[llvm] [IRBuilder] Fold binary intrinsics (PR #80743)

[Nikita Popov via llvm-commits]

nikic wrote:

> @nikic So the suggestion is to keep the SLPVectorizer code as it is right now and maybe create a separate PR to move SLPVectorizer to TargetFolder instead?

Yes, exactly! (Or move SLPVectorizer to TargetFolder first.)

> Wouldn't you consider it an improvement to extract the existing folding code from SLPVectorizer into IR/ConstantFolder?

No, because it sets a bad precedent. The ConstantFolding / ConstantFold split is already annoying enough as it is, without introducing actual duplication between them.

https://github.com/llvm/llvm-project/pull/80743