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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: Wed, 08 Mar 2023 12:06:37 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109031

--- Comment #8 from Martin Li=C5=A1ka <marxin at gcc dot gnu.org> ---
(In reply to David Binderman from comment #7)
> (In reply to David Binderman from comment #4)
> > Created attachment 54596 [details]
> > C source code
> >=20
> > After 3 hours further reduction.
>=20
> I am struggling with further reduction. My bash knowledge is short.
>=20
> My cvise script is:
>=20
> /usr/bin/gcc -w -Werror=3Dimplicit bug892.c \
> && (./a.out 1 > 1) \
> && /home/dcb36/gcc/results/bin/gcc -w -O2 -fno-strict-aliasing bug892.c=20
> \
> && (./a.out 1 > 2) \
> && diff 1 2; \
>=20
> but then if diff returns 1, the script should return 0 and
> if diff returns 0, then the script should return 1.

You can take an inspiration here:
https://github.com/marxin/gcc-util/blob/master/bisect/reduce.sh

and you can use multiple `if` statements.=