[PATCH] D150923: [KnownBits] Factor out and improve the lowbit computation for {u,s}div

[NAKAMURA Takumi via Phabricator via llvm-commits]

chapuni added a comment.

@goldstein.w.n
I am sorry. As far as I have been investigating, this is not the cause but 1st commit to trigger. The failure was hidden when I added debug codes, heisenbug.
The failure can be seen in my internal builders.

The failure is;

- Observable for targeting aarch64. PerfReader.cpp sometimes differs.
- I have not seen for targeting x86-64.
- I have seen for targeting aarch64, on aarch64-linux and cross on x86_64-linux.
  - Differs between aarh64-host and x86_64-host (for targeting aarch64)
  - Differs between stage2 and stage3 on aarch64-linux.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D150923/new/

https://reviews.llvm.org/D150923