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From: "dcb314 at hotmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/109184] csmith: really old bug with -O3
Date: Sat, 18 Mar 2023 12:42:46 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109184

--- Comment #3 from David Binderman <dcb314 at hotmail dot com> ---
After checking the flags that move -O2 to -O3, flag -floop-interchange
seems to be at fault.

$ ~/gcc/results/bin/gcc -w -O2 -fno-strict-aliasing bug897.c
$ ./a.out 1 > 1
$ ~/gcc/results/bin/gcc -w -O2 -floop-interchange -fno-strict-aliasing bug8=
97.c
$./a.out 1 > 2
$ diff 1 2 | head

2038c2038
< ...checksum after hashing g_1731[i][j] : 351CD463
---
> ...checksum after hashing g_1731[i][j] : 7739D31E
2040c2040
< ...checksum after hashing g_1731[i][j] : 791FAA71
---
> ...checksum after hashing g_1731[i][j] : FEBF8F12=