Use double for tns, inspired by pr155

Signed-off-by: James Cherry <cherry@parallaxsw.com>

graph/DelayNormal1.cc

@@ -63,6 +63,12 @@ Delay::Delay(const Delay &delay) :
 {
 }
 
+Delay::Delay(const DelayDbl &delay) :
+  mean_(delay.mean_),
+  sigma2_(delay.sigma2_)
+{
+}
+
 Delay::Delay(float mean) :
   mean_(mean),
   sigma2_(0.0)
@@ -173,6 +179,35 @@ Delay::operator==(const Delay &delay) const
 
 ////////////////////////////////////////////////////////////////
 
+DelayDbl::DelayDbl() :
+  mean_(0.0),
+  sigma2_(0.0)
+{
+}
+
+void
+DelayDbl::operator=(float delay)
+{
+  mean_ = delay;
+  sigma2_ = 0.0;
+}
+
+void
+DelayDbl::operator+=(const Delay &delay)
+{
+  mean_ += delay.mean_;
+  sigma2_ += delay.sigma2_;
+}
+
+void
+DelayDbl::operator-=(const Delay &delay)
+{
+  mean_ -= delay.mean_;
+  sigma2_ += delay.sigma2_;
+}
+
+////////////////////////////////////////////////////////////////
+
 Delay
 makeDelay(float delay,
 	  float sigma,

graph/DelayNormal2.cc

@@ -64,6 +64,13 @@ Delay::Delay(const Delay &delay) :
   sigma2_[EarlyLate::lateIndex()] = delay.sigma2_[EarlyLate::lateIndex()];
 }
 
+Delay::Delay(const DelayDbl &delay) :
+  mean_(delay.mean_)
+{
+  sigma2_[EarlyLate::earlyIndex()] = delay.sigma2_[EarlyLate::earlyIndex()];
+  sigma2_[EarlyLate::lateIndex()] = delay.sigma2_[EarlyLate::lateIndex()];
+}
+
 Delay::Delay(float mean) :
   mean_(mean),
   sigma2_{0.0, 0.0}
@@ -196,6 +203,38 @@ Delay::operator==(const Delay &delay) const
 
 ////////////////////////////////////////////////////////////////
 
+DelayDbl::DelayDbl() :
+  mean_(0.0),
+  sigma2_{0.0, 0.0}
+{
+}
+
+void
+DelayDbl::operator=(float delay)
+{
+  mean_ = delay;
+  sigma2_[early_index] = 0.0;
+  sigma2_[late_index] = 0.0;
+}
+
+void
+DelayDbl::operator+=(const Delay &delay)
+{
+  mean_ += delay.mean_;
+  sigma2_[early_index] += delay.sigma2_[early_index];
+  sigma2_[late_index] += delay.sigma2_[late_index];
+}
+
+void
+DelayDbl::operator-=(const Delay &delay)
+{
+  mean_ -= delay.mean_;
+  sigma2_[early_index] += delay.sigma2_[early_index];
+  sigma2_[late_index] += delay.sigma2_[late_index];
+}
+
+////////////////////////////////////////////////////////////////
+
 Delay
 makeDelay(float delay,
 	  float sigma_early,

include/sta/DelayFloat.hh

@@ -25,6 +25,8 @@ namespace sta {
 class StaState;
 
 typedef float Delay;
+// Delay double for accumulating Delays.
+typedef double DelayDbl;
 
 const Delay delay_zero = 0.0;
 

include/sta/DelayNormal1.hh

@@ -21,6 +21,7 @@
 namespace sta {
 
 class Delay;
+class DelayDbl;
 class StaState;
 
 // Normal distribution with std deviation.
@@ -29,6 +30,7 @@ class Delay
 public:
   Delay();
   Delay(const Delay &delay);
+  Delay(const DelayDbl &delay);
   Delay(float mean);
   Delay(float mean,
 	float sigma2);
@@ -53,6 +55,29 @@ private:
   float mean_;
   // Sigma^2
   float sigma2_;
+
+  friend class DelayDbl;
+};
+
+// Dwlay with doubles for accumulating delays.
+class DelayDbl
+{
+public:
+  DelayDbl();
+  float mean() const { return mean_; }
+  float sigma() const;
+  // sigma^2
+  float sigma2() const;
+  void operator=(float delay);
+  void operator+=(const Delay &delay);
+  void operator-=(const Delay &delay);
+
+private:
+  double mean_;
+  // Sigma^2
+  double sigma2_;
+
+  friend class Delay;
 };
 
 const Delay delay_zero(0.0);

include/sta/DelayNormal2.hh

@@ -21,6 +21,7 @@
 namespace sta {
 
 class Delay;
+class DelayDbl;
 class StaState;
 
 // Normal distribution with early(left)/late(right) std deviations.
@@ -29,6 +30,7 @@ class Delay
 public:
   Delay();
   Delay(const Delay &delay);
+  Delay(const DelayDbl &delay);
   Delay(float mean);
   Delay(float mean,
 	float sigma2_early,
@@ -60,6 +62,33 @@ private:
   float mean_;
   // Sigma^2
   float sigma2_[EarlyLate::index_count];
+
+  friend class DelayDbl;
+};
+
+// Dwlay with doubles for accumulating delays.
+class DelayDbl
+{
+public:
+  DelayDbl();
+  float mean() const { return mean_; }
+  float sigma() const;
+  // sigma^2
+  float sigma2() const;
+  void operator=(float delay);
+  void operator+=(const Delay &delay);
+  void operator-=(const Delay &delay);
+
+protected:
+  static const int early_index = 0;
+  static const int late_index = 1;
+
+private:
+  double mean_;
+  // Sigma^2
+  double sigma2_[EarlyLate::index_count];
+
+  friend class Delay;
 };
 
 const Delay delay_zero(0.0);

include/sta/Search.hh

@@ -60,6 +60,7 @@ typedef UnorderedSet<TagGroup*, TagGroupHash, TagGroupEqual> TagGroupSet;
 typedef Map<Vertex*, Slack> VertexSlackMap;
 typedef Vector<VertexSlackMap> VertexSlackMapSeq;
 typedef Vector<WorstSlacks> WorstSlacksSeq;
+typedef vector<DelayDbl> DelayDblSeq;
 
 class Search : public StaState
 {
@@ -570,7 +571,7 @@ protected:
   // Endpoint vertices with slacks that have changed since tns was found.
   VertexSet *invalid_tns_;
   // Indexed by path_ap->index().
-  SlackSeq tns_;
+  DelayDblSeq tns_;
   // Indexed by path_ap->index().
   VertexSlackMapSeq tns_slacks_;
   std::mutex tns_lock_;