[Bug tree-optimization/84777] -Os inhibits all vectorization

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84777

--- Comment #5 from rguenther at suse dot de <rguenther at suse dot de> ---
On Fri, 9 Mar 2018, linux at carewolf dot com wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84777
> 
> --- Comment #4 from Allan Jensen <linux at carewolf dot com> ---
> I will try the patch. I just tried -fopt-info-vec-missed and the message
> reported for every loop was:
> 
> note: not vectorized: latch block not empty.
> note: bad loop form.

Yeah, that's the effect for while () / for () style loops that haven't
been transformed to do {} while () style by loop header copying.