https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113144
--- Comment #16 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Tamar Christina <tnfch...@gcc.gnu.org>: https://gcc.gnu.org/g:9e7c77c7933b1bb0dd07214333e52a9a896fa349 commit r14-7101-g9e7c77c7933b1bb0dd07214333e52a9a896fa349 Author: Tamar Christina <tamar.christ...@arm.com> Date: Wed Jan 10 12:51:54 2024 +0000 middle-end: Fix dominators updates when peeling with multiple exits [PR113144] When we peel at_exit we are moving the new loop at the exit of the previous loop. This means that the blocks outside the loop dat the previous loop used to dominate are no longer being dominated by it. The new dominators however are hard to predict since if the loop has multiple exits and all the exits are an "early" one then we always execute the scalar loop. In this case the scalar loop can completely dominate the new loop. If we later have skip_vector then there's an additional skip edge added that might change the dominators. The previous patch would force an update of all blocks reachable from the new exits. This one updates *only* blocks that we know the scalar exits dominated. For the examples this reduces the blocks to update from 18 to 3. gcc/ChangeLog: PR tree-optimization/113144 PR tree-optimization/113145 * tree-vect-loop-manip.cc (slpeel_tree_duplicate_loop_to_edge_cfg): Update all BB that the original exits dominated. gcc/testsuite/ChangeLog: PR tree-optimization/113144 PR tree-optimization/113145 * gcc.dg/vect/vect-early-break_94-pr113144.c: New test.
