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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 17:12:25 +0000 [thread overview] Message-ID: <bug-109031-4-ZzznW1DyAP@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-109031-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109031 --- Comment #18 from David Binderman <dcb314 at hotmail dot com> --- Part way through reduction, the C code seems to be int crc32_tab_0; int crc32_context = 0xFFFFFFFFUL; void main(int , char []) { { int crc; int i; i = 0; for (; i < 256; i++) crc32_tab_0 = crc; { { crc32_context = 0 ^ crc32_tab_0; } } printf("...checksum after hashing %s : %lX\n", "g_50", crc32_context ^ 0xFFFFFFFFUL); } } This looks to me like reading rubbish off the local variable stack in main and then hashing it. AFAIK not a bug in gcc, but may be a bug in csmith.
next prev parent reply other threads:[~2023-03-08 17:12 UTC|newest] Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-03-05 21:26 [Bug c/109031] New: " dcb314 at hotmail dot com 2023-03-06 15:05 ` [Bug middle-end/109031] " dcb314 at hotmail dot com 2023-03-06 16:03 ` dcb314 at hotmail dot com 2023-03-06 17:43 ` dcb314 at hotmail dot com 2023-03-06 20:33 ` dcb314 at hotmail dot com 2023-03-06 20:41 ` pinskia at gcc dot gnu.org 2023-03-07 0:10 ` pinskia at gcc dot gnu.org 2023-03-08 11:10 ` dcb314 at hotmail dot com 2023-03-08 12:06 ` marxin at gcc dot gnu.org 2023-03-08 13:39 ` dcb314 at hotmail dot com 2023-03-08 13:43 ` marxin at gcc dot gnu.org 2023-03-08 13:56 ` dcb314 at hotmail dot com 2023-03-08 14:01 ` marxin at gcc dot gnu.org 2023-03-08 14:08 ` dcb314 at hotmail dot com 2023-03-08 14:10 ` marxin at gcc dot gnu.org 2023-03-08 14:16 ` dcb314 at hotmail dot com 2023-03-08 14:24 ` marxin at gcc dot gnu.org 2023-03-08 16:45 ` dcb314 at hotmail dot com 2023-03-08 17:12 ` dcb314 at hotmail dot com [this message] 2023-03-09 8:44 ` marxin at gcc dot gnu.org 2023-03-09 8:48 ` jakub at gcc dot gnu.org 2023-03-09 8:59 ` marxin at gcc dot gnu.org 2023-03-09 9:25 ` dcb314 at hotmail dot com 2023-03-09 9:41 ` [Bug middle-end/109031] csmith: possible bad code with -O2 -fno-strict-aliasing since r13-254-gdd3c7873a61019e9 marxin at gcc dot gnu.org 2023-03-09 9:45 ` dcb314 at hotmail dot com 2023-03-09 10:18 ` marxin at gcc dot gnu.org 2023-03-09 10:20 ` marxin at gcc dot gnu.org 2023-03-09 10:29 ` marxin at gcc dot gnu.org 2023-03-09 10:35 ` marxin at gcc dot gnu.org 2023-03-09 13:41 ` roger at nextmovesoftware dot com 2023-03-09 14:25 ` jakub at gcc dot gnu.org 2023-03-12 22:55 ` cvs-commit at gcc dot gnu.org 2023-03-14 7:33 ` roger at nextmovesoftware dot com
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