https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93946
Bug ID: 93946
Summary: Bogus redundant store removal
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: rguenth at gcc dot gnu.org
Target Milestone: ---
union U { long long i; long f; };
struct a {union U u;};
struct aa {struct a a;};
struct b {union U u;};
struct bb {struct b b;};
long
foo (struct bb *bv, void *ptr)
{
struct aa *a = ptr;
struct bb *b = ptr;
bv->b.u.f = 1;
a->a.u.i = 0;
b->b.u.f = 0;
return bv->b.u.f;
}
int
main ()
{
union C {struct aa aa; struct bb bb;} v;
if (foo (&v.bb, &v) != 0)
__builtin_abort ();
return 0;
}
we treat b->b.u.f = 0 as redundant because the alias-set of that and the
a->a.u.i = 0 store are actually the same.
