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llvm-mirror/lib/CodeGen/MachineVerifier.cpp
Jakob Stoklund Olesen efc28b164d Verify the consistency of inline asm operands. 
The operands on an INLINEASM machine instruction are divided into groups
headed by immediate flag operands. Verify this structure.

Extract verifyTiedOperands(), and only call it for non-inlineasm
instructions.

llvm-svn: 162849
2012-08-29 18:11:05 +00:00

1601 lines
56 KiB
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//===-- MachineVerifier.cpp - Machine Code Verifier -----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Pass to verify generated machine code. The following is checked:
//
// Operand counts: All explicit operands must be present.
//
// Register classes: All physical and virtual register operands must be
// compatible with the register class required by the instruction descriptor.
//
// Register live intervals: Registers must be defined only once, and must be
// defined before use.
//
// The machine code verifier is enabled from LLVMTargetMachine.cpp with the
// command-line option -verify-machineinstrs, or by defining the environment
// variable LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive
// the verifier errors.
//===----------------------------------------------------------------------===//
#include "llvm/BasicBlock.h"
#include "llvm/InlineAsm.h"
#include "llvm/Instructions.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineInstrBundle.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
struct MachineVerifier {
MachineVerifier(Pass *pass, const char *b) :
PASS(pass),
Banner(b),
OutFileName(getenv("LLVM_VERIFY_MACHINEINSTRS"))
{}
bool runOnMachineFunction(MachineFunction &MF);
Pass *const PASS;
const char *Banner;
const char *const OutFileName;
raw_ostream *OS;
const MachineFunction *MF;
const TargetMachine *TM;
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
const MachineRegisterInfo *MRI;
unsigned foundErrors;
typedef SmallVector<unsigned, 16> RegVector;
typedef SmallVector<const uint32_t*, 4> RegMaskVector;
typedef DenseSet<unsigned> RegSet;
typedef DenseMap<unsigned, const MachineInstr*> RegMap;
typedef SmallPtrSet<const MachineBasicBlock*, 8> BlockSet;
const MachineInstr *FirstTerminator;
BlockSet FunctionBlocks;
BitVector regsReserved;
BitVector regsAllocatable;
RegSet regsLive;
RegVector regsDefined, regsDead, regsKilled;
RegMaskVector regMasks;
RegSet regsLiveInButUnused;
SlotIndex lastIndex;
// Add Reg and any sub-registers to RV
void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
RV.push_back(Reg);
if (TargetRegisterInfo::isPhysicalRegister(Reg))
for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
RV.push_back(*SubRegs);
}
struct BBInfo {
// Is this MBB reachable from the MF entry point?
bool reachable;
// Vregs that must be live in because they are used without being
// defined. Map value is the user.
RegMap vregsLiveIn;
// Regs killed in MBB. They may be defined again, and will then be in both
// regsKilled and regsLiveOut.
RegSet regsKilled;
// Regs defined in MBB and live out. Note that vregs passing through may
// be live out without being mentioned here.
RegSet regsLiveOut;
// Vregs that pass through MBB untouched. This set is disjoint from
// regsKilled and regsLiveOut.
RegSet vregsPassed;
// Vregs that must pass through MBB because they are needed by a successor
// block. This set is disjoint from regsLiveOut.
RegSet vregsRequired;
// Set versions of block's predecessor and successor lists.
BlockSet Preds, Succs;
BBInfo() : reachable(false) {}
// Add register to vregsPassed if it belongs there. Return true if
// anything changed.
bool addPassed(unsigned Reg) {
if (!TargetRegisterInfo::isVirtualRegister(Reg))
return false;
if (regsKilled.count(Reg) || regsLiveOut.count(Reg))
return false;
return vregsPassed.insert(Reg).second;
}
// Same for a full set.
bool addPassed(const RegSet &RS) {
bool changed = false;
for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
if (addPassed(*I))
changed = true;
return changed;
}
// Add register to vregsRequired if it belongs there. Return true if
// anything changed.
bool addRequired(unsigned Reg) {
if (!TargetRegisterInfo::isVirtualRegister(Reg))
return false;
if (regsLiveOut.count(Reg))
return false;
return vregsRequired.insert(Reg).second;
}
// Same for a full set.
bool addRequired(const RegSet &RS) {
bool changed = false;
for (RegSet::const_iterator I = RS.begin(), E = RS.end(); I != E; ++I)
if (addRequired(*I))
changed = true;
return changed;
}
// Same for a full map.
bool addRequired(const RegMap &RM) {
bool changed = false;
for (RegMap::const_iterator I = RM.begin(), E = RM.end(); I != E; ++I)
if (addRequired(I->first))
changed = true;
return changed;
}
// Live-out registers are either in regsLiveOut or vregsPassed.
bool isLiveOut(unsigned Reg) const {
return regsLiveOut.count(Reg) || vregsPassed.count(Reg);
}
};
// Extra register info per MBB.
DenseMap<const MachineBasicBlock*, BBInfo> MBBInfoMap;
bool isReserved(unsigned Reg) {
return Reg < regsReserved.size() && regsReserved.test(Reg);
}
bool isAllocatable(unsigned Reg) {
return Reg < regsAllocatable.size() && regsAllocatable.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);
void visitMachineInstrBefore(const MachineInstr *MI);
void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
void visitMachineInstrAfter(const MachineInstr *MI);
void visitMachineBundleAfter(const MachineInstr *MI);
void visitMachineBasicBlockAfter(const MachineBasicBlock *MBB);
void visitMachineFunctionAfter();
void report(const char *msg, const MachineFunction *MF);
void report(const char *msg, const MachineBasicBlock *MBB);
void report(const char *msg, const MachineInstr *MI);
void report(const char *msg, const MachineOperand *MO, unsigned MONum);
void report(const char *msg, const MachineFunction *MF,
const LiveInterval &LI);
void report(const char *msg, const MachineBasicBlock *MBB,
const LiveInterval &LI);
void verifyInlineAsm(const MachineInstr *MI);
void verifyTiedOperands(const MachineInstr *MI);
void checkLiveness(const MachineOperand *MO, unsigned MONum);
void markReachable(const MachineBasicBlock *MBB);
void calcRegsPassed();
void checkPHIOps(const MachineBasicBlock *MBB);
void calcRegsRequired();
void verifyLiveVariables();
void verifyLiveIntervals();
void verifyLiveInterval(const LiveInterval&);
void verifyLiveIntervalValue(const LiveInterval&, VNInfo*);
void verifyLiveIntervalSegment(const LiveInterval&,
LiveInterval::const_iterator);
};
struct MachineVerifierPass : public MachineFunctionPass {
static char ID; // Pass ID, replacement for typeid
const char *const Banner;
MachineVerifierPass(const char *b = 0)
: MachineFunctionPass(ID), Banner(b) {
initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool runOnMachineFunction(MachineFunction &MF) {
MF.verify(this, Banner);
return false;
}
};
}
char MachineVerifierPass::ID = 0;
INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
"Verify generated machine code", false, false)
FunctionPass *llvm::createMachineVerifierPass(const char *Banner) {
return new MachineVerifierPass(Banner);
}
void MachineFunction::verify(Pass *p, const char *Banner) const {
MachineVerifier(p, Banner)
.runOnMachineFunction(const_cast<MachineFunction&>(*this));
}
bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
raw_ostream *OutFile = 0;
if (OutFileName) {
std::string ErrorInfo;
OutFile = new raw_fd_ostream(OutFileName, ErrorInfo,
raw_fd_ostream::F_Append);
if (!ErrorInfo.empty()) {
errs() << "Error opening '" << OutFileName << "': " << ErrorInfo << '\n';
exit(1);
}
OS = OutFile;
} else {
OS = &errs();
}
foundErrors = 0;
this->MF = &MF;
TM = &MF.getTarget();
TII = TM->getInstrInfo();
TRI = TM->getRegisterInfo();
MRI = &MF.getRegInfo();
LiveVars = NULL;
LiveInts = NULL;
LiveStks = NULL;
Indexes = NULL;
if (PASS) {
LiveInts = PASS->getAnalysisIfAvailable<LiveIntervals>();
// We don't want to verify LiveVariables if LiveIntervals is available.
if (!LiveInts)
LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
LiveStks = PASS->getAnalysisIfAvailable<LiveStacks>();
Indexes = PASS->getAnalysisIfAvailable<SlotIndexes>();
}
visitMachineFunctionBefore();
for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
MFI!=MFE; ++MFI) {
visitMachineBasicBlockBefore(MFI);
// Keep track of the current bundle header.
const MachineInstr *CurBundle = 0;
for (MachineBasicBlock::const_instr_iterator MBBI = MFI->instr_begin(),
MBBE = MFI->instr_end(); MBBI != MBBE; ++MBBI) {
if (MBBI->getParent() != MFI) {
report("Bad instruction parent pointer", MFI);
*OS << "Instruction: " << *MBBI;
continue;
}
// Is this a bundle header?
if (!MBBI->isInsideBundle()) {
if (CurBundle)
visitMachineBundleAfter(CurBundle);
CurBundle = MBBI;
visitMachineBundleBefore(CurBundle);
} else if (!CurBundle)
report("No bundle header", MBBI);
visitMachineInstrBefore(MBBI);
for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
visitMachineOperand(&MBBI->getOperand(I), I);
visitMachineInstrAfter(MBBI);
}
if (CurBundle)
visitMachineBundleAfter(CurBundle);
visitMachineBasicBlockAfter(MFI);
}
visitMachineFunctionAfter();
if (OutFile)
delete OutFile;
else if (foundErrors)
report_fatal_error("Found "+Twine(foundErrors)+" machine code errors.");
// Clean up.
regsLive.clear();
regsDefined.clear();
regsDead.clear();
regsKilled.clear();
regMasks.clear();
regsLiveInButUnused.clear();
MBBInfoMap.clear();
return false; // no changes
}
void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
assert(MF);
*OS << '\n';
if (!foundErrors++) {
if (Banner)
*OS << "# " << Banner << '\n';
MF->print(*OS, Indexes);
}
*OS << "*** Bad machine code: " << msg << " ***\n"
<< "- function: " << MF->getName() << "\n";
}
void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
assert(MBB);
report(msg, MBB->getParent());
*OS << "- basic block: BB#" << MBB->getNumber()
<< ' ' << MBB->getName()
<< " (" << (void*)MBB << ')';
if (Indexes)
*OS << " [" << Indexes->getMBBStartIdx(MBB)
<< ';' << Indexes->getMBBEndIdx(MBB) << ')';
*OS << '\n';
}
void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
assert(MI);
report(msg, MI->getParent());
*OS << "- instruction: ";
if (Indexes && Indexes->hasIndex(MI))
*OS << Indexes->getInstructionIndex(MI) << '\t';
MI->print(*OS, TM);
}
void MachineVerifier::report(const char *msg,
const MachineOperand *MO, unsigned MONum) {
assert(MO);
report(msg, MO->getParent());
*OS << "- operand " << MONum << ": ";
MO->print(*OS, TM);
*OS << "\n";
}
void MachineVerifier::report(const char *msg, const MachineFunction *MF,
const LiveInterval &LI) {
report(msg, MF);
*OS << "- interval: ";
if (TargetRegisterInfo::isVirtualRegister(LI.reg))
*OS << PrintReg(LI.reg, TRI);
else
*OS << PrintRegUnit(LI.reg, TRI);
*OS << ' ' << LI << '\n';
}
void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB,
const LiveInterval &LI) {
report(msg, MBB);
*OS << "- interval: ";
if (TargetRegisterInfo::isVirtualRegister(LI.reg))
*OS << PrintReg(LI.reg, TRI);
else
*OS << PrintRegUnit(LI.reg, TRI);
*OS << ' ' << LI << '\n';
}
void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
BBInfo &MInfo = MBBInfoMap[MBB];
if (!MInfo.reachable) {
MInfo.reachable = true;
for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
SuE = MBB->succ_end(); SuI != SuE; ++SuI)
markReachable(*SuI);
}
}
void MachineVerifier::visitMachineFunctionBefore() {
lastIndex = SlotIndex();
regsReserved = TRI->getReservedRegs(*MF);
// A sub-register of a reserved register is also reserved
for (int Reg = regsReserved.find_first(); Reg>=0;
Reg = regsReserved.find_next(Reg)) {
for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
// FIXME: This should probably be:
// assert(regsReserved.test(*SubRegs) && "Non-reserved sub-register");
regsReserved.set(*SubRegs);
}
}
regsAllocatable = TRI->getAllocatableSet(*MF);
markReachable(&MF->front());
// Build a set of the basic blocks in the function.
FunctionBlocks.clear();
for (MachineFunction::const_iterator
I = MF->begin(), E = MF->end(); I != E; ++I) {
FunctionBlocks.insert(I);
BBInfo &MInfo = MBBInfoMap[I];
MInfo.Preds.insert(I->pred_begin(), I->pred_end());
if (MInfo.Preds.size() != I->pred_size())
report("MBB has duplicate entries in its predecessor list.", I);
MInfo.Succs.insert(I->succ_begin(), I->succ_end());
if (MInfo.Succs.size() != I->succ_size())
report("MBB has duplicate entries in its successor list.", I);
}
}
// 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 = 0;
if (MRI->isSSA()) {
// If this block has allocatable physical registers live-in, check that
// it is an entry block or landing pad.
for (MachineBasicBlock::livein_iterator LI = MBB->livein_begin(),
LE = MBB->livein_end();
LI != LE; ++LI) {
unsigned reg = *LI;
if (isAllocatable(reg) && !MBB->isLandingPad() &&
MBB != MBB->getParent()->begin()) {
report("MBB has allocable live-in, but isn't entry or landing-pad.", MBB);
}
}
}
// Count the number of landing pad successors.
SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs;
for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
E = MBB->succ_end(); I != E; ++I) {
if ((*I)->isLandingPad())
LandingPadSuccs.insert(*I);
if (!FunctionBlocks.count(*I))
report("MBB has successor that isn't part of the function.", MBB);
if (!MBBInfoMap[*I].Preds.count(MBB)) {
report("Inconsistent CFG", MBB);
*OS << "MBB is not in the predecessor list of the successor BB#"
<< (*I)->getNumber() << ".\n";
}
}
// Check the predecessor list.
for (MachineBasicBlock::const_pred_iterator I = MBB->pred_begin(),
E = MBB->pred_end(); I != E; ++I) {
if (!FunctionBlocks.count(*I))
report("MBB has predecessor that isn't part of the function.", MBB);
if (!MBBInfoMap[*I].Succs.count(MBB)) {
report("Inconsistent CFG", MBB);
*OS << "MBB is not in the successor list of the predecessor BB#"
<< (*I)->getNumber() << ".\n";
}
}
const MCAsmInfo *AsmInfo = TM->getMCAsmInfo();
const BasicBlock *BB = MBB->getBasicBlock();
if (LandingPadSuccs.size() > 1 &&
!(AsmInfo &&
AsmInfo->getExceptionHandlingType() == ExceptionHandling::SjLj &&
BB && isa<SwitchInst>(BB->getTerminator())))
report("MBB has more than one landing pad successor", MBB);
// Call AnalyzeBranch. If it succeeds, there several more conditions to check.
MachineBasicBlock *TBB = 0, *FBB = 0;
SmallVector<MachineOperand, 4> Cond;
if (!TII->AnalyzeBranch(*const_cast<MachineBasicBlock *>(MBB),
TBB, FBB, Cond)) {
// Ok, AnalyzeBranch thinks it knows what's going on with this block. Let's
// check whether its answers match up with reality.
if (!TBB && !FBB) {
// Block falls through to its successor.
MachineFunction::const_iterator MBBI = MBB;
++MBBI;
if (MBBI == MF->end()) {
// It's possible that the block legitimately ends with a noreturn
// call or an unreachable, in which case it won't actually fall
// out the bottom of the function.
} else if (MBB->succ_size() == LandingPadSuccs.size()) {
// It's possible that the block legitimately ends with a noreturn
// call or an unreachable, in which case it won't actuall fall
// out of the block.
} else if (MBB->succ_size() != 1+LandingPadSuccs.size()) {
report("MBB exits via unconditional fall-through but doesn't have "
"exactly one CFG successor!", MBB);
} else if (!MBB->isSuccessor(MBBI)) {
report("MBB exits via unconditional fall-through but its successor "
"differs from its CFG successor!", MBB);
}
if (!MBB->empty() && getBundleStart(&MBB->back())->isBarrier() &&
!TII->isPredicated(getBundleStart(&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 (MBB->succ_size() != 1+LandingPadSuccs.size()) {
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 (!getBundleStart(&MBB->back())->isBarrier()) {
report("MBB exits via unconditional branch but doesn't end with a "
"barrier instruction!", MBB);
} else if (!getBundleStart(&MBB->back())->isTerminator()) {
report("MBB exits via unconditional branch but the branch isn't a "
"terminator instruction!", MBB);
}
} else if (TBB && !FBB && !Cond.empty()) {
// Block conditionally branches somewhere, otherwise falls through.
MachineFunction::const_iterator MBBI = MBB;
++MBBI;
if (MBBI == MF->end()) {
report("MBB conditionally falls through out of function!", MBB);
} 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 (getBundleStart(&MBB->back())->isBarrier()) {
report("MBB exits via conditional branch/fall-through but ends with a "
"barrier instruction!", MBB);
} else if (!getBundleStart(&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 (!getBundleStart(&MBB->back())->isBarrier()) {
report("MBB exits via conditional branch/branch but doesn't end with a "
"barrier instruction!", MBB);
} else if (!getBundleStart(&MBB->back())->isTerminator()) {
report("MBB exits via conditional branch/branch but the branch "
"isn't a terminator instruction!", MBB);
}
if (Cond.empty()) {
report("MBB exits via conditinal branch/branch but there's no "
"condition!", MBB);
}
} else {
report("AnalyzeBranch returned invalid data!", MBB);
}
}
regsLive.clear();
for (MachineBasicBlock::livein_iterator I = MBB->livein_begin(),
E = MBB->livein_end(); I != E; ++I) {
if (!TargetRegisterInfo::isPhysicalRegister(*I)) {
report("MBB live-in list contains non-physical register", MBB);
continue;
}
regsLive.insert(*I);
for (MCSubRegIterator SubRegs(*I, TRI); SubRegs.isValid(); ++SubRegs)
regsLive.insert(*SubRegs);
}
regsLiveInButUnused = regsLive;
const MachineFrameInfo *MFI = MF->getFrameInfo();
assert(MFI && "Function has no frame info");
BitVector PR = MFI->getPristineRegs(MBB);
for (int I = PR.find_first(); I>0; I = PR.find_next(I)) {
regsLive.insert(I);
for (MCSubRegIterator SubRegs(I, TRI); SubRegs.isValid(); ++SubRegs)
regsLive.insert(*SubRegs);
}
regsKilled.clear();
regsDefined.clear();
if (Indexes)
lastIndex = Indexes->getMBBStartIdx(MBB);
}
// This function gets called for all bundle headers, including normal
// stand-alone unbundled instructions.
void MachineVerifier::visitMachineBundleBefore(const MachineInstr *MI) {
if (Indexes && Indexes->hasIndex(MI)) {
SlotIndex idx = Indexes->getInstructionIndex(MI);
if (!(idx > lastIndex)) {
report("Instruction index out of order", MI);
*OS << "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);
*OS << "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, and Extra_IsAlignStack = 2.
if (!isUInt<2>(MI->getOperand(1).getImm()))
report("Unknown asm flags", &MI->getOperand(1), 1);
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);
}
}
// Verify the consistency of tied operands.
void MachineVerifier::verifyTiedOperands(const MachineInstr *MI) {
const MCInstrDesc &MCID = MI->getDesc();
SmallVector<unsigned, 4> Defs;
SmallVector<unsigned, 4> Uses;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || !MO.isTied())
continue;
if (MO.isDef()) {
Defs.push_back(i);
continue;
}
Uses.push_back(i);
if (Defs.size() < Uses.size()) {
report("No tied def for tied use", &MO, i);
break;
}
if (i >= MCID.getNumOperands())
continue;
int DefIdx = MCID.getOperandConstraint(i, MCOI::TIED_TO);
if (unsigned(DefIdx) != Defs[Uses.size() - 1]) {
report(" def doesn't match MCInstrDesc", &MO, i);
*OS << "Descriptor says tied def should be operand " << DefIdx << ".\n";
}
}
if (Defs.size() > Uses.size()) {
unsigned i = Defs[Uses.size() - 1];
report("No tied use for tied def", &MI->getOperand(i), i);
}
}
void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
const MCInstrDesc &MCID = MI->getDesc();
if (MI->getNumOperands() < MCID.getNumOperands()) {
report("Too few operands", MI);
*OS << MCID.getNumOperands() << " operands expected, but "
<< MI->getNumExplicitOperands() << " given.\n";
}
// Check the tied operands.
if (MI->isInlineAsm())
verifyInlineAsm(MI);
else
verifyTiedOperands(MI);
// Check the MachineMemOperands for basic consistency.
for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
E = MI->memoperands_end(); I != E; ++I) {
if ((*I)->isLoad() && !MI->mayLoad())
report("Missing mayLoad flag", MI);
if ((*I)->isStore() && !MI->mayStore())
report("Missing mayStore flag", MI);
}
// Debug values must not have a slot index.
// Other instructions must have one, unless they are inside a bundle.
if (LiveInts) {
bool mapped = !LiveInts->isNotInMIMap(MI);
if (MI->isDebugValue()) {
if (mapped)
report("Debug instruction has a slot index", MI);
} else if (MI->isInsideBundle()) {
if (mapped)
report("Instruction inside bundle has a slot index", MI);
} else {
if (!mapped)
report("Missing slot index", MI);
}
}
StringRef ErrorInfo;
if (!TII->verifyInstruction(MI, ErrorInfo))
report(ErrorInfo.data(), MI);
}
void
MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const MCInstrDesc &MCID = MI->getDesc();
// The first MCID.NumDefs operands must be explicit register defines
if (MONum < MCID.getNumDefs()) {
const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
if (!MO->isReg())
report("Explicit definition must be a register", MO, MONum);
else if (!MO->isDef() && !MCOI.isOptionalDef())
report("Explicit definition marked as use", MO, MONum);
else if (MO->isImplicit())
report("Explicit definition marked as implicit", MO, MONum);
} else if (MONum < MCID.getNumOperands()) {
const MCOperandInfo &MCOI = MCID.OpInfo[MONum];
// Don't check if it's the last operand in a variadic instruction. See,
// e.g., LDM_RET in the arm back end.
if (MO->isReg() &&
!(MI->isVariadic() && MONum == MCID.getNumOperands()-1)) {
if (MO->isDef() && !MCOI.isOptionalDef())
report("Explicit operand marked as def", MO, MONum);
if (MO->isImplicit())
report("Explicit operand marked as implicit", MO, MONum);
}
if (MCID.getOperandConstraint(MONum, MCOI::TIED_TO) != -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 (MO->isReg() && MO->isTied())
report("Explicit operand should not be tied", MO, MONum);
} else {
// ARM adds %reg0 operands to indicate predicates. We'll allow that.
if (MO->isReg() && !MO->isImplicit() && !MI->isVariadic() && MO->getReg())
report("Extra explicit operand on non-variadic instruction", MO, MONum);
}
switch (MO->getType()) {
case MachineOperand::MO_Register: {
const unsigned Reg = MO->getReg();
if (!Reg)
return;
if (MRI->tracksLiveness() && !MI->isDebugValue())
checkLiveness(MO, MONum);
// Verify two-address constraints after leaving SSA form.
unsigned DefIdx;
if (!MRI->isSSA() && MO->isUse() &&
MI->isRegTiedToDefOperand(MONum, &DefIdx) &&
Reg != MI->getOperand(DefIdx).getReg())
report("Two-address instruction operands must be identical", MO, MONum);
// Check register classes.
if (MONum < MCID.getNumOperands() && !MO->isImplicit()) {
unsigned SubIdx = MO->getSubReg();
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
if (SubIdx) {
report("Illegal subregister index for physical register", MO, MONum);
return;
}
if (const TargetRegisterClass *DRC =
TII->getRegClass(MCID, MONum, TRI, *MF)) {
if (!DRC->contains(Reg)) {
report("Illegal physical register for instruction", MO, MONum);
*OS << TRI->getName(Reg) << " is not a "
<< DRC->getName() << " register.\n";
}
}
} else {
// Virtual register.
const TargetRegisterClass *RC = MRI->getRegClass(Reg);
if (SubIdx) {
const TargetRegisterClass *SRC =
TRI->getSubClassWithSubReg(RC, SubIdx);
if (!SRC) {
report("Invalid subregister index for virtual register", MO, MONum);
*OS << "Register class " << RC->getName()
<< " does not support subreg index " << SubIdx << "\n";
return;
}
if (RC != SRC) {
report("Invalid register class for subregister index", MO, MONum);
*OS << "Register class " << RC->getName()
<< " does not fully support subreg index " << SubIdx << "\n";
return;
}
}
if (const TargetRegisterClass *DRC =
TII->getRegClass(MCID, MONum, TRI, *MF)) {
if (SubIdx) {
const TargetRegisterClass *SuperRC =
TRI->getLargestLegalSuperClass(RC);
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);
*OS << "Expected a " << DRC->getName() << " register, but got a "
<< RC->getName() << " register\n";
}
}
}
}
break;
}
case MachineOperand::MO_RegisterMask:
regMasks.push_back(MO->getRegMask());
break;
case MachineOperand::MO_MachineBasicBlock:
if (MI->isPHI() && !MO->getMBB()->isSuccessor(MI->getParent()))
report("PHI operand is not in the CFG", MO, MONum);
break;
case MachineOperand::MO_FrameIndex:
if (LiveStks && LiveStks->hasInterval(MO->getIndex()) &&
LiveInts && !LiveInts->isNotInMIMap(MI)) {
LiveInterval &LI = LiveStks->getInterval(MO->getIndex());
SlotIndex Idx = LiveInts->getInstructionIndex(MI);
if (MI->mayLoad() && !LI.liveAt(Idx.getRegSlot(true))) {
report("Instruction loads from dead spill slot", MO, MONum);
*OS << "Live stack: " << LI << '\n';
}
if (MI->mayStore() && !LI.liveAt(Idx.getRegSlot())) {
report("Instruction stores to dead spill slot", MO, MONum);
*OS << "Live stack: " << LI << '\n';
}
}
break;
default:
break;
}
}
void MachineVerifier::checkLiveness(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const unsigned Reg = MO->getReg();
// Both use and def operands can read a register.
if (MO->readsReg()) {
regsLiveInButUnused.erase(Reg);
if (MO->isKill())
addRegWithSubRegs(regsKilled, Reg);
// Check that LiveVars knows this kill.
if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg) &&
MO->isKill()) {
LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
if (std::find(VI.Kills.begin(), VI.Kills.end(), MI) == VI.Kills.end())
report("Kill missing from LiveVariables", MO, MONum);
}
// Check LiveInts liveness and kill.
if (LiveInts && !LiveInts->isNotInMIMap(MI)) {
SlotIndex UseIdx = LiveInts->getInstructionIndex(MI);
// Check the cached regunit intervals.
if (TargetRegisterInfo::isPhysicalRegister(Reg) && !isReserved(Reg)) {
for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
if (const LiveInterval *LI = LiveInts->getCachedRegUnit(*Units)) {
LiveRangeQuery LRQ(*LI, UseIdx);
if (!LRQ.valueIn()) {
report("No live range at use", MO, MONum);
*OS << UseIdx << " is not live in " << PrintRegUnit(*Units, TRI)
<< ' ' << *LI << '\n';
}
if (MO->isKill() && !LRQ.isKill()) {
report("Live range continues after kill flag", MO, MONum);
*OS << PrintRegUnit(*Units, TRI) << ' ' << *LI << '\n';
}
}
}
}
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
if (LiveInts->hasInterval(Reg)) {
// This is a virtual register interval.
const LiveInterval &LI = LiveInts->getInterval(Reg);
LiveRangeQuery LRQ(LI, UseIdx);
if (!LRQ.valueIn()) {
report("No live range at use", MO, MONum);
*OS << UseIdx << " is not live in " << LI << '\n';
}
// Check for extra kill flags.
// Note that we allow missing kill flags for now.
if (MO->isKill() && !LRQ.isKill()) {
report("Live range continues after kill flag", MO, MONum);
*OS << "Live range: " << LI << '\n';
}
} else {
report("Virtual register has no live interval", MO, MONum);
}
}
}
// Use of a dead register.
if (!regsLive.count(Reg)) {
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
// Reserved registers may be used even when 'dead'.
if (!isReserved(Reg))
report("Using an undefined physical register", MO, MONum);
} else if (MRI->def_empty(Reg)) {
report("Reading virtual register without a def", MO, MONum);
} else {
BBInfo &MInfo = MBBInfoMap[MI->getParent()];
// We don't know which virtual registers are live in, so only complain
// if vreg was killed in this MBB. Otherwise keep track of vregs that
// must be live in. PHI instructions are handled separately.
if (MInfo.regsKilled.count(Reg))
report("Using a killed virtual register", MO, MONum);
else if (!MI->isPHI())
MInfo.vregsLiveIn.insert(std::make_pair(Reg, MI));
}
}
}
if (MO->isDef()) {
// Register defined.
// TODO: verify that earlyclobber ops are not used.
if (MO->isDead())
addRegWithSubRegs(regsDead, Reg);
else
addRegWithSubRegs(regsDefined, Reg);
// Verify SSA form.
if (MRI->isSSA() && TargetRegisterInfo::isVirtualRegister(Reg) &&
llvm::next(MRI->def_begin(Reg)) != MRI->def_end())
report("Multiple virtual register defs in SSA form", MO, MONum);
// Check LiveInts for a live range, but only for virtual registers.
if (LiveInts && TargetRegisterInfo::isVirtualRegister(Reg) &&
!LiveInts->isNotInMIMap(MI)) {
SlotIndex DefIdx = LiveInts->getInstructionIndex(MI);
DefIdx = DefIdx.getRegSlot(MO->isEarlyClobber());
if (LiveInts->hasInterval(Reg)) {
const LiveInterval &LI = LiveInts->getInterval(Reg);
if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) {
assert(VNI && "NULL valno is not allowed");
if (VNI->def != DefIdx) {
report("Inconsistent valno->def", MO, MONum);
*OS << "Valno " << VNI->id << " is not defined at "
<< DefIdx << " in " << LI << '\n';
}
} else {
report("No live range at def", MO, MONum);
*OS << DefIdx << " is not live in " << LI << '\n';
}
} else {
report("Virtual register has no Live interval", MO, MONum);
}
}
}
}
void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
}
// This function gets called after visiting all instructions in a bundle. The
// argument points to the bundle header.
// Normal stand-alone instructions are also considered 'bundles', and this
// function is called for all of them.
void MachineVerifier::visitMachineBundleAfter(const MachineInstr *MI) {
BBInfo &MInfo = MBBInfoMap[MI->getParent()];
set_union(MInfo.regsKilled, regsKilled);
set_subtract(regsLive, regsKilled); regsKilled.clear();
// Kill any masked registers.
while (!regMasks.empty()) {
const uint32_t *Mask = regMasks.pop_back_val();
for (RegSet::iterator I = regsLive.begin(), E = regsLive.end(); I != E; ++I)
if (TargetRegisterInfo::isPhysicalRegister(*I) &&
MachineOperand::clobbersPhysReg(Mask, *I))
regsDead.push_back(*I);
}
set_subtract(regsLive, regsDead); regsDead.clear();
set_union(regsLive, regsDefined); regsDefined.clear();
}
void
MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
MBBInfoMap[MBB].regsLiveOut = regsLive;
regsLive.clear();
if (Indexes) {
SlotIndex stop = Indexes->getMBBEndIdx(MBB);
if (!(stop > lastIndex)) {
report("Block ends before last instruction index", MBB);
*OS << "Block ends at " << stop
<< " last instruction was at " << lastIndex << '\n';
}
lastIndex = stop;
}
}
// Calculate the largest possible vregsPassed sets. These are the registers that
// can pass through an MBB live, but may not be live every time. It is assumed
// that all vregsPassed sets are empty before the call.
void MachineVerifier::calcRegsPassed() {
// First push live-out regs to successors' vregsPassed. Remember the MBBs that
// have any vregsPassed.
SmallPtrSet<const MachineBasicBlock*, 8> todo;
for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
MFI != MFE; ++MFI) {
const MachineBasicBlock &MBB(*MFI);
BBInfo &MInfo = MBBInfoMap[&MBB];
if (!MInfo.reachable)
continue;
for (MachineBasicBlock::const_succ_iterator SuI = MBB.succ_begin(),
SuE = MBB.succ_end(); SuI != SuE; ++SuI) {
BBInfo &SInfo = MBBInfoMap[*SuI];
if (SInfo.addPassed(MInfo.regsLiveOut))
todo.insert(*SuI);
}
}
// Iteratively push vregsPassed to successors. This will converge to the same
// final state regardless of DenseSet iteration order.
while (!todo.empty()) {
const MachineBasicBlock *MBB = *todo.begin();
todo.erase(MBB);
BBInfo &MInfo = MBBInfoMap[MBB];
for (MachineBasicBlock::const_succ_iterator SuI = MBB->succ_begin(),
SuE = MBB->succ_end(); SuI != SuE; ++SuI) {
if (*SuI == MBB)
continue;
BBInfo &SInfo = MBBInfoMap[*SuI];
if (SInfo.addPassed(MInfo.vregsPassed))
todo.insert(*SuI);
}
}
}
// Calculate the set of virtual registers that must be passed through each basic
// block in order to satisfy the requirements of successor blocks. This is very
// similar to calcRegsPassed, only backwards.
void MachineVerifier::calcRegsRequired() {
// First push live-in regs to predecessors' vregsRequired.
SmallPtrSet<const MachineBasicBlock*, 8> todo;
for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
MFI != MFE; ++MFI) {
const MachineBasicBlock &MBB(*MFI);
BBInfo &MInfo = MBBInfoMap[&MBB];
for (MachineBasicBlock::const_pred_iterator PrI = MBB.pred_begin(),
PrE = MBB.pred_end(); PrI != PrE; ++PrI) {
BBInfo &PInfo = MBBInfoMap[*PrI];
if (PInfo.addRequired(MInfo.vregsLiveIn))
todo.insert(*PrI);
}
}
// Iteratively push vregsRequired to predecessors. This will converge to the
// same final state regardless of DenseSet iteration order.
while (!todo.empty()) {
const MachineBasicBlock *MBB = *todo.begin();
todo.erase(MBB);
BBInfo &MInfo = MBBInfoMap[MBB];
for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
if (*PrI == MBB)
continue;
BBInfo &SInfo = MBBInfoMap[*PrI];
if (SInfo.addRequired(MInfo.vregsRequired))
todo.insert(*PrI);
}
}
}
// Check PHI instructions at the beginning of MBB. It is assumed that
// calcRegsPassed has been run so BBInfo::isLiveOut is valid.
void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
SmallPtrSet<const MachineBasicBlock*, 8> seen;
for (MachineBasicBlock::const_iterator BBI = MBB->begin(), BBE = MBB->end();
BBI != BBE && BBI->isPHI(); ++BBI) {
seen.clear();
for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2) {
unsigned Reg = BBI->getOperand(i).getReg();
const MachineBasicBlock *Pre = BBI->getOperand(i + 1).getMBB();
if (!Pre->isSuccessor(MBB))
continue;
seen.insert(Pre);
BBInfo &PrInfo = MBBInfoMap[Pre];
if (PrInfo.reachable && !PrInfo.isLiveOut(Reg))
report("PHI operand is not live-out from predecessor",
&BBI->getOperand(i), i);
}
// Did we see all predecessors?
for (MachineBasicBlock::const_pred_iterator PrI = MBB->pred_begin(),
PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
if (!seen.count(*PrI)) {
report("Missing PHI operand", BBI);
*OS << "BB#" << (*PrI)->getNumber()
<< " is a predecessor according to the CFG.\n";
}
}
}
}
void MachineVerifier::visitMachineFunctionAfter() {
calcRegsPassed();
for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
MFI != MFE; ++MFI) {
BBInfo &MInfo = MBBInfoMap[MFI];
// Skip unreachable MBBs.
if (!MInfo.reachable)
continue;
checkPHIOps(MFI);
}
// Now check liveness info if available
calcRegsRequired();
// Check for killed virtual registers that should be live out.
for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
MFI != MFE; ++MFI) {
BBInfo &MInfo = MBBInfoMap[MFI];
for (RegSet::iterator
I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E;
++I)
if (MInfo.regsKilled.count(*I)) {
report("Virtual register killed in block, but needed live out.", MFI);
*OS << "Virtual register " << PrintReg(*I)
<< " is used after the block.\n";
}
}
if (!MF->empty()) {
BBInfo &MInfo = MBBInfoMap[&MF->front()];
for (RegSet::iterator
I = MInfo.vregsRequired.begin(), E = MInfo.vregsRequired.end(); I != E;
++I)
report("Virtual register def doesn't dominate all uses.",
MRI->getVRegDef(*I));
}
if (LiveVars)
verifyLiveVariables();
if (LiveInts)
verifyLiveIntervals();
}
void MachineVerifier::verifyLiveVariables() {
assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
LiveVariables::VarInfo &VI = LiveVars->getVarInfo(Reg);
for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
MFI != MFE; ++MFI) {
BBInfo &MInfo = MBBInfoMap[MFI];
// Our vregsRequired should be identical to LiveVariables' AliveBlocks
if (MInfo.vregsRequired.count(Reg)) {
if (!VI.AliveBlocks.test(MFI->getNumber())) {
report("LiveVariables: Block missing from AliveBlocks", MFI);
*OS << "Virtual register " << PrintReg(Reg)
<< " must be live through the block.\n";
}
} else {
if (VI.AliveBlocks.test(MFI->getNumber())) {
report("LiveVariables: Block should not be in AliveBlocks", MFI);
*OS << "Virtual register " << PrintReg(Reg)
<< " is not needed live through the block.\n";
}
}
}
}
}
void MachineVerifier::verifyLiveIntervals() {
assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts");
for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
// Spilling and splitting may leave unused registers around. Skip them.
if (MRI->reg_nodbg_empty(Reg))
continue;
if (!LiveInts->hasInterval(Reg)) {
report("Missing live interval for virtual register", MF);
*OS << 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 LiveInterval *LI = LiveInts->getCachedRegUnit(i))
verifyLiveInterval(*LI);
}
void MachineVerifier::verifyLiveIntervalValue(const LiveInterval &LI,
VNInfo *VNI) {
if (VNI->isUnused())
return;
const VNInfo *DefVNI = LI.getVNInfoAt(VNI->def);
if (!DefVNI) {
report("Valno not live at def and not marked unused", MF, LI);
*OS << "Valno #" << VNI->id << '\n';
return;
}
if (DefVNI != VNI) {
report("Live range at def has different valno", MF, LI);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< " where valno #" << DefVNI->id << " is live\n";
return;
}
const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def);
if (!MBB) {
report("Invalid definition index", MF, LI);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< " in " << LI << '\n';
return;
}
if (VNI->isPHIDef()) {
if (VNI->def != LiveInts->getMBBStartIdx(MBB)) {
report("PHIDef value is not defined at MBB start", MBB, LI);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< ", not at the beginning of BB#" << MBB->getNumber() << '\n';
}
return;
}
// Non-PHI def.
const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
if (!MI) {
report("No instruction at def index", MBB, LI);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def << '\n';
return;
}
bool hasDef = false;
bool isEarlyClobber = false;
for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) {
if (!MOI->isReg() || !MOI->isDef())
continue;
if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
if (MOI->getReg() != LI.reg)
continue;
} else {
if (!TargetRegisterInfo::isPhysicalRegister(MOI->getReg()) ||
!TRI->hasRegUnit(MOI->getReg(), LI.reg))
continue;
}
hasDef = true;
if (MOI->isEarlyClobber())
isEarlyClobber = true;
}
if (!hasDef) {
report("Defining instruction does not modify register", MI);
*OS << "Valno #" << VNI->id << " in " << LI << '\n';
}
// Early clobber defs begin at USE slots, but other defs must begin at
// DEF slots.
if (isEarlyClobber) {
if (!VNI->def.isEarlyClobber()) {
report("Early clobber def must be at an early-clobber slot", MBB, LI);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def << '\n';
}
} else if (!VNI->def.isRegister()) {
report("Non-PHI, non-early clobber def must be at a register slot",
MBB, LI);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def << '\n';
}
}
void
MachineVerifier::verifyLiveIntervalSegment(const LiveInterval &LI,
LiveInterval::const_iterator I) {
const VNInfo *VNI = I->valno;
assert(VNI && "Live range has no valno");
if (VNI->id >= LI.getNumValNums() || VNI != LI.getValNumInfo(VNI->id)) {
report("Foreign valno in live range", MF, LI);
*OS << *I << " has a bad valno\n";
}
if (VNI->isUnused()) {
report("Live range valno is marked unused", MF, LI);
*OS << *I << '\n';
}
const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(I->start);
if (!MBB) {
report("Bad start of live segment, no basic block", MF, LI);
*OS << *I << '\n';
return;
}
SlotIndex MBBStartIdx = LiveInts->getMBBStartIdx(MBB);
if (I->start != MBBStartIdx && I->start != VNI->def) {
report("Live segment must begin at MBB entry or valno def", MBB, LI);
*OS << *I << '\n';
}
const MachineBasicBlock *EndMBB =
LiveInts->getMBBFromIndex(I->end.getPrevSlot());
if (!EndMBB) {
report("Bad end of live segment, no basic block", MF, LI);
*OS << *I << '\n';
return;
}
// No more checks for live-out segments.
if (I->end == LiveInts->getMBBEndIdx(EndMBB))
return;
// RegUnit intervals are allowed dead phis.
if (!TargetRegisterInfo::isVirtualRegister(LI.reg) && VNI->isPHIDef() &&
I->start == VNI->def && I->end == VNI->def.getDeadSlot())
return;
// The live segment is ending inside EndMBB
const MachineInstr *MI =
LiveInts->getInstructionFromIndex(I->end.getPrevSlot());
if (!MI) {
report("Live segment doesn't end at a valid instruction", EndMBB, LI);
*OS << *I << '\n';
return;
}
// The block slot must refer to a basic block boundary.
if (I->end.isBlock()) {
report("Live segment ends at B slot of an instruction", EndMBB, LI);
*OS << *I << '\n';
}
if (I->end.isDead()) {
// Segment ends on the dead slot.
// That means there must be a dead def.
if (!SlotIndex::isSameInstr(I->start, I->end)) {
report("Live segment ending at dead slot spans instructions", EndMBB, LI);
*OS << *I << '\n';
}
}
// A live segment can only end at an early-clobber slot if it is being
// redefined by an early-clobber def.
if (I->end.isEarlyClobber()) {
if (I+1 == LI.end() || (I+1)->start != I->end) {
report("Live segment ending at early clobber slot must be "
"redefined by an EC def in the same instruction", EndMBB, LI);
*OS << *I << '\n';
}
}
// The following checks only apply to virtual registers. Physreg liveness
// is too weird to check.
if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
// A live range can end with either a redefinition, a kill flag on a
// use, or a dead flag on a def.
bool hasRead = false;
bool hasDeadDef = false;
for (ConstMIBundleOperands MOI(MI); MOI.isValid(); ++MOI) {
if (!MOI->isReg() || MOI->getReg() != LI.reg)
continue;
if (MOI->readsReg())
hasRead = true;
if (MOI->isDef() && MOI->isDead())
hasDeadDef = true;
}
if (I->end.isDead()) {
if (!hasDeadDef) {
report("Instruction doesn't have a dead def operand", MI);
I->print(*OS);
*OS << " in " << LI << '\n';
}
} else {
if (!hasRead) {
report("Instruction ending live range doesn't read the register", MI);
*OS << *I << " in " << LI << '\n';
}
}
}
// Now check all the basic blocks in this live segment.
MachineFunction::const_iterator MFI = MBB;
// Is this live range the beginning of a non-PHIDef VN?
if (I->start == VNI->def && !VNI->isPHIDef()) {
// Not live-in to any blocks.
if (MBB == EndMBB)
return;
// Skip this block.
++MFI;
}
for (;;) {
assert(LiveInts->isLiveInToMBB(LI, MFI));
// We don't know how to track physregs into a landing pad.
if (!TargetRegisterInfo::isVirtualRegister(LI.reg) &&
MFI->isLandingPad()) {
if (&*MFI == EndMBB)
break;
++MFI;
continue;
}
// Is VNI a PHI-def in the current block?
bool IsPHI = VNI->isPHIDef() &&
VNI->def == LiveInts->getMBBStartIdx(MFI);
// Check that VNI is live-out of all predecessors.
for (MachineBasicBlock::const_pred_iterator PI = MFI->pred_begin(),
PE = MFI->pred_end(); PI != PE; ++PI) {
SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI);
const VNInfo *PVNI = LI.getVNInfoBefore(PEnd);
// All predecessors must have a live-out value.
if (!PVNI) {
report("Register not marked live out of predecessor", *PI, LI);
*OS << "Valno #" << VNI->id << " live into BB#" << MFI->getNumber()
<< '@' << LiveInts->getMBBStartIdx(MFI) << ", not live before "
<< PEnd << '\n';
continue;
}
// Only PHI-defs can take different predecessor values.
if (!IsPHI && PVNI != VNI) {
report("Different value live out of predecessor", *PI, LI);
*OS << "Valno #" << PVNI->id << " live out of BB#"
<< (*PI)->getNumber() << '@' << PEnd
<< "\nValno #" << VNI->id << " live into BB#" << MFI->getNumber()
<< '@' << LiveInts->getMBBStartIdx(MFI) << '\n';
}
}
if (&*MFI == EndMBB)
break;
++MFI;
}
}
void MachineVerifier::verifyLiveInterval(const LiveInterval &LI) {
for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
I!=E; ++I)
verifyLiveIntervalValue(LI, *I);
for (LiveInterval::const_iterator I = LI.begin(), E = LI.end(); I!=E; ++I)
verifyLiveIntervalSegment(LI, I);
// Check the LI only has one connected component.
if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
ConnectedVNInfoEqClasses ConEQ(*LiveInts);
unsigned NumComp = ConEQ.Classify(&LI);
if (NumComp > 1) {
report("Multiple connected components in live interval", MF, LI);
for (unsigned comp = 0; comp != NumComp; ++comp) {
*OS << comp << ": valnos";
for (LiveInterval::const_vni_iterator I = LI.vni_begin(),
E = LI.vni_end(); I!=E; ++I)
if (comp == ConEQ.getEqClass(*I))
*OS << ' ' << (*I)->id;
*OS << '\n';
}
}
}
}
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