1655   size_t               prev_foot;  /* Size of previous chunk (if free).  */  member
1737 #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) ))
1743 #define get_foot(p, s)  (((mchunkptr)((char*)(p) + (s)))->prev_foot)
1744 #define set_foot(p, s)  (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s))
1755   (!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_MMAPPED_BIT))
1861   size_t                    prev_foot;  member
2484   (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic))
2488     (chunksize(p))))->prev_foot ^ mparams.magic))
2638   size_t len = (sz + (p->prev_foot & ~IS_MMAPPED_BIT) + MMAP_FOOT_PAD);  in do_check_mmapped_chunk()
2672       assert(next->prev_foot == sz);  in do_check_free_chunk()
3223       p->prev_foot = offset | IS_MMAPPED_BIT;  in mmap_alloc()
3251     size_t offset = oldp->prev_foot & ~IS_MMAPPED_BIT;  in mmap_resize()
3951           newp->prev_foot = p->prev_foot + leadsize;  in internal_memalign()
4279           size_t prevsize = p->prev_foot;  in dlfree()
4680           size_t prevsize = p->prev_foot;  in mspace_free()