Subzero: Improve the output with the --timing-focus=xxx option.

src/IceTimerTree.h

 //===- subzero/src/IceTimerTree.h - Pass timer defs -------------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the TimerTree class, which allows flat and
@@ skipping 34 matching lines @@
 
 public:
   enum TimerTag {
 #define X(tag) TT_##tag,
     TIMERTREE_TABLE
 #undef X
         TT__num
   };
   TimerStack(const IceString &Name);
   TimerIdT getTimerID(const IceString &Name);
+  void setName(const IceString &NewName) { Name = NewName; }
   void push(TimerIdT ID);
   void pop(TimerIdT ID);
+  void reset();
   void dump(Ostream &Str, bool DumpCumulative);
 
 private:
   void update();
   static double timestamp();
-  const IceString Name;
-  const double FirstTimestamp;
+  IceString Name;
+  double FirstTimestamp;
   double LastTimestamp;
   uint64_t StateChangeCount;
   // IDsIndex maps a symbolic timer name to its integer ID.
   std::map<IceString, TimerIdT> IDsIndex;
   std::vector<IceString> IDs;        // indexed by TimerIdT
   std::vector<TimerTreeNode> Nodes;  // indexed by TTindex
   std::vector<double> LeafTimes;     // indexed by TimerIdT
   TTindex StackTop;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETIMERTREE_H