3276   mchunkptr oldfirst = align_as_chunk(oldbase);  in prepend_alloc()  local
3277   size_t psize = (char*)oldfirst - (char*)p;  in prepend_alloc()
3282   assert((char*)oldfirst > (char*)q);  in prepend_alloc()
3283   assert(pinuse(oldfirst));  in prepend_alloc()
3287   if (oldfirst == m->top) {  in prepend_alloc()
3293   else if (oldfirst == m->dv) {  in prepend_alloc()
3299     if (!cinuse(oldfirst)) {  in prepend_alloc()
3300       size_t nsize = chunksize(oldfirst);  in prepend_alloc()
3301       unlink_chunk(m, oldfirst, nsize);  in prepend_alloc()
3302       oldfirst = chunk_plus_offset(oldfirst, nsize);  in prepend_alloc()
3305     set_free_with_pinuse(q, qsize, oldfirst);  in prepend_alloc()