struct A {
    int x;
    int y;
} a1, a2;
A a3;

struct B {
    float x;
    float y[2];
    layout(binding=1) A z;
};
B b1, b2, b3;

void main() {
    a1.x = 0;
    b1.x = 0;
    sk_FragColor.r = half(a1.x) + half(b1.x);
}