[llvm] [X86][SimplifyCFG] Support hoisting load/store with conditional faulting (PR #96878)

[via llvm-commits]

DianQK wrote:

> > 1. run these three transforms of SimplifyCFG rightly before CodeGenPrepare if the target supports conditional faulting, to avoid the awkwardness?
> > 2. extend LLVM IR to support scalar versioned masked.load/store.
> > 3. enhance the support for masked loads/stores for 1x %T throughout the middle-end passes after SimplifyCFG
> > 
> > dtcxzyw: I prefer the second one.
> 
> @nikic @DianQK Vote?

Sorry, I don't really have any good suggestions. :) But from the discussion above, it looks like we still have a lot of work to do. I would suggest going with the first one, and then gradually working through the second one and the various mis-compilations. At least that seems smoother?

https://github.com/llvm/llvm-project/pull/96878