https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88367
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think even the old
if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
set_value_range_to_nonnull (vr, expr_type);
code is wrong with -fno-delete-null-pointer-checks (which is overloaded with
the case that address zero is a valid pointer to an object). So IMHO you
can simplify the patch and guard the affected places with
flag_delete_null_pointer_checks.
Strictly the kernel case of computing NULL - 24 invokes UB and needs
-fwrapv-pointer (but IIRC the kernel uses -fno-strict-overflow which
enables that already). I don't think we exploint wrapping UB for
pointers in the VRP case though.
