[Bug tree-optimization/113026] Bogus -Wstringop-overflow warning on simple memcpy type loop

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113026

--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:b3cc5a1efead520bc977b4ba51f1328d01b3e516

commit r14-7003-gb3cc5a1efead520bc977b4ba51f1328d01b3e516
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Dec 15 10:32:29 2023 +0100

    tree-optimization/113026 - avoid vector epilog in more cases

    The following avoids creating a niter peeling epilog more consistently,
    matching what peeling later uses for the skip_vector condition, in
    particular when versioning is required which then also ensures the
    vector loop is entered unless the epilog is vectorized.  This should
    ideally match LOOP_VINFO_VERSIONING_THRESHOLD which is only computed
    later, some refactoring could make that better matching.

    The patch also makes sure to adjust the upper bound of the epilogues
    when we do not have a skip edge around the vector loop.

            PR tree-optimization/113026
            * tree-vect-loop.cc (vect_need_peeling_or_partial_vectors_p):
            Avoid an epilog in more cases.
            * tree-vect-loop-manip.cc (vect_do_peeling): Adjust the
            epilogues niter upper bounds and estimates.

            * gcc.dg/torture/pr113026-1.c: New testcase.
            * gcc.dg/torture/pr113026-2.c: Likewise.