[builtins] FastNewClosureStub becomes a builtin.

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/builtins/builtins-utils.h"
+#include "src/builtins/builtins.h"
+#include "src/code-factory.h"
+#include "src/code-stub-assembler.h"
+#include "src/interface-descriptors.h"
+
+namespace v8 {
+namespace internal {
+
+typedef compiler::Node Node;
+
+Node* ConstructorBuiltinsAssembler::EmitFastNewClosure(Node* shared_info,
+                                                       Node* context) {
+  typedef compiler::CodeAssembler::Label Label;
+  typedef compiler::CodeAssembler::Variable Variable;
+
+  Isolate* isolate = this->isolate();
+  Factory* factory = isolate->factory();
+  IncrementCounter(isolate->counters()->fast_new_closure_total(), 1);
+
+  // Create a new closure from the given function info in new space
+  Node* result = Allocate(JSFunction::kSize);
+
+  // Calculate the index of the map we should install on the function based on
+  // the FunctionKind and LanguageMode of the function.
+  // Note: Must be kept in sync with Context::FunctionMapIndex
+  Node* compiler_hints =
+      LoadObjectField(shared_info, SharedFunctionInfo::kCompilerHintsOffset,
+                      MachineType::Uint32());
+  Node* is_strict = Word32And(
+      compiler_hints, Int32Constant(1 << SharedFunctionInfo::kStrictModeBit));
+
+  Label if_normal(this), if_generator(this), if_async(this),
+      if_class_constructor(this), if_function_without_prototype(this),
+      load_map(this);
+  Variable map_index(this, MachineType::PointerRepresentation());
+
+  STATIC_ASSERT(FunctionKind::kNormalFunction == 0);
+  Node* is_not_normal =
+      Word32And(compiler_hints,
+                Int32Constant(SharedFunctionInfo::kAllFunctionKindBitsMask));
+  GotoUnless(is_not_normal, &if_normal);
+
+  Node* is_generator = Word32And(
+      compiler_hints, Int32Constant(FunctionKind::kGeneratorFunction
+                                    << SharedFunctionInfo::kFunctionKindShift));
+  GotoIf(is_generator, &if_generator);
+
+  Node* is_async = Word32And(
+      compiler_hints, Int32Constant(FunctionKind::kAsyncFunction
+                                    << SharedFunctionInfo::kFunctionKindShift));
+  GotoIf(is_async, &if_async);
+
+  Node* is_class_constructor = Word32And(
+      compiler_hints, Int32Constant(FunctionKind::kClassConstructor
+                                    << SharedFunctionInfo::kFunctionKindShift));
+  GotoIf(is_class_constructor, &if_class_constructor);
+
+  if (FLAG_debug_code) {
+    // Function must be a function without a prototype.
+    CSA_ASSERT(
+        this,
+        Word32And(compiler_hints,
+                  Int32Constant((FunctionKind::kAccessorFunction |
+                                 FunctionKind::kArrowFunction |
+                                 FunctionKind::kConciseMethod)
+                                << SharedFunctionInfo::kFunctionKindShift)));
+  }
+  Goto(&if_function_without_prototype);
+
+  Bind(&if_normal);
+  {
+    map_index.Bind(SelectIntPtrConstant(is_strict,
+                                        Context::STRICT_FUNCTION_MAP_INDEX,
+                                        Context::SLOPPY_FUNCTION_MAP_INDEX));
+    Goto(&load_map);
+  }
+
+  Bind(&if_generator);
+  {
+    map_index.Bind(SelectIntPtrConstant(
+        is_strict, Context::STRICT_GENERATOR_FUNCTION_MAP_INDEX,
+        Context::SLOPPY_GENERATOR_FUNCTION_MAP_INDEX));
+    Goto(&load_map);
+  }
+
+  Bind(&if_async);
+  {
+    map_index.Bind(SelectIntPtrConstant(
+        is_strict, Context::STRICT_ASYNC_FUNCTION_MAP_INDEX,
+        Context::SLOPPY_ASYNC_FUNCTION_MAP_INDEX));
+    Goto(&load_map);
+  }
+
+  Bind(&if_class_constructor);
+  {
+    map_index.Bind(IntPtrConstant(Context::CLASS_FUNCTION_MAP_INDEX));
+    Goto(&load_map);
+  }
+
+  Bind(&if_function_without_prototype);
+  {
+    map_index.Bind(
+        IntPtrConstant(Context::STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX));
+    Goto(&load_map);
+  }
+
+  Bind(&load_map);
+
+  // 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_literals_array = HeapConstant(factory->empty_literals_array());
+  StoreObjectFieldNoWriteBarrier(result, JSObject::kPropertiesOffset,
+                                 empty_fixed_array);
+  StoreObjectFieldNoWriteBarrier(result, JSObject::kElementsOffset,
+                                 empty_fixed_array);
+  StoreObjectFieldNoWriteBarrier(result, JSFunction::kLiteralsOffset,
+                                 empty_literals_array);
+  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),
+                IntPtrConstant(Code::kHeaderSize - kHeapObjectTag));
+  StoreObjectFieldNoWriteBarrier(result, JSFunction::kCodeEntryOffset,
+                                 lazy_builtin_entry,
+                                 MachineType::PointerRepresentation());
+  StoreObjectFieldNoWriteBarrier(result, JSFunction::kNextFunctionLinkOffset,
+                                 UndefinedConstant());
+
+  return result;
+}
+
+TF_BUILTIN(FastNewClosure, ConstructorBuiltinsAssembler) {
+  Node* shared = Parameter(FastNewClosureDescriptor::kSharedFunctionInfo);
+  Node* context = Parameter(FastNewClosureDescriptor::kContext);
+  Return(EmitFastNewClosure(shared, context));
+}
+
+}  // namespace internal
+}  // namespace v8