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From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/109031] csmith: possible bad code with -O2
 -fno-strict-aliasing
Date: Thu, 09 Mar 2023 08:59:18 +0000
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X-Bugzilla-Keywords: needs-bisection, needs-reduction, wrong-code
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109031

--- Comment #21 from Martin Li=C5=A1ka <marxin at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #20)
> Well, cvise reduction of runtime testcases is always problematic, and try=
ing
> to ensure
> the reduction doesn't introduce uninitialized var uses which weren't there
> before (perhaps with checking for new -Wmaybe-uninitialized -Wuninitializ=
ed
> warnings or even all -Wall -W warnings; or perhaps with
> -ftrivial-var-init=3Dsomething) as well as using some timeout on the exec=
ution
> because the execution could very well loop forever is minimum what needs =
to
> be done.

Yes, one can mitigate that with -fsanitize=3Dundefined,address, I used that=
 time
to time for csmith test-cases.=