MAP_ENTRY_SPLIT_BOUNDARY_INDEX
bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(fs->entry);
bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
bidx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);
bdry_idx = MAP_ENTRY_SPLIT_BOUNDARY_INDEX(entry);