[Bug tree-optimization/96722] [8/9/10/11 Regression] Clobbers on NULL since r8-1519

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96722

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:dff497c29a4f2a4cb3f0cb693e14f30734888845

commit r10-8671-gdff497c29a4f2a4cb3f0cb693e14f30734888845
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Aug 25 13:49:40 2020 +0200

    gimple: Ignore *0 = {CLOBBER} in path isolation [PR96722]

    Clobbers of MEM_REF with NULL address are just fancy nops, something we
just
    ignore and don't emit any code for it (ditto for other clobbers), they just
    mark end of life on something, so we shouldn't infer from those that there
    is some UB.

    2020-08-25  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/96722
            * gimple.c (infer_nonnull_range): Formatting fix.
            (infer_nonnull_range_by_dereference): Return false for clobber
stmts.

            * g++.dg/opt/pr96722.C: New test.

    (cherry picked from commit a5b15fcb954ba63d58f0daa700281aba33b5f24a)