[PATCH] D37348: Tighten conditions for converting ISD::CTTZ_ZERO_UNDEF to ISD::CTTZ

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added a comment.

I think the instruction behavior is to return -1 on 0 input. IIRC we handle this and fold that for ctlz already, just not cttz.


Repository:
  rL LLVM

https://reviews.llvm.org/D37348