/*
 * This is a common helper function for find_next_bit, find_next_zero_bit, and
 * find_next_and_bit. The differences are:
 *  - The "invert" argument, which is XORed with each fetched word before
 *    searching it for one bits.
 *  - The optional "addr2", which is anded with "addr1" if present.
 */
static inline unsigned long _find_next_bit(const unsigned long *addr1,
                const unsigned long *addr2, unsigned long nbits,
                unsigned long start, unsigned long invert)
{
        unsigned long tmp;

        if (unlikely(start >= nbits))
                return nbits;

        tmp = addr1[start / BITS_PER_LONG];
        if (addr2)
                tmp &= addr2[start / BITS_PER_LONG];
        tmp ^= invert;

        /* Handle 1st word */
        tmp &= BITMAP_FIRST_WORD_MASK(start);
        start = round_down(start, BITS_PER_LONG);

        while (!tmp) {
                start += BITS_PER_LONG;
                if (start >= nbits)
                        return nbits;

                tmp = addr1[start / BITS_PER_LONG];
                if (addr2)
                        tmp &= addr2[start / BITS_PER_LONG];
                tmp ^= invert;
        }

        return min(start + __ffs(tmp), nbits);
}