Check elimination now sets known successor branch of HCompareObjectEqAndBranch (correctness fix).

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4270 matching lines @@
 
 
 class HCompareObjectEqAndBranch : public HTemplateControlInstruction<2, 2> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P2(HCompareObjectEqAndBranch, HValue*, HValue*);
   DECLARE_INSTRUCTION_FACTORY_P4(HCompareObjectEqAndBranch, HValue*, HValue*,
                                  HBasicBlock*, HBasicBlock*);
 
   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;
+  }
+
   HValue* left() { return OperandAt(0); }
   HValue* right() { return OperandAt(1); }
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
     return Representation::Tagged();
   }
 
   virtual Representation observed_input_representation(int index) V8_OVERRIDE {
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(CompareObjectEqAndBranch)
 
  private:
   HCompareObjectEqAndBranch(HValue* left,
                             HValue* right,
                             HBasicBlock* true_target = NULL,
-                            HBasicBlock* false_target = NULL) {
+                            HBasicBlock* false_target = NULL)
+      : known_successor_index_(kNoKnownSuccessorIndex) {
     ASSERT(!left->IsConstant() ||
            (!HConstant::cast(left)->HasInteger32Value() ||
             HConstant::cast(left)->HasSmiValue()));
     ASSERT(!right->IsConstant() ||
            (!HConstant::cast(right)->HasInteger32Value() ||
             HConstant::cast(right)->HasSmiValue()));
     SetOperandAt(0, left);
     SetOperandAt(1, right);
     SetSuccessorAt(0, true_target);
     SetSuccessorAt(1, false_target);
   }
+
+  int known_successor_index_;
 };
 
 
 class HIsObjectAndBranch V8_FINAL : public HUnaryControlInstruction {
  public:
   DECLARE_INSTRUCTION_FACTORY_P1(HIsObjectAndBranch, HValue*);
   DECLARE_INSTRUCTION_FACTORY_P3(HIsObjectAndBranch, HValue*,
                                  HBasicBlock*, HBasicBlock*);
 
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
@@ skipping 3173 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_