https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98906
Bug ID: 98906 Summary: [8/9/10/11 Regression] Miscompiles code even at -O1 Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: wrong-code Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: amonakov at gcc dot gnu.org Target Milestone: --- Created attachment 50097 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50097&action=edit testcase The attached testcase is clean w.r.t ASan and UBSan. At -O1+, 'main' is miscompiled to a single basic block reporting an error on initial loop iteration, since gcc-6, while -Og and '-O1 -fno-inline' yield expected code. .optimized dump is wrong, so one of GIMPLE passes is the culprit, but a bit hard to see which one exactly.