[pixel shader]
uniform float4 x;

float4 main() : SV_TARGET
{
    return x.x ? x : x - 1;
}

[test]
uniform 0 float4 2.0 3.0 4.0 5.0
draw quad
probe all rgba (2.0, 3.0, 4.0, 5.0)
uniform 0 float4 0.0 10.0 11.0 12.0
draw quad
probe all rgba (-1.0, 9.0, 10.0, 11.0)