Implement class id checks as a separate instruction and add a local CSE optimization pass.

runtime/vm/flow_graph_optimizer.h

 // 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.
 
 #ifndef VM_FLOW_GRAPH_OPTIMIZER_H_
 #define VM_FLOW_GRAPH_OPTIMIZER_H_
 
 #include "vm/intermediate_language.h"
 #include "vm/flow_graph.h"
 
 namespace dart {
 
 template <typename T> class GrowableArray;
 
 class FlowGraphOptimizer : public FlowGraphVisitor {
  public:
-  explicit FlowGraphOptimizer(const FlowGraph& flow_graph)
-      : FlowGraphVisitor(flow_graph.reverse_postorder()) {}
+  FlowGraphOptimizer(const FlowGraph& flow_graph, bool use_ssa)
+      : FlowGraphVisitor(flow_graph.reverse_postorder()), use_ssa_(use_ssa) {}
   virtual ~FlowGraphOptimizer() {}
 
   void ApplyICData();
 
   void OptimizeComputations();
 
   virtual void VisitStaticCall(StaticCallComp* comp, BindInstr* instr);
   virtual void VisitInstanceCall(InstanceCallComp* comp, BindInstr* instr);
   virtual void VisitRelationalOp(RelationalOpComp* comp, BindInstr* instr);
   virtual void VisitEqualityCompare(EqualityCompareComp* comp,
@@ skipping 10 matching lines @@
   bool TryReplaceWithUnaryOp(BindInstr* instr,
                              InstanceCallComp* comp,
                              Token::Kind op_kind);
 
   bool TryInlineInstanceGetter(BindInstr* instr,
                                InstanceCallComp* comp);
   bool TryInlineInstanceSetter(BindInstr* instr, InstanceCallComp* comp);
 
   bool TryInlineInstanceMethod(BindInstr* instr, InstanceCallComp* comp);
 
+  bool use_ssa_;
+
   DISALLOW_COPY_AND_ASSIGN(FlowGraphOptimizer);
 };
 
 
 // Analyze the generated flow graph. Currently only if it is a leaf
 // method, i.e., does not contain any calls to runtime or other Dart code.
 class FlowGraphAnalyzer : public ValueObject {
  public:
   explicit FlowGraphAnalyzer(const FlowGraph& flow_graph)
       : blocks_(flow_graph.reverse_postorder()), is_leaf_(false) {}
@@ skipping 41 matching lines @@
   virtual void VisitPushArgument(PushArgumentInstr* bind);
 
  private:
   const ParsedFunction& parsed_function_;
   const bool is_ssa_;  // TODO(regis): Remove once virtual frame backend is
                        // removed.
   bool still_changing_;
   DISALLOW_COPY_AND_ASSIGN(FlowGraphTypePropagator);
 };
 
+
+class LocalCSE : public ValueObject {
+ public:
+  explicit LocalCSE(const FlowGraph& flow_graph)
+      : blocks_(flow_graph.reverse_postorder()) { }
+
+  void Optimize();
+
+ private:
+  const GrowableArray<BlockEntryInstr*>& blocks_;
+
+  DISALLOW_COPY_AND_ASSIGN(LocalCSE);
+};
+
+
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_