https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99322
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:a3ad6489d38982434faef3bc5f33e3c28c5f7c74 commit r11-7533-ga3ad6489d38982434faef3bc5f33e3c28c5f7c74 Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Mar 5 21:52:35 2021 +0100 openmp: Avoid ICEs due to orphaned labels in OpenMP regions [PR99322] When performing cfg cleanup at the end of cfg pass, if there are any OpenMP regions and some basic blocks are unreachable and contain forced labels, remove_bb moves the labels to previous bb, but if the two bb belong to different OpenMP regions, that means it will end up in a different function from where it was assumed to be and checked e.g. during gimplification or OpenMP region SESE checking. The following patch will place the labels to some bb from the right OpenMP region if the previous bb is not that. I think it should happen very rarely, normally the bbs from each OpenMP region should be from the before-cfg pass adjacent and the problems will usually be only if the OpenMP regions are no-return, so I hope it isn't fatal that it searches through all bbs on the miss. If it turns out to be a problem, it can always lazily create some better data structure and maintain it through bb removals when it reaches that case the first time. 2021-03-05 Jakub Jelinek <ja...@redhat.com> PR middle-end/99322 * tree-cfg.c (bb_to_omp_idx): New variable. (execute_build_cfg): Release the bb_to_omp_idx vector after cleanup_tree_cfg returns. (handle_abnormal_edges): Remove bb_to_omp_idx argument, adjust for bb_to_omp_idx being a vec<int> instead of pointer to array of ints. (make_edges): Remove bb_to_omp_idx local variable, don't pass it to handle_abnormal_edges, adjust for bb_to_omp_idx being a vec<int> instead of pointer to array of ints and don't free/release it at the end. (remove_bb): When removing a bb and placing forced label somewhere else, ensure it is put into the same OpenMP region during cfg pass if possible or to entry successor as fallback. Unregister bb from bb_to_omp_idx. * c-c++-common/gomp/pr99322.c: New test.