[llvm] [Loads] Support dereferenceable assumption with variable size. (PR #128436)

[Florian Hahn via llvm-commits]

fhahn wrote:


> Could you pls add a test in `early_exit_legality.ll` to show that the dereferencability and alignment bundles allow early exit vectorization without the need for statically allocated arrays (the existing tests in the patch show why predication wouldn’t be needed). It works as expected when I tried, will be useful just to showcase that additional benefit.

Now that https://github.com/llvm/llvm-project/pull/128061 has landed, the code there also needs to be taught to use info from deref assumptions. I'd prefer to do that separately.

https://github.com/llvm/llvm-project/pull/128436