/// getGlobalBaseReg - Return a virtual register initialized with the
/// the global base register value. Output instructions required to
/// initialize the register in the function entry block, if necessary.
///
unsigned MipsInstrInfo::getGlobalBaseReg(MachineFunction *MF) const {
MipsFunctionInfo *MipsFI = MF->getInfo<MipsFunctionInfo>();
unsigned GlobalBaseReg = MipsFI->getGlobalBaseReg();
if (GlobalBaseReg != 0)
return GlobalBaseReg;
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
MachineRegisterInfo &RegInfo = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
GlobalBaseReg = RegInfo.createVirtualRegister(Mips::CPURegsRegisterClass);
BuildMI(FirstMBB, MBBI, DebugLoc(), TII->get(TargetOpcode::COPY),
GlobalBaseReg).addReg(Mips::GP);
RegInfo.addLiveIn(Mips::GP);
MipsFI->setGlobalBaseReg(GlobalBaseReg);
return GlobalBaseReg;
}
/// getGlobalBaseReg - Return a virtual register initialized with the
/// the global base register value. Output instructions required to
/// initialize the register in the function entry block, if necessary.
///
unsigned MipsInstrInfo::getGlobalBaseReg(MachineFunction *MF) const {
MipsFunctionInfo *MipsFI = MF->getInfo<MipsFunctionInfo>();
unsigned GlobalBaseReg = MipsFI->getGlobalBaseReg();
if (GlobalBaseReg != 0)
return GlobalBaseReg;
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
MachineRegisterInfo &RegInfo = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
GlobalBaseReg = RegInfo.createVirtualRegister(Mips::CPURegsRegisterClass);
bool Ok = TII->copyRegToReg(FirstMBB, MBBI, GlobalBaseReg, Mips::GP,
Mips::CPURegsRegisterClass,
Mips::CPURegsRegisterClass);
assert(Ok && "Couldn't assign to global base register!");
Ok = Ok; // Silence warning when assertions are turned off.
RegInfo.addLiveIn(Mips::GP);
MipsFI->setGlobalBaseReg(GlobalBaseReg);
return GlobalBaseReg;
}
