UZ_SLIDE_CHUNK
(unsigned)(((WSIZE+UZ_SLIDE_CHUNK-1)/UZ_SLIDE_CHUNK > HSIZE) ? \
(WSIZE+UZ_SLIDE_CHUNK-1)/UZ_SLIDE_CHUNK : HSIZE)
G.area.Slide = (uch *)zcalloc(UZ_NUMOF_CHUNKS, UZ_SLIDE_CHUNK);