ParagonIE_Sodium_Core32_Int64::shiftRight

    public function shiftRight($c = 0)
    {
        ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
        $c = (int) $c;
        /** @var int $c */
        $return = new ParagonIE_Sodium_Core32_Int64();
        $return->unsignedInt = $this->unsignedInt;
        $c &= 63;

        $negative = -(($this->limbs[0] >> 15) & 1);
        if ($c >= 16) {
            if ($c >= 48) {
                $return->limbs = array(
                    (int) ($negative & 0xffff),
                    (int) ($negative & 0xffff),
                    (int) ($negative & 0xffff),
                    (int) $this->limbs[0]
                );
            } elseif ($c >= 32) {
                $return->limbs = array(
                    (int) ($negative & 0xffff),
                    (int) ($negative & 0xffff),
                    (int) $this->limbs[0],
                    (int) $this->limbs[1]
                );
            } else {
                $return->limbs = array(
                    (int) ($negative & 0xffff),
                    (int) $this->limbs[0],
                    (int) $this->limbs[1],
                    (int) $this->limbs[2]
                );
            }
            return $return->shiftRight($c & 15);
        }

        if ($c === 0) {
            $return->limbs = $this->limbs;
        } elseif ($c < 0) {
            return $this->shiftLeft(-$c);
        } else {
            if (!is_int($c)) {
                throw new TypeError();
            }
            /** @var int $carryRight */
            $carryRight = ($negative & 0xffff);
            $mask = (int) (((1 << ($c + 1)) - 1) & 0xffff);
            for ($i = 0; $i < 4; ++$i) {
                $return->limbs[$i] = (int) (
                    (($this->limbs[$i] >> $c) | ($carryRight << (16 - $c))) & 0xffff
                );
                $carryRight = (int) ($this->limbs[$i] & $mask);
            }
        }
        return $return;
    }