[turbofan][x64] Improve code generation for external reference access.

src/compiler/instruction-selector.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_INSTRUCTION_SELECTOR_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_H_
 
 #include <map>
 
 #include "src/compiler/common-operator.h"
@@ skipping 31 matching lines @@
 };
 
 // Instruction selection generates an InstructionSequence for a given Schedule.
 class InstructionSelector final {
  public:
   // Forward declarations.
   class Features;
 
   enum SourcePositionMode { kCallSourcePositions, kAllSourcePositions };
   enum EnableScheduling { kDisableScheduling, kEnableScheduling };
+  enum EnableSerialization { kDisableSerialization, kEnableSerialization };
 
   InstructionSelector(
       Zone* zone, size_t node_count, Linkage* linkage,
       InstructionSequence* sequence, Schedule* schedule,
       SourcePositionTable* source_positions, Frame* frame,
       SourcePositionMode source_position_mode = kCallSourcePositions,
       Features features = SupportedFeatures(),
       EnableScheduling enable_scheduling = FLAG_turbo_instruction_scheduling
                                                ? kEnableScheduling
-                                               : kDisableScheduling);
+                                               : kDisableScheduling,
+      EnableSerialization enable_serialization = kDisableSerialization);
 
   // Visit code for the entire graph with the included schedule.
   bool SelectInstructions();
 
   void StartBlock(RpoNumber rpo);
   void EndBlock(RpoNumber rpo);
   void AddInstruction(Instruction* instr);
 
   // ===========================================================================
   // ============= Architecture-independent code emission methods. =============
@@ skipping 119 matching lines @@
 
   // Checks if {node} is currently live.
   bool IsLive(Node* node) const { return !IsDefined(node) && IsUsed(node); }
 
   // Gets the effect level of {node}.
   int GetEffectLevel(Node* node) const;
 
   int GetVirtualRegister(const Node* node);
   const std::map<NodeId, int> GetVirtualRegistersForTesting() const;
 
+  // Check if we can generate loads and stores of ExternalConstants relative
+  // to the roots register, i.e. if both a root register is available for this
+  // compilation unit and the serializer is disabled.
+  bool CanAddressRelativeToRootsRegister() const;
+
   Isolate* isolate() const { return sequence()->isolate(); }
 
  private:
   friend class OperandGenerator;
 
   bool UseInstructionScheduling() const {
     return (enable_scheduling_ == kEnableScheduling) &&
            InstructionScheduler::SchedulerSupported();
   }
 
@@ skipping 137 matching lines @@
   Schedule* const schedule_;
   BasicBlock* current_block_;
   ZoneVector<Instruction*> instructions_;
   BoolVector defined_;
   BoolVector used_;
   IntVector effect_level_;
   IntVector virtual_registers_;
   IntVector virtual_register_rename_;
   InstructionScheduler* scheduler_;
   EnableScheduling enable_scheduling_;
+  EnableSerialization enable_serialization_;
   Frame* frame_;
   bool instruction_selection_failed_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_