[turbofan] cleanup InstructionSequence

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 <deque>
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/machine-operator.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Forward declarations.
 struct CallBuffer;  // TODO(bmeurer): Remove this.
 class FlagsContinuation;
 
 class InstructionSelector FINAL {
  public:
   // Forward declarations.
   class Features;
 
-  InstructionSelector(InstructionSequence* sequence, Schedule* schedule,
-                      SourcePositionTable* source_positions,
+  InstructionSelector(Linkage* linkage, InstructionSequence* sequence,
+                      Schedule* schedule, SourcePositionTable* source_positions,
                       Features features = SupportedFeatures());
 
   // Visit code for the entire graph with the included schedule.
   void SelectInstructions();
 
   // ===========================================================================
   // ============= Architecture-independent code emission methods. =============
   // ===========================================================================
 
   Instruction* Emit(InstructionCode opcode, InstructionOperand* output,
@@ skipping 136 matching lines @@
   void VisitConstant(Node* node);
   void VisitCall(Node* call);
   void VisitGoto(BasicBlock* target);
   void VisitBranch(Node* input, BasicBlock* tbranch, BasicBlock* fbranch);
   void VisitReturn(Node* value);
   void VisitThrow(Node* value);
   void VisitDeoptimize(Node* deopt);
 
   // ===========================================================================
 
-  Linkage* linkage() const { return sequence()->linkage(); }
   Schedule* schedule() const { return schedule_; }
+  Linkage* linkage() const { return linkage_; }
   InstructionSequence* sequence() const { return sequence_; }
   Zone* instruction_zone() const { return sequence()->zone(); }
   Zone* zone() { return &zone_; }
 
   // ===========================================================================
 
   Zone zone_;
-  InstructionSequence* sequence_;
-  SourcePositionTable* source_positions_;
+  Linkage* const linkage_;
+  InstructionSequence* const sequence_;
+  SourcePositionTable* const source_positions_;
   Features features_;
-  Schedule* schedule_;
+  Schedule* const schedule_;
   BasicBlock* current_block_;
   ZoneDeque<Instruction*> instructions_;
   BoolVector defined_;
   BoolVector used_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_