using namespace llvm;
char LiveVariables::ID = 0;
-static RegisterPass<LiveVariables> X("livevars", "Live Variable Analysis");
+INITIALIZE_PASS(LiveVariables, "livevars",
+ "Live Variable Analysis", false, false);
void LiveVariables::getAnalysisUsage(AnalysisUsage &AU) const {
MachineInstr *LastDef = PhysRegDef[Reg];
MachineInstr *LastUse = PhysRegUse[Reg];
if (!LastDef && !LastUse)
- return false;
+ return 0;
MachineInstr *LastRefOrPartRef = LastUse ? LastUse : LastDef;
unsigned LastRefOrPartRefDist = DistanceMap[LastRefOrPartRef];
- MachineInstr *LastPartDef = 0;
unsigned LastPartDefDist = 0;
for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
unsigned SubReg = *SubRegs; ++SubRegs) {
// There was a def of this sub-register in between. This is a partial
// def, keep track of the last one.
unsigned Dist = DistanceMap[Def];
- if (Dist > LastPartDefDist) {
+ if (Dist > LastPartDefDist)
LastPartDefDist = Dist;
- LastPartDef = Def;
- }
- continue;
- }
- if (MachineInstr *Use = PhysRegUse[SubReg]) {
+ } else if (MachineInstr *Use = PhysRegUse[SubReg]) {
unsigned Dist = DistanceMap[Use];
if (Dist > LastRefOrPartRefDist) {
LastRefOrPartRefDist = Dist;
}
}
- if (LastRefOrPartRef == PhysRegDef[Reg] && LastRefOrPartRef != MI) {
- if (LastPartDef)
- // The last partial def kills the register.
- LastPartDef->addOperand(MachineOperand::CreateReg(Reg, false/*IsDef*/,
- true/*IsImp*/, true/*IsKill*/));
- else {
- MachineOperand *MO =
- LastRefOrPartRef->findRegisterDefOperand(Reg, false, TRI);
- bool NeedEC = MO->isEarlyClobber() && MO->getReg() != Reg;
- // If the last reference is the last def, then it's not used at all.
- // That is, unless we are currently processing the last reference itself.
- LastRefOrPartRef->addRegisterDead(Reg, TRI, true);
- if (NeedEC) {
- // If we are adding a subreg def and the superreg def is marked early
- // clobber, add an early clobber marker to the subreg def.
- MO = LastRefOrPartRef->findRegisterDefOperand(Reg);
- if (MO)
- MO->setIsEarlyClobber();
- }
- }
- } else if (!PhysRegUse[Reg]) {
+ if (!PhysRegUse[Reg]) {
// Partial uses. Mark register def dead and add implicit def of
// sub-registers which are used.
// EAX<dead> = op AL<imp-def>
for (const unsigned *SS = TRI->getSubRegisters(SubReg); *SS; ++SS)
PartUses.erase(*SS);
}
+ } else if (LastRefOrPartRef == PhysRegDef[Reg] && LastRefOrPartRef != MI) {
+ if (LastPartDef)
+ // The last partial def kills the register.
+ LastPartDef->addOperand(MachineOperand::CreateReg(Reg, false/*IsDef*/,
+ true/*IsImp*/, true/*IsKill*/));
+ else {
+ MachineOperand *MO =
+ LastRefOrPartRef->findRegisterDefOperand(Reg, false, TRI);
+ bool NeedEC = MO->isEarlyClobber() && MO->getReg() != Reg;
+ // If the last reference is the last def, then it's not used at all.
+ // That is, unless we are currently processing the last reference itself.
+ LastRefOrPartRef->addRegisterDead(Reg, TRI, true);
+ if (NeedEC) {
+ // If we are adding a subreg def and the superreg def is marked early
+ // clobber, add an early clobber marker to the subreg def.
+ MO = LastRefOrPartRef->findRegisterDefOperand(Reg);
+ if (MO)
+ MO->setIsEarlyClobber();
+ }
+ }
} else
LastRefOrPartRef->addRegisterKilled(Reg, TRI, true);
return true;
}
}
-namespace {
- struct RegSorter {
- const TargetRegisterInfo *TRI;
-
- RegSorter(const TargetRegisterInfo *tri) : TRI(tri) { }
- bool operator()(unsigned A, unsigned B) {
- if (TRI->isSubRegister(A, B))
- return true;
- else if (TRI->isSubRegister(B, A))
- return false;
- return A < B;
- }
- };
-}
-
bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
MF = &mf;
MRI = &mf.getRegInfo();
PHIVarInfo = new SmallVector<unsigned, 4>[MF->getNumBlockIDs()];
std::fill(PhysRegDef, PhysRegDef + NumRegs, (MachineInstr*)0);
std::fill(PhysRegUse, PhysRegUse + NumRegs, (MachineInstr*)0);
+ PHIJoins.clear();
/// Get some space for a respectable number of registers.
VirtRegInfo.resize(64);
// Mark live-in registers as live-in.
SmallVector<unsigned, 4> Defs;
- for (MachineBasicBlock::const_livein_iterator II = MBB->livein_begin(),
+ for (MachineBasicBlock::livein_iterator II = MBB->livein_begin(),
EE = MBB->livein_end(); II != EE; ++II) {
assert(TargetRegisterInfo::isPhysicalRegister(*II) &&
"Cannot have a live-in virtual register!");
for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
I != E; ++I) {
MachineInstr *MI = I;
+ if (MI->isDebugValue())
+ continue;
DistanceMap.insert(std::make_pair(MI, Dist++));
// Process all of the operands of the instruction...
// Unless it is a PHI node. In this case, ONLY process the DEF, not any
// of the uses. They will be handled in other basic blocks.
- if (MI->getOpcode() == TargetInstrInfo::PHI)
+ if (MI->isPHI())
NumOperandsToProcess = 1;
+ // Clear kill and dead markers. LV will recompute them.
SmallVector<unsigned, 4> UseRegs;
SmallVector<unsigned, 4> DefRegs;
for (unsigned i = 0; i != NumOperandsToProcess; ++i) {
- const MachineOperand &MO = MI->getOperand(i);
+ MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || MO.getReg() == 0)
continue;
unsigned MOReg = MO.getReg();
- if (MO.isUse())
+ if (MO.isUse()) {
+ MO.setIsKill(false);
UseRegs.push_back(MOReg);
- if (MO.isDef())
+ } else /*MO.isDef()*/ {
+ MO.setIsDead(false);
DefRegs.push_back(MOReg);
+ }
}
// Process all uses.
// Finally, if the last instruction in the block is a return, make sure to
// mark it as using all of the live-out values in the function.
- if (!MBB->empty() && MBB->back().getDesc().isReturn()) {
+ // Things marked both call and return are tail calls; do not do this for
+ // them. The tail callee need not take the same registers as input
+ // that it produces as output, and there are dependencies for its input
+ // registers elsewhere.
+ if (!MBB->empty() && MBB->back().getDesc().isReturn()
+ && !MBB->back().getDesc().isCall()) {
MachineInstr *Ret = &MBB->back();
for (MachineRegisterInfo::liveout_iterator
for (MachineFunction::const_iterator I = Fn.begin(), E = Fn.end();
I != E; ++I)
for (MachineBasicBlock::const_iterator BBI = I->begin(), BBE = I->end();
- BBI != BBE && BBI->getOpcode() == TargetInstrInfo::PHI; ++BBI)
+ BBI != BBE && BBI->isPHI(); ++BBI)
for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
PHIVarInfo[BBI->getOperand(i + 1).getMBB()->getNumber()]
.push_back(BBI->getOperand(i).getReg());
// All registers used by PHI nodes in SuccBB must be live through BB.
for (MachineBasicBlock::const_iterator BBI = SuccBB->begin(),
- BBE = SuccBB->end();
- BBI != BBE && BBI->getOpcode() == TargetInstrInfo::PHI; ++BBI)
+ BBE = SuccBB->end(); BBI != BBE && BBI->isPHI(); ++BBI)
for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
if (BBI->getOperand(i+1).getMBB() == BB)
getVarInfo(BBI->getOperand(i).getReg()).AliveBlocks.set(NumNew);
projects / oota-llvm.git / blobdiff