[PATCH] D113772: [Analysis] Fix getNumberOfParts to return 0 when the answer is unknown

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

> When asking how many parts are required for a scalable vector type there are occasions when it cannot be computed. For example, `<vscale x 1 x i3>` is one such vector for AArch64+SVE because no matter how we promote the `i3` type we never end up with a legal vector.

Not sure I agree with the premise here.  Legalizing to `<vscale x 2 x i64>` should be a viable strategy.  I mean, under most circumstances I wouldn't expect the vectorizer to construct `vscale x 1` vectors, but we've already done a significant amount of work to allow lowering such vectors.


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  https://reviews.llvm.org/D113772/new/

https://reviews.llvm.org/D113772