public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/38534] gcc 4.2.1 and above: No need to save called-saved registers in 'noreturn' function
Date: Wed, 28 Feb 2024 08:15:40 +0000	[thread overview]
Message-ID: <bug-38534-4-O47GP93sQn@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-38534-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38534

--- Comment #41 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Lukas Grätz from comment #40)
> It seems that the reason for <optimized out> is ultimately -Og, not this
> patch. See Bug 78685.

No.  When PR78685 would be fixed by adding artificial hidden uses of variables
at the end of their scopes, this bug would trigger far more often.  The vars
would be live across the calls, so if there would be callee-saved registers
available, the compiler
would use them to hold the variables across the calls.  And this bug would
break that.
Anyway, I've posted 
https://gcc.gnu.org/pipermail/gcc-patches/2024-February/646649.html
patch which will not revert the #c15/#c24 changes, but guard them with a
non-default option.  People who don't care about the harder debugging can use
that option in their code, but widely used shared libraries with noreturn
entrypoints will no longer screw up the debugging for all the packages that use
them.

  parent reply	other threads:[~2024-02-28  8:15 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-38534-4@http.gcc.gnu.org/bugzilla/>
2011-11-07  0:15 ` js at alien8 dot de
2024-01-12 21:22 ` hjl.tools at gmail dot com
2024-01-13  6:05 ` sjames at gcc dot gnu.org
2024-01-14 12:05 ` lukas.graetz@tu-darmstadt.de
2024-01-14 12:08 ` lukas.graetz@tu-darmstadt.de
2024-01-14 14:12 ` hjl.tools at gmail dot com
2024-01-14 22:32 ` lukas.graetz@tu-darmstadt.de
2024-01-14 22:44 ` hjl.tools at gmail dot com
2024-01-14 22:54 ` lukas.graetz@tu-darmstadt.de
2024-01-15 10:22 ` lukas.graetz@tu-darmstadt.de
2024-01-15 10:49 ` lukas.graetz@tu-darmstadt.de
2024-01-15 12:23 ` lukas.graetz@tu-darmstadt.de
2024-01-27 12:19 ` cvs-commit at gcc dot gnu.org
2024-01-27 12:54 ` jakub at gcc dot gnu.org
2024-01-27 13:09 ` jakub at gcc dot gnu.org
2024-01-27 13:31 ` hjl.tools at gmail dot com
2024-01-27 13:45 ` jakub at gcc dot gnu.org
2024-01-27 13:47 ` jakub at gcc dot gnu.org
2024-01-27 15:05 ` aburgess at redhat dot com
2024-01-27 16:08 ` hjl.tools at gmail dot com
2024-01-27 20:42 ` hjl.tools at gmail dot com
2024-01-29 13:29 ` cvs-commit at gcc dot gnu.org
2024-02-01 12:23 ` lukas.graetz@tu-darmstadt.de
2024-02-01 12:43 ` jakub at gcc dot gnu.org
2024-02-01 14:40 ` lukas.graetz@tu-darmstadt.de
2024-02-27 10:18 ` jakub at gcc dot gnu.org
2024-02-27 12:17 ` lukas.graetz@tu-darmstadt.de
2024-02-27 12:32 ` jakub at gcc dot gnu.org
2024-02-27 13:07 ` lukas.graetz@tu-darmstadt.de
2024-02-27 13:17 ` jakub at gcc dot gnu.org
2024-02-27 13:38 ` lukas.graetz@tu-darmstadt.de
2024-02-27 14:03 ` jakub at gcc dot gnu.org
2024-02-27 14:39 ` jakub at gcc dot gnu.org
2024-02-27 17:00 ` lukas.graetz@tu-darmstadt.de
2024-02-27 17:10 ` jakub at gcc dot gnu.org
2024-02-27 18:15 ` lukas.graetz@tu-darmstadt.de
2024-02-27 23:54 ` tromey at gcc dot gnu.org
2024-02-28  8:09 ` lukas.graetz@tu-darmstadt.de
2024-02-28  8:15 ` jakub at gcc dot gnu.org [this message]
2024-02-28  9:43 ` lukas.graetz@tu-darmstadt.de
2024-02-28 13:31 ` lukas.graetz@tu-darmstadt.de
2024-02-29 17:56 ` lukas.graetz@tu-darmstadt.de
2024-02-29 20:12 ` lukas.graetz@tu-darmstadt.de
2024-03-08  8:30 ` cvs-commit at gcc dot gnu.org
2008-12-15 19:00 [Bug c/38534] New: " thutt at vmware dot com
2008-12-15 23:27 ` [Bug rtl-optimization/38534] " pinskia at gcc dot gnu dot org
2008-12-16 14:05 ` thutt at vmware 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-38534-4-O47GP93sQn@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).