__log2
u_int32_t __log2(u_int32_t);
hashp->BSHIFT = __log2(hashp->BSIZE);
hashp->BSHIFT = __log2(info->bsize);
l2 = __log2(MAXIMUM(nelem, 2));
nsegs = 1 << __log2(nsegs);
spare_ndx = __log2(hashp->MAX_BUCKET + 1);
(B) + hashp->HDRPAGES + ((B) ? hashp->SPARES[__log2((B)+1)-1] : 0)