Supporting AllocationSiteInfo for Nested arrays

src/runtime.cc

 // 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 122 matching lines @@
 // and store it in a LanguageMode variable with the given name.
 #define CONVERT_LANGUAGE_MODE_ARG(name, index)                       \
   ASSERT(args[index]->IsSmi());                                      \
   ASSERT(args.smi_at(index) == CLASSIC_MODE ||                       \
          args.smi_at(index) == STRICT_MODE ||                        \
          args.smi_at(index) == EXTENDED_MODE);                       \
   LanguageMode name =                                                \
       static_cast<LanguageMode>(args.smi_at(index));
 
 
-MUST_USE_RESULT static MaybeObject* DeepCopyBoilerplate(Isolate* isolate,
-                                                   JSObject* boilerplate) {
+
+MUST_USE_RESULT MaybeObject* Runtime::DeepCopyBoilerplate(
+    Isolate* isolate,
+    JSObject* boilerplate,
+    AllocationSiteMode allocation_site_mode) {
   StackLimitCheck check(isolate);
   if (check.HasOverflowed()) return isolate->StackOverflow();
 
   Heap* heap = isolate->heap();
   Object* result;
-  { MaybeObject* maybe_result = heap->CopyJSObject(boilerplate);
+  AllocationSiteMode current_object_mode = DONT_TRACK_ALLOCATION_SITE;
+  if (allocation_site_mode == TRACK_ALLOCATION_SITE &&
+      boilerplate->ShouldTrackAllocationInfo()) {
+    current_object_mode = TRACK_ALLOCATION_SITE;
+  }
+
+  { MaybeObject* maybe_result = heap->CopyJSObject(boilerplate,
+                                                   current_object_mode);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   JSObject* copy = JSObject::cast(result);
 
   // Deep copy local properties.
   if (copy->HasFastProperties()) {
     FixedArray* properties = copy->properties();
     for (int i = 0; i < properties->length(); i++) {
       Object* value = properties->get(i);
       if (value->IsJSObject()) {
         JSObject* js_object = JSObject::cast(value);
-        { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate, js_object);
+        { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate, js_object,
+                                                          allocation_site_mode);
           if (!maybe_result->ToObject(&result)) return maybe_result;
         }
         properties->set(i, result);
       }
     }
     int nof = copy->map()->inobject_properties();
     for (int i = 0; i < nof; i++) {
       Object* value = copy->InObjectPropertyAt(i);
       if (value->IsJSObject()) {
         JSObject* js_object = JSObject::cast(value);
-        { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate, js_object);
+        { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate, js_object,
+                                                          allocation_site_mode);
           if (!maybe_result->ToObject(&result)) return maybe_result;
         }
         copy->InObjectPropertyAtPut(i, result);
       }
     }
   } else {
     { MaybeObject* maybe_result =
           heap->AllocateFixedArray(copy->NumberOfLocalProperties());
       if (!maybe_result->ToObject(&result)) return maybe_result;
     }
     FixedArray* names = FixedArray::cast(result);
     copy->GetLocalPropertyNames(names, 0);
     for (int i = 0; i < names->length(); i++) {
       ASSERT(names->get(i)->IsString());
       String* key_string = String::cast(names->get(i));
       PropertyAttributes attributes =
           copy->GetLocalPropertyAttribute(key_string);
       // Only deep copy fields from the object literal expression.
       // In particular, don't try to copy the length attribute of
       // an array.
       if (attributes != NONE) continue;
       Object* value =
           copy->GetProperty(key_string, &attributes)->ToObjectUnchecked();
       if (value->IsJSObject()) {
         JSObject* js_object = JSObject::cast(value);
-        { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate, js_object);
+        { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate, js_object,
+                                                          allocation_site_mode);
           if (!maybe_result->ToObject(&result)) return maybe_result;
         }
         { MaybeObject* maybe_result =
               // Creating object copy for literals. No strict mode needed.
               copy->SetProperty(key_string, result, NONE, kNonStrictMode);
           if (!maybe_result->ToObject(&result)) return maybe_result;
         }
       }
     }
   }
@@ skipping 16 matching lines @@
 #endif
       } else {
         for (int i = 0; i < elements->length(); i++) {
           Object* value = elements->get(i);
           ASSERT(value->IsSmi() ||
                  value->IsTheHole() ||
                  (IsFastObjectElementsKind(copy->GetElementsKind())));
           if (value->IsJSObject()) {
             JSObject* js_object = JSObject::cast(value);
             { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate,
-                                                              js_object);
+                  js_object,
+                  allocation_site_mode);
               if (!maybe_result->ToObject(&result)) return maybe_result;
             }
             elements->set(i, result);
           }
         }
       }
       break;
     }
     case DICTIONARY_ELEMENTS: {
       SeededNumberDictionary* element_dictionary = copy->element_dictionary();
       int capacity = element_dictionary->Capacity();
       for (int i = 0; i < capacity; i++) {
         Object* k = element_dictionary->KeyAt(i);
         if (element_dictionary->IsKey(k)) {
           Object* value = element_dictionary->ValueAt(i);
           if (value->IsJSObject()) {
             JSObject* js_object = JSObject::cast(value);
             { MaybeObject* maybe_result = DeepCopyBoilerplate(isolate,
-                                                              js_object);
+                  js_object,
+                  allocation_site_mode);
               if (!maybe_result->ToObject(&result)) return maybe_result;
             }
             element_dictionary->ValueAtPut(i, result);
           }
         }
       }
       break;
     }
     case NON_STRICT_ARGUMENTS_ELEMENTS:
       UNIMPLEMENTED();
@@ skipping 313 matching lines @@
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateObjectLiteral) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, literals, 0);
   CONVERT_SMI_ARG_CHECKED(literals_index, 1);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, constant_properties, 2);
   CONVERT_SMI_ARG_CHECKED(flags, 3);
   bool should_have_fast_elements = (flags & ObjectLiteral::kFastElements) != 0;
   bool has_function_literal = (flags & ObjectLiteral::kHasFunction) != 0;
+  bool allocation_sites_allowed =
+      (flags & ObjectLiteral::kAllocationSiteInfoAllowed) != 0;

[danno, 2013/02/11 15:05:21]

The flag tells object literal instantiation to create allocation sites wherever
possible, so does it make sense to rename this flag to
"kCreateAllocationSiteInfos", since they are not allowed, they are desired, and
requested to be created if the boilerplate object supports them. If you agree,
rename the boolean variable appropriately.

[mvstanton, 2013/02/15 07:36:43]

"they are not allowed, they are desired." Beautiful :).

+

[danno, 2013/02/11 15:05:21]

Also, perhaps you should fashion the calculation of this boolean value to
include "&& FLAG_track_allocation_sites" as you do later in this file for
consistency. Even better, to reduce the number of sites that need to check
"FLAG_track_allocation_sites", just make sure never to set the
"kAllocationSiteInfoAllowed" flag if FLAG_track_allocation_sites is false, then
you don't have to check the flag at the the sites in this file.

[mvstanton, 2013/02/15 07:36:43]

right on, done.

+  AllocationSiteMode allocation_site_mode = DONT_TRACK_ALLOCATION_SITE;
+  if (FLAG_track_allocation_sites && allocation_sites_allowed) {
+    allocation_site_mode = TRACK_ALLOCATION_SITE;
+  }
 
   // Check if boilerplate exists. If not, create it first.
   Handle<Object> boilerplate(literals->get(literals_index), isolate);
   if (*boilerplate == isolate->heap()->undefined_value()) {
     boilerplate = CreateObjectLiteralBoilerplate(isolate,
                                                  literals,
                                                  constant_properties,
                                                  should_have_fast_elements,
                                                  has_function_literal);
     if (boilerplate.is_null()) return Failure::Exception();
     // Update the functions literal and return the boilerplate.
     literals->set(literals_index, *boilerplate);
   }
-  return DeepCopyBoilerplate(isolate, JSObject::cast(*boilerplate));
+
+  return Runtime::DeepCopyBoilerplate(isolate,
+                                      JSObject::cast(*boilerplate),
+                                      allocation_site_mode);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateObjectLiteralShallow) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, literals, 0);
   CONVERT_SMI_ARG_CHECKED(literals_index, 1);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, constant_properties, 2);
   CONVERT_SMI_ARG_CHECKED(flags, 3);
   bool should_have_fast_elements = (flags & ObjectLiteral::kFastElements) != 0;
   bool has_function_literal = (flags & ObjectLiteral::kHasFunction) != 0;
+  bool allocation_site_info_allowed =
+      (flags & ObjectLiteral::kAllocationSiteInfoAllowed) != 0
+      && FLAG_track_allocation_sites;
 
   // Check if boilerplate exists. If not, create it first.
   Handle<Object> boilerplate(literals->get(literals_index), isolate);
   if (*boilerplate == isolate->heap()->undefined_value()) {
     boilerplate = CreateObjectLiteralBoilerplate(isolate,
                                                  literals,
                                                  constant_properties,
                                                  should_have_fast_elements,
                                                  has_function_literal);
     if (boilerplate.is_null()) return Failure::Exception();
     // Update the functions literal and return the boilerplate.
     literals->set(literals_index, *boilerplate);
   }
-  return isolate->heap()->CopyJSObject(JSObject::cast(*boilerplate));
+
+  AllocationSiteMode mode = allocation_site_info_allowed
+      ? TRACK_ALLOCATION_SITE
+      : DONT_TRACK_ALLOCATION_SITE;
+  return isolate->heap()->CopyJSObject(JSObject::cast(*boilerplate),
+                                       mode);

[danno, 2013/02/11 15:05:21]

nit: mode fits on previous line.

[mvstanton, 2013/02/15 07:36:43]

Changes based on other recommendations affected this line differently.

 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateArrayLiteral) {
   HandleScope scope(isolate);
-  ASSERT(args.length() == 3);
+  ASSERT(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, literals, 0);
   CONVERT_SMI_ARG_CHECKED(literals_index, 1);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, elements, 2);
+  CONVERT_SMI_ARG_CHECKED(flags, 3);
+  bool allocation_sites_allowed =
+      (flags & ArrayLiteral::kAllocationSiteInfoAllowed) != 0;
+
+  AllocationSiteMode allocation_site_mode = DONT_TRACK_ALLOCATION_SITE;
+  if (FLAG_track_allocation_sites && allocation_sites_allowed) {
+    allocation_site_mode = TRACK_ALLOCATION_SITE;
+  }
 
   // Check if boilerplate exists. If not, create it first.
   Handle<Object> boilerplate(literals->get(literals_index), isolate);
   if (*boilerplate == isolate->heap()->undefined_value()) {
     ASSERT(*elements != isolate->heap()->empty_fixed_array());
     boilerplate =
         Runtime::CreateArrayLiteralBoilerplate(isolate, literals, elements);
     if (boilerplate.is_null()) return Failure::Exception();
     // Update the functions literal and return the boilerplate.
     literals->set(literals_index, *boilerplate);
   }
-  return DeepCopyBoilerplate(isolate, JSObject::cast(*boilerplate));
+
+  return Runtime::DeepCopyBoilerplate(isolate,
+                                      JSObject::cast(*boilerplate),
+                                      allocation_site_mode);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateArrayLiteralShallow) {
   HandleScope scope(isolate);
-  ASSERT(args.length() == 3);
+  ASSERT(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, literals, 0);
   CONVERT_SMI_ARG_CHECKED(literals_index, 1);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, elements, 2);
+  CONVERT_SMI_ARG_CHECKED(flags, 3);
+  bool allocation_site_info_allowed = FLAG_track_allocation_sites &&
+      ((flags & ArrayLiteral::kAllocationSiteInfoAllowed) != 0);
 
   // Check if boilerplate exists. If not, create it first.
   Handle<Object> boilerplate(literals->get(literals_index), isolate);
   if (*boilerplate == isolate->heap()->undefined_value()) {
     ASSERT(*elements != isolate->heap()->empty_fixed_array());
     boilerplate =
         Runtime::CreateArrayLiteralBoilerplate(isolate, literals, elements);
     if (boilerplate.is_null()) return Failure::Exception();
     // Update the functions literal and return the boilerplate.
     literals->set(literals_index, *boilerplate);
   }
   if (JSObject::cast(*boilerplate)->elements()->map() ==
       isolate->heap()->fixed_cow_array_map()) {
     isolate->counters()->cow_arrays_created_runtime()->Increment();
   }
 
   JSObject* boilerplate_object = JSObject::cast(*boilerplate);
-  AllocationSiteMode mode = AllocationSiteInfo::GetMode(
-      boilerplate_object->GetElementsKind());
+  AllocationSiteMode mode = allocation_site_info_allowed &&
+      boilerplate_object->ShouldTrackAllocationInfo()

[danno, 2013/02/11 15:05:21]

nite: Just for clarity and easy, separate the boolean calculation into a
temporary variable then used in the ternary operator.

[mvstanton, 2013/02/15 07:36:43]

Done.

+      ? TRACK_ALLOCATION_SITE
+      : DONT_TRACK_ALLOCATION_SITE;
   return isolate->heap()->CopyJSObject(boilerplate_object, mode);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateJSProxy) {
   ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(JSReceiver, handler, 0);
   Object* prototype = args[1];
   Object* used_prototype =
       prototype->IsJSReceiver() ? prototype : isolate->heap()->null_value();
@@ skipping 12840 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal