mulInt64 example

->shiftRight(6)
                    ->mask(0x3ffffff)
            )->toInt64();
            $h4 = $h4->addInt32(
                ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($message, 12, 4))
                    ->shiftRight(8)
                    ->orInt32($hibit)
            )->toInt64();

            /* h *= r */
            $d0 = $zero
                ->addInt64($h0->mulInt64($r0, 27))
                ->addInt64($s4->mulInt64($h1, 27))
                ->addInt64($s3->mulInt64($h2, 27))
                ->addInt64($s2->mulInt64($h3, 27))
                ->addInt64($s1->mulInt64($h4, 27));

            $d1 = $zero
                ->addInt64($h0->mulInt64($r1, 27))
                ->addInt64($h1->mulInt64($r0, 27))
                ->addInt64($s4->mulInt64($h2, 27))
                ->addInt64($s3->mulInt64($h3, 27))
                ->addInt64($s2->mulInt64($h4, 27));

            

$g4_19 = $g4->mulInt(19, 5);
        $g5_19 = $g5->mulInt(19, 5);
        $g6_19 = $g6->mulInt(19, 5);
        $g7_19 = $g7->mulInt(19, 5);
        $g8_19 = $g8->mulInt(19, 5);
        $g9_19 = $g9->mulInt(19, 5);
        $f1_2 = $f1->shiftLeft(1);
        $f3_2 = $f3->shiftLeft(1);
        $f5_2 = $f5->shiftLeft(1);
        $f7_2 = $f7->shiftLeft(1);
        $f9_2 = $f9->shiftLeft(1);
        $f0g0    = $f0->mulInt64($g0, 27);
        $f0g1    = $f0->mulInt64($g1, 27);
        $f0g2    = $f0->mulInt64($g2, 27);
        $f0g3    = $f0->mulInt64($g3, 27);
        $f0g4    = $f0->mulInt64($g4, 27);
        $f0g5    = $f0->mulInt64($g5, 27);
        $f0g6    = $f0->mulInt64($g6, 27);
        $f0g7    = $f0->mulInt64($g7, 27);
        $f0g8    = $f0->mulInt64($g8, 27);
        $f0g9    = $f0->mulInt64($g9, 27);
        $f1g0    = $f1->mulInt64($g0, 27);
        $f1g1_2  = $f1_2->mulInt64($g1, 27);
        

return true;
        }
        /** @var float $end */
        $end = 0.0;
        /** @var float $start */
        $start = microtime(true);
        /** @var ParagonIE_Sodium_Core32_Int64 $a */
        $a = ParagonIE_Sodium_Core32_Int64::fromInt(random_int(3, 1 << 16));
        for ($i = 0; $i < $iterations; ++$i) {
            /** @var ParagonIE_Sodium_Core32_Int64 $b */
            $b = ParagonIE_Sodium_Core32_Int64::fromInt(random_int(3, 1 << 16));
            $a->mulInt64($b);
        }
        /** @var float $end */
        $end = microtime(true);
        /** @var int $diff */
        $diff = (int) ceil(($end - $start) * 1000);
        return $diff < $maxTimeout;
    }

    /** * Add two numbers (little-endian unsigned), storing the value in the first * parameter. * * This mutates $val. * * @param string $val * @param string $addv * @return void * @throws SodiumException */