https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118211
Torbjorn SVENSSON <azoff at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |azoff at gcc dot gnu.org
--- Comment #10 from Torbjorn SVENSSON <azoff at gcc dot gnu.org> ---
(In reply to GCC Commits from comment #4)
> 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>
This commit causes regression for arm-none-eabi:
FAIL: gcc.dg/tree-ssa/predcom-8.c scan-tree-dump-not pcom "Invalid sum"
FAIL: gcc.dg/vect/vect-early-break_65.c -flto -ffat-lto-objects
scan-tree-dump-times vect "vectorized 1 loops" 1
FAIL: gcc.dg/vect/vect-early-break_65.c scan-tree-dump-times vect "vectorized 1
loops" 1
This is tested on r15-7014-g413985b632a.
