Fuse compare with branch at graph building time.

runtime/vm/flow_graph_compiler.cc

 // 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
@@ skipping 458 matching lines @@
   }
 }
 
 
 void FlowGraphCompiler::EmitDoubleCompareBranch(Condition true_condition,
                                                 XmmRegister left,
                                                 XmmRegister right,
                                                 BranchInstr* branch) {
   ASSERT(branch != NULL);
   assembler()->comisd(left, right);
-  BlockEntryInstr* nan_result = branch->is_negated() ?
+  BlockEntryInstr* nan_result = (true_condition == NOT_EQUAL) ?
       branch->true_successor() : branch->false_successor();
   assembler()->j(PARITY_EVEN, GetBlockLabel(nan_result));
   branch->EmitBranchOnCondition(this, true_condition);
 }
 
 
 
 void FlowGraphCompiler::EmitDoubleCompareBool(Condition true_condition,
                                               XmmRegister left,
                                               XmmRegister right,
@@ skipping 303 matching lines @@
       return;
     }
   }
 
   // This move is not blocked.
   EmitMove(index);
 }
 
 
 }  // namespace dart