- /// findReachingDefs - Assuming that LI is live-in to KillMBB and killed at
- /// Kill, search for values that can reach KillMBB. All blocks that need LI
- /// to be live-in are added to LiveIn. If a unique reaching def is found,
- /// its value is returned, if Kill is jointly dominated by multiple values,
- /// NULL is returned.
- VNInfo *findReachingDefs(LiveInterval *LI,
- MachineBasicBlock *KillMBB,
- SlotIndex Kill);
+ /// Assuming that LI is live-in to KillMBB and killed at Kill, find the set
+ /// of defs that can reach it.
+ ///
+ /// If only one def can reach Kill, all paths from the def to kill are added
+ /// to LI, and the function returns true.
+ ///
+ /// If multiple values can reach Kill, the blocks that need LI to be live in
+ /// are added to the LiveIn array, and the function returns false.
+ ///
+ /// PhysReg, when set, is used to verify live-in lists on basic blocks.
+ bool findReachingDefs(LiveInterval *LI,
+ MachineBasicBlock *KillMBB,
+ SlotIndex Kill,
+ unsigned PhysReg);