optimize Time::Get methods

src/simulator/nstime.h

@@ -110,7 +110,7 @@ public:
    * \return the ns3::HighPrecision object which holds the value 
    *         stored in this Time<N> type.
    */
-  HighPrecision GetHighPrecision (void) const;
+  HighPrecision const &GetHighPrecision (void) const;
   HighPrecision *PeekHighPrecision (void);
 
 private:
@@ -138,7 +138,7 @@ TimeUnit<N>::TimeUnit (HighPrecision data)
 {}
 
 template <int N>
-HighPrecision
+HighPrecision const &
 TimeUnit<N>::GetHighPrecision (void) const
 {
   return m_data;

src/simulator/time.cc

@@ -36,23 +36,21 @@ Time::Time (HighPrecision const& value)
 double 
 Time::GetSeconds (void) const
 {
-  HighPrecision seconds = GetHighPrecision ();
-  seconds.Div (HighPrecision (1000000000, false));
-  return seconds.GetDouble ();
+  double ns = GetHighPrecision ().GetDouble ();
+  return ns/1000000000.0;
 }
 int32_t 
 Time::GetMilliSeconds (void) const
 {
-  HighPrecision ms = GetHighPrecision ();
-  ms.Div (HighPrecision (1000000, false));
-  return (int32_t) ms.GetInteger ();
+  int64_t ns = GetHighPrecision ().GetInteger ();
+  ns /= 1000000;
+  return ns;
 }
 int64_t 
 Time::GetMicroSeconds (void) const
 {
-  HighPrecision us = GetHighPrecision ();
-  us.Div (HighPrecision (1000, false));
-  return us.GetInteger ();
+  int64_t ns = GetHighPrecision ().GetInteger ();
+  return ns/1000;
 }
 int64_t 
 Time::GetNanoSeconds (void) const