https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125509
--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Tamar Christina <[email protected]>: https://gcc.gnu.org/g:e375d01bcdf0f985f1daac09e9760079d0fb8211 commit r17-1249-ge375d01bcdf0f985f1daac09e9760079d0fb8211 Author: Tamar Christina <[email protected]> Date: Wed Jun 3 09:37:32 2026 +0100 vect: fix prologue peeling dominator updates [PR125509] In the change to enable vectorization without needing a scalar epilogue I disabled the dominators update for prolog peeling with the assumption that since I don't need to go to rewire the exits when we vectorize the main loop we don't end up with the complicated merge block for which the updates were needed. And indeed no test failed. But it turns out we now get a different form so the updates are still needed. The merge block is still a mess so determining manually who is the new dominator of whom is still quite difficult so I couldn't simplify the updates. This re-enabled dominator updates after prolog peeling. gcc/ChangeLog: PR tree-optimization/125509 * tree-vect-loop-manip.cc (vect_do_peeling): Re-enable dominators update for prolog peeling. gcc/testsuite/ChangeLog: PR tree-optimization/125509 * gcc.dg/vect/pr125509.c: New test.
