[pixel shader]
float4 main(uniform float4 u) : sv_target
{
    return float4(pow(u.y, 3), pow(u.xy, u.zw), pow(0.5, u.w));
}

[test]
uniform 0 float4 0.4 0.8 2.5 2.0
draw quad
probe all rgba (0.512, 0.101192884, 0.64, 0.25) 4