/// its virtual register, and it is guaranteed to be a block-local register.
///
bool RAFast::isLastUseOfLocalReg(MachineOperand &MO) {
- // Check for non-debug uses or defs following MO.
- // This is the most likely way to fail - fast path it.
- MachineOperand *Next = &MO;
- while ((Next = Next->getNextOperandForReg()))
- if (!Next->isDebug())
- return false;
-
// If the register has ever been spilled or reloaded, we conservatively assume
// it is a global register used in multiple blocks.
if (StackSlotForVirtReg[MO.getReg()] != -1)
return false;
// Check that the use/def chain has exactly one operand - MO.
- return &MRI->reg_nodbg_begin(MO.getReg()).getOperand() == &MO;
+ MachineRegisterInfo::reg_nodbg_iterator I = MRI->reg_nodbg_begin(MO.getReg());
+ if (&I.getOperand() != &MO)
+ return false;
+ return ++I == MRI->reg_nodbg_end();
}
/// addKillFlag - Set kill flags on last use of a virtual register.