ParagonIE_Sodium_Core_Curve25519::fe_sq

    public static function fe_sq(ParagonIE_Sodium_Core_Curve25519_Fe $f)
    {
        $f0 = (int) $f[0];
        $f1 = (int) $f[1];
        $f2 = (int) $f[2];
        $f3 = (int) $f[3];
        $f4 = (int) $f[4];
        $f5 = (int) $f[5];
        $f6 = (int) $f[6];
        $f7 = (int) $f[7];
        $f8 = (int) $f[8];
        $f9 = (int) $f[9];

        /** @var int $f0_2 */
        $f0_2 = $f0 << 1;
        /** @var int $f1_2 */
        $f1_2 = $f1 << 1;
        /** @var int $f2_2 */
        $f2_2 = $f2 << 1;
        /** @var int $f3_2 */
        $f3_2 = $f3 << 1;
        /** @var int $f4_2 */
        $f4_2 = $f4 << 1;
        /** @var int $f5_2 */
        $f5_2 = $f5 << 1;
        /** @var int $f6_2 */
        $f6_2 = $f6 << 1;
        /** @var int $f7_2 */
        $f7_2 = $f7 << 1;
        $f5_38 = self::mul($f5, 38, 6);
        $f6_19 = self::mul($f6, 19, 5);
        $f7_38 = self::mul($f7, 38, 6);
        $f8_19 = self::mul($f8, 19, 5);
        $f9_38 = self::mul($f9, 38, 6);
        $f0f0    = self::mul($f0,    $f0,    25);
        $f0f1_2  = self::mul($f0_2,  $f1,    24);
        $f0f2_2  = self::mul($f0_2,  $f2,    25);
        $f0f3_2  = self::mul($f0_2,  $f3,    24);
        $f0f4_2  = self::mul($f0_2,  $f4,    25);
        $f0f5_2  = self::mul($f0_2,  $f5,    25);
        $f0f6_2  = self::mul($f0_2,  $f6,    25);
        $f0f7_2  = self::mul($f0_2,  $f7,    24);
        $f0f8_2  = self::mul($f0_2,  $f8,    25);
        $f0f9_2  = self::mul($f0_2,  $f9,    25);
        $f1f1_2  = self::mul($f1_2,  $f1,    24);
        $f1f2_2  = self::mul($f1_2,  $f2,    25);
        $f1f3_4  = self::mul($f1_2,  $f3_2,  25);
        $f1f4_2  = self::mul($f1_2,  $f4,    25);
        $f1f5_4  = self::mul($f1_2,  $f5_2,  26);
        $f1f6_2  = self::mul($f1_2,  $f6,    25);
        $f1f7_4  = self::mul($f1_2,  $f7_2,  25);
        $f1f8_2  = self::mul($f1_2,  $f8,    25);
        $f1f9_76 = self::mul($f9_38, $f1_2,  25);
        $f2f2    = self::mul($f2,    $f2,    25);
        $f2f3_2  = self::mul($f2_2,  $f3,    24);
        $f2f4_2  = self::mul($f2_2,  $f4,    25);
        $f2f5_2  = self::mul($f2_2,  $f5,    25);
        $f2f6_2  = self::mul($f2_2,  $f6,    25);
        $f2f7_2  = self::mul($f2_2,  $f7,    24);
        $f2f8_38 = self::mul($f8_19, $f2_2,  26);
        $f2f9_38 = self::mul($f9_38, $f2,    25);
        $f3f3_2  = self::mul($f3_2,  $f3,    24);
        $f3f4_2  = self::mul($f3_2,  $f4,    25);
        $f3f5_4  = self::mul($f3_2,  $f5_2,  26);
        $f3f6_2  = self::mul($f3_2,  $f6,    25);
        $f3f7_76 = self::mul($f7_38, $f3_2,  25);
        $f3f8_38 = self::mul($f8_19, $f3_2,  25);
        $f3f9_76 = self::mul($f9_38, $f3_2,  25);
        $f4f4    = self::mul($f4,    $f4,    25);
        $f4f5_2  = self::mul($f4_2,  $f5,    25);
        $f4f6_38 = self::mul($f6_19, $f4_2,  26);
        $f4f7_38 = self::mul($f7_38, $f4,    25);
        $f4f8_38 = self::mul($f8_19, $f4_2,  26);
        $f4f9_38 = self::mul($f9_38, $f4,    25);
        $f5f5_38 = self::mul($f5_38, $f5,    25);
        $f5f6_38 = self::mul($f6_19, $f5_2,  26);
        $f5f7_76 = self::mul($f7_38, $f5_2,  26);
        $f5f8_38 = self::mul($f8_19, $f5_2,  26);
        $f5f9_76 = self::mul($f9_38, $f5_2,  26);
        $f6f6_19 = self::mul($f6_19, $f6,    25);
        $f6f7_38 = self::mul($f7_38, $f6,    25);
        $f6f8_38 = self::mul($f8_19, $f6_2,  26);
        $f6f9_38 = self::mul($f9_38, $f6,    25);
        $f7f7_38 = self::mul($f7_38, $f7,    24);
        $f7f8_38 = self::mul($f8_19, $f7_2,  25);
        $f7f9_76 = self::mul($f9_38, $f7_2,  25);
        $f8f8_19 = self::mul($f8_19, $f8,    25);
        $f8f9_38 = self::mul($f9_38, $f8,    25);
        $f9f9_38 = self::mul($f9_38, $f9,    25);
        $h0 = $f0f0   + $f1f9_76 + $f2f8_38 + $f3f7_76 + $f4f6_38 + $f5f5_38;
        $h1 = $f0f1_2 + $f2f9_38 + $f3f8_38 + $f4f7_38 + $f5f6_38;
        $h2 = $f0f2_2 + $f1f1_2  + $f3f9_76 + $f4f8_38 + $f5f7_76 + $f6f6_19;
        $h3 = $f0f3_2 + $f1f2_2  + $f4f9_38 + $f5f8_38 + $f6f7_38;
        $h4 = $f0f4_2 + $f1f3_4  + $f2f2    + $f5f9_76 + $f6f8_38 + $f7f7_38;
        $h5 = $f0f5_2 + $f1f4_2  + $f2f3_2  + $f6f9_38 + $f7f8_38;
        $h6 = $f0f6_2 + $f1f5_4  + $f2f4_2  + $f3f3_2  + $f7f9_76 + $f8f8_19;
        $h7 = $f0f7_2 + $f1f6_2  + $f2f5_2  + $f3f4_2  + $f8f9_38;
        $h8 = $f0f8_2 + $f1f7_4  + $f2f6_2  + $f3f5_4  + $f4f4    + $f9f9_38;
        $h9 = $f0f9_2 + $f1f8_2  + $f2f7_2  + $f3f6_2  + $f4f5_2;

        /** @var int $carry0 */
        $carry0 = ($h0 + (1 << 25)) >> 26;
        $h1 += $carry0;
        $h0 -= $carry0 << 26;
        /** @var int $carry4 */
        $carry4 = ($h4 + (1 << 25)) >> 26;
        $h5 += $carry4;
        $h4 -= $carry4 << 26;

        /** @var int $carry1 */
        $carry1 = ($h1 + (1 << 24)) >> 25;
        $h2 += $carry1;
        $h1 -= $carry1 << 25;
        /** @var int $carry5 */
        $carry5 = ($h5 + (1 << 24)) >> 25;
        $h6 += $carry5;
        $h5 -= $carry5 << 25;

        /** @var int $carry2 */
        $carry2 = ($h2 + (1 << 25)) >> 26;
        $h3 += $carry2;
        $h2 -= $carry2 << 26;
        /** @var int $carry6 */
        $carry6 = ($h6 + (1 << 25)) >> 26;
        $h7 += $carry6;
        $h6 -= $carry6 << 26;

        /** @var int $carry3 */
        $carry3 = ($h3 + (1 << 24)) >> 25;
        $h4 += $carry3;
        $h3 -= $carry3 << 25;
        /** @var int $carry7 */
        $carry7 = ($h7 + (1 << 24)) >> 25;
        $h8 += $carry7;
        $h7 -= $carry7 << 25;

        /** @var int $carry4 */
        $carry4 = ($h4 + (1 << 25)) >> 26;
        $h5 += $carry4;
        $h4 -= $carry4 << 26;
        /** @var int $carry8 */
        $carry8 = ($h8 + (1 << 25)) >> 26;
        $h9 += $carry8;
        $h8 -= $carry8 << 26;

        /** @var int $carry9 */
        $carry9 = ($h9 + (1 << 24)) >> 25;
        $h0 += self::mul($carry9, 19, 5);
        $h9 -= $carry9 << 25;

        /** @var int $carry0 */
        $carry0 = ($h0 + (1 << 25)) >> 26;
        $h1 += $carry0;
        $h0 -= $carry0 << 26;

        return ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(
            array(
                (int) $h0,
                (int) $h1,
                (int) $h2,
                (int) $h3,
                (int) $h4,
                (int) $h5,
                (int) $h6,
                (int) $h7,
                (int) $h8,
                (int) $h9
            )
        );
    }