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 1599 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) {
   Zone* zone = this->zone();
 
   NoObservableSideEffectsScope no_effects(this);
 
   // All sizes here are multiples of kPointerSize.
   int size = JSArray::kSize;
   if (mode == TRACK_ALLOCATION_SITE) {
@@ skipping 16 matching lines @@
                                          size_in_bytes,
                                          HType::JSObject(),
                                          allocate_flags));
 
   // 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));
     }
   }

[Hannes Payer (out of office), 2013/06/25 16:35:07]

ASSERT if boilerplate and allocation_site->boilerplate are the same

 
   // 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 =
         AddInstruction(new(zone) HInnerAllocatedObject(object, elems_offset));
     AddStore(object, HObjectAccess::ForElementsPointer(), object_elements);
 
@@ skipping 67 matching lines @@
       }
     }
   }
 
   if_nil.CaptureContinuation(continuation);
 }
 
 
 HValue* HGraphBuilder::BuildCreateAllocationSiteInfo(HValue* previous_object,
                                                      int previous_object_size,
-                                                     HValue* payload) {
-  HInnerAllocatedObject* alloc_site = new(zone())
+                                                     HValue* alloc_site) {
+  HInnerAllocatedObject* alloc_site_info = new(zone())
         HInnerAllocatedObject(previous_object, previous_object_size);
-  AddInstruction(alloc_site);
-  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;
+  AddInstruction(alloc_site_info);
+  Handle<Map> alloc_site_info_map(
+      isolate()->heap()->allocation_site_info_map());
+  AddStoreMapConstant(alloc_site_info, alloc_site_info_map);
+  HObjectAccess access = HObjectAccess::ForAllocationSiteInfoPayload();
+  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 = AddInstruction(new(zone())
       HGlobalObject(context));
   HObjectAccess access = HObjectAccess::ForJSObjectOffset(
       GlobalObject::kNativeContextOffset);
   return AddLoad(global_object, access);
@@ skipping 13 matching lines @@
 HGraphBuilder::JSArrayBuilder::JSArrayBuilder(HGraphBuilder* builder,
                                               ElementsKind kind,
                                               HValue* allocation_site_payload,
                                               bool disable_allocation_sites) :
         builder_(builder),
         kind_(kind),
         allocation_site_payload_(allocation_site_payload),
         constructor_function_(NULL) {
   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 4072 matching lines @@
   if (original_boilerplate->IsJSObject() &&
       IsFastLiteral(Handle<JSObject>::cast(original_boilerplate),
                     kMaxFastLiteralDepth,
                     &max_properties,
                     &data_size,
                     &pointer_size)) {
     Handle<JSObject> original_boilerplate_object =
         Handle<JSObject>::cast(original_boilerplate);
     Handle<JSObject> boilerplate_object =
         DeepCopy(original_boilerplate_object);
-
+    Handle<FixedArray> literals(closure->literals(), isolate());

[Hannes Payer (out of office), 2013/06/25 16:35:07]

Literals can be removed.

[mvstanton, 2013/07/02 13:55:11]

Done.

     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 93 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());
-
-  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), 2013/06/25 16:35:07]

why can't you reuse the allocation site generated in full code gen?

[mvstanton, 2013/07/02 13:55:11]

The reason is that we don't create the AllocationSite at compile time, we create
it when we create the boilerplate object. So we don't have one to look at if we
don't have a boilerplate.

I guess we don't come into this case very much (where we are crankshafting but
apparently we never ran the code even once in full codegen, which would have
created the boilerplate).

+    /*
+    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 3892 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) {
   Zone* zone = this->zone();
   int total_size = data_size + pointer_size;
 
   NoObservableSideEffectsScope no_effects(this);
 
   HAllocate::Flags flags = HAllocate::CAN_ALLOCATE_IN_NEW_SPACE;
   // TODO(hpayer): add support for old data space
   if (isolate()->heap()->ShouldGloballyPretenure() &&
       data_size == 0) {
     flags = static_cast<HAllocate::Flags>(
         flags | HAllocate::CAN_ALLOCATE_IN_OLD_POINTER_SPACE);
   }
 
   HValue* size_in_bytes =
       AddInstruction(new(zone) HConstant(total_size,
           Representation::Integer32()));
   HInstruction* result =
       AddInstruction(new(zone) HAllocate(context,
                                          size_in_bytes,
                                          HType::JSObject(),
                                          flags));
   int offset = 0;
-  BuildEmitDeepCopy(boilerplate_object, original_boilerplate_object, result,
-                    &offset, mode);
+  BuildEmitDeepCopy(boilerplate_object, original_boilerplate_object,
+                    allocation_site, result, &offset, mode);
   return result;
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitDeepCopy(
     Handle<JSObject> boilerplate_object,
     Handle<JSObject> original_boilerplate_object,
+    Handle<Object> allocation_site_object,
     HInstruction* target,
     int* 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();
 
   // Increase the offset so that subsequent objects end up right after
   // this object and its backing store.
   int object_offset = *offset;
   int object_size = boilerplate_object->map()->instance_size();
   int elements_size = (elements->length() > 0 &&
@@ skipping 15 matching lines @@
   HValue* object_properties =
       AddInstruction(new(zone) HInnerAllocatedObject(target, object_offset));
   BuildEmitInObjectProperties(boilerplate_object, original_boilerplate_object,
       object_properties, target, offset);
 
   // Create allocation site info.
   if (mode == TRACK_ALLOCATION_SITE &&
       boilerplate_object->map()->CanTrackAllocationSite()) {
     elements_offset += AllocationSiteInfo::kSize;
     *offset += AllocationSiteInfo::kSize;
-    HInstruction* original_boilerplate = AddInstruction(new(zone) HConstant(
-        original_boilerplate_object, Representation::Tagged()));
-    BuildCreateAllocationSiteInfo(target, JSArray::kSize, original_boilerplate);
+    BuildCreateAllocationSiteInfo(target, JSArray::kSize, allocation_site);
   }
 }
 
 
 HValue* HOptimizedGraphBuilder::BuildEmitObjectHeader(
     Handle<JSObject> boilerplate_object,
     HInstruction* target,
     int object_offset,
     int elements_offset,
     int elements_size) {
@@ skipping 75 matching lines @@
         HObjectAccess::ForJSArrayOffset(property_offset) :
         HObjectAccess::ForJSObjectOffset(property_offset);
 
     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 =
           AddInstruction(new(zone) HInnerAllocatedObject(target, *offset));
-
       AddStore(object_properties, access, value_instruction);
-
-      BuildEmitDeepCopy(value_object, original_value_object, target,
-          offset, DONT_TRACK_ALLOCATION_SITE);
+      BuildEmitDeepCopy(value_object, original_value_object,
+                        Handle<Object>::null(), target, offset,
+                        DONT_TRACK_ALLOCATION_SITE);
     } else {
       Representation representation = details.representation();
       HInstruction* value_instruction = AddInstruction(new(zone) HConstant(
           value, Representation::Tagged()));
 
       if (representation.IsDouble()) {
         // Allocate a HeapNumber box and store the value into it.
         HInstruction* double_box =
             AddInstruction(new(zone) HInnerAllocatedObject(target, *offset));
         AddStoreMapConstant(double_box,
@@ skipping 86 matching lines @@
     Handle<Object> value(fast_elements->get(i), isolate());
     HValue* key_constant = AddInstruction(new(zone) 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 =
           AddInstruction(new(zone) HInnerAllocatedObject(target, *offset));
       AddInstruction(new(zone) HStoreKeyed(
           object_elements, key_constant, value_instruction, kind));
-      BuildEmitDeepCopy(value_object, original_value_object, target,
-          offset, DONT_TRACK_ALLOCATION_SITE);
+      BuildEmitDeepCopy(value_object, original_value_object,
+                        Handle<Object>::null(), target,
+                        offset, DONT_TRACK_ALLOCATION_SITE);
     } else {
       HInstruction* value_instruction =
           AddInstruction(new(zone) HLoadKeyed(
               boilerplate_elements, key_constant, NULL, kind,
               ALLOW_RETURN_HOLE));
       AddInstruction(new(zone) HStoreKeyed(
           object_elements, key_constant, value_instruction, kind));
     }
   }
 }
@@ skipping 1346 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal