[code-stubs] Add LoadMapElementsKind helper

src/code-stub-assembler.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/code-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 #include "src/ic/handler-configuration.h"
 #include "src/ic/stub-cache.h"
@@ skipping 949 matching lines @@
 }
 
 Node* CodeStubAssembler::LoadMapBitField3(Node* map) {
   return LoadObjectField(map, Map::kBitField3Offset, MachineType::Uint32());
 }
 
 Node* CodeStubAssembler::LoadMapInstanceType(Node* map) {
   return LoadObjectField(map, Map::kInstanceTypeOffset, MachineType::Uint8());
 }
 
+Node* CodeStubAssembler::LoadMapElementsKind(Node* map) {
+  Node* bit_field2 = LoadMapBitField2(map);
+  return BitFieldDecode<Map::ElementsKindBits>(bit_field2);
+}
+
 Node* CodeStubAssembler::LoadMapDescriptors(Node* map) {
   return LoadObjectField(map, Map::kDescriptorsOffset);
 }
 
 Node* CodeStubAssembler::LoadMapPrototype(Node* map) {
   return LoadObjectField(map, Map::kPrototypeOffset);
 }
 
 Node* CodeStubAssembler::LoadMapInstanceSize(Node* map) {
   return ChangeUint32ToWord(
@@ skipping 2721 matching lines @@
 void CodeStubAssembler::TryLookupElement(Node* object, Node* map,
                                          Node* instance_type,
                                          Node* intptr_index, Label* if_found,
                                          Label* if_not_found,
                                          Label* if_bailout) {
   // Handle special objects in runtime.
   GotoIf(Int32LessThanOrEqual(instance_type,
                               Int32Constant(LAST_SPECIAL_RECEIVER_TYPE)),
          if_bailout);
 
-  Node* bit_field2 = LoadMapBitField2(map);
-  Node* elements_kind = BitFieldDecode<Map::ElementsKindBits>(bit_field2);
+  Node* elements_kind = LoadMapElementsKind(map);
 
   // TODO(verwaest): Support other elements kinds as well.
   Label if_isobjectorsmi(this), if_isdouble(this), if_isdictionary(this),
       if_isfaststringwrapper(this), if_isslowstringwrapper(this), if_oob(this);
   // clang-format off
   int32_t values[] = {
       // Handled by {if_isobjectorsmi}.
       FAST_SMI_ELEMENTS, FAST_HOLEY_SMI_ELEMENTS, FAST_ELEMENTS,
           FAST_HOLEY_ELEMENTS,
       // Handled by {if_isdouble}.
@@ skipping 1089 matching lines @@
          &slow);
 
   Node* key = p->name;
   TryToName(key, &if_index, &var_index, &if_unique_name, &slow);
 
   Bind(&if_index);
   {
     Comment("integer index");
     Node* index = var_index.value();
     Node* elements = LoadElements(receiver);
-    Node* bitfield2 = LoadMapBitField2(receiver_map);
-    Node* elements_kind = BitFieldDecode<Map::ElementsKindBits>(bitfield2);
+    Node* elements_kind = LoadMapElementsKind(receiver_map);
     Node* is_jsarray_condition =
         Word32Equal(instance_type, Int32Constant(JS_ARRAY_TYPE));
     Variable var_double_value(this, MachineRepresentation::kFloat64);
     Label rebox_double(this, &var_double_value);
 
     // Unimplemented elements kinds fall back to a runtime call.
     Label* unimplemented_elements_kind = &slow;
     IncrementCounter(isolate()->counters()->ic_keyed_load_generic_smi(), 1);
     EmitElementLoad(receiver, elements, elements_kind, index,
                     is_jsarray_condition, &if_element_hole, &rebox_double,
@@ skipping 888 matching lines @@
                        Heap::kTheHoleValueRootIndex);
 
   // Store the WeakCell in the feedback vector.
   StoreFixedArrayElement(feedback_vector, slot, cell, UPDATE_WRITE_BARRIER,
                          CodeStubAssembler::SMI_PARAMETERS);
   return cell;
 }
 
 }  // namespace internal
 }  // namespace v8