src/hotspot/share/gc/z/zForwardingEntry.hpp

*** 30,73 ****
  
  //
  // Forwarding entry layout
  // -----------------------
  //
! //   6                      4 4                                             0
! //   3                      2 1                                             0
! //  +------------------------+-----------------------------------------------+
! //  |11111111 11111111 111111|11 11111111 11111111 11111111 11111111 11111111|
! //  +------------------------+-----------------------------------------------+
! //  |                        |
! //  |                        * 41-0 To Object Offset (42-bits)
  //  |
! //  * 63-42 From Object Index (22-bits)
  //
  
  class ZForwardingEntry {
    friend struct PrimitiveConversions;
  
  private:
!   typedef ZBitField<uint64_t, size_t, 0,  42> field_to_offset;
!   typedef ZBitField<uint64_t, size_t, 42, 22> field_from_index;
  
    uint64_t _entry;
  
-   static uintptr_t empty() {
-     return (uintptr_t)-1;
-   }
- 
  public:
    ZForwardingEntry() :
!       _entry(empty()) {}
  
    ZForwardingEntry(size_t from_index, size_t to_offset) :
!       _entry(field_from_index::encode(from_index) |
!              field_to_offset::encode(to_offset)) {}
  
!   bool is_empty() const {
!     return _entry == empty();
    }
  
    size_t to_offset() const {
      return field_to_offset::decode(_entry);
    }
--- 30,73 ----
  
  //
  // Forwarding entry layout
  // -----------------------
  //
! //   6                  4 4
! //   3                  6 5                                                1 0
! //  +--------------------+--------------------------------------------------+-+
! //  |11111111 11111111 11|111111 11111111 11111111 11111111 11111111 1111111|1|
! //  +--------------------+--------------------------------------------------+-+
! //  |                    |                                                  |
! //  |                    |                      0-0 Populated Flag (1-bits) *
! //  |                    |
! //  |                    * 45-1 To Object Offset (45-bits)
  //  |
! //  * 63-46 From Object Index (18-bits)
  //
  
  class ZForwardingEntry {
    friend struct PrimitiveConversions;
  
  private:
!   typedef ZBitField<uint64_t, bool,   0,   1> field_populated;
!   typedef ZBitField<uint64_t, size_t, 1,  45> field_to_offset;
!   typedef ZBitField<uint64_t, size_t, 46, 18> field_from_index;
  
    uint64_t _entry;
  
  public:
    ZForwardingEntry() :
!       _entry(0) {}
  
    ZForwardingEntry(size_t from_index, size_t to_offset) :
!       _entry(field_populated::encode(true) |
!              field_to_offset::encode(to_offset) |
!              field_from_index::encode(from_index)) {}
  
!   bool populated() const {
!     return field_populated::decode(_entry);
    }
  
    size_t to_offset() const {
      return field_to_offset::decode(_entry);
    }