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From: "ldeng at mail dot ustc.edu.cn" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/96293] Extraneously noisy "taking address of packed member may result in an unaligned pointer value"
Date: Wed, 06 Jul 2022 10:05:57 +0000	[thread overview]
Message-ID: <bug-96293-4-GliEZv0R51@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-96293-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96293

--- Comment #6 from Long Deng <ldeng at mail dot ustc.edu.cn> ---
I met the same problem. I found that gcc issue this warning probably because
`struct S` can located any address, which means that `s.d` may not alignment to
4.
So as Richard said, you can use `__attribute__((packed, aligned(4))` to get rid
of this warning, it still guaranteed that you struct is packed (i.e. `sizeof(S)
== 8`), and struct itself will alignment to 4, so `s.d` will aligns correctly.

  parent reply	other threads:[~2022-07-06 10:05 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-23  0:23 [Bug c/96293] New: " lavr at ncbi dot nlm.nih.gov
2020-07-23  6:02 ` [Bug c/96293] " rguenth at gcc dot gnu.org
2020-07-23 14:59 ` lavr at ncbi dot nlm.nih.gov
2020-07-23 15:01 ` lavr at ncbi dot nlm.nih.gov
2020-07-27 11:15 ` jakub at gcc dot gnu.org
2020-07-27 16:08 ` lavr at ncbi dot nlm.nih.gov
2022-07-06 10:05 ` ldeng at mail dot ustc.edu.cn [this message]
2022-07-06 14:05 ` lavr at ncbi dot nlm.nih.gov
2022-07-06 15:15 ` lavr at ncbi dot nlm.nih.gov
2022-07-07  8:23 ` ldeng at mail dot ustc.edu.cn
2022-07-07 13:13 ` lavr at ncbi dot nlm.nih.gov

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