#include "llvm/CodeGen/LiveVariables.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/ADT/DenseSet.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
- struct VISIBILITY_HIDDEN MachineVerifier : public MachineFunctionPass {
- static char ID; // Pass ID, replacement for typeid
+ struct MachineVerifier {
- MachineVerifier(bool allowDoubleDefs = false) :
- MachineFunctionPass(&ID),
+ MachineVerifier(Pass *pass, bool allowDoubleDefs) :
+ PASS(pass),
allowVirtDoubleDefs(allowDoubleDefs),
allowPhysDoubleDefs(allowDoubleDefs),
OutFileName(getenv("LLVM_VERIFY_MACHINEINSTRS"))
- {}
-
- void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesAll();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
+ {}
bool runOnMachineFunction(MachineFunction &MF);
+ Pass *const PASS;
const bool allowVirtDoubleDefs;
const bool allowPhysDoubleDefs;
// 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
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);
return Reg < regsReserved.size() && regsReserved.test(Reg);
}
+ // Analysis information if available
+ LiveVariables *LiveVars;
+
void visitMachineFunctionBefore();
void visitMachineBasicBlockBefore(const MachineBasicBlock *MBB);
void visitMachineInstrBefore(const MachineInstr *MI);
void calcMaxRegsPassed();
void calcMinRegsPassed();
void checkPHIOps(const MachineBasicBlock *MBB);
+
+ void calcRegsRequired();
+ void verifyLiveVariables();
};
+
+ struct MachineVerifierPass : public MachineFunctionPass {
+ static char ID; // Pass ID, replacement for typeid
+ bool AllowDoubleDefs;
+
+ explicit MachineVerifierPass(bool allowDoubleDefs = false)
+ : MachineFunctionPass(&ID),
+ AllowDoubleDefs(allowDoubleDefs) {}
+
+ void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+ bool runOnMachineFunction(MachineFunction &MF) {
+ MF.verify(this, AllowDoubleDefs);
+ return false;
+ }
+ };
+
}
-char MachineVerifier::ID = 0;
-static RegisterPass<MachineVerifier>
+char MachineVerifierPass::ID = 0;
+static RegisterPass<MachineVerifierPass>
MachineVer("machineverifier", "Verify generated machine code");
static const PassInfo *const MachineVerifyID = &MachineVer;
FunctionPass *llvm::createMachineVerifierPass(bool allowPhysDoubleDefs) {
- return new MachineVerifier(allowPhysDoubleDefs);
+ return new MachineVerifierPass(allowPhysDoubleDefs);
+}
+
+void MachineFunction::verify(Pass *p, bool allowDoubleDefs) const {
+ MachineVerifier(p, allowDoubleDefs)
+ .runOnMachineFunction(const_cast<MachineFunction&>(*this));
}
bool MachineVerifier::runOnMachineFunction(MachineFunction &MF) {
errs() << "Error opening '" << OutFileName << "': " << ErrorInfo << '\n';
exit(1);
}
-
+
OS = OutFile;
} else {
OS = &errs();
TRI = TM->getRegisterInfo();
MRI = &MF.getRegInfo();
+ if (PASS) {
+ LiveVars = PASS->getAnalysisIfAvailable<LiveVariables>();
+ } else {
+ LiveVars = NULL;
+ }
+
visitMachineFunctionBefore();
for (MachineFunction::const_iterator MFI = MF.begin(), MFE = MF.end();
MFI!=MFE; ++MFI) {
<< "- function: " << MF->getFunction()->getNameStr() << "\n";
}
-void
-MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB)
-{
+void MachineVerifier::report(const char *msg, const MachineBasicBlock *MBB) {
assert(MBB);
report(msg, MBB->getParent());
- *OS << "- basic block: " << MBB->getBasicBlock()->getNameStr()
+ *OS << "- basic block: " << MBB->getName()
<< " " << (void*)MBB
- << " (#" << MBB->getNumber() << ")\n";
+ << " (BB#" << MBB->getNumber() << ")\n";
}
-void
-MachineVerifier::report(const char *msg, const MachineInstr *MI)
-{
+void MachineVerifier::report(const char *msg, const MachineInstr *MI) {
assert(MI);
report(msg, MI->getParent());
*OS << "- instruction: ";
MI->print(*OS, TM);
}
-void
-MachineVerifier::report(const char *msg,
- const MachineOperand *MO, unsigned MONum)
-{
+void MachineVerifier::report(const char *msg,
+ const MachineOperand *MO, unsigned MONum) {
assert(MO);
report(msg, MO->getParent());
*OS << "- operand " << MONum << ": ";
*OS << "\n";
}
-void
-MachineVerifier::markReachable(const MachineBasicBlock *MBB)
-{
+void MachineVerifier::markReachable(const MachineBasicBlock *MBB) {
BBInfo &MInfo = MBBInfoMap[MBB];
if (!MInfo.reachable) {
MInfo.reachable = true;
}
}
-void
-MachineVerifier::visitMachineFunctionBefore()
-{
+void MachineVerifier::visitMachineFunctionBefore() {
regsReserved = TRI->getReservedRegs(*MF);
// A sub-register of a reserved register is also reserved
markReachable(&MF->front());
}
+// Does iterator point to a and b as the first two elements?
+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)
-{
+MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
- // Start with minimal CFG sanity checks.
- MachineFunction::const_iterator MBBI = MBB;
- ++MBBI;
- if (MBBI != MF->end()) {
- // Block is not last in function.
- if (!MBB->isSuccessor(MBBI)) {
- // Block does not fall through.
- if (MBB->empty()) {
- report("MBB doesn't fall through but is empty!", MBB);
- }
- }
- if (TII->BlockHasNoFallThrough(*MBB)) {
- if (MBB->empty()) {
- report("TargetInstrInfo says the block has no fall through, but the "
- "block is empty!", MBB);
- } else if (!MBB->back().getDesc().isBarrier()) {
- report("TargetInstrInfo says the block has no fall through, but the "
- "block does not end in a barrier!", MBB);
- }
- }
- } else {
- // Block is last in function.
- if (MBB->empty()) {
- report("MBB is last in function but is empty!", MBB);
- }
- }
-
// Call AnalyzeBranch. If it succeeds, there several more conditions to check.
MachineBasicBlock *TBB = 0, *FBB = 0;
SmallVector<MachineOperand, 4> Cond;
} if (MBB->succ_size() != 2) {
report("MBB exits via conditional branch/fall-through but doesn't have "
"exactly two CFG successors!", MBB);
- } else if ((MBB->succ_begin()[0] == TBB && MBB->succ_end()[1] == MBBI) ||
- (MBB->succ_begin()[1] == TBB && MBB->succ_end()[0] == MBBI)) {
+ } 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->succ_size() != 2) {
report("MBB exits via conditional branch/branch but doesn't have "
"exactly two CFG successors!", MBB);
- } else if ((MBB->succ_begin()[0] == TBB && MBB->succ_end()[1] == FBB) ||
- (MBB->succ_begin()[1] == TBB && MBB->succ_end()[0] == FBB)) {
+ } 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);
}
regsDefined.clear();
}
-void
-MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI)
-{
+void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
const TargetInstrDesc &TI = MI->getDesc();
- if (MI->getNumExplicitOperands() < TI.getNumOperands()) {
+ if (MI->getNumOperands() < TI.getNumOperands()) {
report("Too few operands", MI);
*OS << TI.getNumOperands() << " operands expected, but "
<< MI->getNumExplicitOperands() << " given.\n";
}
- if (!TI.isVariadic()) {
- if (MI->getNumExplicitOperands() > TI.getNumOperands()) {
- report("Too many 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);
}
}
void
-MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum)
-{
+MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
const MachineInstr *MI = MO->getParent();
const TargetInstrDesc &TI = MI->getDesc();
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()) {
} else if (MO->isUse()) {
regsLiveInButUnused.erase(Reg);
+ bool isKill = false;
if (MO->isKill()) {
- addRegWithSubRegs(regsKilled, Reg);
+ isKill = true;
// Tied operands on two-address instuctions MUST NOT have a <kill> flag.
if (MI->isRegTiedToDefOperand(MONum))
report("Illegal kill flag on two-address instruction operand",
unsigned defIdx;
if (MI->isRegTiedToDefOperand(MONum, &defIdx) &&
MI->getOperand(defIdx).getReg() == Reg)
- addRegWithSubRegs(regsKilled, Reg);
+ isKill = true;
}
+ if (isKill) {
+ addRegWithSubRegs(regsKilled, Reg);
+
+ // Check that LiveVars knows this kill
+ if (LiveVars && TargetRegisterInfo::isVirtualRegister(Reg)) {
+ 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);
+ }
+ }
+
// Use of a dead register.
if (!regsLive.count(Reg)) {
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
}
break;
}
- // Can PHI instrs refer to MBBs not in the CFG? X86 and ARM do.
- // case MachineOperand::MO_MachineBasicBlock:
- // if (MI->getOpcode() == TargetInstrInfo::PHI) {
- // if (!MO->getMBB()->isSuccessor(MI->getParent()))
- // report("PHI operand is not in the CFG", MO, MONum);
- // }
- // break;
+
+ case MachineOperand::MO_MachineBasicBlock:
+ if (MI->getOpcode() == TargetInstrInfo::PHI) {
+ if (!MO->getMBB()->isSuccessor(MI->getParent()))
+ report("PHI operand is not in the CFG", MO, MONum);
+ }
+ break;
+
default:
break;
}
}
-void
-MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI)
-{
+void MachineVerifier::visitMachineInstrAfter(const MachineInstr *MI) {
BBInfo &MInfo = MBBInfoMap[MI->getParent()];
set_union(MInfo.regsKilled, regsKilled);
set_subtract(regsLive, regsKilled);
}
void
-MachineVerifier::visitMachineBasicBlockAfter(const MachineBasicBlock *MBB)
-{
+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::calcMaxRegsPassed()
-{
+void MachineVerifier::calcMaxRegsPassed() {
// First push live-out regs to successors' vregsPassed. Remember the MBBs that
// have any vregsPassed.
DenseSet<const MachineBasicBlock*> todo;
// Calculate the minimum vregsPassed set. These are the registers that always
// pass live through an MBB. The calculation assumes that calcMaxRegsPassed has
// been called earlier.
-void
-MachineVerifier::calcMinRegsPassed()
-{
+void MachineVerifier::calcMinRegsPassed() {
DenseSet<const MachineBasicBlock*> todo;
for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
MFI != MFE; ++MFI)
}
}
+// 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 calcMaxRegsPassed, 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
// calcMinRegsPassed has been run so BBInfo::isLiveOut is valid.
-void
-MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB)
-{
+void MachineVerifier::checkPHIOps(const MachineBasicBlock *MBB) {
for (MachineBasicBlock::const_iterator BBI = MBB->begin(), BBE = MBB->end();
BBI != BBE && BBI->getOpcode() == TargetInstrInfo::PHI; ++BBI) {
DenseSet<const MachineBasicBlock*> seen;
PrE = MBB->pred_end(); PrI != PrE; ++PrI) {
if (!seen.count(*PrI)) {
report("Missing PHI operand", BBI);
- *OS << "MBB #" << (*PrI)->getNumber()
+ *OS << "BB#" << (*PrI)->getNumber()
<< " is a predecessor according to the CFG.\n";
}
}
}
}
-void
-MachineVerifier::visitMachineFunctionAfter()
-{
+void MachineVerifier::visitMachineFunctionAfter() {
calcMaxRegsPassed();
// With the maximal set of vregsPassed we can verify dead-in registers.
report("Live-in physical register is not live-out from predecessor",
MFI);
*OS << "Register " << TRI->getName(*I)
- << " is not live-out from MBB #" << (*PrI)->getNumber()
+ << " is not live-out from BB#" << (*PrI)->getNumber()
<< ".\n";
}
}
}
}
}
+
+ // Now check LiveVariables info if available
+ if (LiveVars) {
+ calcRegsRequired();
+ verifyLiveVariables();
+ }
+}
+
+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";
+ }
+ }
+ }
+ }
}
+
+