[PATCH] D110867: X86InstrInfo: Support immediates that are +1/-1 different in optimizeCompareInstr

Thu Dec 9 08:04:55 PST 2021

lebedev.ri added a comment.

In D110867#3182991 <https://reviews.llvm.org/D110867#3182991>, @bgraur wrote:

> We have root caused to this revision a mis-compile affecting `AMD Rome` machines.
> I have attached a reproducer program that shows the problem when compiled with `-O2` or `-O3`.
>
> Please revert this change until you have a chance to look at the problem.
>
> NOTE: the repro uses the abseil library that can be found at https://github.com/abseil/abseil-cpp.
> The reproducer might probably be reduced more (if needed) but it would be great if you could revert early.
>
> Reproducer: F20964863: repro_git.cc <https://reviews.llvm.org/F20964863>

Please post standalone reproducer, one that does not require guessing versions of external dependecies,
and the actual reproduction steps, as in the actual complete compilation and run command.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110867/new/

https://reviews.llvm.org/D110867