- const cluster_t mid_start = (start + 7) / 8 * 8;
- const cluster_t mid_end = end / 8 * 8;
- cluster_t c;
- cluster_t byte;
-
- for (c = start; c < mid_start; c++)
- if (BMAP_GET(bitmap, c) == 0)
- {
- BMAP_SET(bitmap, c);
- return c + EXFAT_FIRST_DATA_CLUSTER;
- }
-
- for (byte = mid_start / 8; byte < mid_end / 8; byte++)
- if (bitmap[byte] != 0xff)
- {
- cluster_t bit;
-
- for (bit = 0; bit < 8; bit++)
- if (!(bitmap[byte] & (1u << bit)))
- {
- bitmap[byte] |= (1u << bit);
- return byte * 8 + bit + EXFAT_FIRST_DATA_CLUSTER;
- }
- }
-
- for (c = mid_end; c < end; c++)
- if (BMAP_GET(bitmap, c) == 0)
- {
- BMAP_SET(bitmap, c);
- return c + EXFAT_FIRST_DATA_CLUSTER;
- }
+ const size_t start_index = start / 8;
+ const size_t end_index = DIV_ROUND_UP(end, 8);
+ size_t i;
+ size_t c;