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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/115954] Alignment of _Atomic structs incompatible
 between GCC and LLVM
Date: Tue, 16 Jul 2024 11:18:02 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D115954

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> Not sure what the x86 psABI says here (possibly nothing for aggregate
> _Atomic).

It doesn't consider _Atomic [influencing the ABI] at all.

Note I think your test queries actual object alignment which a compiler
can of course increase vs. what the ABI requires as minimum alignment,
you should possibly cross-check with alignof/sizeof of the type.

On x86 clang returns size 8 and align 8 for the atomic A7 type (GCC does no=
t).=