https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118558
Bug ID: 118558
Summary: csmith: another runtime error with march=znver3
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
Created attachment 60207
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60207&action=edit
C source code
The attached C source code, generated by csmith, does this:
foundBugs $ ~/gcc/results/bin/gcc -w bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : 991033EB
...checksum after hashing g_256[i] : 79991091
...checksum after hashing g_256[i] : AB373C07
foundBugs $ ~/gcc/results/bin/gcc -w -O1 bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : 991033EB
...checksum after hashing g_256[i] : 79991091
...checksum after hashing g_256[i] : AB373C07
foundBugs $ ~/gcc/results/bin/gcc -w -O2 bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : 991033EB
...checksum after hashing g_256[i] : 79991091
...checksum after hashing g_256[i] : AB373C07
foundBugs $ ~/gcc/results/bin/gcc -w -O3 bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : 991033EB
...checksum after hashing g_256[i] : 79991091
...checksum after hashing g_256[i] : AB373C07
foundBugs $ ~/gcc/results/bin/gcc -w -O3 -march=znver3 bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : D02808C8
...checksum after hashing g_256[i] : 19CE3B74
...checksum after hashing g_256[i] : 25043566
foundBugs $
Adding -march=znver3 seems to cause problems.
I have a reduction running.
The problem first seems to appear sometime before 20241218:
foundBugs $ ~/gcc/results.20241218.asan.ubsan/bin/gcc -w -O3 bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : 991033EB
...checksum after hashing g_256[i] : 79991091
...checksum after hashing g_256[i] : AB373C07
foundBugs $ ~/gcc/results.20241218.asan.ubsan/bin/gcc -w -O3 -march=znver3
bug1076.c
foundBugs $ ./a.out 1 | grep g_256
...checksum after hashing g_256[i] : D02808C8
...checksum after hashing g_256[i] : 19CE3B74
...checksum after hashing g_256[i] : 25043566
foundBugs $
