Revert r3952

TBR=ager@chromium.org
Review URL: http://codereview.chromium.org/660086

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3953 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -1206,7 +1206,7 @@ Object* Heap::AllocateMap(InstanceType instance_type, int instance_size) {
   map->set_inobject_properties(0);
   map->set_pre_allocated_property_fields(0);
   map->set_instance_descriptors(empty_descriptor_array());
-  map->set_code_cache(undefined_value());
+  map->set_code_cache(empty_fixed_array());
   map->set_unused_property_fields(0);
   map->set_bit_field(0);
   map->set_bit_field2(1 << Map::kIsExtensible);
@@ -1221,16 +1221,6 @@ Object* Heap::AllocateMap(InstanceType instance_type, int instance_size) {
 }
 
 
-Object* Heap::AllocateCodeCache() {
-  Object* result = AllocateStruct(CODE_CACHE_TYPE);
-  if (result->IsFailure()) return result;
-  CodeCache* code_cache = CodeCache::cast(result);
-  code_cache->set_default_cache(empty_fixed_array());
-  code_cache->set_normal_type_cache(undefined_value());
-  return code_cache;
-}
-
-
 const Heap::StringTypeTable Heap::string_type_table[] = {
 #define STRING_TYPE_ELEMENT(type, size, name, camel_name)                      \
   {type, size, k##camel_name##MapRootIndex},
@@ -1287,13 +1277,13 @@ bool Heap::CreateInitialMaps() {
 
   // Fix the instance_descriptors for the existing maps.
   meta_map()->set_instance_descriptors(empty_descriptor_array());
-  meta_map()->set_code_cache(undefined_value());
+  meta_map()->set_code_cache(empty_fixed_array());
 
   fixed_array_map()->set_instance_descriptors(empty_descriptor_array());
-  fixed_array_map()->set_code_cache(undefined_value());
+  fixed_array_map()->set_code_cache(empty_fixed_array());
 
   oddball_map()->set_instance_descriptors(empty_descriptor_array());
-  oddball_map()->set_code_cache(undefined_value());
+  oddball_map()->set_code_cache(empty_fixed_array());
 
   // Fix prototype object for existing maps.
   meta_map()->set_prototype(null_value());

src/heap.h

@@ -345,9 +345,6 @@ class Heap : public AllStatic {
   // Allocate a map for the specified function
   static Object* AllocateInitialMap(JSFunction* fun);
 
-  // Allocates an empty code cache.
-  static Object* AllocateCodeCache();
-
   // Allocates and fully initializes a String.  There are two String
   // encodings: ASCII and two byte. One should choose between the three string
   // allocation functions based on the encoding of the string buffer used to

src/objects-debug.cc

@@ -644,24 +644,6 @@ void Map::MapVerify() {
 }
 
 
-void CodeCache::CodeCachePrint() {
-  HeapObject::PrintHeader("CodeCache");
-  PrintF("\n - default_cache: ");
-  default_cache()->ShortPrint();
-  PrintF("\n - normal_type_cache: ");
-  normal_type_cache()->ShortPrint();
-}
-
-
-void CodeCache::CodeCacheVerify() {
-  VerifyHeapPointer(default_cache());
-  VerifyHeapPointer(normal_type_cache());
-  ASSERT(default_cache()->IsFixedArray());
-  ASSERT(normal_type_cache()->IsUndefined()
-         || normal_type_cache()->IsCodeCacheHashTable());
-}
-
-
 void FixedArray::FixedArrayPrint() {
   HeapObject::PrintHeader("FixedArray");
   PrintF(" - length: %d", length());

src/objects-inl.h

@@ -564,11 +564,6 @@ bool Object::IsCompilationCacheTable() {
 }
 
 
-bool Object::IsCodeCacheHashTable() {
-  return IsHashTable();
-}
-
-
 bool Object::IsMapCache() {
   return IsHashTable();
 }
@@ -1568,7 +1563,6 @@ CAST_ACCESSOR(FixedArray)
 CAST_ACCESSOR(DescriptorArray)
 CAST_ACCESSOR(SymbolTable)
 CAST_ACCESSOR(CompilationCacheTable)
-CAST_ACCESSOR(CodeCacheHashTable)
 CAST_ACCESSOR(MapCache)
 CAST_ACCESSOR(String)
 CAST_ACCESSOR(SeqString)
@@ -2261,7 +2255,7 @@ void Map::set_prototype(Object* value, WriteBarrierMode mode) {
 
 ACCESSORS(Map, instance_descriptors, DescriptorArray,
           kInstanceDescriptorsOffset)
-ACCESSORS(Map, code_cache, Object, kCodeCacheOffset)
+ACCESSORS(Map, code_cache, FixedArray, kCodeCacheOffset)
 ACCESSORS(Map, constructor, Object, kConstructorOffset)
 
 ACCESSORS(JSFunction, shared, SharedFunctionInfo, kSharedFunctionInfoOffset)
@@ -2399,9 +2393,6 @@ INT_ACCESSORS(SharedFunctionInfo, this_property_assignments_count,
               kThisPropertyAssignmentsCountOffset)
 
 
-ACCESSORS(CodeCache, default_cache, FixedArray, kDefaultCacheOffset)
-ACCESSORS(CodeCache, normal_type_cache, Object, kNormalTypeCacheOffset)
-
 bool Script::HasValidSource() {
   Object* src = this->source();
   if (!src->IsString()) return true;
@@ -3002,8 +2993,8 @@ void Map::ClearCodeCache() {
   // No write barrier is needed since empty_fixed_array is not in new space.
   // Please note this function is used during marking:
   //  - MarkCompactCollector::MarkUnmarkedObject
-  ASSERT(!Heap::InNewSpace(Heap::undefined_value()));
-  WRITE_FIELD(this, kCodeCacheOffset, Heap::undefined_value());
+  ASSERT(!Heap::InNewSpace(Heap::raw_unchecked_empty_fixed_array()));
+  WRITE_FIELD(this, kCodeCacheOffset, Heap::raw_unchecked_empty_fixed_array());
 }
 
 

src/objects.cc

@@ -3033,79 +3033,19 @@ Object* Map::CopyDropTransitions() {
 
 
 Object* Map::UpdateCodeCache(String* name, Code* code) {
-  // Allocate the code cache if not present.
-  if (code_cache()->IsUndefined()) {
-    Object* result = Heap::AllocateCodeCache();
-    if (result->IsFailure()) return result;
-    set_code_cache(result);
-  }
-
-  // Update the code cache.
-  return CodeCache::cast(code_cache())->Update(name, code);
-}
-
-
-Object* Map::FindInCodeCache(String* name, Code::Flags flags) {
-  // Do a lookup if a code cache exists.
-  if (!code_cache()->IsUndefined()) {
-    return CodeCache::cast(code_cache())->Lookup(name, flags);
-  } else {
-    return Heap::undefined_value();
-  }
-}
-
-
-int Map::IndexInCodeCache(Code* code) {
-  // Get the internal index if a code cache exists.
-  if (!code_cache()->IsUndefined()) {
-    return CodeCache::cast(code_cache())->GetIndex(code);
-  }
-  return -1;
-}
-
-
-void Map::RemoveFromCodeCache(int index) {
-  // No GC is supposed to happen between a call to IndexInCodeCache and
-  // RemoveFromCodeCache so the code cache must be there.
-  ASSERT(!code_cache()->IsUndefined());
-  return CodeCache::cast(code_cache())->RemoveByIndex(index);
-}
-
-
-Object* CodeCache::Update(String* name, Code* code) {
   ASSERT(code->ic_state() == MONOMORPHIC);
+  FixedArray* cache = code_cache();
 
-  // The number of monomorphic stubs for normal load/store/call IC's can grow to
-  // a large number and therefore they need to go into a hash table. They are
-  // used to load global properties from cells.
-  if (code->type() == NORMAL) {
-    // Make sure that a hash table is allocated for the normal load code cache.
-    if (normal_type_cache()->IsUndefined()) {
-      Object* result =
-          CodeCacheHashTable::Allocate(CodeCacheHashTable::kInitialSize);
-      if (result->IsFailure()) return result;
-      set_normal_type_cache(result);
-    }
-    return UpdateNormalTypeCache(name, code);
-  } else {
-    ASSERT(default_cache()->IsFixedArray());
-    return UpdateDefaultCache(name, code);
-  }
-}
-
-
-Object* CodeCache::UpdateDefaultCache(String* name, Code* code) {
-  // When updating the default code cache we disregard the type encoded in the
+  // When updating the code cache we disregard the type encoded in the
   // flags. This allows call constant stubs to overwrite call field
   // stubs, etc.
   Code::Flags flags = Code::RemoveTypeFromFlags(code->flags());
 
   // First check whether we can update existing code cache without
   // extending it.
-  FixedArray* cache = default_cache();
   int length = cache->length();
   int deleted_index = -1;
-  for (int i = 0; i < length; i += kCodeCacheEntrySize) {
+  for (int i = 0; i < length; i += 2) {
     Object* key = cache->get(i);
     if (key->IsNull()) {
       if (deleted_index < 0) deleted_index = i;
@@ -3113,15 +3053,14 @@ Object* CodeCache::UpdateDefaultCache(String* name, Code* code) {
     }
     if (key->IsUndefined()) {
       if (deleted_index >= 0) i = deleted_index;
-      cache->set(i + kCodeCacheEntryNameOffset, name);
-      cache->set(i + kCodeCacheEntryCodeOffset, code);
+      cache->set(i + 0, name);
+      cache->set(i + 1, code);
       return this;
     }
     if (name->Equals(String::cast(key))) {
-      Code::Flags found =
-          Code::cast(cache->get(i + kCodeCacheEntryCodeOffset))->flags();
+      Code::Flags found = Code::cast(cache->get(i + 1))->flags();
       if (Code::RemoveTypeFromFlags(found) == flags) {
-        cache->set(i + kCodeCacheEntryCodeOffset, code);
+        cache->set(i + 1, code);
         return this;
       }
     }
@@ -3130,180 +3069,61 @@ Object* CodeCache::UpdateDefaultCache(String* name, Code* code) {
   // Reached the end of the code cache.  If there were deleted
   // elements, reuse the space for the first of them.
   if (deleted_index >= 0) {
-    cache->set(deleted_index + kCodeCacheEntryNameOffset, name);
-    cache->set(deleted_index + kCodeCacheEntryCodeOffset, code);
+    cache->set(deleted_index + 0, name);
+    cache->set(deleted_index + 1, code);
     return this;
   }
 
-  // Extend the code cache with some new entries (at least one). Must be a
-  // multiple of the entry size.
-  int new_length = length + ((length >> 1)) + kCodeCacheEntrySize;
-  new_length = new_length - new_length % kCodeCacheEntrySize;
-  ASSERT((new_length % kCodeCacheEntrySize) == 0);
+  // Extend the code cache with some new entries (at least one).
+  int new_length = length + ((length >> 1) & ~1) + 2;
+  ASSERT((new_length & 1) == 0);  // must be a multiple of two
   Object* result = cache->CopySize(new_length);
   if (result->IsFailure()) return result;
 
   // Add the (name, code) pair to the new cache.
   cache = FixedArray::cast(result);
-  cache->set(length + kCodeCacheEntryNameOffset, name);
-  cache->set(length + kCodeCacheEntryCodeOffset, code);
-  set_default_cache(cache);
+  cache->set(length + 0, name);
+  cache->set(length + 1, code);
+  set_code_cache(cache);
   return this;
 }
 
 
-Object* CodeCache::UpdateNormalTypeCache(String* name, Code* code) {
-  // Adding a new entry can cause a new cache to be allocated.
-  CodeCacheHashTable* cache = CodeCacheHashTable::cast(normal_type_cache());
-  Object* new_cache = cache->Put(name, code);
-  if (new_cache->IsFailure()) return new_cache;
-  set_normal_type_cache(new_cache);
-  return this;
-}
-
-
-Object* CodeCache::Lookup(String* name, Code::Flags flags) {
-  if (Code::ExtractTypeFromFlags(flags) == NORMAL) {
-    return LookupNormalTypeCache(name, flags);
-  } else {
-    return LookupDefaultCache(name, flags);
-  }
-}
-
-
-Object* CodeCache::LookupDefaultCache(String* name, Code::Flags flags) {
-  FixedArray* cache = default_cache();
+Object* Map::FindInCodeCache(String* name, Code::Flags flags) {
+  FixedArray* cache = code_cache();
   int length = cache->length();
-  for (int i = 0; i < length; i += kCodeCacheEntrySize) {
-    Object* key = cache->get(i + kCodeCacheEntryNameOffset);
+  for (int i = 0; i < length; i += 2) {
+    Object* key = cache->get(i);
     // Skip deleted elements.
     if (key->IsNull()) continue;
     if (key->IsUndefined()) return key;
     if (name->Equals(String::cast(key))) {
-      Code* code = Code::cast(cache->get(i + kCodeCacheEntryCodeOffset));
-      if (code->flags() == flags) {
-        return code;
-      }
+      Code* code = Code::cast(cache->get(i + 1));
+      if (code->flags() == flags) return code;
     }
   }
   return Heap::undefined_value();
 }
 
 
-Object* CodeCache::LookupNormalTypeCache(String* name, Code::Flags flags) {
-  if (!normal_type_cache()->IsUndefined()) {
-    CodeCacheHashTable* cache = CodeCacheHashTable::cast(normal_type_cache());
-    return cache->Lookup(name, flags);
-  } else {
-    return Heap::undefined_value();
-  }
-}
-
-
-int CodeCache::GetIndex(Code* code) {
-  // This is not used for normal load/store/call IC's.
-  ASSERT(code->type() != NORMAL);
-
-  FixedArray* array = default_cache();
+int Map::IndexInCodeCache(Code* code) {
+  FixedArray* array = code_cache();
   int len = array->length();
-  for (int i = 0; i < len; i += kCodeCacheEntrySize) {
-    if (array->get(i + kCodeCacheEntryCodeOffset) == code) return i + 1;
+  for (int i = 0; i < len; i += 2) {
+    if (array->get(i + 1) == code) return i + 1;
   }
   return -1;
 }
 
 
-void CodeCache::RemoveByIndex(int index) {
-  FixedArray* array = default_cache();
+void Map::RemoveFromCodeCache(int index) {
+  FixedArray* array = code_cache();
   ASSERT(array->length() >= index && array->get(index)->IsCode());
   // Use null instead of undefined for deleted elements to distinguish
   // deleted elements from unused elements.  This distinction is used
   // when looking up in the cache and when updating the cache.
-  ASSERT_EQ(1, kCodeCacheEntryCodeOffset - kCodeCacheEntryNameOffset);
-  array->set_null(index - 1);  // Name.
-  array->set_null(index);  // Code.
-}
-
-
-// The key in the code cache hash table consists of the property name and the
-// code object. The actual match is on the name and the code flags. If a key
-// is created using the flags and not a code object it can only be used for
-// lookup not to create a new entry.
-class CodeCacheHashTableKey : public HashTableKey {
- public:
-  CodeCacheHashTableKey(String* name, Code::Flags flags)
-      : name_(name), flags_(flags), code_(NULL) { }
-
-  CodeCacheHashTableKey(String* name, Code* code)
-      : name_(name),
-        flags_(code->flags()),
-        code_(code) { }
-
-
-  bool IsMatch(Object* other) {
-    if (!other->IsFixedArray()) return false;
-    FixedArray* pair = FixedArray::cast(other);
-    String* name = String::cast(pair->get(0));
-    Code::Flags flags = Code::cast(pair->get(1))->flags();
-    if (flags != flags_) {
-      return false;
-    }
-    return name_->Equals(name);
-  }
-
-  static uint32_t NameFlagsHashHelper(String* name, Code::Flags flags) {
-    return name->Hash() ^ flags;
-  }
-
-  uint32_t Hash() { return NameFlagsHashHelper(name_, flags_); }
-
-  uint32_t HashForObject(Object* obj) {
-    FixedArray* pair = FixedArray::cast(obj);
-    String* name = String::cast(pair->get(0));
-    Code* code = Code::cast(pair->get(1));
-    return NameFlagsHashHelper(name, code->flags());
-  }
-
-  Object* AsObject() {
-    ASSERT(code_ != NULL);
-    Object* obj = Heap::AllocateFixedArray(2);
-    if (obj->IsFailure()) return obj;
-    FixedArray* pair = FixedArray::cast(obj);
-    pair->set(0, name_);
-    pair->set(1, code_);
-    return pair;
-  }
-
- private:
-  String* name_;
-  Code::Flags flags_;
-  Code* code_;
-};
-
-
-Object* CodeCacheHashTable::Lookup(String* name, Code::Flags flags) {
-  CodeCacheHashTableKey key(name, flags);
-  int entry = FindEntry(&key);
-  if (entry == kNotFound) return Heap::undefined_value();
-  return get(EntryToIndex(entry) + 1);
-}
-
-
-Object* CodeCacheHashTable::Put(String* name, Code* code) {
-  CodeCacheHashTableKey key(name, code);
-  Object* obj = EnsureCapacity(1, &key);
-
-  // Don't use this, as the table might have grown.
-  CodeCacheHashTable* cache = reinterpret_cast<CodeCacheHashTable*>(obj);
-
-  int entry = cache->FindInsertionEntry(key.Hash());
-  Object* k = key.AsObject();
-  if (k->IsFailure()) return k;
-
-  cache->set(EntryToIndex(entry), k);
-  cache->set(EntryToIndex(entry) + 1, code);
-  cache->ElementAdded();
-  return cache;
+  array->set_null(index - 1);  // key
+  array->set_null(index);  // code
 }
 
 
@@ -7161,6 +6981,7 @@ Object* HashTable<Shape, Key>::EnsureCapacity(int n, Key key) {
 }
 
 
+
 template<typename Shape, typename Key>
 uint32_t HashTable<Shape, Key>::FindInsertionEntry(uint32_t hash) {
   uint32_t capacity = Capacity();

src/objects.h

@@ -72,7 +72,6 @@
 //             - Dictionary
 //             - SymbolTable
 //             - CompilationCacheTable
-//             - CodeCacheHashTable
 //             - MapCache
 //           - Context
 //           - GlobalContext
@@ -103,7 +102,6 @@
 //         - TypeSwitchInfo
 //         - DebugInfo
 //         - BreakPointInfo
-//         - CodeCache
 //
 // Formats of Object*:
 //  Smi:        [31 bit signed int] 0
@@ -271,7 +269,6 @@ enum PropertyNormalizationMode {
   V(SIGNATURE_INFO_TYPE)                                                       \
   V(TYPE_SWITCH_INFO_TYPE)                                                     \
   V(SCRIPT_TYPE)                                                               \
-  V(CODE_CACHE_TYPE)                                                           \
                                                                                \
   V(JS_VALUE_TYPE)                                                             \
   V(JS_OBJECT_TYPE)                                                            \
@@ -367,8 +364,7 @@ enum PropertyNormalizationMode {
   V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info)            \
   V(SIGNATURE_INFO, SignatureInfo, signature_info)                             \
   V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info)                        \
-  V(SCRIPT, Script, script)                                                    \
-  V(CODE_CACHE, CodeCache, code_cache)
+  V(SCRIPT, Script, script)
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 #define STRUCT_LIST_DEBUGGER(V)                                                \
@@ -472,7 +468,6 @@ enum InstanceType {
   SIGNATURE_INFO_TYPE,
   TYPE_SWITCH_INFO_TYPE,
   SCRIPT_TYPE,
-  CODE_CACHE_TYPE,
 #ifdef ENABLE_DEBUGGER_SUPPORT
   DEBUG_INFO_TYPE,
   BREAK_POINT_INFO_TYPE,
@@ -606,7 +601,6 @@ class Object BASE_EMBEDDED {
   inline bool IsDictionary();
   inline bool IsSymbolTable();
   inline bool IsCompilationCacheTable();
-  inline bool IsCodeCacheHashTable();
   inline bool IsMapCache();
   inline bool IsPrimitive();
   inline bool IsGlobalObject();
@@ -2928,7 +2922,7 @@ class Map: public HeapObject {
   DECL_ACCESSORS(instance_descriptors, DescriptorArray)
 
   // [stub cache]: contains stubs compiled for this map.
-  DECL_ACCESSORS(code_cache, Object)
+  DECL_ACCESSORS(code_cache, FixedArray)
 
   Object* CopyDropDescriptors();
 
@@ -3032,11 +3026,6 @@ class Map: public HeapObject {
   static const int kNeedsLoading = 0;
   static const int kIsExtensible = 1;
 
-  // Layout of the default cache. It holds alternating name and code objects.
-  static const int kCodeCacheEntrySize = 2;
-  static const int kCodeCacheEntryNameOffset = 0;
-  static const int kCodeCacheEntryCodeOffset = 1;
-
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
 };
@@ -3722,93 +3711,6 @@ class CompilationCacheTable: public HashTable<CompilationCacheShape,
 };
 
 
-class CodeCache: public Struct {
- public:
-  DECL_ACCESSORS(default_cache, FixedArray)
-  DECL_ACCESSORS(normal_type_cache, Object)
-
-  // Add the code object to the cache.
-  Object* Update(String* name, Code* code);
-
-  // Lookup code object in the cache. Returns code object if found.
-  Object* Lookup(String* name, Code::Flags flags);
-
-  // Get the internal index of a code object in the cache. Returns -1 if the
-  // code object is not in that cache. This index can be used to later call
-  // RemoveByIndex. The cache cannot be modified between a call to GetIndex and
-  // RemoveByIndex.
-  int GetIndex(Code* code);
-
-  // Remove an object from the cache with the provided internal index.
-  void RemoveByIndex(int index);
-
-  static inline CodeCache* cast(Object* obj);
-
-#ifdef DEBUG
-  void CodeCachePrint();
-  void CodeCacheVerify();
-#endif
-
-  static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
-  static const int kNormalTypeCacheOffset =
-      kDefaultCacheOffset + kPointerSize;
-  static const int kSize = kNormalTypeCacheOffset + kPointerSize;
-
- private:
-  Object* UpdateDefaultCache(String* name, Code* code);
-  Object* UpdateNormalTypeCache(String* name, Code* code);
-  Object* LookupDefaultCache(String* name, Code::Flags flags);
-  Object* LookupNormalTypeCache(String* name, Code::Flags flags);
-
-  // Code cache layout of the default cache. Elements are alternating name and
-  // code objects for non normal load/store/call IC's.
-  static const int kCodeCacheEntrySize = 2;
-  static const int kCodeCacheEntryNameOffset = 0;
-  static const int kCodeCacheEntryCodeOffset = 1;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
-};
-
-
-class CodeCacheHashTableShape {
- public:
-  static inline bool IsMatch(HashTableKey* key, Object* value) {
-    return key->IsMatch(value);
-  }
-
-  static inline uint32_t Hash(HashTableKey* key) {
-    return key->Hash();
-  }
-
-  static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
-    return key->HashForObject(object);
-  }
-
-  static Object* AsObject(HashTableKey* key) {
-    return key->AsObject();
-  }
-
-  static const int kPrefixSize = 0;
-  static const int kEntrySize = 2;
-};
-
-
-class CodeCacheHashTable: public HashTable<CodeCacheHashTableShape,
-                                           HashTableKey*> {
- public:
-  Object* Lookup(String* name, Code::Flags flags);
-  Object* Put(String* name, Code* code);
-
-  static inline CodeCacheHashTable* cast(Object* obj);
-
-  // Initial size of the fixed array backing the hash table.
-  static const int kInitialSize = 64;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable);
-};
-
-
 enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
 enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};