BMAP_WSIZE
#define MEM_LEN(l) (ROUNDUP((l), BMAP_BPW) * BMAP_WSIZE)
m = cp->c_mlen / BMAP_WSIZE;
#define BMAP_BPW (BMAP_WSIZE * 8)
#define BMAP_CHUNK_BYTES (BMAP_CHUNK_WORDS * BMAP_WSIZE)