[PATCH] D81632: Fix undefined behavior in PeepholeOptimizer.

[Bill Wendling via Phabricator via llvm-commits]

void added a comment.

I think SubIdx is supposed to be set by `TII->isCoalescableExtInstr()`. If it's not doing that, then the error's probably in that call and not in this function.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D81632/new/

https://reviews.llvm.org/D81632