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From: "luto at kernel dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/55522] -funsafe-math-optimizations is unexpectedly harmful, especially w/ -shared
Date: Thu, 08 Sep 2022 17:09:29 +0000	[thread overview]
Message-ID: <bug-55522-4-erhn3i6OsK@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-55522-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55522

--- Comment #16 from Andy Lutomirski <luto at kernel dot org> ---
(In reply to Andrew Pinski from comment #13)
> Patient: Doctor it hurts when I do this.
> Doctor: then don't do that and if you read the instructions I gave you I
> told you I would hurt this way.

I think this analogy is off.  Maybe for most questionable optimization or
codegen options it would apply, but -ffast-math is more like:

Patient: Doctor, it hurts me when my neighbor does this.
Doctor: Then tell your neighbor not to read that and to read the fine print on
the box.

If nitroglycerin pills have side effects and patients need to read the label,
maybe fine.  But if they start exploding and breaking other peoples' windows,
that's a whole different problem.

  parent reply	other threads:[~2022-09-08 17:09 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-29  0:52 [Bug c++/55522] New: " luto at mit dot edu
2012-11-29  1:49 ` [Bug c++/55522] " luto at mit dot edu
2012-11-29  8:57 ` [Bug target/55522] " rguenth at gcc dot gnu.org
2012-11-30  1:41 ` luto at mit dot edu
2015-04-28 18:23 ` orion at cora dot nwra.com
2021-10-06  1:15 ` ilya.konstantinov at gmail dot com
2022-09-06 22:40 ` foom at fuhm dot net
2022-09-06 22:55 ` pinskia at gcc dot gnu.org
2022-09-06 22:57 ` sam at gentoo dot org
2022-09-07 10:06 ` egallager at gcc dot gnu.org
2022-09-08 17:09 ` luto at kernel dot org [this message]
2022-09-09 10:32 ` rguenth at gcc dot gnu.org
2022-09-09 10:50 ` rguenth at gcc dot gnu.org
2022-09-11 15:46 ` brendandg at nyu dot edu
2022-09-12  7:01 ` rguenth at gcc dot gnu.org
2022-09-12  9:47 ` fw at gcc dot gnu.org
2022-09-14 17:03 ` brendandg at nyu dot edu
2022-10-07  9:27 ` aph at gcc dot gnu.org
2022-10-07 17:00 ` hjl.tools at gmail dot com
2022-10-10  9:17 ` fw at gcc dot gnu.org
2022-10-10 16:45 ` hjl.tools at gmail dot com
2022-10-10 16:46 ` hjl.tools at gmail dot com
2022-10-10 19:33 ` brendandg at nyu dot edu
2022-12-19 10:36 ` cvs-commit at gcc dot gnu.org
2022-12-26  1:12 ` cvs-commit at gcc dot gnu.org
2023-01-12 13:46 ` rguenth at gcc dot gnu.org
2023-01-13  3:35 ` sam at gentoo dot org
2023-01-13  7:47 ` rguenth at gcc dot gnu.org
2023-01-13 11:14 ` cvs-commit at gcc dot gnu.org
2023-01-13 11:14 ` cvs-commit at gcc dot gnu.org
2023-01-16 13:31 ` cvs-commit at gcc dot gnu.org
2023-01-18  2:46 ` cvs-commit at gcc dot gnu.org
2023-01-23 12:34 ` cvs-commit at gcc dot gnu.org
2023-01-27  3:26 ` cvs-commit at gcc dot gnu.org
2023-01-27 14:47 ` cvs-commit at gcc dot gnu.org
2023-01-27 14:47 ` cvs-commit at gcc dot gnu.org
2023-01-27 14:47 ` cvs-commit at gcc dot gnu.org
2023-01-27 14:47 ` cvs-commit at gcc dot gnu.org
2023-01-27 14:47 ` rguenth at gcc dot gnu.org
2023-04-30  3:58 ` arthur200126 at gmail dot com
2023-10-16 15:36 ` o.hlinka at gmail dot com
2023-10-17  7:08 ` rguenth at gcc dot gnu.org

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