InstrSet PHIsInCycle;
if (IsSingleValuePHICycle(MI, SingleValReg, PHIsInCycle) &&
SingleValReg != 0) {
- MRI->replaceRegWith(MI->getOperand(0).getReg(), SingleValReg);
+ unsigned OldReg = MI->getOperand(0).getReg();
+ if (!MRI->constrainRegClass(SingleValReg, MRI->getRegClass(OldReg)))
+ continue;
+
+ MRI->replaceRegWith(OldReg, SingleValReg);
MI->eraseFromParent();
++NumPHICycles;
Changed = true;