[stubs] Refactor StringCompareStub and use it for HStringCompareAndBranch.

src/hydrogen-instructions.h

 // Copyright 2012 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_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include <cstring>
 #include <iosfwd>
 
@@ skipping 4508 matching lines @@
   DECLARE_CONCRETE_INSTRUCTION(IsUndetectableAndBranch)
 
  private:
   HIsUndetectableAndBranch(HValue* value,
                            HBasicBlock* true_target = NULL,
                            HBasicBlock* false_target = NULL)
       : HUnaryControlInstruction(value, true_target, false_target) {}
 };
 
 
-class HStringCompareAndBranch : public HTemplateControlInstruction<2, 3> {
+class HStringCompareAndBranch final : public HTemplateControlInstruction<2, 3> {
  public:
   DECLARE_INSTRUCTION_WITH_CONTEXT_FACTORY_P3(HStringCompareAndBranch,
                                               HValue*,
                                               HValue*,
                                               Token::Value);
 
-  HValue* context() { return OperandAt(0); }
-  HValue* left() { return OperandAt(1); }
-  HValue* right() { return OperandAt(2); }
+  HValue* context() const { return OperandAt(0); }
+  HValue* left() const { return OperandAt(1); }
+  HValue* right() const { return OperandAt(2); }
   Token::Value token() const { return token_; }
 
-  std::ostream& PrintDataTo(std::ostream& os) const override;  // NOLINT
+  std::ostream& PrintDataTo(std::ostream& os) const final;  // NOLINT
 
-  Representation RequiredInputRepresentation(int index) override {
-    return Representation::Tagged();
-  }
-
-  Representation GetInputRepresentation() const {
+  Representation RequiredInputRepresentation(int index) final {
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(StringCompareAndBranch)
 
  private:
-  HStringCompareAndBranch(HValue* context,
-                          HValue* left,
-                          HValue* right,
+  HStringCompareAndBranch(HValue* context, HValue* left, HValue* right,
                           Token::Value token)
       : token_(token) {
     DCHECK(Token::IsCompareOp(token));
     SetOperandAt(0, context);
     SetOperandAt(1, left);
     SetOperandAt(2, right);
     set_representation(Representation::Tagged());
     SetChangesFlag(kNewSpacePromotion);
+    SetDependsOnFlag(kStringChars);
+    SetDependsOnFlag(kStringLengths);
   }
 
-  Token::Value token_;
+  Token::Value const token_;
 };
 
 
 class HIsConstructCallAndBranch : public HTemplateControlInstruction<2, 0> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P0(HIsConstructCallAndBranch);
 
   Representation RequiredInputRepresentation(int index) override {
     return Representation::None();
   }
@@ skipping 3398 matching lines @@
 };
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_