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

runtime/vm/compiler.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 52 matching lines @@
   sequence_node->CollectAllNodes(&all_nodes);
   GrowableArray<intptr_t> node_ids;
   const GrowableObjectArray& ic_data_objs =
       GrowableObjectArray::Handle(GrowableObjectArray::New());
   code.ExtractIcDataArraysAtCalls(&node_ids, ic_data_objs);
   ICData& ic_data_obj = ICData::Handle();
   for (intptr_t i = 0; i < node_ids.length(); i++) {
     intptr_t node_id = node_ids[i];
     bool found_node = false;
     for (intptr_t n = 0; n < all_nodes.length(); n++) {
-      if (all_nodes[n]->HasId(node_id)) {
+      if (all_nodes[n]->id() == node_id) {
         found_node = true;
         // Make sure we assign ic data array only once.
-        ASSERT(all_nodes[n]->ICDataAtId(node_id).IsNull());
+        ASSERT(all_nodes[n]->ic_data().IsNull());
         ic_data_obj ^= ic_data_objs.At(i);
-        all_nodes[n]->SetIcDataAtId(node_id, ic_data_obj);
+        all_nodes[n]->set_ic_data(ic_data_obj);
       }
     }
     ASSERT(found_node);
   }
 }
 
 
 RawError* Compiler::Compile(const Library& library, const Script& script) {
   Isolate* isolate = Isolate::Current();
   LongJump* base = isolate->long_jump_base();
@@ skipping 423 matching lines @@
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 
 }  // namespace dart