ROUNDDOWN
p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
start = ROUNDDOWN(start, startalign);
maxstop = ROUNDDOWN(chunk->stop, stopalign);
maxstop = ROUNDDOWN(ending_sector, stopalign);
stop = ROUNDDOWN(stop, stopalign);
lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER));
char inbuf[ROUNDDOWN(BUFSIZ, 4) + 1];