VM: Move branch optimizations into a separate file.

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"
 
@@ skipping 317 matching lines @@
   static void Optimize(FlowGraph* graph);
 };
 
 
 class DeadCodeElimination : public AllStatic {
  public:
   static void EliminateDeadPhis(FlowGraph* graph);
 };
 
 
-// Rewrite branches to eliminate materialization of boolean values after
-// inlining, and to expose other optimizations (e.g., constant folding of
-// branches, unreachable code elimination).
-class BranchSimplifier : public AllStatic {
- public:
-  static void Simplify(FlowGraph* flow_graph);
-
-  // Replace a target entry instruction with a join entry instruction.  Does
-  // not update the original target's predecessors to point to the new block
-  // and does not replace the target in already computed block order lists.
-  static JoinEntryInstr* ToJoinEntry(Zone* zone,
-                                     TargetEntryInstr* target);
-
- private:
-  // Match an instance of the pattern to rewrite.  See the implementation
-  // for the patterns that are handled by this pass.
-  static bool Match(JoinEntryInstr* block);
-
-  // Duplicate a branch while replacing its comparison's left and right
-  // inputs.
-  static BranchInstr* CloneBranch(Zone* zone,
-                                  BranchInstr* branch,
-                                  Value* new_left,
-                                  Value* new_right);
-};
-
-
-// Rewrite diamond control flow patterns that materialize values to use more
-// efficient branchless code patterns if such are supported on the current
-// platform.
-class IfConverter : public AllStatic {
- public:
-  static void Simplify(FlowGraph* flow_graph);
-};
-
-
 class AllocationSinking : public ZoneAllocated {
  public:
   explicit AllocationSinking(FlowGraph* flow_graph)
       : flow_graph_(flow_graph),
         candidates_(5),
         materializations_(5) { }
 
   const GrowableArray<Definition*>& candidates() const {
     return candidates_;
   }
@@ skipping 63 matching lines @@
 // Optimize spill stores inside try-blocks by identifying values that always
 // contain a single known constant at catch block entry.
 class TryCatchAnalyzer : public AllStatic {
  public:
   static void Optimize(FlowGraph* flow_graph);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_