[Bug target/106022] [12/13 Regression] Enable vectorizer generates extra load

["rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106022

--- Comment #15 from rguenther at suse dot de <rguenther at suse dot de> ---
On Mon, 27 Jun 2022, hjl.tools at gmail dot com wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106022
> 
> --- Comment #14 from H.J. Lu <hjl.tools at gmail dot com> ---
> (In reply to rguenther@suse.de from comment #13)
> > On Fri, 24 Jun 2022, hjl.tools at gmail dot com wrote:
> > 
> > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106022
> > > 
> > > --- Comment #12 from H.J. Lu <hjl.tools at gmail dot com> ---
> > > (In reply to Richard Biener from comment #11)
> > > > No, I think you would need to pattern match an actual store sequence,
> > > > for example by looking at
> > > > 
> > > >  if (STMT_VINFO_GROUPED_ACCESS (stmt_info)
> > > >      && pow2p_hwi (DR_GROUP_STORE_COUNT (stmt_info)))
> > > >    /* cost a possibly merged store only once (but with larger mode?) */
> > > >    if (DR_GROUP_FIRST_ELEMENT (stmt_info) == stmt_info)
> > > >      ...
> > > 
> > > The information aren't available in add_stmt_cost.
> > 
> > They should be ...
> 
> I meant that DR_GROUP_STORE_COUNT (stmt_info) was zero.

Ah, OK - use DR_GROUP_SIZE then.