src/hotspot/share/gc/g1/g1FullGCCompactionPoint.cpp

@@ -94,13 +94,18 @@
  }
  
  void G1FullGCCompactionPoint::forward(oop object, size_t size) {
    assert(_current_region != nullptr, "Must have been initialized");
  
+   size_t old_size = size;
+   size_t new_size = object->copy_size(old_size, object->mark());
+   size = cast_from_oop<HeapWord*>(object) != _compaction_top ? new_size : old_size;
+ 
    // Ensure the object fit in the current region.
    while (!object_will_fit(size)) {
      switch_region();
+     size = cast_from_oop<HeapWord*>(object) != _compaction_top ? new_size : old_size;
    }
  
    // Store a forwarding pointer if the object should be moved.
    if (cast_from_oop<HeapWord*>(object) != _compaction_top) {
      if (!object->is_forwarded()) {

@@ -151,12 +156,13 @@
  
  void G1FullGCCompactionPoint::forward_humongous(G1HeapRegion* hr) {
    assert(hr->is_starts_humongous(), "Sanity!");
  
    oop obj = cast_to_oop(hr->bottom());
-   size_t obj_size = obj->size();
-   uint num_regions = (uint)G1CollectedHeap::humongous_obj_size_in_regions(obj_size);
+   size_t old_size = obj->size();
+   size_t new_size = obj->copy_size(old_size, obj->mark());
+   uint num_regions = (uint)G1CollectedHeap::humongous_obj_size_in_regions(new_size);
  
    if (!has_regions()) {
      return;
    }
  

@@ -170,10 +176,11 @@
  
    // Preserve the mark for the humongous object as the region was initially not compacting.
    preserved_stack()->push_if_necessary(obj, obj->mark());
  
    G1HeapRegion* dest_hr = _compaction_regions->at(range_begin);
+   assert(hr->bottom() != dest_hr->bottom(), "assuming actual humongous move");
    FullGCForwarding::forward_to(obj, cast_to_oop(dest_hr->bottom()));
    assert(FullGCForwarding::is_forwarded(obj), "Object must be forwarded!");
  
    // Add the humongous object regions to the compaction point.
    add_humongous(hr);