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

[Nikita Popov via llvm-commits]

nikic wrote:

> > > A generalization of the proposed x * 3/2 -> x + (x >> 1) transformation.
> > 
> > 
> > Proposed where?
> 
> This question was not answered. The way this is written implies there was some discussion separate from this PR that proposed something. There should be a link to that proposal or this commit message should be rephrased.

A variant of this PR was originally part of https://github.com/llvm/llvm-project/pull/88193. What was "proposed" is that these unrelated changes be removed from that PR.

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