GC_unmap_gap      430 gc/allchblk.c  		GC_unmap_gap((ptr_t)h, size, (ptr_t)next, nexthdr -> hb_sz);
GC_unmap_gap     1772 gc/include/private/gc_priv.h   void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2);