LibertyPort::setIsLatchOutput

Signed-off-by: James Cherry <cherry@CerezoBook.local>

include/sta/Liberty.hh

@@ -861,6 +861,8 @@ public:
   void setIsRegOutput(bool is_reg_out);
   bool isLatchData() const { return is_latch_data_; }
   void setIsLatchData(bool is_latch_data);
+  bool isLatchOutput() const { return is_latch_output_; }
+  void setIsLatchOutput(bool is_latch_output);
   // Is the clock for timing checks.
   bool isCheckClk() const { return is_check_clk_; }
   void setIsCheckClk(bool is_clk);
@@ -956,6 +958,7 @@ protected:
   bool is_reg_clk_:1 {false};
   bool is_reg_output_:1 {false};
   bool is_latch_data_: 1 {false};
+  bool is_latch_output_:1 {false};
   bool is_check_clk_:1 {false};
   bool is_clk_gate_clk_:1 {false};
   bool is_clk_gate_enable_:1 {false};

include/sta/Network.hh

@@ -319,6 +319,7 @@ public:
   // Pin clocks a timing check.
   [[nodiscard]] bool isCheckClk(const Pin *pin) const;
   [[nodiscard]] bool isLatchData(const Pin *pin) const;
+  [[nodiscard]] bool isLatchOutput(const Pin *pin) const;
 
   // Iterate over all of the pins connected to a pin and the parent
   // and child nets it is hierarchically connected to (port, leaf and

liberty/Liberty.cc

@@ -1769,6 +1769,7 @@ LibertyCell::makeLatchEnable(LibertyPort *d,
   latch_d_to_q_map_[d_to_q] = idx;
   latch_check_map_[setup_check] = idx;
   d->setIsLatchData(true);
+  q->setIsLatchOutput(true);
   debugPrint(debug, "liberty_latch", 1,
              "latch {} -> {} | {} {} -> {} | {} {} -> {} setup",
              d->name(),
@@ -2434,6 +2435,13 @@ LibertyPort::setIsLatchData(bool is_latch_data)
   setMemberFlag(is_latch_data, &LibertyPort::setIsLatchData);
 }
 
+void
+LibertyPort::setIsLatchOutput(bool is_latch_output)
+{
+  is_latch_output_ = is_latch_output;
+  setMemberFlag(is_latch_output, &LibertyPort::setIsLatchOutput);
+}
+
 void
 LibertyPort::setIsCheckClk(bool is_clk)
 {

network/Network.cc

@@ -636,6 +636,16 @@ Network::isLatchData(const Pin *pin) const
     return false;
 }
 
+bool
+Network::isLatchOutput(const Pin *pin) const
+{
+  LibertyPort *port = libertyPort(pin);
+  if (port)
+    return port->isLatchOutput();
+  else
+    return false;
+}
+
 ////////////////////////////////////////////////////////////////
 
 std::string

search/Search.cc

@@ -1132,15 +1132,10 @@ ArrivalVisitor::setAlwaysToEndpoints(bool to_endpoints)
 void
 ArrivalVisitor::visit(Vertex *vertex)
 {
-  VertexInEdgeIterator edge_iter(vertex, graph_);
-  while (edge_iter.hasNext()) {
-    Edge *edge = edge_iter.next();
-    if (edge->role()->isLatchDtoQ()) {
-      search_->enqueueLatchOutput(vertex);
-      return;
-    }
-  }
-  visit(vertex, false);
+  if (network_->isLatchOutput(vertex->pin()))
+    search_->enqueueLatchOutput(vertex);
+  else
+    visit(vertex, false);
 }
 
 void