Don't emit code for instructions that are hiding behind an HSoftDeoptimize

src/hydrogen.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 359 matching lines @@
     uint32_instructions_->Add(instr, zone());
   }
 
  private:
   HConstant* GetConstant(SetOncePointer<HConstant>* pointer,
                          Handle<Object> value);
   HConstant* GetConstantInt32(SetOncePointer<HConstant>* pointer,
                               int32_t integer_value);
 
   void MarkAsDeoptimizingRecursively(HBasicBlock* block);
+  void NullifyUnreachableInstructions();
   void InsertTypeConversions(HInstruction* instr);
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
   void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
   void InsertRepresentationChangeForUse(HValue* value,
                                         HValue* use_value,
                                         int use_index,
                                         Representation to);
   void InsertRepresentationChangesForValue(HValue* value);
   void InferTypes(ZoneList<HValue*>* worklist);
   void InitializeInferredTypes(int from_inclusive, int to_inclusive);
@@ skipping 559 matching lines @@
   HOptimizedGraphBuilder(CompilationInfo* info, TypeFeedbackOracle* oracle);
 
   virtual bool BuildGraph();
 
   // Simple accessors.
   BreakAndContinueScope* break_scope() const { return break_scope_; }
   void set_break_scope(BreakAndContinueScope* head) { break_scope_ = head; }
 
   bool inline_bailout() { return inline_bailout_; }
 
+  void AddSoftDeoptimize();
+
   // Bailout environment manipulation.
   void Push(HValue* value) { environment()->Push(value); }
   HValue* Pop() { return environment()->Pop(); }
 
   void Bailout(const char* reason);
 
   HBasicBlock* CreateJoin(HBasicBlock* first,
                           HBasicBlock* second,
                           BailoutId join_id);
 
@@ skipping 586 matching lines @@
   const char* filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_