varying lowp float xx;

void main()
{
	int x;

    int i = (x=(xx>0.5?2:4)); // side effects!
    
    if (x < 2)
        discard;

    lowp float c = 0.0;
    for (; i < 4; ++i)
        c += xx;
    gl_FragColor = vec4(c);
}