https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109184
Bug ID: 109184
Summary: csmith: really old bug with -O3
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
Created attachment 54701
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54701&action=edit
C source code
For the attached C code, compiled with -O2 and -O3, produces different answers:
$ ~/gcc/results/bin/gcc -w -O2 -fno-strict-aliasing bug897.c
$ ./a.out 1 > 1
$ $ ~/gcc/results/bin/gcc -w -O3 -fno-strict-aliasing bug897.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
The bug seems to exist since sometime before 20220403, nearly a year ago.
Flag -ftrivial-auto-var-init=zero doesn't seem to help.
