BMAP_BPW
#define MEM_LEN(l) (ROUNDUP((l), BMAP_BPW) * BMAP_WSIZE)
if (++cnt >= BMAP_BPW) {
for (i = 0; i < m; q += BMAP_BPW, bp++, i++)
if (++cnt >= BMAP_BPW) {
#define BMAP_CHUNK_BITS (BMAP_CHUNK_WORDS * BMAP_BPW)