ParagonIE_Sodium_Core32_Int32::toInt64

    public function toInt64()
    {
        $return = new ParagonIE_Sodium_Core32_Int64();
        $return->unsignedInt = $this->unsignedInt;
        if ($this->unsignedInt) {
            $return->limbs[0] += (($this->overflow >> 16) & 0xffff);
            $return->limbs[1] += (($this->overflow) & 0xffff);
        } else {
            $neg = -(($this->limbs[0] >> 15) & 1);
            $return->limbs[0] = (int)($neg & 0xffff);
            $return->limbs[1] = (int)($neg & 0xffff);
        }
        $return->limbs[2] = (int) ($this->limbs[0] & 0xffff);
        $return->limbs[3] = (int) ($this->limbs[1] & 0xffff);
        return $return;
    }