[llvm] [DAG] select (sext m), (add X, C), X --> (add X, (and C, (sext m)))) (PR #83640)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

@elhewaty Thank you, I'm trying to tag more "good first issue" tickets and include some likely steps for each - please keep looking if you're interested.

https://github.com/llvm/llvm-project/pull/83640