public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/103554] -mavx generates worse code on scalar code
Date: Tue, 07 Dec 2021 02:26:23 +0000	[thread overview]
Message-ID: <bug-103554-4-mhGMINeQYy@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-103554-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103554

--- Comment #8 from Hongtao.liu <crazylht at gmail dot com> ---
> but the x86 backend chooses to not let the vectorizer compare costs with
> different vector sizes but instead asks it to pick the first working
> solution from the vector of modes to consider (and in that order).  We
> might want to reconsider that (maybe at least for BB vectorization and
> maybe with some extra special mode?).

Shouldn't the vectorizer compare costs of different vector factors and choose
the samllest one, or vectorizer already support the corresponding framework,
but the x86 backend doesn't implement the corresponding target_hook?

  parent reply	other threads:[~2021-12-07  2:26 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-04 15:37 [Bug target/103554] New: " avi at scylladb dot com
2021-12-04 22:08 ` [Bug target/103554] " pinskia at gcc dot gnu.org
2021-12-06  8:36 ` rguenth at gcc dot gnu.org
2021-12-06  9:00 ` avi at scylladb dot com
2021-12-06 11:00 ` rguenther at suse dot de
2021-12-06 11:23 ` avi at scylladb dot com
2021-12-06 11:52 ` rguenther at suse dot de
2021-12-06 11:59 ` avi at scylladb dot com
2021-12-07  2:26 ` crazylht at gmail dot com [this message]
2021-12-07  8:36 ` rguenth at gcc dot gnu.org
2021-12-07  9:51 ` crazylht at gmail dot com
2021-12-07 10:28 ` rguenther at suse dot de
2021-12-09  3:07 ` crazylht at gmail dot com

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-103554-4-mhGMINeQYy@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).