https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113727
Bug ID: 113727 Summary: csmith: differences from nothing to -O1 Product: gcc Version: 14.0 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 57298 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57298&action=edit C source code The attached C code seems to produce different answers between no optimisation flags and -O1: foundBugs $ ../results/bin/gcc -w bug1002.c foundBugs $ valgrind -q ./a.out 1 > 0 foundBugs $ ../results/bin/gcc -w -O1 bug1002.c foundBugs $ valgrind -q ./a.out 1 > 1 foundBugs $ diff 0 1 469,478c469,478 < ...checksum after hashing g_994.f3 : 5F99C263 < ...checksum after hashing g_994.f4 : 6E61EEE1 < ...checksum after hashing g_994.f5 : 8A4973F3 < ...checksum after hashing g_994.f6 : 1A47F5E1 < ...checksum after hashing g_994.f7 : CD2C240E < ...checksum after hashing g_994.f8 : 7E61A9F < ...checksum after hashing g_1368 : 74B15A31 < ...checksum after hashing g_1659 : 322B1FCB < ...checksum after hashing g_1720 : 65F2763C < checksum = 65F2763C --- > ...checksum after hashing g_994.f3 : 3D4A5D24 > ...checksum after hashing g_994.f4 : 23E1696C > ...checksum after hashing g_994.f5 : B115BFA4 > ...checksum after hashing g_994.f6 : E3A4BBDA > ...checksum after hashing g_994.f7 : D44B3E01 > ...checksum after hashing g_994.f8 : 656901A2 > ...checksum after hashing g_1368 : 3B45689 > ...checksum after hashing g_1659 : EBA715C1 > ...checksum after hashing g_1720 : BDD5FC31 > checksum = BDD5FC31 I have a reduction running. The bug first seems to occur sometime between dates 20231001 and 20231119. Git hashes are g:5f3da480e7541a9c and eaeaad3fcac4d7a3.