struct VS_OUTPUT        {
    float4 Position             : SV_Position;
    float3 clip0                : SV_ClipDistance0;  // multiple semantic IDs, vec3+float (pack)
    float  clip1                : SV_ClipDistance1;  // ...
};

float4 main(VS_OUTPUT v) : SV_Target0
{
    return v.Position + v.clip0.x + v.clip1;
}