[llvm] [LV] Enable auto-vectorisation of loops with uncountable exits (PR #133099)

[David Sherwood via llvm-commits]

david-arm wrote:

Hi @bgra8, so there is a known issue with forcing vector interleaving with `-mllvm -force-vector-interleave=2`. @fhahn has been working on trying to add support for interleaving with early exit loops. It is currently disabled if you attempt to vectorise normally or using the C level pragma, but you can still force it with `-force-vector-interleave`.

If I remove the `-force-vector-interleave=2` argument it builds fine. I'll create a patch to disable the use of `-force-vector-interleave` with early exit loops for now and we can continue working on it after the release branch point.

https://github.com/llvm/llvm-project/pull/133099