const MachineOperand &MO = MI->getOperand(i);
if (!MO.isRegister())
continue;
- if (TRI->isSuperRegister(SubReg, MO.getReg()))
+ if (TRI->isSuperRegister(SubReg, MO.getReg())) {
if (MO.isUse())
SeenSuperUse = true;
else if (MO.isImplicit())
SeenSuperDef = true;
+ }
}
return SeenSuperDef && SeenSuperUse;
}
/// setUsed - Set the register and its sub-registers as being used.
-void RegScavenger::setUsed(unsigned Reg) {
+void RegScavenger::setUsed(unsigned Reg, bool ImpDef) {
RegsAvailable.reset(Reg);
+ ImplicitDefed[Reg] = ImpDef;
for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
- unsigned SubReg = *SubRegs; ++SubRegs)
+ unsigned SubReg = *SubRegs; ++SubRegs) {
RegsAvailable.reset(SubReg);
+ ImplicitDefed[SubReg] = ImpDef;
+ }
}
/// setUnused - Set the register and its sub-registers as being unused.
void RegScavenger::setUnused(unsigned Reg, const MachineInstr *MI) {
RegsAvailable.set(Reg);
+ ImplicitDefed.reset(Reg);
for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
unsigned SubReg = *SubRegs; ++SubRegs)
- if (!RedefinesSuperRegPart(MI, Reg, TRI))
+ if (!RedefinesSuperRegPart(MI, Reg, TRI)) {
RegsAvailable.set(SubReg);
+ ImplicitDefed.reset(SubReg);
+ }
}
void RegScavenger::enterBasicBlock(MachineBasicBlock *mbb) {
- const MachineFunction &MF = *mbb->getParent();
+ MachineFunction &MF = *mbb->getParent();
const TargetMachine &TM = MF.getTarget();
TII = TM.getInstrInfo();
TRI = TM.getRegisterInfo();
if (!MBB) {
NumPhysRegs = TRI->getNumRegs();
RegsAvailable.resize(NumPhysRegs);
+ ImplicitDefed.resize(NumPhysRegs);
// Create reserved registers bitvector.
ReservedRegs = TRI->getReservedRegs(MF);
setUnused(ChangedRegs);
// Process defs.
+ bool IsImpDef = MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (RedefinesSuperRegPart(MI, MO, TRI))
continue;
- // Implicit def is allowed to "re-define" any register.
+ // Implicit def is allowed to "re-define" any register. Similarly,
+ // implicitly defined registers can be clobbered.
assert((isReserved(Reg) || isUnused(Reg) ||
- MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF ||
+ IsImpDef || isImplicitlyDefined(Reg) ||
isLiveInButUnusedBefore(Reg, MI, MBB, TRI, MRI)) &&
"Re-defining a live register!");
- setUsed(Reg);
+ setUsed(Reg, IsImpDef);
}
}