enable f16;
var<private> t : f32;
fn m() -> mat2x2<f32> {
    t = t + 1.0f;
    return mat2x2<f32>(1.0f, 2.0f,
                       3.0f, 4.0f);
}
fn f() {
    var v : mat2x2<f16> = mat2x2<f16>(m());
}