https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99034
--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:8a6114146001eafc1921b60e40bf5c0e4f4b8e64 commit r9-9423-g8a6114146001eafc1921b60e40bf5c0e4f4b8e64 Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Feb 19 12:14:39 2021 +0100 tree-cfg: Fix up gimple_merge_blocks FORCED_LABEL handling [PR99034] The verifiers require that DECL_NONLOCAL or EH_LANDING_PAD_NR labels are always the first label if there is more than one label. When merging blocks, we don't honor that though. On the following testcase, we try to merge blocks: <bb 13> [count: 0]: <L2>: S::~S (&s); and <bb 15> [count: 0]: <L0>: resx 1 where <L2> is landing pad and <L0> is FORCED_LABEL. And the code puts the FORCED_LABEL before the landing pad label, violating the verification requirements. The following patch fixes it by moving the FORCED_LABEL after the DECL_NONLOCAL or EH_LANDING_PAD_NR label if it is the first label. 2021-02-19 Jakub Jelinek <ja...@redhat.com> PR ipa/99034 * tree-cfg.c (gimple_merge_blocks): If bb a starts with eh landing pad or non-local label, put FORCED_LABELs from bb b after that label rather than before it. * g++.dg/opt/pr99034.C: New test. (cherry picked from commit 33be24d77d3d8f0c992eb344ce63f78e14cf753d)
