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llvm-6502/lib/CodeGen/MachineVerifier.cpp
Jakob Stoklund Olesen 1c163d2a06 Add kill flag verification. 
At least X86FloatingPoint requires correct kill flags after register allocation,
and targets using register scavenging benefit. Conservative kill flags are not
enough.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117960 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-01 21:51:31 +00:00

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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/Function.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/LiveStackAnalysis.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/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) :
PASS(pass),
OutFileName(getenv("LLVM_VERIFY_MACHINEINSTRS"))
{}
bool runOnMachineFunction(MachineFunction &MF);
Pass *const PASS;
const char *const OutFileName;
raw_ostream *OS;
const MachineFunction *MF;
const TargetMachine *TM;
const TargetRegisterInfo *TRI;
const MachineRegisterInfo *MRI;
unsigned foundErrors;
typedef SmallVector<unsigned, 16> RegVector;
typedef DenseSet<unsigned> RegSet;
typedef DenseMap<unsigned, const MachineInstr*> RegMap;
BitVector regsReserved;
RegSet regsLive;
RegVector regsDefined, regsDead, regsKilled;
RegSet regsLiveInButUnused;
// Add Reg and any sub-registers to RV
void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
RV.push_back(Reg);
if (TargetRegisterInfo::isPhysicalRegister(Reg))
for (const unsigned *R = TRI->getSubRegisters(Reg); *R; R++)
RV.push_back(*R);
}
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;
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);
}
// Analysis information if available
LiveVariables *LiveVars;
LiveIntervals *LiveInts;
LiveStacks *LiveStks;
SlotIndexes *Indexes;
void visitMachineFunctionBefore();
void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
void visitMachineInstrBefore(const MachineInstr *MI);
void visitMachineOperand(const MachineOperand *MO, unsigned MONum);
void visitMachineInstrAfter(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 markReachable(const MachineBasicBlock *MBB);
void calcRegsPassed();
void checkPHIOps(const MachineBasicBlock *MBB);
void calcRegsRequired();
void verifyLiveVariables();
void verifyLiveIntervals();
};
struct MachineVerifierPass : public MachineFunctionPass {
static char ID; // Pass ID, replacement for typeid
MachineVerifierPass()
: MachineFunctionPass(ID) {
initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool runOnMachineFunction(MachineFunction &MF) {
MF.verify(this);
return false;
}
};
}
char MachineVerifierPass::ID = 0;
INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
"Verify generated machine code", false, false)
FunctionPass *llvm::createMachineVerifierPass() {
return new MachineVerifierPass();
}
void MachineFunction::verify(Pass *p) const {
MachineVerifier(p).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();
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);
for (MachineBasicBlock::const_iterator MBBI = MFI->begin(),
MBBE = MFI->end(); MBBI != MBBE; ++MBBI) {
visitMachineInstrBefore(MBBI);
for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
visitMachineOperand(&MBBI->getOperand(I), I);
visitMachineInstrAfter(MBBI);
}
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();
regsLiveInButUnused.clear();
MBBInfoMap.clear();
return false; // no changes
}
void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
assert(MF);
*OS << '\n';
if (!foundErrors++)
MF->print(*OS, Indexes);
*OS << "*** Bad machine code: " << msg << " ***\n"
<< "- function: " << MF->getFunction()->getNameStr() << "\n";
}
void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
assert(MBB);
report(msg, MBB->getParent());
*OS << "- basic block: " << MBB->getName()
<< " " << (void*)MBB
<< " (BB#" << MBB->getNumber() << ")";
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::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() {
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 (const unsigned *Sub = TRI->getSubRegisters(Reg); *Sub; ++Sub) {
// FIXME: This should probably be:
// assert(regsReserved.test(*Sub) && "Non-reserved sub-register");
regsReserved.set(*Sub);
}
}
markReachable(&MF->front());
}
// 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) {
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
// Count the number of landing pad successors.
unsigned LandingPadSuccs = 0;
for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
E = MBB->succ_end(); I != E; ++I)
LandingPadSuccs += (*I)->isLandingPad();
if (LandingPadSuccs > 1)
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) {
// 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) {
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().getDesc().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 (MBB->succ_size() != 1+LandingPadSuccs) {
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().getDesc().isBarrier()) {
report("MBB exits via unconditional branch but doesn't end with a "
"barrier instruction!", MBB);
} else if (!MBB->back().getDesc().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() != 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().getDesc().isBarrier()) {
report("MBB exits via conditional branch/fall-through but ends with a "
"barrier instruction!", MBB);
} else if (!MBB->back().getDesc().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() != 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().getDesc().isBarrier()) {
report("MBB exits via conditional branch/branch but doesn't end with a "
"barrier instruction!", MBB);
} else if (!MBB->back().getDesc().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 (const unsigned *R = TRI->getSubRegisters(*I); *R; R++)
regsLive.insert(*R);
}
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 (const unsigned *R = TRI->getSubRegisters(I); *R; R++)
regsLive.insert(*R);
}
regsKilled.clear();
regsDefined.clear();
}
void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
const TargetInstrDesc &TI = MI->getDesc();
if (MI->getNumOperands() < TI.getNumOperands()) {
report("Too few operands", MI);
*OS << TI.getNumOperands() << " operands expected, but "
<< MI->getNumExplicitOperands() << " given.\n";
}
// Check the MachineMemOperands for basic consistency.
for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
E = MI->memoperands_end(); I != E; ++I) {
if ((*I)->isLoad() && !TI.mayLoad())
report("Missing mayLoad flag", MI);
if ((*I)->isStore() && !TI.mayStore())
report("Missing mayStore flag", MI);
}
// Debug values must not have a slot index.
// Other instructions must have one.
if (LiveInts) {
bool mapped = !LiveInts->isNotInMIMap(MI);
if (MI->isDebugValue()) {
if (mapped)
report("Debug instruction has a slot index", MI);
} else {
if (!mapped)
report("Missing slot index", MI);
}
}
}
void
MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const TargetInstrDesc &TI = MI->getDesc();
// The first TI.NumDefs operands must be explicit register defines
if (MONum < TI.getNumDefs()) {
if (!MO->isReg())
report("Explicit definition must be a register", MO, MONum);
else if (!MO->isDef())
report("Explicit definition marked as use", MO, MONum);
else if (MO->isImplicit())
report("Explicit definition marked as implicit", MO, MONum);
} else if (MONum < TI.getNumOperands()) {
if (MO->isReg()) {
if (MO->isDef())
report("Explicit operand marked as def", MO, MONum);
if (MO->isImplicit())
report("Explicit operand marked as implicit", MO, MONum);
}
} else {
// ARM adds %reg0 operands to indicate predicates. We'll allow that.
if (MO->isReg() && !MO->isImplicit() && !TI.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;
// Check Live Variables.
if (MO->isUndef()) {
// An <undef> doesn't refer to any register, so just skip it.
} else if (MO->isUse()) {
regsLiveInButUnused.erase(Reg);
bool isKill = false;
unsigned defIdx;
if (MI->isRegTiedToDefOperand(MONum, &defIdx)) {
// A two-addr use counts as a kill if use and def are the same.
unsigned DefReg = MI->getOperand(defIdx).getReg();
if (Reg == DefReg) {
isKill = true;
// And in that case an explicit kill flag is not allowed.
if (MO->isKill())
report("Illegal kill flag on two-address instruction operand",
MO, MONum);
} else if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
report("Two-address instruction operands must be identical",
MO, MONum);
}
} else
isKill = MO->isKill();
if (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 (TargetRegisterInfo::isVirtualRegister(Reg) &&
LiveInts && !LiveInts->isNotInMIMap(MI)) {
SlotIndex UseIdx = LiveInts->getInstructionIndex(MI).getUseIndex();
if (LiveInts->hasInterval(Reg)) {
const LiveInterval &LI = LiveInts->getInterval(Reg);
if (!LI.liveAt(UseIdx)) {
report("No live range at use", MO, MONum);
*OS << UseIdx << " is not live in " << LI << '\n';
}
// Verify isKill == LI.killedAt.
if (!MI->isRegTiedToDefOperand(MONum)) {
bool liKill = LI.killedAt(UseIdx.getDefIndex());
if (isKill && !liKill) {
report("Live range continues after kill flag", MO, MONum);
*OS << "Live range: " << LI << '\n';
}
if (!isKill && liKill) {
report("Live range ends without 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 {
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));
}
}
} else {
assert(MO->isDef());
// Register defined.
// TODO: verify that earlyclobber ops are not used.
if (MO->isDead())
addRegWithSubRegs(regsDead, Reg);
else
addRegWithSubRegs(regsDefined, Reg);
// Check LiveInts for a live range, but only for virtual registers.
if (LiveInts && TargetRegisterInfo::isVirtualRegister(Reg) &&
!LiveInts->isNotInMIMap(MI)) {
SlotIndex DefIdx = LiveInts->getInstructionIndex(MI).getDefIndex();
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);
}
}
}
// Check register classes.
if (MONum < TI.getNumOperands() && !MO->isImplicit()) {
const TargetOperandInfo &TOI = TI.OpInfo[MONum];
unsigned SubIdx = MO->getSubReg();
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
unsigned sr = Reg;
if (SubIdx) {
unsigned s = TRI->getSubReg(Reg, SubIdx);
if (!s) {
report("Invalid subregister index for physical register",
MO, MONum);
return;
}
sr = s;
}
if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
if (!DRC->contains(sr)) {
report("Illegal physical register for instruction", MO, MONum);
*OS << TRI->getName(sr) << " is not a "
<< DRC->getName() << " register.\n";
}
}
} else {
// Virtual register.
const TargetRegisterClass *RC = MRI->getRegClass(Reg);
if (SubIdx) {
const TargetRegisterClass *SRC = RC->getSubRegisterRegClass(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;
}
RC = SRC;
}
if (const TargetRegisterClass *DRC = TOI.getRegClass(TRI)) {
if (RC != DRC && !RC->hasSuperClass(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_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 (TI.mayLoad() && !LI.liveAt(Idx.getUseIndex())) {
report("Instruction loads from dead spill slot", MO, MONum);
*OS << "Live stack: " << LI << '\n';
}
if (TI.mayStore() && !LI.liveAt(Idx.getDefIndex())) {
report("Instruction stores to dead spill slot", MO, MONum);
*OS << "Live stack: " << LI << '\n';
}
}
break;
default:
break;
}
}
void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
BBInfo &MInfo = MBBInfoMap[MI->getParent()];
set_union(MInfo.regsKilled, regsKilled);
set_subtract(regsLive, regsKilled); regsKilled.clear();
set_subtract(regsLive, regsDead); regsDead.clear();
set_union(regsLive, regsDefined); regsDefined.clear();
}
void
MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB) {
MBBInfoMap[MBB].regsLiveOut = regsLive;
regsLive.clear();
}
// 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.
DenseSet<const MachineBasicBlock*> 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.
DenseSet<const MachineBasicBlock*> 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) {
for (MachineBasicBlock::const_iterator BBI = MBB->begin(), BBE = MBB->end();
BBI != BBE && BBI->isPHI(); ++BBI) {
DenseSet<const MachineBasicBlock*> seen;
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
if (LiveVars || LiveInts)
calcRegsRequired();
if (LiveVars)
verifyLiveVariables();
if (LiveInts)
verifyLiveIntervals();
}
void MachineVerifier::verifyLiveVariables() {
assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
for (unsigned Reg = TargetRegisterInfo::FirstVirtualRegister,
RegE = MRI->getLastVirtReg()-1; Reg != RegE; ++Reg) {
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 %reg" << 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 %reg" << Reg
<< " is not needed live through the block.\n";
}
}
}
}
}
void MachineVerifier::verifyLiveIntervals() {
assert(LiveInts && "Don't call verifyLiveIntervals without LiveInts");
for (LiveIntervals::const_iterator LVI = LiveInts->begin(),
LVE = LiveInts->end(); LVI != LVE; ++LVI) {
const LiveInterval &LI = *LVI->second;
// Spilling and splitting may leave unused registers around. Skip them.
if (MRI->use_empty(LI.reg))
continue;
// Physical registers have much weirdness going on, mostly from coalescing.
// We should probably fix it, but for now just ignore them.
if (TargetRegisterInfo::isPhysicalRegister(LI.reg))
continue;
assert(LVI->first == LI.reg && "Invalid reg to interval mapping");
for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
I!=E; ++I) {
VNInfo *VNI = *I;
const VNInfo *DefVNI = LI.getVNInfoAt(VNI->def);
if (!DefVNI) {
if (!VNI->isUnused()) {
report("Valno not live at def and not marked unused", MF);
*OS << "Valno #" << VNI->id << " in " << LI << '\n';
}
continue;
}
if (VNI->isUnused())
continue;
if (DefVNI != VNI) {
report("Live range at def has different valno", MF);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< " where valno #" << DefVNI->id << " is live in " << LI << '\n';
continue;
}
const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(VNI->def);
if (!MBB) {
report("Invalid definition index", MF);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< " in " << LI << '\n';
continue;
}
if (VNI->isPHIDef()) {
if (VNI->def != LiveInts->getMBBStartIdx(MBB)) {
report("PHIDef value is not defined at MBB start", MF);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< ", not at the beginning of BB#" << MBB->getNumber()
<< " in " << LI << '\n';
}
} else {
// Non-PHI def.
if (!VNI->def.isDef()) {
report("Non-PHI def must be at a DEF slot", MF);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< " in " << LI << '\n';
}
const MachineInstr *MI = LiveInts->getInstructionFromIndex(VNI->def);
if (!MI) {
report("No instruction at def index", MF);
*OS << "Valno #" << VNI->id << " is defined at " << VNI->def
<< " in " << LI << '\n';
} else if (!MI->modifiesRegister(LI.reg, TRI)) {
report("Defining instruction does not modify register", MI);
*OS << "Valno #" << VNI->id << " in " << LI << '\n';
}
}
}
for (LiveInterval::const_iterator I = LI.begin(), E = LI.end(); I!=E; ++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);
I->print(*OS);
*OS << " has a valno not in " << LI << '\n';
}
if (VNI->isUnused()) {
report("Live range valno is marked unused", MF);
I->print(*OS);
*OS << " in " << LI << '\n';
}
const MachineBasicBlock *MBB = LiveInts->getMBBFromIndex(I->start);
if (!MBB) {
report("Bad start of live segment, no basic block", MF);
I->print(*OS);
*OS << " in " << LI << '\n';
continue;
}
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);
I->print(*OS);
*OS << " in " << LI << '\n' << "Basic block starts at "
<< MBBStartIdx << '\n';
}
const MachineBasicBlock *EndMBB =
LiveInts->getMBBFromIndex(I->end.getPrevSlot());
if (!EndMBB) {
report("Bad end of live segment, no basic block", MF);
I->print(*OS);
*OS << " in " << LI << '\n';
continue;
}
if (I->end != LiveInts->getMBBEndIdx(EndMBB)) {
// 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);
I->print(*OS);
*OS << " in " << LI << '\n' << "Basic block starts at "
<< MBBStartIdx << '\n';
} else if (TargetRegisterInfo::isVirtualRegister(LI.reg) &&
!MI->readsVirtualRegister(LI.reg)) {
// FIXME: Should we require a kill flag?
report("Instruction killing live segment doesn't read register", MI);
I->print(*OS);
*OS << " in " << LI << '\n';
}
}
// Now check all the basic blocks in this live segment.
MachineFunction::const_iterator MFI = MBB;
// Is LI live-in to MBB and not a PHIDef?
if (I->start == VNI->def) {
// Not live-in to any blocks.
if (MBB == EndMBB)
continue;
// Skip this block.
++MFI;
}
for (;;) {
assert(LiveInts->isLiveInToMBB(LI, MFI));
// We don't know how to track physregs into a landing pad.
if (TargetRegisterInfo::isPhysicalRegister(LI.reg) &&
MFI->isLandingPad()) {
if (&*MFI == EndMBB)
break;
++MFI;
continue;
}
// 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).getPrevSlot();
const VNInfo *PVNI = LI.getVNInfoAt(PEnd);
if (!PVNI) {
report("Register not marked live out of predecessor", *PI);
*OS << "Valno #" << VNI->id << " live into BB#" << MFI->getNumber()
<< '@' << LiveInts->getMBBStartIdx(MFI) << ", not live at "
<< PEnd << " in " << LI << '\n';
} else if (PVNI != VNI) {
report("Different value live out of predecessor", *PI);
*OS << "Valno #" << PVNI->id << " live out of BB#"
<< (*PI)->getNumber() << '@' << PEnd
<< "\nValno #" << VNI->id << " live into BB#" << MFI->getNumber()
<< '@' << LiveInts->getMBBStartIdx(MFI) << " in " << LI << '\n';
}
}
if (&*MFI == EndMBB)
break;
++MFI;
}
}
// 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);
*OS << NumComp << " components in " << LI << '\n';
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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