Track side-effect free paths in the graph to allow CSE and LICM for instructions that depend on som…

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 {
 
+class CSEInstructionMap;
 template <typename T> class GrowableArray;
-template <typename T> class DirectChainedHashMap;
-template <typename T> class PointerKeyValueTrait;
+class ParsedFunction;
 
 class FlowGraphOptimizer : public FlowGraphVisitor {
  public:
   FlowGraphOptimizer(FlowGraph* flow_graph,
                      GrowableArray<Field*>* guarded_fields)
       : FlowGraphVisitor(flow_graph->reverse_postorder()),
         flow_graph_(flow_graph),
         guarded_fields_(guarded_fields) { }
   virtual ~FlowGraphOptimizer() {}
 
@@ skipping 144 matching lines @@
 
   void AddToGuardedFields(Field* field);
 
   FlowGraph* flow_graph_;
   GrowableArray<Field*>* guarded_fields_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphOptimizer);
 };
 
 
-class ParsedFunction;
-
-
 // Loop invariant code motion.
 class LICM : public ValueObject {
  public:
   explicit LICM(FlowGraph* flow_graph);
 
   void Optimize();
 
  private:
   FlowGraph* flow_graph() const { return flow_graph_; }
 
@@ skipping 15 matching lines @@
 class DominatorBasedCSE : public AllStatic {
  public:
   // Return true, if the optimization changed the flow graph.
   // False, if nothing changed.
   static bool Optimize(FlowGraph* graph);
 
  private:
   static bool OptimizeRecursive(
       FlowGraph* graph,
       BlockEntryInstr* entry,
-      DirectChainedHashMap<PointerKeyValueTrait<Instruction> >* map);
+      CSEInstructionMap* map);
 };
 
 
 // Sparse conditional constant propagation and unreachable code elimination.
 // Assumes that use lists are computed and preserves them.
 class ConstantPropagator : public FlowGraphVisitor {
  public:
   ConstantPropagator(FlowGraph* graph,
                      const GrowableArray<BlockEntryInstr*>& ignored);
 
@@ skipping 89 matching lines @@
 // platform.
 class IfConverter : public AllStatic {
  public:
   static void Simplify(FlowGraph* flow_graph);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_