public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/113609] EQ/NE comparison between avx512 kmask and -1 can be optimized with kxortest with checking CF.
Date: Fri, 26 Jan 2024 07:58:21 +0000	[thread overview]
Message-ID: <bug-113609-4-sJYEto19op@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-113609-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113609

--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Hongtao Liu from comment #1)
> Since they're different modes, CCZ for cmp, but CCS for kortest, it could be
> diffcult to optimize it in RA stage by adding alternatives(like we did for
> compared to 0). So the easy way could be adding peephole to hanlde that.

You can use pre-reload split for this. Please see for example how *jcc_bt<mode>
and *bt<mode>_setcqi provide compound operation (constructed from CCZmode
compare) that is later split to CCCmode operation. You will have to provide jcc
and setcc patterns to fully handle mode change.

  parent reply	other threads:[~2024-01-26  7:58 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-26  3:17 [Bug target/113609] New: " liuhongt at gcc dot gnu.org
2024-01-26  3:37 ` [Bug target/113609] " liuhongt at gcc dot gnu.org
2024-01-26  7:58 ` ubizjak at gmail dot com [this message]
2024-06-03  5:44 ` cvs-commit at gcc dot gnu.org
2024-06-03  6:50 ` liuhongt at gcc dot gnu.org

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-113609-4-sJYEto19op@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).