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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/115278] [13/14/15 Regression]
 -ftree-vectorize optimizes away volatile write on x86_64 since r13-3219
Date: Fri, 31 May 2024 08:25:58 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D115278

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to avieira from comment #5)
> > I think we fixed similar bug on the read side.
>=20
> I don't have the best memory, but the one I can remember is PR 111882, wh=
ere
> we had the SAVE_EXPR. And the the fix was to not lower bitfields with
> non-constant offsets.
>=20
> Should dse_classify_store not return *_DEAD for volatiles?

It's a low-level worker, it relies on the caller to have performed sanity
checking on the stmt itself.  I'm testing a patch doing that.=