https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120052
Bug ID: 120052 Summary: internal compiler error: in scan_omp_1_op, at omp-low.cc:4005 Product: gcc Version: 16.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: ldalessandro at gmail dot com Target Milestone: --- UBSan + OpenMP ICE C-Vise reduced test case, compile with -fsanitize=undefined -fopenmp. void copy_n(int, long, int); unsigned long n_ranks; long rank; enum { TYPE_COUNT } ingest_data___trans_tmp_1; auto ingest_data() { long counts[TYPE_COUNT][n_ranks]; #pragma omp parallel for (int i;;) copy_n(ingest_data___trans_tmp_1, counts[i][rank], 0); } This only triggers with **both** UBSan and OpenMP. Live: https://godbolt.org/z/oKqa6jMrq [May 1st, 2025]