNI);
report_context(DefIdx);
}
} else {
report("No live segment at def", MO, MONum);
report_context_liverange(LR);
report_context_vreg_regunit(VRegOrUnit);
if (LaneMask.any())
report_context_lanemask(LaneMask);
report_context(DefIdx);
}
// Check that, if the dead def flag is present, LiveInts agree.
if (MO->isDead()) {
LiveQueryResult LRQ = LR.Query(DefIdx);
if (!LRQ.isDeadDef()) {
assert(Register::isVirtualRegister(VRegOrUnit) &&
"Expecting a virtual register.");
// A dead subreg def only tells us that the specific subreg is dead. There
// could be other non-dead defs of other subregs, or we could have other
// parts of the register being live through the instruction. So unless we
// are checking liveness for a subrange it is ok for the live range to
// continue, given that we have a dead def of a subregister.
if (SubRangeCheck || MO->getSubReg() == 0) {
report("Live range continues after dead def flag", MO, MONum);
report_context_liverange(LR);
report_context_vreg_regunit(VRegOrUnit);
if (LaneMask.any())
report_context_lanemask(LaneMask);
}
}
}
}
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()) {
if (MO->isKill())
addRegWithSubRegs(regsKilled, Reg);
// Check that LiveVars knows this kill.
if (LiveVars && Register::isVirtualRegister(Reg) && MO->isKill()) {
LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
if (!is_contained(VI.Kills, MI))
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 (Register::isPhysicalRegister(Reg) && !isReserved(Reg)) {
for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
if (MRI->isReservedRegUnit(*Units))
continue;
if (const LiveRange *LR = LiveInts->getCachedRegUnit(*Units))
checkLivenessAtUse(MO, MONum, UseIdx, *LR, *Units);
}
}
if (Register::isVirtualRegister(Reg)) {
if (LiveInts->hasInterval(Reg)) {
// This is a virtual register interval.
const LiveInterval &LI = LiveInts->getInterval(Reg);
checkLivenessAtUse(MO, MONum, UseIdx, LI, Reg);
if (LI.hasSubRanges() && !MO->isDef()) {
unsigned SubRegIdx = MO->getSubReg();
LaneBitmask MOMask = SubRegIdx != 0
? TRI->getSubRegIndexLaneMask(SubRegIdx)
: MRI->getMaxLaneMaskForVReg(Reg);
LaneBitmask LiveInMask;
for (const LiveInterval::SubRange &SR : LI.subranges()) {
if ((MOMask & SR.LaneMask).none())
continue;
checkLivenessAtUse(MO, MONum, UseIdx, SR, Reg, SR.LaneMask);
LiveQueryResult LRQ = SR.Query(UseIdx);
if (LRQ.valueIn())
LiveInMask |= SR.LaneMask;
}
// At least parts of the register has to be live at the use.
if ((LiveInMask & MOMask).none()) {
report("No live subrange at use", MO, MONum);
report_context(LI);
report_context(UseIdx);
}
}
} else {
report("Virtual register has no live interval", MO, MONum);
}
}
}
// Use of a dead register.
if (!regsLive.count(Reg)) {
if (Register::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 (const MCPhysReg &SubReg : TRI->subregs(Reg)) {
if (regsLive.count(SubReg)) {
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() || !MOP.isImplicit())
continue;
if (!Register::isPhysicalRegister(MOP.getReg()))
continue;
for (const MCPhysReg &SubReg : TRI->subregs(MOP.getReg())) {
if (SubReg == 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() && Register::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 && !LiveInts->isNotInMIMap(*MI)) {
SlotIndex DefIdx = LiveInts->getInstructionIndex(*MI);
DefIdx = DefIdx.getRegSlot(MO->isEarlyClobber());
if (Register::isVirtualRegister(Reg)) {
if (LiveInts->hasInterval(Reg)) {
const LiveInterval &LI = LiveInts->getInterval(Reg);
checkLivenessAtDef(MO, MONum, DefIdx, LI, Reg);
if (LI.hasSubRanges()) {
unsigned SubRegIdx = MO->getSubReg();
LaneBitmask MOMask = SubRegIdx != 0
? TRI->getSubRegIndexLaneMask(SubRegIdx)
: MRI->getMaxLaneMaskForVReg(Reg);
for (const LiveInterval::SubRange &SR : LI.subranges()) {
if ((SR.LaneMask & MOMask).none())
continue;
checkLivenessAtDef(MO, MONum, DefIdx, SR, Reg, true, SR.LaneMask);
}
}
} else {
report("Virtual register has no Live interval", MO, MONum);
}
}
}
}
}
// 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 (unsigned Reg : regsLive)
if (Register::isPhysicalRegister(Reg) &&
MachineOperand::clobbersPhysReg(Mask, Reg))
regsDead.push_back(Reg);
}
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;
}
}
namespace {
// This implements a set of registers that serves as a filter: can filter other
// sets by passing through elements not in the filter and blocking those that
// are. Any filter implicitly includes the full set of physical registers upon
// creation, thus filtering them all out. The filter itself as a set only grows,
// and needs to be as efficient as possible.
struct VRegFilter {
// Add elements to the filter itself. \pre Input set \p FromRegSet must have
// no duplicates. Both virtual and physical registers are fine.
template <typename RegSetT> void add(const RegSetT &FromRegSet) {
SmallVector<unsigned, 0> VRegsBuffer;
filterAndAdd(FromRegSet, VRegsBuffer);
}
// Filter \p FromRegSet through the filter and append passed elements into \p
// ToVRegs. All elements appended are then added to the filter itself.
// \returns true if anything changed.
template <typename RegSetT>
bool filterAndAdd(const RegSetT &FromRegSet,
SmallVectorImpl<unsigned> &ToVRegs) {
unsigned SparseUniverse = Sparse.size();
unsigned NewSparseUniverse = SparseUniverse;
unsigned NewDenseSize = Dense.size();
size_t Begin = ToVRegs.size();
for (unsigned Reg : FromRegSet) {
if (!Register::isVirtualRegister(Reg))
continue;
unsigned Index = Register::virtReg2Index(Reg);
if (Index < SparseUniverseMax) {
if (Index < SparseUniverse && Sparse.test(Index))
continue;
NewSparseUniverse = std::max(NewSparseUniverse, Index + 1);
} else {
if (Dense.count(Reg))
continue;
++NewDenseSize;
}
ToVRegs.push_back(Reg);
}
size_t End = ToVRegs.size();
if (Begin == End)
return false;
// Reserving space in sets once performs better than doing so continuously
// and pays easily for double look-ups (even in Dense with SparseUniverseMax
// tuned all the way down) and double iteration (the second one is over a
// SmallVector, which is a lot cheaper compared to DenseSet or BitVector).
Sparse.resize(NewSparseUniverse);
Dense.reserve(NewDenseSize);
for (unsigned I = Begin; I < End; ++I) {
unsigned Reg = ToVRegs[I];
unsigned Index = Register::virtReg2Index(Reg);
if (Index < SparseUniverseMax)
Sparse.set(Index);
else
Dense.insert(Reg);
}
return true;
}
private:
static constexpr unsigned SparseUniverseMax = 10 * 1024 * 8;
// VRegs indexed within SparseUniverseMax are tracked by Sparse, those beyound
// are tracked by Dense. The only purpose of the threashold and the Dense set
// is to have a reasonably growing memory usage in pathological cases (large
// number of very sparse VRegFilter instances live at the same time). In
// practice even in the worst-by-execution time cases having all elements
// tracked by Sparse (very large SparseUniverseMax scenario) tends to be more
// space efficient than if tracked by Dense. The threashold is set to keep the
// worst-case memory usage within 2x of figures determined empirically for
// "all Dense" scenario in such worst-by-execution-time cases.
BitVector Sparse;
DenseSet<unsigned> Dense;
};
// Implements both a transfer function and a (binary, in-place) join operator
// for a dataflow over register sets with set union join and filtering transfer
// (out_b = in_b \ filter_b). filter_b is expected to be set-up ahead of time.
// Maintains out_b as its state, allowing for O(n) iteration over it at any
// time, where n is the size of the set (as opposed to O(U) where U is the
// universe). filter_b implicitly contains all physical registers at all times.
class FilteringVRegSet {
VRegFilter Filter;
SmallVector<unsigned, 0> VRegs;
public:
// Set-up the filter_b. \pre Input register set \p RS must have no duplicates.
// Both virtual and physical registers are fine.
template <typename RegSetT> void addToFilter(const RegSetT &RS) {
Filter.add(RS);
}
// Passes \p RS through the filter_b (transfer function) and adds what's left
// to itself (out_b).
template <typename RegSetT> bool add(const RegSetT &RS) {
// Double-duty the Filter: to maintain VRegs a set (and the join operation
// a set union) just add everything being added here to the Filter as well.
return Filter.filterAndAdd(RS, VRegs);
}
using const_iterator = decltype(VRegs)::const_iterator;
const_iterator begin() const { return VRegs.begin(); }
const_iterator end() const { return VRegs.end(); }
size_t size() const { return VRegs.size(); }
};
} // namespace
// 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() {
// This is a forward dataflow, doing it in RPO. A standard map serves as a
// priority (sorting by RPO number) queue, deduplicating worklist, and an RPO
// number to MBB mapping all at once.
std::map<unsigned, const MachineBasicBlock *> RPOWorklist;
DenseMap<const MachineBasicBlock *, unsigned> RPONumbers;
if (MF->empty()) {
// ReversePostOrderTraversal doesn't handle empty functions.
return;
}
std::vector<FilteringVRegSet> VRegsPassedSets(MF->size());
for (const MachineBasicBlock *MBB :
ReversePostOrderTraversal<const MachineFunction *>(MF)) {
// Careful with the evaluation order, fetch next number before allocating.
unsigned Number = RPONumbers.size();
RPONumbers[MBB] = Number;
// Set-up the transfer functions for all blocks.
const BBInfo &MInfo = MBBInfoMap[MBB];
VRegsPassedSets[Number].addToFilter(MInfo.regsKilled);
VRegsPassedSets[Number].addToFilter(MInfo.regsLiveOut);
}
// First push live-out regs to successors' vregsPassed. Remember the MBBs that
// have any vregsPassed.
for (const MachineBasicBlock &MBB : *MF) {
const BBInfo &MInfo = MBBInfoMap[&MBB];
if (!MInfo.reachable)
continue;
for (const MachineBasicBlock *Succ : MBB.successors()) {
unsigned SuccNumber = RPONumbers[Succ];
FilteringVRegSet &SuccSet = VRegsPassedSets[SuccNumber];
if (SuccSet.add(MInfo.regsLiveOut))
RPOWorklist.emplace(SuccNumber, Succ);
}
}
// Iteratively push vregsPassed to successors.
while (!RPOWorklist.empty()) {
auto Next = RPOWorklist.begin();
const MachineBasicBlock *MBB = Next->second;
RPOWorklist.erase(Next);
FilteringVRegSet &MSet = VRegsPassedSets[RPONumbers[MBB]];
for (const MachineBasicBlock *Succ : MBB->successors()) {
if (Succ == MBB)
continue;
unsigned SuccNumber = RPONumbers[Succ];
FilteringVRegSet &SuccSet = VRegsPassedSets[SuccNumber];
if (SuccSet.add(MSet))
RPOWorklist.emplace(SuccNumber, Succ);
}
}
// Copy the results back to BBInfos.
for (const MachineBasicBlock &MBB : *MF) {
BBInfo &MInfo = MBBInfoMap[&MBB];
if (!MInfo.reachable)
continue;
const FilteringVRegSet &MSet = VRegsPassedSets[RPONumbers[&MBB]];
MInfo.vregsPassed.reserve(MSet.size());
MInfo.vregsPassed.insert(MSet.begin(), MSet.end());
}
}
// 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 (const MachineBasicBlock *Pred : MBB.predecessors()) {
BBInfo &PInfo = MBBInfoMap[Pred];
if (PInfo.addRequired(MInfo.vregsLiveIn))
todo.insert(Pred);
}
}
// 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 (const MachineBasicBlock *Pred : MBB->predecessors()) {
if (Pred == MBB)
continue;
BBInfo &SInfo = MBBInfoMap[Pred];
if (SInfo.addRequired(MInfo.vregsRequired))
todo.insert(Pred);
}
}
}
// 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) {
BBInfo &MInfo = MBBInfoMap[&MBB];
SmallPtrSet<const MachineBasicBlock*, 8> seen;
for (const MachineInstr &Phi : MBB) {
if (!Phi.isPHI())
break;
seen.clear();
const MachineOperand &MODef = Phi.getOperand(0);
if (!MODef.isReg() || !MODef.isDef()) {
report("Expected first PHI operand to be a register def", &MODef, 0);
continue;
}
if (MODef.isTied() || MODef.isImplicit() || MODef.isInternalRead() ||
MODef.isEarlyClobber() || MODef.isDebug())
report("Unexpected flag on PHI operand", &MODef, 0);
Register DefReg = MODef.getReg();
if (!Register::isVirtualRegister(DefReg))
report("Expected first PHI operand to be a virtual register", &MODef, 0);
for (unsigned I = 1, E = Phi.getNumOperands(); I != E; I += 2) {
const MachineOperand &MO0 = Phi.getOperand(I);
if (!MO0.isReg()) {
report("Expected PHI operand to be a register", &MO0, I);
continue;
}
if (MO0.isImplicit() || MO0.isInternalRead() || MO0.isEarlyClobber() ||
MO0.isDebug() || MO0.isTied())
report("Unexpected flag on PHI operand", &MO0, I);
const MachineOperand &MO1 = Phi.getOperand(I + 1);
if (!MO1.isMBB()) {
report("Expected PHI operand to be a basic block", &MO1, I + 1);
continue;
}
const MachineBasicBlock &Pre = *MO1.getMBB();
if (!Pre.isSuccessor(&MBB)) {
report("PHI input is not a predecessor block", &MO1, I + 1);
continue;
}
if (MInfo.reachable) {
seen.insert(&Pre);
BBInfo &PrInfo = MBBInfoMap[&Pre];
if (!MO0.isUndef() && PrInfo.reachable &&
!PrInfo.isLiveOut(MO0.getReg()))
report("PHI operand is not live-out from predecessor", &MO0, I);
}
}
// Did we see all predecessors?
if (MInfo.reachable) {
for (MachineBasicBlock *Pred : MBB.predecessors()) {
if (!seen.count(Pred)) {
report("Missing PHI operand", &Phi);
errs() << printMBBReference(*Pred)
<< " is a predecessor according to the CFG.\n";
}
}
}
}
}
void MachineVerifier::visitMachineFunctionAfter() {
calcRegsPassed();
for (const MachineBasicBlock &MBB : *MF)
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 (unsigned VReg : MInfo.vregsRequired)
if (MInfo.regsKilled.count(VReg)) {
report("Virtual register killed in block, but needed live out.", &MBB);
errs() << "Virtual register " << printReg(VReg)
<< " is used after the block.\n";
}
}
if (!MF->empty()) {
BBInfo &MInfo = MBBInfoMap[&MF->front()];
for (unsigned VReg : MInfo.vregsRequired) {
report("Virtual register defs don't dominate all uses.", MF);
report_context_vreg(VReg);
}
}
if (LiveVars)
verifyLiveVariables();
if (LiveInts)
verifyLiveIntervals();
// Check live-in list of each MBB. If a register is live into MBB, check
// that the register is in regsLiveOut of each predecessor block. Since
// this must come from a definition in the predecesssor or its live-in
// list, this will catch a live-through case where the predecessor does not
// have the register in its live-in list. This currently only checks
// registers that have no aliases, are not allocatable and are not
// reserved, which could mean a condition code register for instance.
if (MRI->tracksLiveness())
for (const auto &MBB : *MF)
for (MachineBasicBlock::RegisterMaskPair P : MBB.liveins()) {
MCPhysReg LiveInReg = P.PhysReg;
bool hasAliases = MCRegAliasIterator(LiveInReg, TRI, false).isValid();
if (hasAliases || isAllocatable(LiveInReg) || isReserved(LiveInReg))
continue;
for (const MachineBasicBlock *Pred : MBB.predecessors()) {
BBInfo &PInfo = MBBInfoMap[Pred];
if (!PInfo.regsLiveOut.count(LiveInReg)) {
report("Live in register not found to be live out from predecessor.",
&MBB);
errs() << TRI->getName(LiveInReg)
<< " not found to be live out from "
<< printMBBReference(*Pred) << "\n";
}
}
}
for (auto CSInfo : MF->getCallSitesInfo())
if (!CSInfo.first->isCall())
report("Call site info referencing instruction that is not call", MF);
}
void MachineVerifier::verifyLiveVariables() {
assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = Register::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 = Register::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,
LaneBitmask LaneMask) {
if (VNI->isUnused())
return;
const VNInfo *DefVNI = LR.getVNInfoAt(VNI->def);
if (!DefVNI) {
report("Value not live at VNInfo def and not marked unused", MF);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
return;
}
if (DefVNI != VNI) {
report("Live segment at def has different VNInfo", MF);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
return;
}
const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def);
if (!MBB) {
report("Invalid VNInfo definition index", MF);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
return;
}
if (VNI->isPHIDef()) {
if (VNI->def != LiveInts->getMBBStartIdx(MBB)) {
report("PHIDef VNInfo is not defined at MBB start", MBB);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
}
return;
}
// Non-PHI def.
const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
if (!MI) {
report("No instruction at VNInfo def index", MBB);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
return;
}
if (Reg != 0) {
bool hasDef = false;
bool isEarlyClobber = false;
for (ConstMIBundleOperands MOI(*MI); MOI.isValid(); ++MOI) {
if (!MOI->isReg() || !MOI->isDef())
continue;
if (Register::isVirtualRegister(Reg)) {
if (MOI->getReg() != Reg)
continue;
} else {
if (!Register::isPhysicalRegister(MOI->getReg()) ||
!TRI->hasRegUnit(MOI->getReg(), Reg))
continue;
}
if (LaneMask.any() &&
(TRI->getSubRegIndexLaneMask(MOI->getSubReg()) & LaneMask).none())
continue;
hasDef = true;
if (MOI->isEarlyClobber())
isEarlyClobber = true;
}
if (!hasDef) {
report("Defining instruction does not modify register", MI);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
}
// 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);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
}
} else if (!VNI->def.isRegister()) {
report("Non-PHI, non-early clobber def must be at a register slot", MBB);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
}
}
}
void MachineVerifier::verifyLiveRangeSegment(const LiveRange &LR,
const LiveRange::const_iterator I,
unsigned Reg, LaneBitmask 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);
report_context(LR, Reg, LaneMask);
report_context(S);
report_context(*VNI);
}
if (VNI->isUnused()) {
report("Live segment valno is marked unused", MF);
report_context(LR, Reg, LaneMask);
report_context(S);
}
const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(S.start);
if (!MBB) {
report("Bad start of live segment, no basic block", MF);
report_context(LR, Reg, LaneMask);
report_context(S);
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);
report_context(LR, Reg, LaneMask);
report_context(S);
}
const MachineBasicBlock *EndMBB =
LiveInts->getMBBFromIndex(S.end.getPrevSlot());
if (!EndMBB) {
report("Bad end of live segment, no basic block", MF);
report_context(LR, Reg, LaneMask);
report_context(S);
return;
}
// No more checks for live-out segments.
if (S.end == LiveInts->getMBBEndIdx(EndMBB))
return;
// RegUnit intervals are allowed dead phis.
if (!Register::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);
report_context(LR, Reg, LaneMask);
report_context(S);
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);
report_context(LR, Reg, LaneMask);
report_context(S);
}
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);
report_context(LR, Reg, LaneMask);
report_context(S);
}
}
// 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);
report_context(LR, Reg, LaneMask);
report_context(S);
}
}
// The following checks only apply to virtual registers. Physreg liveness
// is too weird to check.
if (Register::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;
bool hasDeadDef = false;
for (ConstMIBundleOperands MOI(*MI); MOI.isValid(); ++MOI) {
if (!MOI->isReg() || MOI->getReg() != Reg)
continue;
unsigned Sub = MOI->getSubReg();
LaneBitmask SLM = Sub != 0 ? TRI->getSubRegIndexLaneMask(Sub)
: LaneBitmask::getAll();
if (MOI->isDef()) {
if (Sub != 0) {
hasSubRegDef = true;
// An operand %0:sub0 reads %0:sub1..n. Invert the lane
// mask for subregister defs. Read-undef defs will be handled by
// readsReg below.
SLM = ~SLM;
}
if (MOI->isDead())
hasDeadDef = true;
}
if (LaneMask.any() && (LaneMask & SLM).none())
continue;
if (MOI->readsReg())
hasRead = true;
}
if (S.end.isDead()) {
// Make sure that the corresponding machine operand for a "dead" live
// range has the dead flag. We cannot perform this check for subregister
// liveranges as partially dead values are allowed.
if (LaneMask.none() && !hasDeadDef) {
report("Instruction ending live segment on dead slot has no dead flag",
MI);
report_context(LR, Reg, LaneMask);
report_context(S);
}
} else {
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.any() ||
!hasSubRegDef) {
report("Instruction ending live segment doesn't read the register",
MI);
report_context(LR, Reg, LaneMask);
report_context(S);
}
}
}
}
// Now check all the basic blocks in this live segment.
MachineFunction::const_iterator MFI = MBB->getIterator();
// 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;
}
SmallVector<SlotIndex, 4> Undefs;
if (LaneMask.any()) {
LiveInterval &OwnerLI = LiveInts->getInterval(Reg);
OwnerLI.computeSubRangeUndefs(Undefs, LaneMask, *MRI, *Indexes);
}
while (true) {
assert(LiveInts->isLiveInToMBB(LR, &*MFI));
// We don't know how to track physregs into a landing pad.
if (!Register::isVirtualRegister(Reg) && MFI->isEHPad()) {
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 (const MachineBasicBlock *Pred : MFI->predecessors()) {
SlotIndex PEnd = LiveInts->getMBBEndIdx(Pred);
const VNInfo *PVNI = LR.getVNInfoBefore(PEnd);
// All predecessors must have a live-out value. However for a phi
// instruction with subregister intervals
// only one of the subregisters (not necessarily the current one) needs to
// be defined.
if (!PVNI && (LaneMask.none() || !IsPHI)) {
if (LiveRangeCalc::isJointlyDominated(Pred, Undefs, *Indexes))
continue;
report("Register not marked live out of predecessor", Pred);
report_context(LR, Reg, LaneMask);
report_context(*VNI);
errs() << " live into " << printMBBReference(*MFI) << '@'
<< 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", Pred);
report_context(LR, Reg, LaneMask);
errs() << "Valno #" << PVNI->id << " live out of "
<< printMBBReference(*Pred) << '@' << PEnd << "\nValno #"
<< VNI->id << " live into " << printMBBReference(*MFI) << '@'
<< LiveInts->getMBBStartIdx(&*MFI) << '\n';
}
}
if (&*MFI == EndMBB)
break;
++MFI;
}
}
void MachineVerifier::verifyLiveRange(const LiveRange &LR, unsigned Reg,
LaneBitmask 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(Register::isVirtualRegister(Reg));
verifyLiveRange(LI, Reg);
LaneBitmask Mask;
LaneBitmask MaxMask = MRI->getMaxLaneMaskForVReg(Reg);
for (const LiveInterval::SubRange &SR : LI.subranges()) {
if ((Mask & SR.LaneMask).any()) {
report("Lane masks of sub ranges overlap in live interval", MF);
report_context(LI);
}
if ((SR.LaneMask & ~MaxMask).any()) {
report("Subrange lanemask is invalid", MF);
report_context(LI);
}
if (SR.empty()) {
report("Subrange must not be empty", MF);
report_context(SR, LI.reg, SR.LaneMask);
}
Mask |= SR.LaneMask;
verifyLiveRange(SR, LI.reg, SR.LaneMask);
if (!LI.covers(SR)) {
report("A Subrange is not covered by the main range", MF);
report_context(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);
report_context(LI);
for (unsigned comp = 0; comp != NumComp; ++comp) {
errs() << comp << ": valnos";
for (const VNInfo *I : LI.valnos)
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() = default;
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 = 0;
int ExitValue = 0;
bool EntryIsSetup = false;
bool ExitIsSetup = false;
};
} // end anonymous 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();
if (FrameSetupOpcode == ~0u && FrameDestroyOpcode == ~0u)
return;
SmallVector<StackStateOfBB, 8> SPState;
SPState.resize(MF->getNumBlockIDs());
df_iterator_default_set<const MachineBasicBlock*> Reachable;
// Visit the MBBs in DFS order.
for (df_ext_iterator<const MachineFunction *,
df_iterator_default_set<const MachineBasicBlock *>>
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) {
if (BBState.ExitIsSetup)
report("FrameSetup is after another FrameSetup", &I);
BBState.ExitValue -= TII->getFrameTotalSize(I);
BBState.ExitIsSetup = true;
}
if (I.getOpcode() == FrameDestroyOpcode) {
int Size = TII->getFrameTotalSize(I);
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 (const MachineBasicBlock *Pred : MBB->predecessors()) {
if (Reachable.count(Pred) &&
(SPState[Pred->getNumber()].ExitValue != BBState.EntryValue ||
SPState[Pred->getNumber()].ExitIsSetup != BBState.EntryIsSetup)) {
report("The exit stack state of a predecessor is inconsistent.", MBB);
errs() << "Predecessor " << printMBBReference(*Pred)
<< " has exit state (" << SPState[Pred->getNumber()].ExitValue
<< ", " << SPState[Pred->getNumber()].ExitIsSetup << "), while "
<< printMBBReference(*MBB) << " has entry state ("
<< BBState.EntryValue << ", " << BBState.EntryIsSetup << ").\n";
}
}
// Make sure the entry state of any successor is consistent with the exit
// state.
for (const MachineBasicBlock *Succ : MBB->successors()) {
if (Reachable.count(Succ) &&
(SPState[Succ->getNumber()].EntryValue != BBState.ExitValue ||
SPState[Succ->getNumber()].EntryIsSetup != BBState.ExitIsSetup)) {
report("The entry stack state of a successor is inconsistent.", MBB);
errs() << "Successor " << printMBBReference(*Succ)
<< " has entry state (" << SPState[Succ->getNumber()].EntryValue
<< ", " << SPState[Succ->getNumber()].EntryIsSetup << "), while "
<< printMBBReference(*MBB) << " 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);
}
}
}
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