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

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 5515 matching lines @@
   Handle<FixedArray> properties(boilerplate->properties());
   if (properties->length() > 0) {
     return false;
   } else {
     Handle<DescriptorArray> descriptors(
         boilerplate->map()->instance_descriptors());
     int limit = boilerplate->map()->NumberOfOwnDescriptors();
     for (int i = 0; i < limit; i++) {
       PropertyDetails details = descriptors->GetDetails(i);
       if (details.type() != FIELD) continue;
-      int index = descriptors->GetFieldIndex(i);
       if ((*max_properties)-- == 0) return false;
-      Handle<Object> value(boilerplate->InObjectPropertyAt(index), isolate);
+      FieldIndex field_index = FieldIndex::ForDescriptor(boilerplate->map(), i);
+      if (boilerplate->IsUnboxedDoubleField(field_index)) continue;
+      Handle<Object> value(boilerplate->RawFastPropertyAt(field_index),
+                           isolate);
       if (value->IsJSObject()) {
         Handle<JSObject> value_object = Handle<JSObject>::cast(value);
         if (!IsFastLiteral(value_object,
                            max_depth - 1,
                            max_properties)) {
           return false;
         }
       }
     }
   }
@@ skipping 282 matching lines @@
       LookupIterator it(object, info->name(),
                         LookupIterator::OWN_SKIP_INTERCEPTOR);
       Handle<Object> value = JSObject::GetDataProperty(&it);
       if (it.IsFound() && it.IsReadOnly() && !it.IsConfigurable()) {
         return New<HConstant>(value);
       }
     }
   }
 
   HObjectAccess access = info->access();
-  if (access.representation().IsDouble()) {
+  if (access.representation().IsDouble() &&
+      (!FLAG_unbox_double_fields || !access.IsInobject())) {
     // Load the heap number.
     checked_object = Add<HLoadNamedField>(
         checked_object, static_cast<HValue*>(NULL),
         access.WithRepresentation(Representation::Tagged()));
     // Load the double value from it.
     access = HObjectAccess::ForHeapNumberValue();
   }
 
   SmallMapList* map_list = info->field_maps();
   if (map_list->length() == 0) {
@@ skipping 11 matching lines @@
 
 HInstruction* HOptimizedGraphBuilder::BuildStoreNamedField(
     PropertyAccessInfo* info,
     HValue* checked_object,
     HValue* value) {
   bool transition_to_field = info->IsTransition();
   // TODO(verwaest): Move this logic into PropertyAccessInfo.
   HObjectAccess field_access = info->access();
 
   HStoreNamedField *instr;
-  if (field_access.representation().IsDouble()) {
+  if (field_access.representation().IsDouble() &&
+      (!FLAG_unbox_double_fields || !field_access.IsInobject())) {
     HObjectAccess heap_number_access =
         field_access.WithRepresentation(Representation::Tagged());
     if (transition_to_field) {
       // The store requires a mutable HeapNumber to be allocated.
       NoObservableSideEffectsScope no_side_effects(this);
       HInstruction* heap_number_size = Add<HConstant>(HeapNumber::kSize);
 
       // TODO(hpayer): Allocation site pretenuring support.
       HInstruction* heap_number = Add<HAllocate>(heap_number_size,
           HType::HeapObject(),
@@ skipping 5295 matching lines @@
     PretenureFlag pretenure_flag) {
   Handle<Map> boilerplate_map(boilerplate_object->map());
   Handle<DescriptorArray> descriptors(boilerplate_map->instance_descriptors());
   int limit = boilerplate_map->NumberOfOwnDescriptors();
 
   int copied_fields = 0;
   for (int i = 0; i < limit; i++) {
     PropertyDetails details = descriptors->GetDetails(i);
     if (details.type() != FIELD) continue;
     copied_fields++;
-    int index = descriptors->GetFieldIndex(i);
-    int property_offset = boilerplate_object->GetInObjectPropertyOffset(index);
+    FieldIndex field_index = FieldIndex::ForDescriptor(*boilerplate_map, i);
+
+
+    int property_offset = field_index.offset();
     Handle<Name> name(descriptors->GetKey(i));
-    Handle<Object> value =
-        Handle<Object>(boilerplate_object->InObjectPropertyAt(index),
-        isolate());
 
     // The access for the store depends on the type of the boilerplate.
     HObjectAccess access = boilerplate_object->IsJSArray() ?
         HObjectAccess::ForJSArrayOffset(property_offset) :
         HObjectAccess::ForMapAndOffset(boilerplate_map, property_offset);
 
+    if (boilerplate_object->IsUnboxedDoubleField(field_index)) {
+      CHECK(!boilerplate_object->IsJSArray());
+      double value = boilerplate_object->RawFastDoublePropertyAt(field_index);
+      access = access.WithRepresentation(Representation::Double());
+      Add<HStoreNamedField>(object, access, Add<HConstant>(value));
+      continue;
+    }
+    Handle<Object> value(boilerplate_object->RawFastPropertyAt(field_index),
+                         isolate());
+
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
       Handle<AllocationSite> current_site = site_context->EnterNewScope();
       HInstruction* result =
           BuildFastLiteral(value_object, site_context);
       site_context->ExitScope(current_site, value_object);
       Add<HStoreNamedField>(object, access, result);
     } else {
       Representation representation = details.representation();
       HInstruction* value_instruction;
@@ skipping 1461 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal