Revert of Embedded constant pools.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 526f20dd1893d148c339fe53e86917914adfa0ab..4f78eb16bce0fda15784457623c551a70f2ca5c6 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -445,6 +445,7 @@
                                                                 \
   V(FIXED_ARRAY_TYPE)                                           \
   V(FIXED_DOUBLE_ARRAY_TYPE)                                    \
+  V(CONSTANT_POOL_ARRAY_TYPE)                                   \
   V(SHARED_FUNCTION_INFO_TYPE)                                  \
   V(WEAK_CELL_TYPE)                                             \
                                                                 \
@@ -736,6 +737,7 @@
   DEBUG_INFO_TYPE,
   BREAK_POINT_INFO_TYPE,
   FIXED_ARRAY_TYPE,
+  CONSTANT_POOL_ARRAY_TYPE,
   SHARED_FUNCTION_INFO_TYPE,
   CELL_TYPE,
   WEAK_CELL_TYPE,
@@ -966,6 +968,7 @@
   V(FixedDoubleArray)              \
   V(WeakFixedArray)                \
   V(ArrayList)                     \
+  V(ConstantPoolArray)             \
   V(Context)                       \
   V(ScriptContextTable)            \
   V(NativeContext)                 \
@@ -2650,6 +2653,312 @@
 };
 
 
+// ConstantPoolArray describes a fixed-sized array containing constant pool
+// entries.
+//
+// A ConstantPoolArray can be structured in two different ways depending upon
+// whether it is extended or small. The is_extended_layout() method can be used
+// to discover which layout the constant pool has.
+//
+// The format of a small constant pool is:
+//   [kSmallLayout1Offset]                    : Small section layout bitmap 1
+//   [kSmallLayout2Offset]                    : Small section layout bitmap 2
+//   [first_index(INT64, SMALL_SECTION)]      : 64 bit entries
+//    ...                                     :  ...
+//   [first_index(CODE_PTR, SMALL_SECTION)]   : code pointer entries
+//    ...                                     :  ...
+//   [first_index(HEAP_PTR, SMALL_SECTION)]   : heap pointer entries
+//    ...                                     :  ...
+//   [first_index(INT32, SMALL_SECTION)]      : 32 bit entries
+//    ...                                     :  ...
+//
+// If the constant pool has an extended layout, the extended section constant
+// pool also contains an extended section, which has the following format at
+// location get_extended_section_header_offset():
+//   [kExtendedInt64CountOffset]              : count of extended 64 bit entries
+//   [kExtendedCodePtrCountOffset]            : count of extended code pointers
+//   [kExtendedHeapPtrCountOffset]            : count of extended heap pointers
+//   [kExtendedInt32CountOffset]              : count of extended 32 bit entries
+//   [first_index(INT64, EXTENDED_SECTION)]   : 64 bit entries
+//    ...                                     :  ...
+//   [first_index(CODE_PTR, EXTENDED_SECTION)]: code pointer entries
+//    ...                                     :  ...
+//   [first_index(HEAP_PTR, EXTENDED_SECTION)]: heap pointer entries
+//    ...                                     :  ...
+//   [first_index(INT32, EXTENDED_SECTION)]   : 32 bit entries
+//    ...                                     :  ...
+//
+class ConstantPoolArray: public HeapObject {
+ public:
+  enum WeakObjectState { NO_WEAK_OBJECTS, WEAK_OBJECTS_IN_OPTIMIZED_CODE };
+
+  enum Type {
+    INT64 = 0,
+    CODE_PTR,
+    HEAP_PTR,
+    INT32,
+    // Number of types stored by the ConstantPoolArrays.
+    NUMBER_OF_TYPES,
+    FIRST_TYPE = INT64,
+    LAST_TYPE = INT32
+  };
+
+  enum LayoutSection {
+    SMALL_SECTION = 0,
+    EXTENDED_SECTION,
+    NUMBER_OF_LAYOUT_SECTIONS
+  };
+
+  class NumberOfEntries BASE_EMBEDDED {
+   public:
+    inline NumberOfEntries() {
+      for (int i = 0; i < NUMBER_OF_TYPES; i++) {
+        element_counts_[i] = 0;
+      }
+    }
+
+    inline NumberOfEntries(int int64_count, int code_ptr_count,
+                           int heap_ptr_count, int int32_count) {
+      element_counts_[INT64] = int64_count;
+      element_counts_[CODE_PTR] = code_ptr_count;
+      element_counts_[HEAP_PTR] = heap_ptr_count;
+      element_counts_[INT32] = int32_count;
+    }
+
+    inline NumberOfEntries(ConstantPoolArray* array, LayoutSection section) {
+      element_counts_[INT64] = array->number_of_entries(INT64, section);
+      element_counts_[CODE_PTR] = array->number_of_entries(CODE_PTR, section);
+      element_counts_[HEAP_PTR] = array->number_of_entries(HEAP_PTR, section);
+      element_counts_[INT32] = array->number_of_entries(INT32, section);
+    }
+
+    inline void increment(Type type);
+    inline int equals(const NumberOfEntries& other) const;
+    inline bool is_empty() const;
+    inline int count_of(Type type) const;
+    inline int base_of(Type type) const;
+    inline int total_count() const;
+    inline int are_in_range(int min, int max) const;
+
+   private:
+    int element_counts_[NUMBER_OF_TYPES];
+  };
+
+  class Iterator BASE_EMBEDDED {
+   public:
+    inline Iterator(ConstantPoolArray* array, Type type)
+        : array_(array),
+          type_(type),
+          final_section_(array->final_section()),
+          current_section_(SMALL_SECTION),
+          next_index_(array->first_index(type, SMALL_SECTION)) {
+      update_section();
+    }
+
+    inline Iterator(ConstantPoolArray* array, Type type, LayoutSection section)
+        : array_(array),
+          type_(type),
+          final_section_(section),
+          current_section_(section),
+          next_index_(array->first_index(type, section)) {
+      update_section();
+    }
+
+    inline int next_index();
+    inline bool is_finished();
+
+   private:
+    inline void update_section();
+    ConstantPoolArray* array_;
+    const Type type_;
+    const LayoutSection final_section_;
+
+    LayoutSection current_section_;
+    int next_index_;
+  };
+
+  // Getters for the first index, the last index and the count of entries of
+  // a given type for a given layout section.
+  inline int first_index(Type type, LayoutSection layout_section);
+  inline int last_index(Type type, LayoutSection layout_section);
+  inline int number_of_entries(Type type, LayoutSection layout_section);
+
+  // Returns the type of the entry at the given index.
+  inline Type get_type(int index);
+  inline bool offset_is_type(int offset, Type type);
+
+  // Setter and getter for pool elements.
+  inline Address get_code_ptr_entry(int index);
+  inline Object* get_heap_ptr_entry(int index);
+  inline int64_t get_int64_entry(int index);
+  inline int32_t get_int32_entry(int index);
+  inline double get_int64_entry_as_double(int index);
+
+  inline void set(int index, Address value);
+  inline void set(int index, Object* value);
+  inline void set(int index, int64_t value);
+  inline void set(int index, double value);
+  inline void set(int index, int32_t value);
+
+  // Setters which take a raw offset rather than an index (for code generation).
+  inline void set_at_offset(int offset, int32_t value);
+  inline void set_at_offset(int offset, int64_t value);
+  inline void set_at_offset(int offset, double value);
+  inline void set_at_offset(int offset, Address value);
+  inline void set_at_offset(int offset, Object* value);
+
+  // Setter and getter for weak objects state
+  inline void set_weak_object_state(WeakObjectState state);
+  inline WeakObjectState get_weak_object_state();
+
+  // Returns true if the constant pool has an extended layout, false if it has
+  // only the small layout.
+  inline bool is_extended_layout();
+
+  // Returns the last LayoutSection in this constant pool array.
+  inline LayoutSection final_section();
+
+  // Set up initial state for a small layout constant pool array.
+  inline void Init(const NumberOfEntries& small);
+
+  // Set up initial state for an extended layout constant pool array.
+  inline void InitExtended(const NumberOfEntries& small,
+                           const NumberOfEntries& extended);
+
+  // Clears the pointer entries with GC safe values.
+  void ClearPtrEntries(Isolate* isolate);
+
+  // returns the total number of entries in the constant pool array.
+  inline int length();
+
+  // Garbage collection support.
+  inline int size();
+
+
+  inline static int MaxInt64Offset(int number_of_int64) {
+    return kFirstEntryOffset + (number_of_int64 * kInt64Size);
+  }
+
+  inline static int SizeFor(const NumberOfEntries& small) {
+    int size = kFirstEntryOffset +
+        (small.count_of(INT64)  * kInt64Size) +
+        (small.count_of(CODE_PTR) * kPointerSize) +
+        (small.count_of(HEAP_PTR) * kPointerSize) +
+        (small.count_of(INT32) * kInt32Size);
+    return RoundUp(size, kPointerSize);
+  }
+
+  inline static int SizeForExtended(const NumberOfEntries& small,
+                                    const NumberOfEntries& extended) {
+    int size = SizeFor(small);
+    size = RoundUp(size, kInt64Size);  // Align extended header to 64 bits.
+    size += kExtendedFirstOffset +
+        (extended.count_of(INT64) * kInt64Size) +
+        (extended.count_of(CODE_PTR) * kPointerSize) +
+        (extended.count_of(HEAP_PTR) * kPointerSize) +
+        (extended.count_of(INT32) * kInt32Size);
+    return RoundUp(size, kPointerSize);
+  }
+
+  inline static int entry_size(Type type) {
+    switch (type) {
+      case INT32:
+        return kInt32Size;
+      case INT64:
+        return kInt64Size;
+      case CODE_PTR:
+      case HEAP_PTR:
+        return kPointerSize;
+      default:
+        UNREACHABLE();
+        return 0;
+    }
+  }
+
+  // Code Generation support.
+  inline int OffsetOfElementAt(int index) {
+    int offset;
+    LayoutSection section;
+    if (is_extended_layout() && index >= first_extended_section_index()) {
+      section = EXTENDED_SECTION;
+      offset = get_extended_section_header_offset() + kExtendedFirstOffset;
+    } else {
+      section = SMALL_SECTION;
+      offset = kFirstEntryOffset;
+    }
+
+    // Add offsets for the preceding type sections.
+    DCHECK(index <= last_index(LAST_TYPE, section));
+    for (Type type = FIRST_TYPE; index > last_index(type, section);
+         type = next_type(type)) {
+      offset += entry_size(type) * number_of_entries(type, section);
+    }
+
+    // Add offset for the index in it's type.
+    Type type = get_type(index);
+    offset += entry_size(type) * (index - first_index(type, section));
+    return offset;
+  }
+
+  DECLARE_CAST(ConstantPoolArray)
+
+  // Garbage collection support.
+  Object** RawFieldOfElementAt(int index) {
+    return HeapObject::RawField(this, OffsetOfElementAt(index));
+  }
+
+  // Small Layout description.
+  static const int kSmallLayout1Offset = HeapObject::kHeaderSize;
+  static const int kSmallLayout2Offset = kSmallLayout1Offset + kInt32Size;
+  static const int kHeaderSize = kSmallLayout2Offset + kInt32Size;
+  static const int kFirstEntryOffset = ROUND_UP(kHeaderSize, kInt64Size);
+
+  static const int kSmallLayoutCountBits = 10;
+  static const int kMaxSmallEntriesPerType = (1 << kSmallLayoutCountBits) - 1;
+
+  // Fields in kSmallLayout1Offset.
+  class Int64CountField: public BitField<int, 1, kSmallLayoutCountBits> {};
+  class CodePtrCountField: public BitField<int, 11, kSmallLayoutCountBits> {};
+  class HeapPtrCountField: public BitField<int, 21, kSmallLayoutCountBits> {};
+  class IsExtendedField: public BitField<bool, 31, 1> {};
+
+  // Fields in kSmallLayout2Offset.
+  class Int32CountField: public BitField<int, 1, kSmallLayoutCountBits> {};
+  class TotalCountField: public BitField<int, 11, 12> {};
+  class WeakObjectStateField: public BitField<WeakObjectState, 23, 2> {};
+
+  // Extended layout description, which starts at
+  // get_extended_section_header_offset().
+  static const int kExtendedInt64CountOffset = 0;
+  static const int kExtendedCodePtrCountOffset =
+      kExtendedInt64CountOffset + kInt32Size;
+  static const int kExtendedHeapPtrCountOffset =
+      kExtendedCodePtrCountOffset + kInt32Size;
+  static const int kExtendedInt32CountOffset =
+      kExtendedHeapPtrCountOffset + kInt32Size;
+  static const int kExtendedFirstOffset =
+      kExtendedInt32CountOffset + kInt32Size;
+
+  // Dispatched behavior.
+  void ConstantPoolIterateBody(ObjectVisitor* v);
+
+  DECLARE_PRINTER(ConstantPoolArray)
+  DECLARE_VERIFIER(ConstantPoolArray)
+
+ private:
+  inline int first_extended_section_index();
+  inline int get_extended_section_header_offset();
+
+  inline static Type next_type(Type type) {
+    DCHECK(type >= FIRST_TYPE && type < NUMBER_OF_TYPES);
+    int type_int = static_cast<int>(type);
+    return static_cast<Type>(++type_int);
+  }
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ConstantPoolArray);
+};
+
+
 // DescriptorArrays are fixed arrays used to hold instance descriptors.
 // The format of the these objects is:
 //   [0]: Number of descriptors
@@ -4976,11 +5285,6 @@
   inline int prologue_offset() const;
   inline void set_prologue_offset(int offset);
 
-  // [constant_pool offset]: Offset of the constant pool.
-  // Valid for FLAG_enable_embedded_constant_pool only
-  inline int constant_pool_offset() const;
-  inline void set_constant_pool_offset(int offset);
-
   // Unchecked accessors to be used during GC.
   inline ByteArray* unchecked_relocation_info();
 
@@ -5114,7 +5418,8 @@
   inline void set_marked_for_deoptimization(bool flag);
 
   // [constant_pool]: The constant pool for this function.
-  inline Address constant_pool();
+  inline ConstantPoolArray* constant_pool();
+  inline void set_constant_pool(Object* constant_pool);
 
   // Get the safepoint entry for the given pc.
   SafepointEntry GetSafepointEntry(Address pc);
@@ -5314,9 +5619,6 @@
   // Max loop nesting marker used to postpose OSR. We don't take loop
   // nesting that is deeper than 5 levels into account.
   static const int kMaxLoopNestingMarker = 6;
-
-  static const int kConstantPoolSize =
-      FLAG_enable_embedded_constant_pool ? kIntSize : 0;
 
   // Layout description.
   static const int kRelocationInfoOffset = HeapObject::kHeaderSize;
@@ -5337,13 +5639,15 @@
   // Note: We might be able to squeeze this into the flags above.
   static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
   static const int kConstantPoolOffset = kPrologueOffset + kIntSize;
-  static const int kHeaderPaddingStart =
-      kConstantPoolOffset + kConstantPoolSize;
+
+  static const int kHeaderPaddingStart = kConstantPoolOffset + kPointerSize;
 
   // Add padding to align the instruction start following right after
   // the Code object header.
   static const int kHeaderSize =
       (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask;
+  // Ensure that the slot for the constant pool pointer is aligned.
+  STATIC_ASSERT((kConstantPoolOffset & kPointerAlignmentMask) == 0);
 
   // Byte offsets within kKindSpecificFlags1Offset.
   static const int kFullCodeFlags = kKindSpecificFlags1Offset;