Revision: 11668
Author:   [email protected]
Date:     Fri May 25 08:26:52 2012
Log:      Revert r11665, r11666 and r11667 due to slowness.

[email protected]

Review URL: https://chromiumcodereview.appspot.com/10447033
http://code.google.com/p/v8/source/detail?r=11668

Modified:
 /branches/bleeding_edge/src/objects.cc
 /branches/bleeding_edge/src/objects.h

=======================================
--- /branches/bleeding_edge/src/objects.cc      Fri May 25 06:39:07 2012
+++ /branches/bleeding_edge/src/objects.cc      Fri May 25 08:26:52 2012
@@ -5088,40 +5088,39 @@

   void Start() {
     ASSERT(!IsIterating());
-    if (HasDescriptors()) *DescriptorArrayHeader() = Smi::FromInt(0);
+    if (HasContentArray()) *ContentHeader() = Smi::FromInt(0);
   }

   bool IsIterating() {
-    return HasDescriptors() && (*DescriptorArrayHeader())->IsSmi();
+    return HasContentArray() && (*ContentHeader())->IsSmi();
   }

   Map* Next() {
     ASSERT(IsIterating());
- // Attention, tricky index manipulation ahead: Two consecutive indices are - // assigned to each descriptor. Most descriptors directly advance to the
-    // next descriptor by adding 2 to the index. The exceptions are the
- // CALLBACKS entries: An even index means we look at its getter, and an odd
-    // index means we look at its setter.
-    int raw_index = Smi::cast(*DescriptorArrayHeader())->value();
-    int index = raw_index / 2;
-    while (index < descriptor_array_->number_of_descriptors()) {
-      PropertyDetails details(RawGetDetails(index));
+    FixedArray* contents = ContentArray();
+ // Attention, tricky index manipulation ahead: Every entry in the contents + // array consists of a value/details pair, so the index is typically even. + // An exception is made for CALLBACKS entries: An even index means we look
+    // at its getter, and an odd index means we look at its setter.
+    int index = Smi::cast(*ContentHeader())->value();
+    while (index < contents->length()) {
+      PropertyDetails details(Smi::cast(contents->get(index | 1)));
       switch (details.type()) {
         case MAP_TRANSITION:
         case CONSTANT_TRANSITION:
         case ELEMENTS_TRANSITION:
           // We definitely have a map transition.
-          *DescriptorArrayHeader() = Smi::FromInt(raw_index + 2);
-          return static_cast<Map*>(RawGetValue(index));
+          *ContentHeader() = Smi::FromInt(index + 2);
+          return static_cast<Map*>(contents->get(index));
         case CALLBACKS: {
           // We might have a map transition in a getter or in a setter.
           AccessorPair* accessors =
-              static_cast<AccessorPair*>(RawGetValue(index));
-          Object* accessor = ((raw_index & 1) == 0)
-              ? accessors->getter()
-              : accessors->setter();
+              static_cast<AccessorPair*>(contents->get(index & ~1));
+          Object* accessor =
+ ((index & 1) == 0) ? accessors->getter() : accessors->setter();
+          index++;
           if (accessor->IsMap()) {
-            *DescriptorArrayHeader() = Smi::FromInt(raw_index + 1);
+            *ContentHeader() = Smi::FromInt(index);
             return static_cast<Map*>(accessor);
           }
           break;
@@ -5133,42 +5132,28 @@
         case INTERCEPTOR:
         case NULL_DESCRIPTOR:
           // We definitely have no map transition.
-          raw_index += 2;
-          ++index;
+          index += 2;
           break;
       }
     }
- *DescriptorArrayHeader() = descriptor_array_->GetHeap()->fixed_array_map();
+    *ContentHeader() = descriptor_array_->GetHeap()->fixed_array_map();
     return NULL;
   }

  private:
-  bool HasDescriptors() {
-    return descriptor_array_-> length() > DescriptorArray::kFirstIndex;
+  bool HasContentArray() {
+ return descriptor_array_-> length() > DescriptorArray::kContentArrayIndex;
   }

-  Object** DescriptorArrayHeader() {
- return HeapObject::RawField(descriptor_array_, DescriptorArray::kMapOffset);
+  FixedArray* ContentArray() {
+ Object* array = descriptor_array_->get(DescriptorArray::kContentArrayIndex);
+    return static_cast<FixedArray*>(array);
   }

-  FixedArray* RawGetContentArray() {
-      Object* array =
-          descriptor_array_->get(DescriptorArray::kContentArrayIndex);
-      return static_cast<FixedArray*>(array);
+  Object** ContentHeader() {
+ return HeapObject::RawField(ContentArray(), DescriptorArray::kMapOffset);
   }

-  Object* RawGetValue(int descriptor_number) {
-    return RawGetContentArray()->get(
-        DescriptorArray::ToValueIndex(descriptor_number));
-  }
-
-  PropertyDetails RawGetDetails(int descriptor_number) {
-    Object* details = RawGetContentArray()->get(
-        DescriptorArray::ToDetailsIndex(descriptor_number));
-    return PropertyDetails(Smi::cast(details));
-  }
-
-
   DescriptorArray* descriptor_array_;
 };

@@ -5266,22 +5251,6 @@
     set_map_no_write_barrier(GetHeap()->meta_map());
     return old_parent;
   }
-
- // Can either be Smi (no instance descriptors), or a descriptor array with the
-  // header overwritten as a Smi (thus iterating).
-  DescriptorArray* MutatedInstanceDescriptors() {
-    Object* object =
-        *HeapObject::RawField(this, kInstanceDescriptorsOrBitField3Offset);
-    if (object->IsSmi()) {
-      return GetHeap()->empty_descriptor_array();
-    } else {
-      DescriptorArray* descriptor_array =
-          static_cast<DescriptorArray*>(object);
-      ASSERT((*HeapObject::RawField(descriptor_array,
- DescriptorArray::kMapOffset))->IsSmi());
-      return descriptor_array;
-    }
-  }

// Start iterating over this map's children, possibly destroying a FixedArray
   // map (see explanation above).
@@ -5294,18 +5263,17 @@
// If we have an unvisited child map, return that one and advance. If we have
   // none, return NULL and reset any destroyed FixedArray maps.
   TraversableMap* ChildIteratorNext() {
+ IntrusiveMapTransitionIterator descriptor_iterator(instance_descriptors());
+    if (descriptor_iterator.IsIterating()) {
+      Map* next = descriptor_iterator.Next();
+      if (next != NULL) return static_cast<TraversableMap*>(next);
+    }
     IntrusivePrototypeTransitionIterator
         proto_iterator(unchecked_prototype_transitions());
     if (proto_iterator.IsIterating()) {
       Map* next = proto_iterator.Next();
       if (next != NULL) return static_cast<TraversableMap*>(next);
     }
-    IntrusiveMapTransitionIterator
-        descriptor_iterator(MutatedInstanceDescriptors());
-    if (descriptor_iterator.IsIterating()) {
-      Map* next = descriptor_iterator.Next();
-      if (next != NULL) return static_cast<TraversableMap*>(next);
-    }
     return NULL;
   }
 };
=======================================
--- /branches/bleeding_edge/src/objects.h       Fri May 25 06:03:34 2012
+++ /branches/bleeding_edge/src/objects.h       Fri May 25 08:26:52 2012
@@ -2588,8 +2588,6 @@
   static const int kMaxNumberOfDescriptors = 1024 + 512;

  private:
-  friend class IntrusiveMapTransitionIterator;
-
   // An entry in a DescriptorArray, represented as an (array, index) pair.
   class Entry {
    public:
@@ -2628,7 +2626,6 @@
   FixedArray* GetContentArray() {
     return FixedArray::cast(get(kContentArrayIndex));
   }
-
   DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray);
 };

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