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From: "tneumann at users dot sourceforge.net" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libgcc/107675] [13 Regression] GCC-13 is significantly slower to startup on C++ statically linked programs
Date: Fri, 09 Dec 2022 22:46:49 +0000	[thread overview]
Message-ID: <bug-107675-4-HS1Rdpi9RO@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107675-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107675

--- Comment #15 from Thomas Neumann <tneumann at users dot sourceforge.net> ---
> You cannot use 'relaxed' atomic load in is_object_initialized - as thread
> performing such load will not observe/synchronize with any modifications
> (other than atomic variable itself) performed by other threads.

you are right, this has to be acquire. Very unfortunate. I thought we would get
away with relaxed because we double-check anyway, but with relaxed we might
miss the writes to the other fields of object.

On systems with strong memory order it does not matter, but on ARM this will
make the check slower.

  parent reply	other threads:[~2022-12-09 22:46 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-14 13:03 [Bug libstdc++/107675] New: [13 Regression] GCC-13 is significantly slower to startup on C++ programs tnfchris at gcc dot gnu.org
2022-11-14 13:09 ` [Bug libstdc++/107675] " tnfchris at gcc dot gnu.org
2022-11-14 13:20 ` jakub at gcc dot gnu.org
2022-11-14 13:27 ` fw at gcc dot gnu.org
2022-11-14 14:28 ` tnfchris at gcc dot gnu.org
2022-11-14 17:54 ` pinskia at gcc dot gnu.org
2022-11-14 17:55 ` pinskia at gcc dot gnu.org
2022-11-17 11:04 ` tnfchris at gcc dot gnu.org
2022-11-17 11:15 ` fw at gcc dot gnu.org
2022-11-17 11:24 ` tnfchris at gcc dot gnu.org
2022-11-20 23:57 ` tnfchris at gcc dot gnu.org
2022-11-20 23:58 ` [Bug libgcc/107675] " tnfchris at gcc dot gnu.org
2022-11-22  9:35 ` tnfchris at gcc dot gnu.org
2022-12-09 19:56 ` [Bug libgcc/107675] [13 Regression] GCC-13 is significantly slower to startup on C++ statically linked programs m.cencora at gmail dot com
2022-12-09 22:46 ` tneumann at users dot sourceforge.net [this message]
2022-12-16 23:55 ` tneumann at users dot sourceforge.net
2022-12-20 15:38 ` rguenth at gcc dot gnu.org

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