Handle HCheckInstanceType and HIsStringAndBranch in check elimination.

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 "v8.h"
 
 #include "allocation.h"
@@ skipping 4405 matching lines @@
   DECLARE_INSTRUCTION_FACTORY_P1(HIsStringAndBranch, HValue*);
   DECLARE_INSTRUCTION_FACTORY_P3(HIsStringAndBranch, HValue*,
                                  HBasicBlock*, HBasicBlock*);
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
     return Representation::Tagged();
   }
 
   virtual bool KnownSuccessorBlock(HBasicBlock** block) V8_OVERRIDE;
 
+  static const int kNoKnownSuccessorIndex = -1;
+  int known_successor_index() const { return known_successor_index_; }
+  void set_known_successor_index(int known_successor_index) {
+    known_successor_index_ = known_successor_index;
+  }
+
   DECLARE_CONCRETE_INSTRUCTION(IsStringAndBranch)
 
  protected:
   virtual int RedefinedOperandIndex() { return 0; }
 
  private:
   HIsStringAndBranch(HValue* value,
                      HBasicBlock* true_target = NULL,
                      HBasicBlock* false_target = NULL)
-    : HUnaryControlInstruction(value, true_target, false_target) {}
+    : HUnaryControlInstruction(value, true_target, false_target),
+      known_successor_index_(kNoKnownSuccessorIndex) { }
+
+  int known_successor_index_;
 };
 
 
 class HIsSmiAndBranch V8_FINAL : public HUnaryControlInstruction {
  public:
   DECLARE_INSTRUCTION_FACTORY_P1(HIsSmiAndBranch, HValue*);
   DECLARE_INSTRUCTION_FACTORY_P3(HIsSmiAndBranch, HValue*,
                                  HBasicBlock*, HBasicBlock*);
 
   DECLARE_CONCRETE_INSTRUCTION(IsSmiAndBranch)
@@ skipping 3268 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_