[llvm] [LAA] Consider unknown SCEVs defined in the loop as IndirectUnsafe. (PR #99239)

[Philip Reames via llvm-commits]

preames wrote:

I'm missing something here.  Why should the index being loop variant prevent us from grouping accesses by underlying objects and proving no-overlap for accesses whose entire access range can't overlap?  Given one access to object A (with a runtime offset), and an object B (which we load that offset from), if A and B can't overlap, why do we need to prevent that vectorization?

Are we maybe failing to perform accurate checking *within* a single object?

https://github.com/llvm/llvm-project/pull/99239