[PATCH] D147982: Account for PATCHABLE instrs in Branch Relaxation

Tue Apr 11 13:16:21 PDT 2023

paquette added a comment.

In D147982#4258991 <https://reviews.llvm.org/D147982#4258991>, @dhoekwater wrote:

> In D147982#4258836 <https://reviews.llvm.org/D147982#4258836>, @paquette wrote:
>
>> I think it would be good to have a MIR testcase for this.
>
> `branch-relax-xray.ll` tests that Branch Relaxation relaxes branches that are out-of-range because of XRay sleds, and `machine-outliner-patchable.ll` tests that XRay sleds aren't outlined. Why the MIR test case?

Because we can see clearly which MIR opcodes should not be outlined, and it defends us against other optimizer changes in earlier passes. Like, if the MIR test starts failing, we know 100% that it's an outliner issue and not some other pass dropping the X-ray ops or something.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D147982/new/

https://reviews.llvm.org/D147982