Re: Enable the vectorizer at -O2 for GCC 12

[Bill Schmidt via Gcc]

On 8/30/21 8:04 AM, Florian Weimer wrote:
There has been a discussion, both off-list and on the gcc-help mailing
list (“Why vectorization didn't turn on by -O2”, spread across several
months), about enabling the auto-vectorizer at -O2, similar to what
Clang does.
I think the review concluded that the very cheap cost model should be
used for that.

Are there any remaining blockers?

Hi Florian,

I don't think I'd characterize it as having blockers, but we are 
continuing to investigate small performance issues that arise with 
very-cheap, including some things that regressed in GCC 12.  Kewen Lin 
is leading that effort.  Kewen, do you feel we have any major remaining 
concerns with this plan?

Thanks,
Bill


Thanks,
Florian