Convert diamond shaped control flow into a single conditional instruction.

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 286 matching lines @@
                                       ConstantInstr* constant);
 
   // Duplicate a branch while replacing its comparison's left and right
   // inputs.
   static BranchInstr* CloneBranch(BranchInstr* branch,
                                   Value* left,
                                   Value* 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);
+};
+
+
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_