PHPに移植するもっともスマートな方法は…

gistfile1.java

  public double vranlc(double n, double x, double a, double y[],int offset){ 
    long Lx = (long)x;
    long La = (long)a;

    for(int i=0;i<n;i++){
      Lx   = (Lx*La) & (i246m1); //long i246m1 = pow(2, 46) - 1
      y[offset+i] = (double)(d2m46* Lx); //double d2m46 = pow(0.5, 46)
    }
    return (double) Lx;
  }