Reland "In-object double fields unboxing (for 64-bit only)."

src/objects-debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/disasm.h"
 #include "src/disassembler.h"
 #include "src/heap/objects-visiting.h"
 #include "src/jsregexp.h"
@@ skipping 257 matching lines @@
       // the allocation of the MutableHeapNumber triggers GC (in this case map
       // is not updated yet).
       CHECK_EQ(map()->unused_property_fields(),
                actual_unused_property_fields - JSObject::kFieldsAdded);
     }
     DescriptorArray* descriptors = map()->instance_descriptors();
     for (int i = 0; i < map()->NumberOfOwnDescriptors(); i++) {
       if (descriptors->GetDetails(i).type() == FIELD) {
         Representation r = descriptors->GetDetails(i).representation();
         FieldIndex index = FieldIndex::ForDescriptor(map(), i);
+        if (IsUnboxedDoubleField(index)) {
+          DCHECK(r.IsDouble());
+          continue;
+        }
         Object* value = RawFastPropertyAt(index);
         if (r.IsDouble()) DCHECK(value->IsMutableHeapNumber());
         if (value->IsUninitialized()) continue;
         if (r.IsSmi()) DCHECK(value->IsSmi());
         if (r.IsHeapObject()) DCHECK(value->IsHeapObject());
         HeapType* field_type = descriptors->GetFieldType(i);
         if (r.IsNone()) {
           CHECK(field_type->Is(HeapType::None()));
         } else if (!HeapType::Any()->Is(field_type)) {
           CHECK(!field_type->NowStable() || field_type->NowContains(value));
@@ skipping 21 matching lines @@
   CHECK(instance_size() == kVariableSizeSentinel ||
          (kPointerSize <= instance_size() &&
           instance_size() < heap->Capacity()));
   VerifyHeapPointer(prototype());
   VerifyHeapPointer(instance_descriptors());
   SLOW_DCHECK(instance_descriptors()->IsSortedNoDuplicates());
   if (HasTransitionArray()) {
     SLOW_DCHECK(transitions()->IsSortedNoDuplicates());
     SLOW_DCHECK(transitions()->IsConsistentWithBackPointers(this));
   }
+  SLOW_DCHECK(!FLAG_unbox_double_fields ||
+              layout_descriptor()->IsConsistentWithMap(this));
 }
 
 
 void Map::DictionaryMapVerify() {
   MapVerify();
   CHECK(is_dictionary_map());
   CHECK(instance_descriptors()->IsEmpty());
   CHECK_EQ(0, pre_allocated_property_fields());
   CHECK_EQ(0, unused_property_fields());
-  CHECK_EQ(StaticVisitorBase::GetVisitorId(instance_type(), instance_size()),
-      visitor_id());
+  CHECK_EQ(StaticVisitorBase::GetVisitorId(this), visitor_id());
 }
 
 
 void Map::VerifyOmittedMapChecks() {
   if (!FLAG_omit_map_checks_for_leaf_maps) return;
   if (!is_stable() ||
       is_deprecated() ||
       HasTransitionArray() ||
       is_dictionary_map()) {
     CHECK_EQ(0, dependent_code()->number_of_entries(
@@ skipping 832 matching lines @@
     if (hash < current) {
       Print();
       return false;
     }
     current = hash;
   }
   return true;
 }
 
 
+bool LayoutDescriptor::IsConsistentWithMap(Map* map) {
+  if (FLAG_unbox_double_fields) {
+    DescriptorArray* descriptors = map->instance_descriptors();
+    int nof_descriptors = map->NumberOfOwnDescriptors();
+    for (int i = 0; i < nof_descriptors; i++) {
+      PropertyDetails details = descriptors->GetDetails(i);
+      if (details.type() != FIELD) continue;
+      FieldIndex field_index = FieldIndex::ForDescriptor(map, i);
+      bool tagged_expected =
+          !field_index.is_inobject() || !details.representation().IsDouble();
+      for (int bit = 0; bit < details.field_width_in_words(); bit++) {
+        bool tagged_actual = IsTagged(details.field_index() + bit);
+        DCHECK_EQ(tagged_expected, tagged_actual);
+        if (tagged_actual != tagged_expected) return false;
+      }
+    }
+  }
+  return true;
+}
+
+
 bool TransitionArray::IsSortedNoDuplicates(int valid_entries) {
   DCHECK(valid_entries == -1);
   Name* prev_key = NULL;
   bool prev_is_data_property = false;
   PropertyAttributes prev_attributes = NONE;
   uint32_t prev_hash = 0;
   for (int i = 0; i < number_of_transitions(); i++) {
     Name* key = GetSortedKey(i);
     uint32_t hash = key->Hash();
     bool is_data_property = false;
@@ skipping 51 matching lines @@
     while (map != heap->roots_array_start()[i++]) {
       CHECK_LT(i, Heap::kStrongRootListLength);
     }
   }
 }
 
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal