aboutsummaryrefslogtreecommitdiffstats
path: root/lib/CodeGen/MachineVerifier.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/CodeGen/MachineVerifier.cpp')
-rw-r--r--lib/CodeGen/MachineVerifier.cpp189
1 files changed, 138 insertions, 51 deletions
diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp
index 8ada60a..7351119 100644
--- a/lib/CodeGen/MachineVerifier.cpp
+++ b/lib/CodeGen/MachineVerifier.cpp
@@ -46,14 +46,16 @@ using namespace llvm;
namespace {
struct MachineVerifier {
- MachineVerifier(Pass *pass) :
+ 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;
@@ -72,6 +74,8 @@ namespace {
RegVector regsDefined, regsDead, regsKilled;
RegSet regsLiveInButUnused;
+ SlotIndex lastIndex;
+
// Add Reg and any sub-registers to RV
void addRegWithSubRegs(RegVector &RV, unsigned Reg) {
RV.push_back(Reg);
@@ -196,9 +200,10 @@ namespace {
struct MachineVerifierPass : public MachineFunctionPass {
static char ID; // Pass ID, replacement for typeid
+ const char *const Banner;
- MachineVerifierPass()
- : MachineFunctionPass(ID) {
+ MachineVerifierPass(const char *b = 0)
+ : MachineFunctionPass(ID), Banner(b) {
initializeMachineVerifierPassPass(*PassRegistry::getPassRegistry());
}
@@ -208,7 +213,7 @@ namespace {
}
bool runOnMachineFunction(MachineFunction &MF) {
- MF.verify(this);
+ MF.verify(this, Banner);
return false;
}
};
@@ -219,12 +224,13 @@ char MachineVerifierPass::ID = 0;
INITIALIZE_PASS(MachineVerifierPass, "machineverifier",
"Verify generated machine code", false, false)
-FunctionPass *llvm::createMachineVerifierPass() {
- return new MachineVerifierPass();
+FunctionPass *llvm::createMachineVerifierPass(const char *Banner) {
+ return new MachineVerifierPass(Banner);
}
-void MachineFunction::verify(Pass *p) const {
- MachineVerifier(p).runOnMachineFunction(const_cast<MachineFunction&>(*this));
+void MachineFunction::verify(Pass *p, const char *Banner) const {
+ MachineVerifier(p, Banner)
+ .runOnMachineFunction(const_cast<MachineFunction&>(*this));
}
bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
@@ -269,6 +275,11 @@ bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
visitMachineBasicBlockBefore(MFI);
for (MachineBasicBlock::const_iterator MBBI = MFI->begin(),
MBBE = MFI->end(); MBBI != MBBE; ++MBBI) {
+ if (MBBI->getParent() != MFI) {
+ report("Bad instruction parent pointer", MFI);
+ *OS << "Instruction: " << *MBBI;
+ continue;
+ }
visitMachineInstrBefore(MBBI);
for (unsigned I = 0, E = MBBI->getNumOperands(); I != E; ++I)
visitMachineOperand(&MBBI->getOperand(I), I);
@@ -297,8 +308,11 @@ bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
void MachineVerifier::report(const char *msg, const MachineFunction *MF) {
assert(MF);
*OS << '\n';
- if (!foundErrors++)
+ if (!foundErrors++) {
+ if (Banner)
+ *OS << "# " << Banner << '\n';
MF->print(*OS, Indexes);
+ }
*OS << "*** Bad machine code: " << msg << " ***\n"
<< "- function: " << MF->getFunction()->getNameStr() << "\n";
}
@@ -344,6 +358,7 @@ void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
}
void MachineVerifier::visitMachineFunctionBefore() {
+ lastIndex = SlotIndex();
regsReserved = TRI->getReservedRegs(*MF);
// A sub-register of a reserved register is also reserved
@@ -373,11 +388,13 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
// Count the number of landing pad successors.
- unsigned LandingPadSuccs = 0;
+ SmallPtrSet<MachineBasicBlock*, 4> LandingPadSuccs;
for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
- E = MBB->succ_end(); I != E; ++I)
- LandingPadSuccs += (*I)->isLandingPad();
- if (LandingPadSuccs > 1)
+ E = MBB->succ_end(); I != E; ++I) {
+ if ((*I)->isLandingPad())
+ LandingPadSuccs.insert(*I);
+ }
+ if (LandingPadSuccs.size() > 1)
report("MBB has more than one landing pad successor", MBB);
// Call AnalyzeBranch. If it succeeds, there several more conditions to check.
@@ -395,11 +412,11 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
// 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) {
+ } 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) {
+ } 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)) {
@@ -417,7 +434,7 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
}
} else if (TBB && !FBB && Cond.empty()) {
// Block unconditionally branches somewhere.
- if (MBB->succ_size() != 1+LandingPadSuccs) {
+ 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)) {
@@ -510,6 +527,9 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
regsKilled.clear();
regsDefined.clear();
+
+ if (Indexes)
+ lastIndex = Indexes->getMBBStartIdx(MBB);
}
void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
@@ -548,6 +568,7 @@ void
MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const TargetInstrDesc &TI = MI->getDesc();
+ const TargetOperandInfo &TOI = TI.OpInfo[MONum];
// The first TI.NumDefs operands must be explicit register defines
if (MONum < TI.getNumDefs()) {
@@ -558,9 +579,11 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned 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);
+ // 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() && !(TI.isVariadic() && MONum == TI.getNumOperands()-1)) {
+ if (MO->isDef() && !TOI.isOptionalDef())
+ report("Explicit operand marked as def", MO, MONum);
if (MO->isImplicit())
report("Explicit operand marked as implicit", MO, MONum);
}
@@ -577,7 +600,9 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
return;
// Check Live Variables.
- if (MO->isUndef()) {
+ if (MI->isDebugValue()) {
+ // Liveness checks are not valid for debug values.
+ } else if (MO->isUndef()) {
// An <undef> doesn't refer to any register, so just skip it.
} else if (MO->isUse()) {
regsLiveInButUnused.erase(Reg);
@@ -622,19 +647,11 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
report("No live range at use", MO, MONum);
*OS << UseIdx << " is not live in " << LI << '\n';
}
- // Verify isKill == LI.killedAt.
- if (!MI->isRegTiedToDefOperand(MONum)) {
- // MI could kill register without a kill flag on MO.
- bool miKill = MI->killsRegister(Reg);
- bool liKill = LI.killedAt(UseIdx.getDefIndex());
- if (miKill && !liKill) {
- report("Live range continues after kill flag", MO, MONum);
- *OS << "Live range: " << LI << '\n';
- }
- if (!miKill && liKill) {
- report("Live range ends without kill flag", MO, MONum);
- *OS << "Live range: " << LI << '\n';
- }
+ // Check for extra kill flags.
+ // Note that we allow missing kill flags for now.
+ if (MO->isKill() && !LI.killedAt(UseIdx.getDefIndex())) {
+ report("Live range continues after kill flag", MO, MONum);
+ *OS << "Live range: " << LI << '\n';
}
} else {
report("Virtual register has no Live interval", MO, MONum);
@@ -675,7 +692,7 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const LiveInterval &LI = LiveInts->getInterval(Reg);
if (const VNInfo *VNI = LI.getVNInfoAt(DefIdx)) {
assert(VNI && "NULL valno is not allowed");
- if (VNI->def != DefIdx) {
+ if (VNI->def != DefIdx && !MO->isEarlyClobber()) {
report("Inconsistent valno->def", MO, MONum);
*OS << "Valno " << VNI->id << " is not defined at "
<< DefIdx << " in " << LI << '\n';
@@ -692,7 +709,6 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
// Check register classes.
if (MONum < TI.getNumOperands() && !MO->isImplicit()) {
- const TargetOperandInfo &TOI = TI.OpInfo[MONum];
unsigned SubIdx = MO->getSubReg();
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
@@ -770,12 +786,31 @@ void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
set_subtract(regsLive, regsKilled); regsKilled.clear();
set_subtract(regsLive, regsDead); regsDead.clear();
set_union(regsLive, regsDefined); regsDefined.clear();
+
+ 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;
+ }
}
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
@@ -907,8 +942,8 @@ void MachineVerifier::visitMachineFunctionAfter() {
void MachineVerifier::verifyLiveVariables() {
assert(LiveVars && "Don't call verifyLiveVariables without LiveVars");
- for (unsigned Reg = TargetRegisterInfo::FirstVirtualRegister,
- RegE = MRI->getLastVirtReg()-1; Reg != RegE; ++Reg) {
+ 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) {
@@ -918,13 +953,13 @@ void MachineVerifier::verifyLiveVariables() {
if (MInfo.vregsRequired.count(Reg)) {
if (!VI.AliveBlocks.test(MFI->getNumber())) {
report("LiveVariables: Block missing from AliveBlocks", MFI);
- *OS << "Virtual register %reg" << Reg
+ *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 %reg" << Reg
+ *OS << "Virtual register " << PrintReg(Reg)
<< " is not needed live through the block.\n";
}
}
@@ -989,11 +1024,6 @@ void MachineVerifier::verifyLiveIntervals() {
}
} 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);
@@ -1003,6 +1033,32 @@ void MachineVerifier::verifyLiveIntervals() {
report("Defining instruction does not modify register", MI);
*OS << "Valno #" << VNI->id << " in " << LI << '\n';
}
+
+ bool isEarlyClobber = false;
+ if (MI) {
+ for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
+ MOE = MI->operands_end(); MOI != MOE; ++MOI) {
+ if (MOI->isReg() && MOI->getReg() == LI.reg && MOI->isDef() &&
+ MOI->isEarlyClobber()) {
+ isEarlyClobber = true;
+ break;
+ }
+ }
+ }
+
+ // Early clobber defs begin at USE slots, but other defs must begin at
+ // DEF slots.
+ if (isEarlyClobber) {
+ if (!VNI->def.isUse()) {
+ report("Early clobber def must be at a USE slot", MF);
+ *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
+ << " in " << LI << '\n';
+ }
+ } else if (!VNI->def.isDef()) {
+ report("Non-PHI, non-early clobber def must be at a DEF slot", MF);
+ *OS << "Valno #" << VNI->id << " is defined at " << VNI->def
+ << " in " << LI << '\n';
+ }
}
}
@@ -1056,17 +1112,31 @@ void MachineVerifier::verifyLiveIntervals() {
<< 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';
+ // A live range can end with either a redefinition, a kill flag on a
+ // use, or a dead flag on a def.
+ // FIXME: Should we check for each of these?
+ bool hasDeadDef = false;
+ for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
+ MOE = MI->operands_end(); MOI != MOE; ++MOI) {
+ if (MOI->isReg() && MOI->getReg() == LI.reg && MOI->isDef() && MOI->isDead()) {
+ hasDeadDef = true;
+ break;
+ }
+ }
+
+ if (!hasDeadDef) {
+ report("Instruction killing live segment neither defines nor reads "
+ "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) {
+ // 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)
continue;
@@ -1088,12 +1158,29 @@ void MachineVerifier::verifyLiveIntervals() {
PE = MFI->pred_end(); PI != PE; ++PI) {
SlotIndex PEnd = LiveInts->getMBBEndIdx(*PI).getPrevSlot();
const VNInfo *PVNI = LI.getVNInfoAt(PEnd);
+
+ if (VNI->isPHIDef() && VNI->def == LiveInts->getMBBStartIdx(MFI)) {
+ if (PVNI && !PVNI->hasPHIKill()) {
+ report("Value live out of predecessor doesn't have PHIKill", MF);
+ *OS << "Valno #" << PVNI->id << " live out of BB#"
+ << (*PI)->getNumber() << '@' << PEnd
+ << " doesn't have PHIKill, but Valno #" << VNI->id
+ << " is PHIDef and defined at the beginning of BB#"
+ << MFI->getNumber() << '@' << LiveInts->getMBBStartIdx(MFI)
+ << " in " << LI << '\n';
+ }
+ continue;
+ }
+
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) {
+ continue;
+ }
+
+ if (PVNI != VNI) {
report("Different value live out of predecessor", *PI);
*OS << "Valno #" << PVNI->id << " live out of BB#"
<< (*PI)->getNumber() << '@' << PEnd
generated by cgit v1.1 at 2025-07-04 20:29:03 +0000