[Bug target/82147] Autovectorization for extraction is slower than done manually

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82147

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
The vectorizer performs interleaving for this kind of loop, your manual one
isn't really vectorized (you only vectorize the load).