[llvm] [InstCombineCompare] Use known bits to insert assume intrinsics. (PR #96017)

[Mikhail Gudim via llvm-commits]

mgudim wrote:

> This kind of speculative assume introduction usually blocks more optimizations than it enables...

Yes, I've read this in IR reference too. But in theory, do you think this is a right thing to do? Or is there some principle problem with using assume intrinsics that can not be fixed? If you can point out some issue with assume intrinsics I can work on it in another MR.

What if I add a flag to explicitly enable this and have this disabled by default?

https://github.com/llvm/llvm-project/pull/96017