Implement global check elimination using the HFlowEngine.

src/hydrogen-check-elimination.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
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@@ skipping 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_HYDROGEN_CHECK_ELIMINATION_H_
 #define V8_HYDROGEN_CHECK_ELIMINATION_H_
 
 #include "hydrogen.h"
+#include "hydrogen-alias-analysis.h"
 
 namespace v8 {
 namespace internal {
 
 
 // Remove CheckMaps instructions through flow- and branch-sensitive analysis.
 class HCheckEliminationPhase : public HPhase {
  public:
   explicit HCheckEliminationPhase(HGraph* graph)
-      : HPhase("H_Check Elimination", graph) { }
+    : HPhase("H_Check Elimination", graph),
+      aliasing_(),
+      redundant_(0),
+      removed_(0),
+      narrowed_(0),
+      loads_(0),
+      empty_(0),
+      compares_true_(0),
+      compares_false_(0),
+      transitions_(0) { }
 
   void Run();
 
+  friend class HCheckTable;
+
  private:
-  void EliminateLocalChecks(HBasicBlock* block);
+  void PrintStats();
+
+  HAliasAnalyzer* aliasing_;
+  int redundant_;
+  int removed_;
+  int narrowed_;
+  int loads_;
+  int empty_;
+  int compares_true_;
+  int compares_false_;
+  int transitions_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_CHECK_ELIMINATION_H_