[llvm] [InstCombine] lshr (mul (X, 2^N + 1)), N -> add (X, lshr(X, N)) (PR #90295)

[via llvm-commits]

AtariDreams wrote:

> A generalization of the proposed x * 3/2 -> x + (x >> 1) transformation.
> 
> 
> 
> Proof: https://alive2.llvm.org/ce/z/u3y_-F

I addressed this and edited the commit. Please see.

https://github.com/llvm/llvm-project/pull/90295