[Bug tree-optimization/96722] [8/9 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 #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:acd97038dba34830520ed58915d509d21348b554

commit r9-8910-gacd97038dba34830520ed58915d509d21348b554
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)