[PATCH] D35192: [ARM] Use ADDCARRY / SUBCARRY

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

The DAG scheduler, my least favorite part of SelectionDAG. :(

There's supposed to be code that ensures we don't end up with a schedule like that (by either changing the schedule, or introducing an cross-class copy).  See ScheduleDAGRRList::DelayForLiveRegsBottomUp and ScheduleDAGRRList::PickNodeToScheduleBottomUp.  It's possible there's a bug somewhere in the handling of optional defs, since they're only used on ARM.


Repository:
  rL LLVM

https://reviews.llvm.org/D35192