public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "law at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/100934] [9/10/11/12 Regression] wrong code at -O3 during unrolling since r9-6299
Date: Mon, 14 Jun 2021 02:48:27 +0000	[thread overview]
Message-ID: <bug-100934-4-bsSf9o1WZS@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-100934-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100934

--- Comment #7 from Jeffrey A. Law <law at gcc dot gnu.org> ---
So when we're finding jump threads we know if we thread through the loop latch
and we note when that's going to create an irreducible region.   We generally
suppress threading through the latch before the loop optimizers have run, but
allow it afterwards.

But I'm not aware of a really good place to adjust the loop bound estimates,
particularly for the backwards threader.  THe backwards threader uses copy_bbs
API, so much of the guts of what's happening is opaque.

Peek at jump_thread_path_registry:::duplicate_thread_path.  All the backwards
threader bits go through there at some point.

  parent reply	other threads:[~2021-06-14  2:48 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-06 20:49 [Bug tree-optimization/100934] New: wrong code at -O3 on x86_64-linux-gnu zhendong.su at inf dot ethz.ch
2021-06-06 21:07 ` [Bug tree-optimization/100934] [9/10/11/12 Regression] wrong code at -O3 during unrolling pinskia at gcc dot gnu.org
2021-06-07  8:38 ` [Bug tree-optimization/100934] [9/10/11/12 Regression] wrong code at -O3 during unrolling since r9-6299 jakub at gcc dot gnu.org
2021-06-07  8:42 ` jakub at gcc dot gnu.org
2021-06-07 10:28 ` rguenth at gcc dot gnu.org
2021-06-07 13:13 ` rguenth at gcc dot gnu.org
2021-06-11  9:28 ` rguenth at gcc dot gnu.org
2021-06-14  2:48 ` law at gcc dot gnu.org [this message]
2021-06-14 12:56 ` rguenth at gcc dot gnu.org
2021-06-14 12:59 ` jakub at gcc dot gnu.org
2021-06-14 13:02 ` rguenther at suse dot de
2021-06-14 14:37 ` cvs-commit at gcc dot gnu.org
2021-06-14 14:39 ` [Bug tree-optimization/100934] [9/10/11 " rguenth at gcc dot gnu.org
2021-06-16 13:12 ` cvs-commit at gcc dot gnu.org
2021-06-16 14:24 ` [Bug tree-optimization/100934] [9/10 " cvs-commit at gcc dot gnu.org
2021-10-13 10:09 ` [Bug tree-optimization/100934] [9 " cvs-commit at gcc dot gnu.org
2021-10-13 10:10 ` rguenth at gcc dot gnu.org
2021-11-09  7:57 ` pinskia 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-100934-4-bsSf9o1WZS@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).