[llvm] [InstCombine] Canonicalize xor with disjoint ops to or disjoint (PR #133139)

[Jeffrey Byrnes via llvm-commits]

jrbyrnes wrote:

> Disjoint is set on or in InstCombineSimplifyDemanded. Move this there with the opcode switch?

Yeah that handling actually already covers the easy `xor` -> `or disjoint` cases

https://godbolt.org/z/5b95qvhqo

So this PR as it is is redundant.

However, we also care about the non easy cases which aren't covered due to the recursion limit

https://godbolt.org/z/Edr4brT1j

My case was accidentally covered since I did CKB on the operands instead of the instruction. I need to investigate how we can canonicalize these complex cases, and will update the PR with that implementation.



https://github.com/llvm/llvm-project/pull/133139