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From: "wuyongwei at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/80878] -mcx16 (enable 128 bit CAS) on x86_64 seems not to work on 7.1.0
Date: Sun, 14 Mar 2021 03:46:25 +0000	[thread overview]
Message-ID: <bug-80878-4-uQVqzdLHi6@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-80878-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80878

--- Comment #28 from Yongwei Wu <wuyongwei at gmail dot com> ---
OK, somewhat answering myself. I was not aware of the fact that 128-bit atomic
read has to be implemented using cmpxchg16b as well, thus defeating some
non-CAS usage scenarios.

The natural question is: which usage scenario is more significant? Or is there
a way to support both?

I still think lock-free data structures are too import to ignore.

  parent reply	other threads:[~2021-03-14  3:46 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-80878-4@http.gcc.gnu.org/bugzilla/>
2020-04-18 17:14 ` avi@cloudius-systems.com
2020-04-18 17:23 ` fw at gcc dot gnu.org
2020-04-18 17:31 ` avi@cloudius-systems.com
2020-04-18 17:40 ` fw at gcc dot gnu.org
2020-04-18 18:13 ` avi@cloudius-systems.com
2020-04-18 18:18 ` avi@cloudius-systems.com
2020-04-18 18:41 ` fw at gcc dot gnu.org
2021-03-14  3:21 ` wuyongwei at gmail dot com
2021-03-14  3:46 ` wuyongwei at gmail dot com [this message]
2021-03-16 16:02 ` wuyongwei at gmail dot com
2021-05-06 17:50 ` s_gccbugzilla at nedprod dot com
2021-05-06 19:32 ` pinskia at gcc dot gnu.org
2021-05-06 20:53 ` liblfds_gccbz at winterflaw dot net
2021-05-07 12:27 ` s_gccbugzilla at nedprod dot com
2021-05-07 14:07 ` redi at gcc dot gnu.org
2021-05-07 14:44 ` s_gccbugzilla at nedprod dot com
2022-11-03  9:55 ` lh_mouse at 126 dot com
2022-11-03 10:04 ` jakub at gcc dot gnu.org
2022-11-03 10:32 ` fw at gcc dot gnu.org
2022-11-03 11:16 ` admin_public at liblfds dot org
2023-11-16  1:33 ` lh_mouse at 126 dot com
2023-12-10  9:54 ` lh_mouse at 126 dot com
2023-12-10 10:32 ` admin_public at liblfds dot org

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