A6
q = r2 + r * r * (A2 + r * (A3 + r * (A4 + r * (A5 + r * (A6 +
A6 = 1.38888888888888888889971139751596836e-3L;
q = r2 + r * r * (A2 + r * (A3 + r * (A4 + r * (A5 + r * (A6 +
q = r2 + z * (A2 + r * A3) + z * z * (A4 + r * A5) + z * z * z * A6;
q = r2 + z * A2 + z * r * (A3 + r * A4 + z * (A5 + r * A6));
A6 = 1.3888891738560272e-3; /* 0x16c16c651633ae.0p-62 */
q = r2 + z * (A2 + r * A3) + z * z * (A4 + r * A5) + z * z * z * A6;