149     cp->threshold = cp->space->initialize_threshold();
 150     cp->space->set_compaction_top(cp->space->bottom());
 151   }
 152 
 153   HeapWord* compact_top = cp->space->compaction_top(); // This is where we are currently compacting to.
 154 
 155   DeadSpacer dead_spacer(space);
 156 
 157   HeapWord*  end_of_live = space->bottom();  // One byte beyond the last byte of the last live object.
 158   HeapWord*  first_dead = NULL; // The first dead object.
 159 
 160   const intx interval = PrefetchScanIntervalInBytes;
 161 
 162   HeapWord* cur_obj = space->bottom();
 163   HeapWord* scan_limit = space->scan_limit();
 164 
 165   while (cur_obj < scan_limit) {
 166     assert(!space->scanned_block_is_obj(cur_obj) ||
 167            oop(cur_obj)->mark_raw()->is_marked() || oop(cur_obj)->mark_raw()->is_unlocked() ||
 168            oop(cur_obj)->mark_raw()->has_bias_pattern(),
 169            "these are the only valid states during a mark sweep");
 170     if (space->scanned_block_is_obj(cur_obj) && oop(cur_obj)->is_gc_marked()) {
 171       // prefetch beyond cur_obj
 172       Prefetch::write(cur_obj, interval);
 173       size_t size = space->scanned_block_size(cur_obj);
 174       compact_top = cp->space->forward(oop(cur_obj), size, cp, compact_top);
 175       cur_obj += size;
 176       end_of_live = cur_obj;
 177     } else {
 178       // run over all the contiguous dead objects
 179       HeapWord* end = cur_obj;
 180       do {
 181         // prefetch beyond end
 182         Prefetch::write(end, interval);
 183         end += space->scanned_block_size(end);
 184       } while (end < scan_limit && (!space->scanned_block_is_obj(end) || !oop(end)->is_gc_marked()));
 185 
 186       // see if we might want to pretend this object is alive so that
 187       // we don't have to compact quite as often.
 188       if (cur_obj == compact_top && dead_spacer.insert_deadspace(cur_obj, end)) {
 189         oop obj = oop(cur_obj);

 149     cp->threshold = cp->space->initialize_threshold();
 150     cp->space->set_compaction_top(cp->space->bottom());
 151   }
 152 
 153   HeapWord* compact_top = cp->space->compaction_top(); // This is where we are currently compacting to.
 154 
 155   DeadSpacer dead_spacer(space);
 156 
 157   HeapWord*  end_of_live = space->bottom();  // One byte beyond the last byte of the last live object.
 158   HeapWord*  first_dead = NULL; // The first dead object.
 159 
 160   const intx interval = PrefetchScanIntervalInBytes;
 161 
 162   HeapWord* cur_obj = space->bottom();
 163   HeapWord* scan_limit = space->scan_limit();
 164 
 165   while (cur_obj < scan_limit) {
 166     assert(!space->scanned_block_is_obj(cur_obj) ||
 167            oop(cur_obj)->mark_raw()->is_marked() || oop(cur_obj)->mark_raw()->is_unlocked() ||
 168            oop(cur_obj)->mark_raw()->has_bias_pattern(),
 169            "these are the only valid states during a mark sweep (%p)", cur_obj);
 170     if (space->scanned_block_is_obj(cur_obj) && oop(cur_obj)->is_gc_marked()) {
 171       // prefetch beyond cur_obj
 172       Prefetch::write(cur_obj, interval);
 173       size_t size = space->scanned_block_size(cur_obj);
 174       compact_top = cp->space->forward(oop(cur_obj), size, cp, compact_top);
 175       cur_obj += size;
 176       end_of_live = cur_obj;
 177     } else {
 178       // run over all the contiguous dead objects
 179       HeapWord* end = cur_obj;
 180       do {
 181         // prefetch beyond end
 182         Prefetch::write(end, interval);
 183         end += space->scanned_block_size(end);
 184       } while (end < scan_limit && (!space->scanned_block_is_obj(end) || !oop(end)->is_gc_marked()));
 185 
 186       // see if we might want to pretend this object is alive so that
 187       // we don't have to compact quite as often.
 188       if (cur_obj == compact_top && dead_spacer.insert_deadspace(cur_obj, end)) {
 189         oop obj = oop(cur_obj);