Simplify translation of conditionals in the flow graph builder.

runtime/vm/flow_graph_builder.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_BUILDER_H_
 #define VM_FLOW_GRAPH_BUILDER_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 213 matching lines @@
   TestGraphVisitor(FlowGraphBuilder* owner, intptr_t temp_index)
       : ValueGraphVisitor(owner, temp_index),
         true_successor_address_(NULL),
         false_successor_address_(NULL) {
   }
 
   // Visit functions overridden by this class.
   virtual void VisitLiteralNode(LiteralNode* node);
   virtual void VisitLoadLocalNode(LoadLocalNode* node);
 
-  bool can_be_true() const {
-    // Either both successors are set or neither is set.
-    ASSERT((true_successor_address_ == NULL) ==
-           (false_successor_address_ == NULL));
-    return true_successor_address_ != NULL;
-  }
-  bool can_be_false() const {
-    // Either both successors are set or neither is set.
-    ASSERT((true_successor_address_ == NULL) ==
-           (false_successor_address_ == NULL));
-    return false_successor_address_ != NULL;
-  }
-
   BlockEntryInstr** true_successor_address() const {
-    ASSERT(can_be_true());
+    ASSERT(true_successor_address_ != NULL);
     return true_successor_address_;
   }
   BlockEntryInstr** false_successor_address() const {
-    ASSERT(can_be_false());
+    ASSERT(false_successor_address_ != NULL);
     return false_successor_address_;
   }
 
  private:
   // Construct and concatenate a Branch instruction to this graph fragment.
   // Closes the fragment and sets the output parameters.
   virtual void ReturnValue(Value* value);
 
   // Specify a computation as the final result.  Adds a Bind instruction to
   // the graph and branches on its value.
   virtual void ReturnComputation(Computation* computation) {
     AddInstruction(new BindInstr(temp_index(), computation));
     ReturnValue(new TempVal(temp_index()));
   }
 
   // Output parameters.
   BlockEntryInstr** true_successor_address_;
   BlockEntryInstr** false_successor_address_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_