+/// RemoveDeadDef - If a def of a live interval is now determined dead, remove
+/// the val# it defines. If the live interval becomes empty, remove it as well.
+bool SimpleRegisterCoalescing::RemoveDeadDef(LiveInterval &li,
+ MachineInstr *DefMI) {
+ unsigned DefIdx = li_->getDefIndex(li_->getInstructionIndex(DefMI));
+ LiveInterval::iterator MLR = li.FindLiveRangeContaining(DefIdx);
+ if (DefIdx != MLR->valno->def)
+ return false;
+ li.removeValNo(MLR->valno);
+ return removeIntervalIfEmpty(li, li_, tri_);
+}
+