[llvm] VectorWiden pass to widen aleady vectorized instrctions (PR #67029)

[Dinar Temirbulatov via llvm-commits]

dtemirbulatov wrote:

> Have you looked at doing this in VectorCombine?
Yes, VecotorCombine deals with a limited number of operations and ussually dependent. Still, we want to widen the whole chain of operations independet from each other, from loads to stores, to build something like an SLP tree.


https://github.com/llvm/llvm-project/pull/67029