[PATCH] D17257: New utility class ReachingPhysDefs for post-ra analysis.

[Quentin Colombet via llvm-commits]

qcolombet added a comment.

Hi Jonas,

> Having discussed a bit with Matthias Braun, we thought perhaps adding a check of live-in lists in the MachineVerifier might be a good thing.


100% agree. We had a few bugs recently that all boiled down to live-in lists being incorrect, so checking them is definitely a good idea.

>   Considering Live-in lists however, it seems that only Reg is part of it (not all the aliases).


I have been thinking about this for a related problem https://reviews.llvm.org/D23172, and the proper solution seems to me that we should track the RegUnit.

> How could one check for liveness of a specific reg disregarding its aliases?

>  Must the class add all aliases?


For both those questions the problem is more about what do we do when we remove a live register from the list. Removing the aliases may be difficult (in the sense expensive).

Again, I believe the proper solution would be to switch everything to RegUnit.

Cheers,
-Quentin


https://reviews.llvm.org/D17257