https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91597
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
As mentioned by Richi,
else if (code == BIT_AND_EXPR)
{
/* For pointer types, we are really only interested in asserting
whether the expression evaluates to non-NULL. */
if (!range_includes_zero_p (&vr0) && !range_includes_zero_p (&vr1))
vr->set_nonzero (expr_type);
is incorrect, even when both pointer value ranges are non-zero, the result of
BIT_AND_EXPR can be zero, as can be seen on this testcase. The first argument
being non-NULL as dereferenced, the other argument constant 1B, the pointer
aligned and thus actually & 1 always zero, not always non-zero, but even if it
would not be always aligned, it could be sometimes zero and sometimes not.
