Create AllocationSite objects, pointed to by AllocationSiteInfo.

src/hydrogen.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 1558 matching lines @@
   if (!pre_fill_with_holes && length != capacity) {
     // Fill unused capacity with the hole.
     BuildFillElementsWithHole(context, to_elements, to_elements_kind,
                               key, capacity);
   }
 }
 
 
 HValue* HGraphBuilder::BuildCloneShallowArray(HContext* context,
                                               HValue* boilerplate,
+                                              HValue* allocation_site,
                                               AllocationSiteMode mode,
                                               ElementsKind kind,
                                               int length) {
   NoObservableSideEffectsScope no_effects(this);
 
   // All sizes here are multiples of kPointerSize.
   int size = JSArray::kSize;
   if (mode == TRACK_ALLOCATION_SITE) {
     size += AllocationSiteInfo::kSize;
   }
@@ skipping 16 matching lines @@
   // Copy the JS array part.
   for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
     if ((i != JSArray::kElementsOffset) || (length == 0)) {
       HObjectAccess access = HObjectAccess::ForJSArrayOffset(i);
       AddStore(object, access, AddLoad(boilerplate, access));
     }
   }
 
   // Create an allocation site info if requested.
   if (mode == TRACK_ALLOCATION_SITE) {
-    BuildCreateAllocationSiteInfo(object, JSArray::kSize, boilerplate);
+    BuildCreateAllocationSiteInfo(object, JSArray::kSize, allocation_site);
   }
 
   if (length > 0) {
     // Get hold of the elements array of the boilerplate and setup the
     // elements pointer in the resulting object.
     HValue* boilerplate_elements = AddLoadElements(boilerplate);
     HValue* object_elements = Add<HInnerAllocatedObject>(object, elems_offset);
     AddStore(object, HObjectAccess::ForElementsPointer(), object_elements);
 
     // Copy the elements array header.
@@ skipping 53 matching lines @@
       if_nil.Deopt();
     }
   }
 
   if_nil.CaptureContinuation(continuation);
 }
 
 
 HValue* HGraphBuilder::BuildCreateAllocationSiteInfo(HValue* previous_object,
                                                      int previous_object_size,
-                                                     HValue* payload) {
-  HInnerAllocatedObject* alloc_site = Add<HInnerAllocatedObject>(
+                                                     HValue* alloc_site) {

[Hannes Payer (out of office), 2013/07/03 15:26:45]

I think we should assert that alloc_site is not Handle<Object>::null().

[mvstanton, 2013/07/05 07:56:14]

good idea, but I'll just check for a NULL pointer since it's an HValue.

+  HInnerAllocatedObject* alloc_site_info = Add<HInnerAllocatedObject>(
       previous_object, previous_object_size);
-  Handle<Map> alloc_site_map(isolate()->heap()->allocation_site_info_map());
-  AddStoreMapConstant(alloc_site, alloc_site_map);
-  HObjectAccess access = HObjectAccess::ForAllocationSitePayload();
-  AddStore(alloc_site, access, payload);
-  return alloc_site;
+  Handle<Map> alloc_site_info_map(
+      isolate()->heap()->allocation_site_info_map());
+  AddStoreMapConstant(alloc_site_info, alloc_site_info_map);
+  HObjectAccess access = HObjectAccess::ForAllocationSiteInfoSite();
+  AddStore(alloc_site_info, access, alloc_site);
+  return alloc_site_info;
 }
 
 
 HInstruction* HGraphBuilder::BuildGetNativeContext(HValue* context) {
   // Get the global context, then the native context
   HInstruction* global_object = Add<HGlobalObject>(context);
   HObjectAccess access = HObjectAccess::ForJSObjectOffset(
       GlobalObject::kNativeContextOffset);
   return AddLoad(global_object, access);
 }
@@ skipping 12 matching lines @@
     ElementsKind kind,
     HValue* allocation_site_payload,
     HValue* constructor_function,
     AllocationSiteOverrideMode override_mode) :
         builder_(builder),
         kind_(kind),
         allocation_site_payload_(allocation_site_payload),
         constructor_function_(constructor_function) {
   mode_ = override_mode == DISABLE_ALLOCATION_SITES
       ? DONT_TRACK_ALLOCATION_SITE
-      : AllocationSiteInfo::GetMode(kind);
+      : AllocationSite::GetMode(kind);
 }
 
 
 HGraphBuilder::JSArrayBuilder::JSArrayBuilder(HGraphBuilder* builder,
                                               ElementsKind kind,
                                               HValue* constructor_function) :
     builder_(builder),
     kind_(kind),
     mode_(DONT_TRACK_ALLOCATION_SITE),
     allocation_site_payload_(NULL),
@@ skipping 3686 matching lines @@
                     &data_size,
                     &pointer_size)) {
     Handle<JSObject> original_boilerplate_object =
         Handle<JSObject>::cast(original_boilerplate);
     Handle<JSObject> boilerplate_object =
         DeepCopy(original_boilerplate_object);
 
     literal = BuildFastLiteral(context,
                                boilerplate_object,
                                original_boilerplate_object,
+                               Handle<Object>::null(),
                                data_size,
                                pointer_size,
                                DONT_TRACK_ALLOCATION_SITE);
   } else {
     NoObservableSideEffectsScope no_effects(this);
     Handle<FixedArray> closure_literals(closure->literals(), isolate());
     Handle<FixedArray> constant_properties = expr->constant_properties();
     int literal_index = expr->literal_index();
     int flags = expr->fast_elements()
         ? ObjectLiteral::kFastElements : ObjectLiteral::kNoFlags;
@@ skipping 87 matching lines @@
 
 void HOptimizedGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ZoneList<Expression*>* subexprs = expr->values();
   int length = subexprs->length();
   HValue* context = environment()->LookupContext();
   HInstruction* literal;
 
+  Handle<AllocationSite> site;
   Handle<FixedArray> literals(environment()->closure()->literals(), isolate());
-  Handle<Object> raw_boilerplate(literals->get(expr->literal_index()),
+  Handle<Object> literals_cell(literals->get(expr->literal_index()),
                                  isolate());

[Hannes Payer (out of office), 2013/07/03 15:26:45]

indent

-
-  if (raw_boilerplate->IsUndefined()) {
+  Handle<Object> raw_boilerplate;
+  if (literals_cell->IsUndefined()) {
     raw_boilerplate = Runtime::CreateArrayLiteralBoilerplate(
         isolate(), literals, expr->constant_elements());
     if (raw_boilerplate.is_null()) {
       return Bailout("array boilerplate creation failed");
     }
-    literals->set(expr->literal_index(), *raw_boilerplate);
+
+    site = isolate()->factory()->NewAllocationSite();
+
+    // We'll want to copy any useful information (statistics?) in the
+    // AllocationSite from the full code gen

[Hannes Payer (out of office), 2013/07/03 15:26:45]

Is the uncommented code still needed? What about the comment about copying
useful information?

[mvstanton, 2013/07/05 07:56:14]

Okay, I went ahead and removed this block, I realized it doesn't make sense. The
deal is that if we came in here, we have apparently never created the
boilerplate, so it means we never created the AllocationSite either. For some
reason I had this idea that we did create one before and now had to copy
information out of it. Weird :p.

+    /*
+    Handle<FixedArray> fullcode_literals(info()->closure()->literals(), isolate());
+    Handle<Object> fullcode_literals_cell(fullcode_literals->get(expr->literal_index()),
+                                          isolate());
+    if (!fullcode_literals_cell->IsUndefined()) {
+      Handle<AllocationSite> old_site = Handle<AllocationSite>::cast(fullcode_literals_cell);
+      // Extract info...
+    }
+    */
+
+    site->set_payload(*raw_boilerplate);
+    literals->set(expr->literal_index(), *site);
+
     if (JSObject::cast(*raw_boilerplate)->elements()->map() ==
         isolate()->heap()->fixed_cow_array_map()) {
       isolate()->counters()->cow_arrays_created_runtime()->Increment();
     }
+  } else {
+    ASSERT(literals_cell->IsAllocationSite());
+    site = Handle<AllocationSite>::cast(literals_cell);
+    raw_boilerplate = Handle<Object>(site->payload(), isolate());
   }
 
+  ASSERT(!raw_boilerplate.is_null());
+  ASSERT(site->IsLiteralSite());
+
   Handle<JSObject> original_boilerplate_object =
       Handle<JSObject>::cast(raw_boilerplate);
   ElementsKind boilerplate_elements_kind =
       Handle<JSObject>::cast(original_boilerplate_object)->GetElementsKind();
 
   // TODO(mvstanton): This heuristic is only a temporary solution.  In the
   // end, we want to quit creating allocation site info after a certain number
   // of GCs for a call site.
-  AllocationSiteMode mode = AllocationSiteInfo::GetMode(
+  AllocationSiteMode mode = AllocationSite::GetMode(
       boilerplate_elements_kind);
 
   // Check whether to use fast or slow deep-copying for boilerplate.
   int data_size = 0;
   int pointer_size = 0;
   int max_properties = kMaxFastLiteralProperties;
   if (IsFastLiteral(original_boilerplate_object,
                     kMaxFastLiteralDepth,
                     &max_properties,
                     &data_size,
                     &pointer_size)) {
     if (mode == TRACK_ALLOCATION_SITE) {
       pointer_size += AllocationSiteInfo::kSize;
     }
 
     Handle<JSObject> boilerplate_object = DeepCopy(original_boilerplate_object);
     literal = BuildFastLiteral(context,
                                boilerplate_object,
                                original_boilerplate_object,
+                               site,
                                data_size,
                                pointer_size,
                                mode);
   } else {
     NoObservableSideEffectsScope no_effects(this);
     // Boilerplate already exists and constant elements are never accessed,
     // pass an empty fixed array to the runtime function instead.
     Handle<FixedArray> constants = isolate()->factory()->empty_fixed_array();
     int literal_index = expr->literal_index();
 
@@ skipping 3816 matching lines @@
   } else {
       return new(zone()) HThisFunction;
   }
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildFastLiteral(
     HValue* context,
     Handle<JSObject> boilerplate_object,
     Handle<JSObject> original_boilerplate_object,
+    Handle<Object> allocation_site,
     int data_size,
     int pointer_size,
     AllocationSiteMode mode) {
   NoObservableSideEffectsScope no_effects(this);
 
   HInstruction* target = NULL;
   HInstruction* data_target = NULL;
 
   HAllocate::Flags flags = HAllocate::DefaultFlags();
 
@@ skipping 17 matching lines @@
       HValue* size_in_bytes = Add<HConstant>(pointer_size);
       target = Add<HAllocate>(context, size_in_bytes, HType::JSObject(), flags);
     }
   } else {
     HValue* size_in_bytes = Add<HConstant>(data_size + pointer_size);
     target = Add<HAllocate>(context, size_in_bytes, HType::JSObject(), flags);
   }
 
   int offset = 0;
   int data_offset = 0;
-  BuildEmitDeepCopy(boilerplate_object, original_boilerplate_object, target,
-                    &offset, data_target, &data_offset, mode);
+  BuildEmitDeepCopy(boilerplate_object, original_boilerplate_object,
+                    allocation_site, target, &offset, data_target,
+                    &data_offset, mode);
   return target;
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitDeepCopy(
     Handle<JSObject> boilerplate_object,
     Handle<JSObject> original_boilerplate_object,
+    Handle<Object> allocation_site_object,
     HInstruction* target,
     int* offset,
     HInstruction* data_target,
     int* data_offset,
     AllocationSiteMode mode) {
+  Zone* zone = this->zone();
+
+  bool create_allocation_site_info = mode == TRACK_ALLOCATION_SITE &&
+      boilerplate_object->map()->CanTrackAllocationSite();
+
+  // If using allocation sites, then the payload on the site should already
+  // be filled in as a valid (boilerplate) array.
+  ASSERT(!create_allocation_site_info ||
+         AllocationSite::cast(*allocation_site_object)->IsLiteralSite());
+
+  HInstruction* allocation_site = NULL;
+
+  if (create_allocation_site_info) {
+    allocation_site = AddInstruction(new(zone) HConstant(
+        allocation_site_object, Representation::Tagged()));
+  }
+
+  // Only elements backing stores for non-COW arrays need to be copied.
   Handle<FixedArrayBase> elements(boilerplate_object->elements());
   Handle<FixedArrayBase> original_elements(
       original_boilerplate_object->elements());
   ElementsKind kind = boilerplate_object->map()->elements_kind();
 
   int object_offset = *offset;
   int object_size = boilerplate_object->map()->instance_size();
   int elements_size = (elements->length() > 0 &&
       elements->map() != isolate()->heap()->fixed_cow_array_map()) ?
           elements->Size() : 0;
@@ skipping 25 matching lines @@
         Add<HInnerAllocatedObject>(target, object_offset);
     BuildEmitInObjectProperties(boilerplate_object, original_boilerplate_object,
         object_properties, target, offset, data_target, data_offset);
   }
 
   // Create allocation site info.
   if (mode == TRACK_ALLOCATION_SITE &&
       boilerplate_object->map()->CanTrackAllocationSite()) {
     elements_offset += AllocationSiteInfo::kSize;
     *offset += AllocationSiteInfo::kSize;
-    HInstruction* original_boilerplate =
-        Add<HConstant>(original_boilerplate_object);
-    BuildCreateAllocationSiteInfo(target, JSArray::kSize, original_boilerplate);
+    BuildCreateAllocationSiteInfo(target, JSArray::kSize, allocation_site);
   }
 }
 
 
 HValue* HOptimizedGraphBuilder::BuildEmitObjectHeader(
     Handle<JSObject> boilerplate_object,
     HInstruction* target,
     HInstruction* data_target,
     int object_offset,
     int elements_offset,
@@ skipping 77 matching lines @@
 
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
       Handle<JSObject> original_value_object = Handle<JSObject>::cast(
           Handle<Object>(original_boilerplate_object->InObjectPropertyAt(index),
               isolate()));
       HInstruction* value_instruction = Add<HInnerAllocatedObject>(target,
                                                                    *offset);
 
       AddStore(object_properties, access, value_instruction);
-
-      BuildEmitDeepCopy(value_object, original_value_object, target,
-          offset, data_target, data_offset, DONT_TRACK_ALLOCATION_SITE);
+      BuildEmitDeepCopy(value_object, original_value_object,
+                        Handle<Object>::null(), target,
+                        offset, data_target, data_offset,
+                        DONT_TRACK_ALLOCATION_SITE);
     } else {
       Representation representation = details.representation();
       HInstruction* value_instruction = Add<HConstant>(value);
 
       if (representation.IsDouble()) {
         // Allocate a HeapNumber box and store the value into it.
         HInstruction* double_box;
         if (data_target != NULL) {
           double_box = Add<HInnerAllocatedObject>(data_target, *data_offset);
           *data_offset += HeapNumber::kSize;
@@ skipping 86 matching lines @@
   for (int i = 0; i < elements_length; i++) {
     Handle<Object> value(fast_elements->get(i), isolate());
     HValue* key_constant = Add<HConstant>(i);
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
       Handle<JSObject> original_value_object = Handle<JSObject>::cast(
           Handle<Object>(original_fast_elements->get(i), isolate()));
       HInstruction* value_instruction = Add<HInnerAllocatedObject>(target,
                                                                    *offset);
       Add<HStoreKeyed>(object_elements, key_constant, value_instruction, kind);
-      BuildEmitDeepCopy(value_object, original_value_object, target,
-          offset, data_target, data_offset, DONT_TRACK_ALLOCATION_SITE);
+      BuildEmitDeepCopy(value_object, original_value_object,
+                        Handle<Object>::null(), target,
+                        offset, data_target, data_offset,
+                        DONT_TRACK_ALLOCATION_SITE);
     } else {
       HInstruction* value_instruction =
           Add<HLoadKeyed>(boilerplate_elements, key_constant,
                           static_cast<HValue*>(NULL), kind,
                           ALLOW_RETURN_HOLE);
       Add<HStoreKeyed>(object_elements, key_constant, value_instruction, kind);
     }
   }
 }
 
@@ skipping 1279 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal