[Bug middle-end/111875] With -Og ubsan check inserted even though __builtin_assume_aligned guarantees no UB

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111875

--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:966cdec2b23b8049c263e2239a3da38937ae01d2

commit r16-4081-g966cdec2b23b8049c263e2239a3da38937ae01d2
Author: Andrew Pinski <andrew.pinski@oss.qualcomm.com>
Date:   Fri Sep 19 20:58:31 2025 -0700

    gimple-fold/fab: Move ASSUME_ALIGNED handling to gimple-fold [PR121762]

    This is the next patch in the series of removing fab.
    This one is simplier than builtin_constant_p because the only
    time we want to simplify this builtin is at the final folding step.

    Note align-5.c needs to change slightly as __builtin_assume_aligned
    is no longer taken into account for the same reason as why PR 111875
    is closed as invalid and why the testcase is failing at -Og
    I added a new testcase align-5a.c where the pointer is explictly aligned
    so that the check is gone there.
    Note __builtin_assume_aligned should really be instrumented for UBSAN,
    I filed PR 122038 for that.

    Bootstrapped and tested on x86_64-linux-gnu.

            PR tree-optimization/121762
    gcc/ChangeLog:

            * gimple-fold.cc (gimple_fold_builtin_assume_aligned): New
function.
            (gimple_fold_builtin): Call gimple_fold_builtin_assume_aligned
            for BUILT_IN_ASSUME_ALIGNED.
            * tree-ssa-ccp.cc (pass_fold_builtins::execute): Remove handling
            of BUILT_IN_ASSUME_ALIGNED.

    gcc/testsuite/ChangeLog:

            * c-c++-common/ubsan/align-5.c: Update as __builtin_assume_aligned
            is no longer taked into account.
            * c-c++-common/ubsan/align-5a.c: New test.

    Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>