@group(0) @binding(0) var<uniform> u : mat4x4<f32>;
@group(0) @binding(1) var<storage, read_write> s : mat4x4<f32>;

@compute @workgroup_size(1)
fn f() {
    s = u;
    s[1] = u[0];
    s[1] = u[0].ywxz;
    s[0][1] = u[1][0];
}