/// This functions walks the use list of Reg until it finds an Instruction
/// that isn't a COPY returns the register class of that instruction.
/// \return The register defined by the first non-COPY instruction.
const TargetRegisterClass *SIFixSGPRCopies::inferRegClassFromUses(
const SIRegisterInfo *TRI,
const MachineRegisterInfo &MRI,
unsigned Reg,
unsigned SubReg) const {
const TargetRegisterClass *RC
= TargetRegisterInfo::isVirtualRegister(Reg) ?
MRI.getRegClass(Reg) :
TRI->getPhysRegClass(Reg);
RC = TRI->getSubRegClass(RC, SubReg);
for (MachineRegisterInfo::use_instr_iterator
I = MRI.use_instr_begin(Reg), E = MRI.use_instr_end(); I != E; ++I) {
switch (I->getOpcode()) {
case AMDGPU::COPY:
RC = TRI->getCommonSubClass(RC, inferRegClassFromUses(TRI, MRI,
I->getOperand(0).getReg(),
I->getOperand(0).getSubReg()));
break;
}
}
return RC;
}
/// This functions walks the use list of Reg until it finds an Instruction
/// that isn't a COPY returns the register class of that instruction.
/// \return The register defined by the first non-COPY instruction.
const TargetRegisterClass *SIFixSGPRCopies::inferRegClassFromUses(
const SIRegisterInfo *TRI,
const MachineRegisterInfo &MRI,
unsigned Reg,
unsigned SubReg) const {
// The Reg parameter to the function must always be defined by either a PHI
// or a COPY, therefore it cannot be a physical register.
assert(TargetRegisterInfo::isVirtualRegister(Reg) &&
"Reg cannot be a physical register");
const TargetRegisterClass *RC = MRI.getRegClass(Reg);
RC = TRI->getSubRegClass(RC, SubReg);
for (MachineRegisterInfo::use_instr_iterator
I = MRI.use_instr_begin(Reg), E = MRI.use_instr_end(); I != E; ++I) {
switch (I->getOpcode()) {
case AMDGPU::COPY:
RC = TRI->getCommonSubClass(RC, inferRegClassFromUses(TRI, MRI,
I->getOperand(0).getReg(),
I->getOperand(0).getSubReg()));
break;
}
}
return RC;
}