Simplify the check when to perform loop invariant code motion.

src/hydrogen.h

 // Copyright 2011 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 125 matching lines @@
 
   // If a target block is tagged as an inline function return, all
   // predecessors should contain the inlined exit sequence:
   //
   // LeaveInlined
   // Simulate (caller's environment)
   // Goto (target block)
   bool IsInlineReturnTarget() const { return is_inline_return_target_; }
   void MarkAsInlineReturnTarget() { is_inline_return_target_ = true; }
 
+  bool IsDeoptimizing() const { return is_deoptimizing_; }
+  void MarkAsDeoptimizing() { is_deoptimizing_ = true; }
+
   inline Zone* zone();
 
 #ifdef DEBUG
   void Verify();
 #endif
 
  private:
   void RegisterPredecessor(HBasicBlock* pred);
   void AddDominatedBlock(HBasicBlock* block);
 
@@ skipping 12 matching lines @@
   ZoneList<HBasicBlock*> dominated_blocks_;
   HEnvironment* last_environment_;
   // Outgoing parameter count at block exit, set during lithium translation.
   int argument_count_;
   // Instruction indices into the lithium code stream.
   int first_instruction_index_;
   int last_instruction_index_;
   ZoneList<int> deleted_phis_;
   HBasicBlock* parent_loop_header_;
   bool is_inline_return_target_;
+  bool is_deoptimizing_;
 };
 
 
 class HLoopInformation: public ZoneObject {
  public:
   explicit HLoopInformation(HBasicBlock* loop_header)
       : back_edges_(4), loop_header_(loop_header), blocks_(8) {
     blocks_.Add(loop_header);
   }
   virtual ~HLoopInformation() {}
@@ skipping 30 matching lines @@
   void InsertRepresentationChanges();
   void MarkDeoptimizeOnUndefined();
   void ComputeMinusZeroChecks();
   bool ProcessArgumentsObject();
   void EliminateRedundantPhis();
   void EliminateUnreachablePhis();
   void Canonicalize();
   void OrderBlocks();
   void AssignDominators();
   void ReplaceCheckedValues();
+  void MarkAsDeoptimizingRecursively(HBasicBlock* block);
 
   // Returns false if there are phi-uses of the arguments-object
   // which are not supported by the optimizing compiler.
   bool CollectPhis();
 
   Handle<Code> Compile(CompilationInfo* info);
 
   void set_undefined_constant(HConstant* constant) {
     undefined_constant_.set(constant);
   }
@@ skipping 955 matching lines @@
   const char* filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_