[llvm] [MachineOutliner] Don't outline ADRP pair to avoid incorrect ICF (PR #160232)

[Peter Smith via llvm-commits]

smithp35 wrote:

> Hi. The idea sounds OK to me. Would it be valid to outline so long as we always outlined both instructions (adrp+add, adrp+ldr) together? We fuse the adrp+add so they should generally be scheduled next to one another.

Yes, as long as the adrp+add, adrp+ldr are in the same section, we don't get the problem, as ICF will remove both or none of them. The comment in https://github.com/llvm/llvm-project/issues/129122#issuecomment-2739009435 has a good summary of the chain of events that lead to the problem.


https://github.com/llvm/llvm-project/pull/160232