https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116126
--- Comment #3 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:68326d5d1a593dc0bf098c03aac25916168bc5a9 commit r15-6807-g68326d5d1a593dc0bf098c03aac25916168bc5a9 Author: Alex Coplan <alex.cop...@arm.com> Date: Mon Mar 11 13:09:10 2024 +0000 vect: Force alignment peeling to vectorize more early break loops [PR118211] This allows us to vectorize more loops with early exits by forcing peeling for alignment to make sure that we're guaranteed to be able to safely read an entire vector iteration without crossing a page boundary. To make this work for VLA architectures we have to allow compile-time non-constant target alignments. We also have to override the result of the target's preferred_vector_alignment hook if it isn't a power-of-two multiple of the TYPE_SIZE of the chosen vector type. gcc/ChangeLog: PR tree-optimization/118211 PR tree-optimization/116126 * tree-vect-data-refs.cc (vect_analyze_early_break_dependences): Set need_peeling_for_alignment flag on read DRs instead of failing vectorization. Punt on gathers. (dr_misalignment): Handle non-constant target alignments. (vect_compute_data_ref_alignment): If need_peeling_for_alignment flag is set on the DR, then override the target alignment chosen by the preferred_vector_alignment hook to choose a safe alignment. (vect_supportable_dr_alignment): Override support_vector_misalignment hook if need_peeling_for_alignment is set on the DR: in this case we must return dr_unaligned_unsupported in order to force peeling. * tree-vect-loop-manip.cc (vect_do_peeling): Allow prolog peeling by a compile-time non-constant amount. * tree-vectorizer.h (dr_vec_info): Add new flag need_peeling_for_alignment. gcc/testsuite/ChangeLog: PR tree-optimization/118211 PR tree-optimization/116126 * gcc.dg/tree-ssa/cunroll-13.c: Don't vectorize. * gcc.dg/tree-ssa/cunroll-14.c: Likewise. * gcc.dg/unroll-6.c: Likewise. * gcc.dg/tree-ssa/gen-vect-28.c: Likewise. * gcc.dg/vect/vect-104.c: Expect to vectorize. * gcc.dg/vect/vect-early-break_108-pr113588.c: Likewise. * gcc.dg/vect/vect-early-break_109-pr113588.c: Likewise. * gcc.dg/vect/vect-early-break_110-pr113467.c: Likewise. * gcc.dg/vect/vect-early-break_3.c: Likewise. * gcc.dg/vect/vect-early-break_65.c: Likewise. * gcc.dg/vect/vect-early-break_8.c: Likewise. * gfortran.dg/vect/vect-5.f90: Likewise. * gfortran.dg/vect/vect-8.f90: Likewise. * gcc.dg/vect/vect-switch-search-line-fast.c: Co-Authored-By: Tamar Christina <tamar.christ...@arm.com>
