ParagonIE_Sodium_Core32_Int64::rotateRight

    public function rotateRight($c = 0)
    {
        ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
        /** @var int $c */
        $c = (int) $c;

        /** @var ParagonIE_Sodium_Core32_Int64 $return */
        $return = new ParagonIE_Sodium_Core32_Int64();
        $return->unsignedInt = $this->unsignedInt;
        $c &= 63;
        /** @var int $c */
        if ($c === 0) {
            // NOP, but we want a copy.
            $return->limbs = $this->limbs;
        } else {
            /** @var array<int, int> $limbs */
            $limbs =& $return->limbs;

            /** @var array<int, int> $myLimbs */
            $myLimbs =& $this->limbs;

            /** @var int $idx_shift */
            $idx_shift = ($c >> 4) & 3;
            /** @var int $sub_shift */
            $sub_shift = $c & 15;

            for ($i = 3; $i >= 0; --$i) {
                /** @var int $j */
                $j = ($i - $idx_shift) & 3;
                /** @var int $k */
                $k = ($i - $idx_shift - 1) & 3;
                $limbs[$i] = (int) (
                    (
                        ((int) ($myLimbs[$j]) >> (int) ($sub_shift))
                            |
                        ((int) ($myLimbs[$k]) << (16 - (int) ($sub_shift)))
                    ) & 0xffff
                );
            }
        }
        return $return;
    }