With removal of increment operations, each node has a unique id.

runtime/vm/opt_code_generator_ia32.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OPT_CODE_GENERATOR_IA32_H_
 #define VM_OPT_CODE_GENERATOR_IA32_H_
 
 #ifndef VM_OPT_CODE_GENERATOR_H_
 #error Do not include opt_code_generator_ia32.h; use opt_code_generator.h.
 #endif
@@ skipping 55 matching lines @@
                                             Register reg1,
                                             Register reg2,
                                             DeoptReasonId reason_id);
   DeoptimizationBlob* AddDeoptimizationBlob(AstNode* node,
                                             Register reg1,
                                             Register reg2,
                                             Register reg3,
                                             DeoptReasonId reason_id);
 
   void InlineInstanceGettersWithSameTarget(AstNode* node,
-                                           intptr_t id,
                                            AstNode* receiver,
                                            const String& field_name,
                                            Register recv_reg);
 
   // Helper method to load a value quickly into register instead of pushing
   // and popping it.
   void VisitLoadOne(AstNode* node, Register reg);
   void VisitLoadTwo(AstNode* left,
                     AstNode* right,
                     Register left_reg,
                     Register right_reg);
 
   void InlineInstanceGetter(AstNode* node,
-                            intptr_t id,
                             AstNode* receiver,
                             const String& field_name,
                             Register recv_reg);
 
   void GenerateInstanceSetter(const InstanceSetterArgs& args);
   void InlineInstanceSetter(AstNode* node,
-                            intptr_t id,
                             AstNode* receiver,
                             const String& field_name,
                             Register recv_reg,
                             Register value_reg);
 
   void CallDeoptimize(intptr_t node_id, intptr_t token_index);
 
   void GenerateSmiUnaryOp(UnaryOpNode* node);
   void GenerateDoubleUnaryOp(UnaryOpNode* node);
 
   void GenerateSmiBinaryOp(BinaryOpNode* node);
   void GenerateSmiShiftBinaryOp(BinaryOpNode* node);
 
   void GenerateDoubleBinaryOp(BinaryOpNode* node, bool receiver_can_be_smi);
   void GenerateMintBinaryOp(BinaryOpNode* node, bool allow_smi);
   void CheckIfDoubleOrSmi(Register reg,
                           Register temp,
                           Label* is_smi,
                           Label* not_double_or_smi);
   void GenerateDirectCall(intptr_t node_id,
                           intptr_t token_index,
                           const Function& target,
                           intptr_t arg_count,
                           const Array& optional_argument_names);
   void GenerateCheckedInstanceCalls(AstNode* node,
                                     AstNode* receiver,
-                                    intptr_t node_id,
                                     intptr_t token_index,
                                     intptr_t num_args,
                                     const Array& optional_arguments_names);
   void GenerateInlineCacheCall(intptr_t node_id,
                                 intptr_t token_index,
                                 const ICData& ic_data,
                                 intptr_t num_args,
                                 const Array& optional_arguments_names);
   void NormalizeClassChecks(const ICData& ic_data,
                             const Function& null_target,
                             GrowableArray<const Class*>* classes,
                             GrowableArray<const Function*>* targets);
   bool GenerateSmiComparison(ComparisonNode* node);
   void GenerateSmiEquality(ComparisonNode* node);
   bool GenerateDoubleComparison(ComparisonNode* node);
   bool GenerateEqualityComparison(ComparisonNode* node);
   void GenerateLogicalBinaryOp(BinaryOpNode* node);
   void GenerateConditionalJumps(const CodeGenInfo& nInfo, Condition condition);
   bool TryInlineInstanceCall(InstanceCallNode* node);
   bool TryInlineStaticCall(StaticCallNode* node);
 
   bool IsResultInEaxRequested(AstNode* node) const;
   bool NodeMayBeSmi(AstNode* node) const;
 
   void HandleResult(AstNode* node, Register result_reg);
   void PropagateBackLocalClass(AstNode* node, const Class& cls);
 
-  void PrintCollectedClassesAtId(AstNode* node, intptr_t id);
+  void PrintCollectedClasses(AstNode* node);
   void TraceOpt(AstNode* node, const char* message);
   void TraceNotOpt(AstNode* node, const char* message);
 
   GrowableArray<DeoptimizationBlob*> deoptimization_blobs_;
   ClassesForLocals* classes_for_locals_;
   const Class& smi_class_;
   const Class& double_class_;
   const Class& growable_object_array_class_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(OptimizingCodeGenerator);
 };
 
 }  // namespace dart
 
 
 #endif  // VM_OPT_CODE_GENERATOR_IA32_H_