Match max property descriptor length to corresponding bit fields

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3352 matching lines @@
   // Is the descriptor array sorted and without duplicates?
   bool IsSortedNoDuplicates(int valid_descriptors = -1);
 
   // Is the descriptor array consistent with the back pointers in targets?
   bool IsConsistentWithBackPointers(Map* current_map);
 
   // Are two DescriptorArrays equal?
   bool IsEqualTo(DescriptorArray* other);
 #endif
 
-  // The maximum number of descriptors we want in a descriptor array (should
-  // fit in a page).
-  static const int kMaxNumberOfDescriptors = 1024 + 512;
-
   // Returns the fixed array length required to hold number_of_descriptors
   // descriptors.
   static int LengthFor(int number_of_descriptors) {
     return ToKeyIndex(number_of_descriptors);
   }
 
  private:
   // An entry in a DescriptorArray, represented as an (array, index) pair.
   class Entry {
    public:
@@ skipping 2315 matching lines @@
   inline void set_bit_field(byte value);
 
   // Bit field 2.
   inline byte bit_field2();
   inline void set_bit_field2(byte value);
 
   // Bit field 3.
   inline uint32_t bit_field3();
   inline void set_bit_field3(uint32_t bits);
 
-  class EnumLengthBits:             public BitField<int,   0, 11> {};
-  class NumberOfOwnDescriptorsBits: public BitField<int,  11, 11> {};
-  class IsShared:                   public BitField<bool, 22,  1> {};
-  class FunctionWithPrototype:      public BitField<bool, 23,  1> {};
-  class DictionaryMap:              public BitField<bool, 24,  1> {};
-  class OwnsDescriptors:            public BitField<bool, 25,  1> {};
-  class HasInstanceCallHandler:     public BitField<bool, 26,  1> {};
-  class Deprecated:                 public BitField<bool, 27,  1> {};
-  class IsFrozen:                   public BitField<bool, 28,  1> {};
-  class IsUnstable:                 public BitField<bool, 29,  1> {};
-  class IsMigrationTarget:          public BitField<bool, 30,  1> {};
+  class EnumLengthBits:             public BitField<int,
+      0, kDescriptorIndexBitCount> {};
+  class NumberOfOwnDescriptorsBits: public BitField<int,
+      kDescriptorIndexBitCount, kDescriptorIndexBitCount> {};
+  STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
+  class IsShared:                   public BitField<bool, 20,  1> {};
+  class FunctionWithPrototype:      public BitField<bool, 21,  1> {};
+  class DictionaryMap:              public BitField<bool, 22,  1> {};
+  class OwnsDescriptors:            public BitField<bool, 23,  1> {};
+  class HasInstanceCallHandler:     public BitField<bool, 24,  1> {};
+  class Deprecated:                 public BitField<bool, 25,  1> {};
+  class IsFrozen:                   public BitField<bool, 26,  1> {};
+  class IsUnstable:                 public BitField<bool, 27,  1> {};
+  class IsMigrationTarget:          public BitField<bool, 28,  1> {};
 
   // Tells whether the object in the prototype property will be used
   // for instances created from this function.  If the prototype
   // property is set to a value that is not a JSObject, the prototype
   // property will not be used to create instances of the function.
   // See ECMA-262, 13.2.2.
   inline void set_non_instance_prototype(bool value);
   inline bool has_non_instance_prototype();
 
   // Tells whether function has special prototype property. If not, prototype
@@ skipping 294 matching lines @@
     set_bit_field3(NumberOfOwnDescriptorsBits::update(bit_field3(), number));
   }
 
   inline Cell* RetrieveDescriptorsPointer();
 
   int EnumLength() {
     return EnumLengthBits::decode(bit_field3());
   }
 
   void SetEnumLength(int length) {
-    if (length != kInvalidEnumCache) {
+    if (length != kInvalidEnumCacheSentinel) {
       ASSERT(length >= 0);
       ASSERT(length == 0 || instance_descriptors()->HasEnumCache());
       ASSERT(length <= NumberOfOwnDescriptors());
     }
     set_bit_field3(EnumLengthBits::update(bit_field3(), length));
   }
 
   inline bool owns_descriptors();
   inline void set_owns_descriptors(bool is_shared);
   inline bool has_instance_call_handler();
@@ skipping 197 matching lines @@
   // and the values are the maps the are transitioned to.
   static const int kMaxCachedPrototypeTransitions = 256;
   static Handle<Map> GetPrototypeTransition(Handle<Map> map,
                                             Handle<Object> prototype);
   static Handle<Map> PutPrototypeTransition(Handle<Map> map,
                                             Handle<Object> prototype,
                                             Handle<Map> target_map);
 
   static const int kMaxPreAllocatedPropertyFields = 255;
 
-  // Constant for denoting that the enum cache is not yet initialized.
-  static const int kInvalidEnumCache = EnumLengthBits::kMax;
-
   // Layout description.
   static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
   static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
   static const int kPrototypeOffset = kInstanceAttributesOffset + kIntSize;
   static const int kConstructorOffset = kPrototypeOffset + kPointerSize;
   // Storage for the transition array is overloaded to directly contain a back
   // pointer if unused. When the map has transitions, the back pointer is
   // transferred to the transition array and accessed through an extra
   // indirection.
   static const int kTransitionsOrBackPointerOffset =
@@ skipping 4299 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_