[Bug tree-optimization/115152] [13/14/15 Regression] wrong code at -O3 with "-fno-tree-fre -fno-tree-dominator-opts -fno-tree-loop-im" on x86_64-linux-gnu since r13-455

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115152

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #5)
> Ugh, slp creates here V1QImode vectors?  Why?  That can't be ever faster
> than just scalar QImode, no?

We do not reject single-lane vectors iff the target happily supports them.
It definitely would have avoided some bugs if we did - but it's also good
we fix those.