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Diffstat (limited to 'lib/CodeGen/LiveVariables.cpp')
-rw-r--r--lib/CodeGen/LiveVariables.cpp169
1 files changed, 132 insertions, 37 deletions
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 0e0fecedf5..310b53a757 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -77,7 +77,10 @@ bool LiveVariables::KillsRegister(MachineInstr *MI, unsigned Reg) const {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && MO.isKill()) {
- if (RegInfo->regsOverlap(Reg, MO.getReg()))
+ if ((MO.getReg() == Reg) ||
+ (MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
+ MRegisterInfo::isPhysicalRegister(Reg) &&
+ RegInfo->isSubRegister(MO.getReg(), Reg)))
return true;
}
}
@@ -87,9 +90,13 @@ bool LiveVariables::KillsRegister(MachineInstr *MI, unsigned Reg) const {
bool LiveVariables::RegisterDefIsDead(MachineInstr *MI, unsigned Reg) const {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
- if (MO.isReg() && MO.isDead())
- if (RegInfo->regsOverlap(Reg, MO.getReg()))
+ if (MO.isReg() && MO.isDead()) {
+ if ((MO.getReg() == Reg) ||
+ (MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
+ MRegisterInfo::isPhysicalRegister(Reg) &&
+ RegInfo->isSubRegister(MO.getReg(), Reg)))
return true;
+ }
}
return false;
}
@@ -97,10 +104,8 @@ bool LiveVariables::RegisterDefIsDead(MachineInstr *MI, unsigned Reg) const {
bool LiveVariables::ModifiesRegister(MachineInstr *MI, unsigned Reg) const {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
- if (MO.isReg() && MO.isDef()) {
- if (RegInfo->regsOverlap(Reg, MO.getReg()))
- return true;
- }
+ if (MO.isReg() && MO.isDef() && MO.getReg() == Reg)
+ return true;
}
return false;
}
@@ -166,57 +171,145 @@ void LiveVariables::HandleVirtRegUse(VarInfo &VRInfo, MachineBasicBlock *MBB,
}
void LiveVariables::addRegisterKilled(unsigned IncomingReg, MachineInstr *MI) {
+ bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
- if (MO.isReg() && MO.isUse() && MO.getReg() == IncomingReg) {
- MO.setIsKill();
- break;
+ if (MO.isReg() && MO.isUse()) {
+ unsigned Reg = MO.getReg();
+ if (!Reg)
+ continue;
+ if (Reg == IncomingReg) {
+ MO.setIsKill();
+ Found = true;
+ break;
+ } else if (MRegisterInfo::isPhysicalRegister(Reg) &&
+ MRegisterInfo::isPhysicalRegister(IncomingReg) &&
+ RegInfo->isSuperRegister(IncomingReg, Reg) &&
+ MO.isKill())
+ // A super-register kill already exists.
+ return;
}
}
+
+ // If not found, this means an alias of one of the operand is killed. Add a
+ // new implicit operand.
+ if (!Found)
+ MI->addRegOperand(IncomingReg, false/*IsDef*/,true/*IsImp*/,true/*IsKill*/);
}
void LiveVariables::addRegisterDead(unsigned IncomingReg, MachineInstr *MI) {
+ bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
- if (MO.isReg() && MO.isDef() && MO.getReg() == IncomingReg) {
- MO.setIsDead();
- break;
+ if (MO.isReg() && MO.isDef()) {
+ unsigned Reg = MO.getReg();
+ if (!Reg)
+ continue;
+ if (Reg == IncomingReg) {
+ MO.setIsDead();
+ Found = true;
+ break;
+ } else if (MRegisterInfo::isPhysicalRegister(Reg) &&
+ MRegisterInfo::isPhysicalRegister(IncomingReg) &&
+ RegInfo->isSuperRegister(IncomingReg, Reg) &&
+ MO.isDead())
+ // There exists a super-register that's marked dead.
+ return;
}
}
+
+ // If not found, this means an alias of one of the operand is dead. Add a
+ // new implicit operand.
+ if (!Found)
+ MI->addRegOperand(IncomingReg, true/*IsDef*/,true/*IsImp*/,false/*IsKill*/,
+ true/*IsDead*/);
}
void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) {
+ // There is a now a proper use, forget about the last partial use.
+ PhysRegPartUse[Reg] = NULL;
+
+ // Turn previous partial def's into read/mod/write.
+ for (unsigned i = 0, e = PhysRegPartDef[Reg].size(); i != e; ++i) {
+ MachineInstr *Def = PhysRegPartDef[Reg][i];
+ // First one is just a def. This means the use is reading some undef bits.
+ if (i != 0)
+ Def->addRegOperand(Reg, false/*IsDef*/,true/*IsImp*/,true/*IsKill*/);
+ Def->addRegOperand(Reg, true/*IsDef*/,true/*IsImp*/);
+ }
+ PhysRegPartDef[Reg].clear();
+
+ // There was an earlier def of a super-register. Add implicit def to that MI.
+ // A: EAX = ...
+ // B: = AX
+ // Add implicit def to A.
+ if (PhysRegInfo[Reg] && !PhysRegUsed[Reg]) {
+ MachineInstr *Def = PhysRegInfo[Reg];
+ if (!Def->findRegisterDefOperand(Reg))
+ Def->addRegOperand(Reg, true/*IsDef*/,true/*IsImp*/);
+ }
+
PhysRegInfo[Reg] = MI;
PhysRegUsed[Reg] = true;
- for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
- unsigned Alias = *AliasSet; ++AliasSet) {
- PhysRegInfo[Alias] = MI;
- PhysRegUsed[Alias] = true;
+ for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg);
+ unsigned SubReg = *SubRegs; ++SubRegs) {
+ PhysRegInfo[SubReg] = MI;
+ PhysRegUsed[SubReg] = true;
}
+
+ // Remember the partial uses.
+ for (const unsigned *SuperRegs = RegInfo->getSuperRegisters(Reg);
+ unsigned SuperReg = *SuperRegs; ++SuperRegs)
+ PhysRegPartUse[SuperReg] = MI;
}
void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI) {
// Does this kill a previous version of this register?
- if (MachineInstr *LastUse = PhysRegInfo[Reg]) {
+ if (MachineInstr *LastRef = PhysRegInfo[Reg]) {
if (PhysRegUsed[Reg])
- addRegisterKilled(Reg, LastUse);
+ addRegisterKilled(Reg, LastRef);
+ else if (PhysRegPartUse[Reg])
+ // Add implicit use / kill to last use of a sub-register.
+ addRegisterKilled(Reg, PhysRegPartUse[Reg]);
else
- addRegisterDead(Reg, LastUse);
+ addRegisterDead(Reg, LastRef);
}
PhysRegInfo[Reg] = MI;
PhysRegUsed[Reg] = false;
-
- for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
- unsigned Alias = *AliasSet; ++AliasSet) {
- if (MachineInstr *LastUse = PhysRegInfo[Alias]) {
- if (PhysRegUsed[Alias])
- addRegisterKilled(Alias, LastUse);
+ PhysRegPartUse[Reg] = NULL;
+
+ for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg);
+ unsigned SubReg = *SubRegs; ++SubRegs) {
+ if (MachineInstr *LastRef = PhysRegInfo[SubReg]) {
+ if (PhysRegUsed[SubReg])
+ addRegisterKilled(SubReg, LastRef);
+ else if (PhysRegPartUse[SubReg])
+ // Add implicit use / kill to last use of a sub-register.
+ addRegisterKilled(SubReg, PhysRegPartUse[SubReg]);
else
- addRegisterDead(Alias, LastUse);
+ addRegisterDead(SubReg, LastRef);
}
- PhysRegInfo[Alias] = MI;
- PhysRegUsed[Alias] = false;
+ PhysRegInfo[SubReg] = MI;
+ PhysRegUsed[SubReg] = false;
+ }
+
+ if (MI)
+ for (const unsigned *SuperRegs = RegInfo->getSuperRegisters(Reg);
+ unsigned SuperReg = *SuperRegs; ++SuperRegs) {
+ if (PhysRegInfo[SuperReg]) {
+ // The larger register is previously defined. Now a smaller part is
+ // being re-defined. Treat it as read/mod/write.
+ // EAX =
+ // AX = EAX<imp-use,kill>, EAX<imp-def>
+ MI->addRegOperand(SuperReg, false/*IsDef*/,true/*IsImp*/,true/*IsKill*/);
+ MI->addRegOperand(SuperReg, true/*IsDef*/,true/*IsImp*/);
+ PhysRegInfo[SuperReg] = MI;
+ PhysRegUsed[SuperReg] = false;
+ } else {
+ // Remember this partial def.
+ PhysRegPartDef[SuperReg].push_back(MI);
+ }
}
}
@@ -228,14 +321,10 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
ReservedRegisters = RegInfo->getReservedRegs(mf);
- // PhysRegInfo - Keep track of which instruction was the last use of a
- // physical register. This is a purely local property, because all physical
- // register references as presumed dead across basic blocks.
- //
- PhysRegInfo = (MachineInstr**)alloca(sizeof(MachineInstr*) *
- RegInfo->getNumRegs());
- PhysRegUsed = (bool*)alloca(sizeof(bool)*RegInfo->getNumRegs());
- std::fill(PhysRegInfo, PhysRegInfo+RegInfo->getNumRegs(), (MachineInstr*)0);
+ PhysRegInfo.resize(RegInfo->getNumRegs(), (MachineInstr*)NULL);
+ PhysRegUsed.resize(RegInfo->getNumRegs());
+ PhysRegPartDef.resize(RegInfo->getNumRegs());
+ PhysRegPartUse.resize(RegInfo->getNumRegs(), (MachineInstr*)NULL);
/// Get some space for a respectable number of registers...
VirtRegInfo.resize(64);
@@ -342,6 +431,12 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
for (unsigned i = 0, e = RegInfo->getNumRegs(); i != e; ++i)
if (PhysRegInfo[i])
HandlePhysRegDef(i, 0);
+
+ // Clear some states between BB's. These are purely local information.
+ for (unsigned i = 0, e = RegInfo->getNumRegs(); i != e; ++i) {
+ PhysRegPartDef[i].clear();
+ PhysRegPartUse[i] = NULL;
+ }
}
// Convert and transfer the dead / killed information we have gathered into
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-04-30 09:58:49 +0000