[llvm] [DAG] Fold nested add(add(reduce(a), b), add(reduce(c), d)) (PR #115150)

[David Sherwood via llvm-commits]

https://github.com/david-arm commented:

The codegen changes look good! Do you have any examples where this type of pattern comes up? I had a few other minor comments.

https://github.com/llvm/llvm-project/pull/115150