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From: "dcb314 at hotmail dot com" <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 13:56:03 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109031

--- Comment #11 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to Martin Li=C5=A1ka from comment #10)
> What about:
>=20
> /usr/bin/gcc -w -Werror=3Dimplicit bug892.c -o one.exe
> 	&& (./one.exe 1 | fgrep "checksum after hashing g_50 :" > 1)=20
> 	&& /home/dcb36/gcc/results/bin/gcc -w -O2 -fno-strict-aliasing bug892.c=
=20
>  -o two.exe
> 	&& (./two.exe 1 | fgrep "checksum after hashing g_50 :" > 2)=20
>=20
> 	if test $? !=3D 0; then=20
> 		exit 1
>=20
> 	diff 1 2;=20
> 	if test $? =3D 0; then=20
> 		exit 1
> 	fi
> 		exit 0
>=20
> ?

Thanks for the idea, but no further forward ;-|. Getting to the diff
is easy. Getting the return code of 1 from the diff out to the calling
perl program converted to 0 is proving to be a challenge.

$ diff 1 2
1c1
< ...checksum after hashing g_50 : 646CF84D
---
> ...checksum after hashing g_50 : C21BF3F9
$ echo $?
1
$=