public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "glisse at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/100366] spurious warning - std::vector::clear followed by std::vector::insert(vec.end(), ...) with -O2
Date: Wed, 05 May 2021 11:01:58 +0000	[thread overview]
Message-ID: <bug-100366-4-Qifku3J61N@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-100366-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100366

--- Comment #6 from Marc Glisse <glisse at gcc dot gnu.org> ---
So, apart from the small missed PHI optimization, this is probably the common
issue that since operator new is replacable, we can't really assume that it
does not clobber anything, and that hurts optimizations :-(
Not sure if there would be any convenient workaround for this specific case.

  parent reply	other threads:[~2021-05-05 11:01 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-01  2:36 [Bug c++/100366] New: " mrsam@courier-mta.com
2021-05-02 11:27 ` [Bug tree-optimization/100366] " glisse at gcc dot gnu.org
2021-05-03 17:51 ` msebor at gcc dot gnu.org
2021-05-03 21:02 ` mrsam@courier-mta.com
2021-05-04  7:39 ` rguenth at gcc dot gnu.org
2021-05-05 10:55 ` glisse at gcc dot gnu.org
2021-05-05 11:01 ` glisse at gcc dot gnu.org [this message]
2021-05-05 11:15 ` glisse at gcc dot gnu.org
2021-05-05 12:18 ` mrsam@courier-mta.com
2021-05-12 23:44 ` msebor at gcc dot gnu.org
2021-12-02 21:14 ` msebor at gcc dot gnu.org
2021-12-06 16:45 ` [Bug tree-optimization/100366] [11/12 Regression] " roystgnr at ices dot utexas.edu
2021-12-28 12:09 ` pinskia at gcc dot gnu.org
2022-01-20 14:03 ` rguenth at gcc dot gnu.org
2022-04-21  7:49 ` rguenth at gcc dot gnu.org
2022-07-05 10:07 ` [Bug tree-optimization/100366] [11/12/13 " hewillk at gmail dot com
2022-11-26 15:53 ` zeranoe at gmail dot com
2022-11-29 15:58 ` redi at gcc dot gnu.org
2022-11-29 17:14 ` cvs-commit at gcc dot gnu.org
2023-04-20 13:57 ` [Bug tree-optimization/100366] [11/12 " cvs-commit at gcc dot gnu.org
2023-05-29 10:04 ` jakub 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-100366-4-Qifku3J61N@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).