[TypeFeedbackVector] Root feedback vectors at function literal site.

src/builtins/builtins-constructor.cc

 // Copyright 2016 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/builtins/builtins-constructor.h"
 #include "src/ast/ast.h"
 #include "src/builtins/builtins-utils.h"
 #include "src/builtins/builtins.h"
 #include "src/code-factory.h"
 #include "src/code-stub-assembler.h"
@@ skipping 102 matching lines @@
 
   // Get the function map in the current native context and set that
   // as the map of the allocated object.
   Node* native_context = LoadNativeContext(context);
   Node* map_slot_value =
       LoadFixedArrayElement(native_context, map_index.value());
   StoreMapNoWriteBarrier(result, map_slot_value);
 
   // Initialize the rest of the function.
   Node* empty_fixed_array = HeapConstant(factory->empty_fixed_array());
-  Node* empty_feedback_vector =
-      HeapConstant(factory->empty_type_feedback_vector());
   StoreObjectFieldNoWriteBarrier(result, JSObject::kPropertiesOffset,
                                  empty_fixed_array);
   StoreObjectFieldNoWriteBarrier(result, JSObject::kElementsOffset,
                                  empty_fixed_array);
+  Node* literals_cell = LoadFixedArrayElement(
+      feedback_vector, slot, 0, CodeStubAssembler::SMI_PARAMETERS);
   StoreObjectFieldNoWriteBarrier(result, JSFunction::kFeedbackVectorOffset,
-                                 empty_feedback_vector);
+                                 literals_cell);
   StoreObjectFieldNoWriteBarrier(
       result, JSFunction::kPrototypeOrInitialMapOffset, TheHoleConstant());
   StoreObjectFieldNoWriteBarrier(result, JSFunction::kSharedFunctionInfoOffset,
                                  shared_info);
   StoreObjectFieldNoWriteBarrier(result, JSFunction::kContextOffset, context);
   Handle<Code> lazy_builtin_handle(
       isolate->builtins()->builtin(Builtins::kCompileLazy));
   Node* lazy_builtin = HeapConstant(lazy_builtin_handle);
   Node* lazy_builtin_entry =
       IntPtrAdd(BitcastTaggedToWord(lazy_builtin),
@@ skipping 253 matching lines @@
                                                         Node* flags,
                                                         Node* context) {
   typedef CodeStubAssembler::Label Label;
   typedef CodeStubAssembler::Variable Variable;
   typedef compiler::Node Node;
 
   Label call_runtime(this, Label::kDeferred), end(this);
 
   Variable result(this, MachineRepresentation::kTagged);
 
-  Node* vector_array =
-      LoadObjectField(closure, JSFunction::kFeedbackVectorOffset);
-  Node* boilerplate = LoadFixedArrayElement(vector_array, literal_index, 0,
+  Node* cell = LoadObjectField(closure, JSFunction::kFeedbackVectorOffset);
+  Node* literals_array = LoadObjectField(cell, Cell::kValueOffset);
+  Node* boilerplate = LoadFixedArrayElement(literals_array, literal_index, 0,
                                             CodeStubAssembler::SMI_PARAMETERS);
   GotoIf(IsUndefined(boilerplate), &call_runtime);
 
   {
     int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
     Node* copy = Allocate(size);
     for (int offset = 0; offset < size; offset += kPointerSize) {
       Node* value = LoadObjectField(boilerplate, offset);
       StoreObjectFieldNoWriteBarrier(copy, offset, value);
     }
@@ skipping 60 matching lines @@
     Node* closure, Node* literal_index, Node* context,
     CodeAssemblerLabel* call_runtime, AllocationSiteMode allocation_site_mode) {
   typedef CodeStubAssembler::Label Label;
   typedef CodeStubAssembler::Variable Variable;
   typedef compiler::Node Node;
 
   Label zero_capacity(this), cow_elements(this), fast_elements(this),
       return_result(this);
   Variable result(this, MachineRepresentation::kTagged);
 
-  Node* vector_array =
-      LoadObjectField(closure, JSFunction::kFeedbackVectorOffset);
+  Node* cell = LoadObjectField(closure, JSFunction::kFeedbackVectorOffset);
+  Node* literals_array = LoadObjectField(cell, Cell::kValueOffset);
   Node* allocation_site = LoadFixedArrayElement(
-      vector_array, literal_index, 0, CodeStubAssembler::SMI_PARAMETERS);
+      literals_array, literal_index, 0, CodeStubAssembler::SMI_PARAMETERS);
 
   GotoIf(IsUndefined(allocation_site), call_runtime);
-  allocation_site = LoadFixedArrayElement(vector_array, literal_index, 0,
+  allocation_site = LoadFixedArrayElement(literals_array, literal_index, 0,
                                           CodeStubAssembler::SMI_PARAMETERS);
 
   Node* boilerplate =
       LoadObjectField(allocation_site, AllocationSite::kTransitionInfoOffset);
   Node* boilerplate_map = LoadMap(boilerplate);
   Node* boilerplate_elements = LoadElements(boilerplate);
   Node* capacity = LoadFixedArrayBaseLength(boilerplate_elements);
   allocation_site =
       allocation_site_mode == TRACK_ALLOCATION_SITE ? allocation_site : nullptr;
 
@@ skipping 131 matching lines @@
   // runtime.
   // TODO(verwaest): Unify this with the heuristic in the runtime.
   return literal_length == 0
              ? JSObject::kInitialGlobalObjectUnusedPropertiesCount
              : literal_length;
 }
 
 Node* ConstructorBuiltinsAssembler::EmitFastCloneShallowObject(
     CodeAssemblerLabel* call_runtime, Node* closure, Node* literals_index,
     Node* properties_count) {
-  Node* vector_array =
-      LoadObjectField(closure, JSFunction::kFeedbackVectorOffset);
+  Node* cell = LoadObjectField(closure, JSFunction::kFeedbackVectorOffset);
+  Node* literals_array = LoadObjectField(cell, Cell::kValueOffset);
   Node* allocation_site = LoadFixedArrayElement(
-      vector_array, literals_index, 0, CodeStubAssembler::SMI_PARAMETERS);
+      literals_array, literals_index, 0, CodeStubAssembler::SMI_PARAMETERS);
   GotoIf(IsUndefined(allocation_site), call_runtime);
 
   // Calculate the object and allocation size based on the properties count.
   Node* object_size = IntPtrAdd(WordShl(properties_count, kPointerSizeLog2),
                                 IntPtrConstant(JSObject::kHeaderSize));
   Node* allocation_size = object_size;
   if (FLAG_allocation_site_pretenuring) {
     allocation_size =
         IntPtrAdd(object_size, IntPtrConstant(AllocationMemento::kSize));
   }
@@ skipping 100 matching lines @@
     case 6:
       return FastCloneShallowObject6();
     default:
       UNREACHABLE();
   }
   return Handle<Code>::null();
 }
 
 }  // namespace internal
 }  // namespace v8