[stubs] Port FastFunctionBindStub to TF

src/builtins/builtins-function.cc

Index: src/builtins/builtins-function.cc
diff --git a/src/builtins/builtins-function.cc b/src/builtins/builtins-function.cc
index 6cd1b283ec6f1e144bc1fe8cff3b5a5783da185c..ceea7694623cf9879bef2ccc0ec6781feba4e544 100644
--- a/src/builtins/builtins-function.cc
+++ b/src/builtins/builtins-function.cc
@@ -5,6 +5,7 @@
 #include "src/builtins/builtins.h"
 #include "src/builtins/builtins-utils.h"
 
+#include "src/code-factory.h"
 #include "src/compiler.h"
 #include "src/string-builder.h"
 
@@ -255,6 +256,195 @@ Object* DoFunctionBind(Isolate* isolate, BuiltinArguments args) {
 // ES6 section 19.2.3.2 Function.prototype.bind ( thisArg, ...args )
 BUILTIN(FunctionPrototypeBind) { return DoFunctionBind(isolate, args); }
 
+void Builtins::Generate_FastFunctionPrototypeBind(
+    compiler::CodeAssemblerState* state) {
+  using compiler::Node;
+  typedef CodeStubAssembler::Label Label;
+  typedef CodeStubAssembler::Variable Variable;
+
+  CodeStubAssembler assembler(state);
+  Label slow(&assembler);
+
+  Node* argc = assembler.Parameter(BuiltinDescriptor::kArgumentsCount);
+  Node* context = assembler.Parameter(BuiltinDescriptor::kContext);
+  Node* new_target = assembler.Parameter(BuiltinDescriptor::kNewTarget);
+
+  CodeStubArguments args(&assembler, argc);
+
+  // Check that receiver has instance type of JS_FUNCTION_TYPE
+  Node* receiver = args.GetReceiver();
+  assembler.GotoIf(assembler.TaggedIsSmi(receiver), &slow);
+
+  Node* receiver_map = assembler.LoadMap(receiver);
+  Node* instance_type = assembler.LoadMapInstanceType(receiver_map);
+  assembler.GotoIf(
+      assembler.Word32NotEqual(instance_type,
+                               assembler.Int32Constant(JS_FUNCTION_TYPE)),
+      &slow);
+
+  // Disallow binding of slow-mode functions. We need to figure out whether the
+  // length and name property are in the original state.
+  assembler.Comment("Disallow binding of slow-mode functions");
+  assembler.GotoIf(assembler.IsDictionaryMap(receiver_map), &slow);
+
+  // Check whether the length and name properties are still present as
+  // AccessorInfo objects. In that case, their value can be recomputed even if
+  // the actual value on the object changes.
+  assembler.Comment("Check descriptor array length");
+  Node* descriptors =
+      assembler.LoadObjectField(receiver_map, Map::kDescriptorsOffset);

[Igor Sheludko, 2016/12/01 16:17:40]

LoadMapDescriptors()

+  Node* descriptors_length = assembler.LoadFixedArrayBaseLength(descriptors);
+  assembler.GotoIf(assembler.SmiLessThanOrEqual(descriptors_length,
+                                                assembler.SmiConstant(1)),
+                   &slow);
+
+  // Check whether the length and name properties are still present as
+  // AccessorInfo objects. In that case, their value can be recomputed even if
+  // the actual value on the object changes.
+  assembler.Comment("Check name and length properties");
+  const int length_index = JSFunction::kLengthDescriptorIndex;
+  Node* maybe_length = assembler.LoadFixedArrayElement(
+      descriptors,
+      assembler.IntPtrConstant(DescriptorArray::ToKeyIndex(length_index)),

[Igor Sheludko, 2016/12/01 16:17:40]

The cleanup CL has landed and you can now write here:
  ... = LoadFixedArrayElement(
    descriptors, DescriptorArray::ToKeyIndex(length_index));

+      CodeStubAssembler::INTPTR_PARAMETERS);
+  assembler.GotoIf(
+      assembler.WordNotEqual(maybe_length,
+                             assembler.LoadRoot(Heap::klength_stringRootIndex)),
+      &slow);
+
+  Node* maybe_length_accessor = assembler.LoadFixedArrayElement(
+      descriptors,
+      assembler.Int32Constant(DescriptorArray::ToValueIndex(length_index)));
+  assembler.GotoIf(assembler.TaggedIsSmi(maybe_length_accessor), &slow);
+  Node* length_value_map = assembler.LoadMap(maybe_length_accessor);
+  assembler.GotoUnless(assembler.IsAccessorInfoMap(length_value_map), &slow);
+
+  const int name_index = JSFunction::kNameDescriptorIndex;
+  Node* maybe_name = assembler.LoadFixedArrayElement(
+      descriptors,
+      assembler.IntPtrConstant(DescriptorArray::ToKeyIndex(name_index)),
+      CodeStubAssembler::INTPTR_PARAMETERS);
+  assembler.GotoIf(
+      assembler.WordNotEqual(maybe_name,
+                             assembler.LoadRoot(Heap::kname_stringRootIndex)),
+      &slow);
+
+  Node* maybe_name_accessor = assembler.LoadFixedArrayElement(
+      descriptors,
+      assembler.IntPtrConstant(DescriptorArray::ToValueIndex(name_index)),
+      CodeStubAssembler::INTPTR_PARAMETERS);
+  assembler.GotoIf(assembler.TaggedIsSmi(maybe_name_accessor), &slow);
+  Node* name_value_map = assembler.LoadMap(maybe_name_accessor);
+  assembler.GotoUnless(assembler.IsAccessorInfoMap(name_value_map), &slow);
+
+  // Choose the right bound function map based on whether the target is
+  // constructable.
+  assembler.Comment("Choose the right bound function map");
+  Variable bound_function_map(&assembler, MachineRepresentation::kTagged);
+  Label with_constructor(&assembler);
+  CodeStubAssembler::VariableList vars({&bound_function_map}, assembler.zone());
+  Label map_done(&assembler, vars);
+  Node* bit_field = assembler.LoadMapBitField(receiver_map);
+  int mask = static_cast<int>(1 << Map::kIsConstructor);
+  assembler.GotoIf(assembler.IsSetWord32(bit_field, mask), &with_constructor);
+
+  Node* native_context = assembler.LoadNativeContext(context);
+  bound_function_map.Bind(assembler.LoadContextElement(
+      native_context, Context::BOUND_FUNCTION_WITHOUT_CONSTRUCTOR_MAP_INDEX));
+  assembler.Goto(&map_done);
+
+  assembler.Bind(&with_constructor);
+  bound_function_map.Bind(assembler.LoadContextElement(

[Igor Sheludko, 2016/12/01 16:17:40]

I think native_context is not available in this block.

+      native_context, Context::BOUND_FUNCTION_WITH_CONSTRUCTOR_MAP_INDEX));
+  assembler.Goto(&map_done);
+
+  assembler.Bind(&map_done);
+
+  // Verify that __proto__ matches that of a the target bound function.
+  assembler.Comment("Verify that __proto__ matches target bound function");
+  Node* prototype = assembler.LoadMapPrototype(receiver_map);
+  Node* expected_prototype =
+      assembler.LoadMapPrototype(bound_function_map.value());
+  assembler.GotoIf(assembler.WordNotEqual(prototype, expected_prototype),
+                   &slow);
+
+  // Allocate the arguments array.
+  assembler.Comment("Allocate the arguments array");
+  Variable argument_array(&assembler, MachineRepresentation::kTagged);
+  Label empty_arguments(&assembler);
+  Label arguments_done(&assembler, &argument_array);
+  assembler.GotoIf(
+      assembler.UintPtrLessThanOrEqual(argc, assembler.IntPtrConstant(1)),
+      &empty_arguments);
+  Node* elements_length =
+      assembler.IntPtrSub(argc, assembler.IntPtrConstant(1));
+  Node* elements = assembler.AllocateFixedArray(
+      FAST_ELEMENTS, elements_length, CodeStubAssembler::INTPTR_PARAMETERS);
+  Variable index(&assembler, MachineType::PointerRepresentation());
+  index.Bind(assembler.IntPtrConstant(0));
+  CodeStubAssembler::VariableList foreach_vars({&index}, assembler.zone());
+  args.ForEach(
+      foreach_vars,
+      [elements, &index](CodeStubAssembler* assembler, compiler::Node* arg) {
+        assembler->StoreFixedArrayElement(elements, index.value(), arg,
+                                          UPDATE_WRITE_BARRIER, 0,
+                                          CodeStubAssembler::INTPTR_PARAMETERS);
+        assembler->Increment(index);
+      },
+      assembler.IntPtrConstant(1));
+  argument_array.Bind(elements);
+  assembler.Goto(&arguments_done);
+
+  assembler.Bind(&empty_arguments);
+  argument_array.Bind(assembler.EmptyFixedArrayConstant());
+  assembler.Goto(&arguments_done);
+
+  assembler.Bind(&arguments_done);
+
+  // Determine bound receiver.
+  assembler.Comment("Determine bound receiver");
+  Variable bound_receiver(&assembler, MachineRepresentation::kTagged);
+  Label has_receiver(&assembler);
+  Label receiver_done(&assembler, &bound_receiver);
+  assembler.GotoIf(assembler.WordNotEqual(argc, assembler.IntPtrConstant(0)),
+                   &has_receiver);
+  bound_receiver.Bind(assembler.UndefinedConstant());
+  assembler.Goto(&receiver_done);
+
+  assembler.Bind(&has_receiver);
+  bound_receiver.Bind(args.AtIndex(0));
+  assembler.Goto(&receiver_done);
+
+  assembler.Bind(&receiver_done);
+
+  // Allocate the resulting bound function.
+  assembler.Comment("Allocate the resulting bound function");
+  Node* bound_function = assembler.Allocate(JSBoundFunction::kSize);
+  assembler.StoreMapNoWriteBarrier(bound_function, bound_function_map.value());
+  assembler.StoreObjectFieldNoWriteBarrier(
+      bound_function, JSBoundFunction::kBoundTargetFunctionOffset, receiver);
+  assembler.StoreObjectFieldNoWriteBarrier(bound_function,
+                                           JSBoundFunction::kBoundThisOffset,
+                                           bound_receiver.value());
+  assembler.StoreObjectFieldNoWriteBarrier(
+      bound_function, JSBoundFunction::kBoundArgumentsOffset,
+      argument_array.value());
+  Node* empty_fixed_array = assembler.EmptyFixedArrayConstant();
+  assembler.StoreObjectFieldNoWriteBarrier(
+      bound_function, JSObject::kPropertiesOffset, empty_fixed_array);
+  assembler.StoreObjectFieldNoWriteBarrier(
+      bound_function, JSObject::kElementsOffset, empty_fixed_array);
+
+  args.PopAndReturn(bound_function);
+  assembler.Bind(&slow);
+
+  Node* target = assembler.LoadFromFrame(
+      StandardFrameConstants::kFunctionOffset, MachineType::TaggedPointer());
+  assembler.TailCallStub(
+      CodeFactory::FunctionPrototypeBind(assembler.isolate()), context, target,
+      new_target, argc);
+}
+
 // TODO(verwaest): This is a temporary helper until the FastFunctionBind stub
 // can tailcall to the builtin directly.
 RUNTIME_FUNCTION(Runtime_FunctionBind) {