set_min/max_delay -from reg/D startpoint warning resolves #265

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

include/sta/Liberty.hh

@@ -489,7 +489,6 @@ public:
   // timing arcs.
   bool hasInferedRegTimingArcs() const { return has_infered_reg_timing_arcs_; }
   TestCell *testCell() const { return test_cell_; }
-  bool isLatchData(LibertyPort *port);
   void latchEnable(const TimingArcSet *arc_set,
 		   // Return values.
 		   const LibertyPort *&enable_port,
@@ -803,6 +802,10 @@ public:
   // Has register/latch rise/fall edges from pin.
   bool isRegClk() const { return is_reg_clk_; }
   void setIsRegClk(bool is_clk);
+  bool isRegOutput() const { return is_reg_output_; }
+  void setIsRegOutput(bool is_reg_out);
+  bool isLatchData() const { return is_latch_data_; }
+  void setIsLatchData(bool is_latch_data);
   // Is the clock for timing checks.
   bool isCheckClk() const { return is_check_clk_; }
   void setIsCheckClk(bool is_clk);
@@ -899,6 +902,8 @@ protected:
   bool min_period_exists_:1;
   bool is_clk_:1;
   bool is_reg_clk_:1;
+  bool is_reg_output_:1;
+  bool is_latch_data_: 1;
   bool is_check_clk_:1;
   bool is_clk_gate_clk_:1;
   bool is_clk_gate_enable_:1;

include/sta/Sdc.hh

@@ -771,6 +771,7 @@ public:
 				   ClockSet *from_clks,
 				   InstanceSet *from_insts,
 				   const RiseFallBoth *from_rf);
+  bool isExceptionStartpoint(const Pin *pin) const;
   // Make an exception -through specification.
   ExceptionThru *makeExceptionThru(PinSet *pins,
 				   NetSet *nets,
@@ -972,10 +973,11 @@ public:
 			ExceptionStateSet *&states) const;
   // Return hierarchical -thru exceptions that start between
   // from_pin and to_pin.
-  ExceptionStateSet *exceptionThruStates(const Pin *from_pin,
+  void exceptionThruStates(const Pin *from_pin,
                            const Pin *to_pin,
                            const RiseFall *to_rf,
-                                         const MinMax *min_max) const;
+                           const MinMax *min_max,
+                           ExceptionStateSet *&states) const;
   // Find the highest priority exception with first exception pt at
   // pin/clk end.
   void exceptionTo(ExceptionPathType type,

include/sta/Sta.hh

@@ -531,7 +531,6 @@ public:
   void checkExceptionFromPins(ExceptionFrom *from,
 			      const char *file,
 			      int line) const;
-  bool exceptionFromInvalid(const Pin *pin) const;
   void deleteExceptionFrom(ExceptionFrom *from);
   // Make an exception -through specification.
   ExceptionThru *makeExceptionThru(PinSet *pins,

liberty/Liberty.cc

@@ -1244,10 +1244,13 @@ LibertyCell::addTimingArcSet(TimingArcSet *arc_set)
   timing_arc_sets_.push_back(arc_set);
 
   LibertyPort *from = arc_set->from();
+  LibertyPort *to = arc_set->to();
   const TimingRole *role = arc_set->role();
   if (role == TimingRole::regClkToQ()
-      || role == TimingRole::latchEnToQ())
+      || role == TimingRole::latchEnToQ()) {
     from->setIsRegClk(true);
+    to->setIsRegOutput(true);
+  }
   if (role->isTimingCheck())
     from->setIsCheckClk(true);
   return set_index;
@@ -1881,7 +1884,7 @@ LibertyCell::makeLatchEnable(LibertyPort *d,
   latch_enables_.push_back(latch_enable);
   latch_d_to_q_map_[d_to_q] = latch_enable;
   latch_check_map_[setup_check] = latch_enable;
-  latch_data_ports_.insert(d);
+  d->setIsLatchData(true);
   debugPrint(debug, "liberty_latch", 1,
              "latch %s -> %s | %s %s -> %s | %s %s -> %s setup",
              d->name(),
@@ -1933,12 +1936,6 @@ LibertyCell::inferLatchRoles(Report *report,
   }
 }
 
-bool
-LibertyCell::isLatchData(LibertyPort *port)
-{
-  return latch_data_ports_.hasKey(port);
-}
-
 void
 LibertyCell::latchEnable(const TimingArcSet *d_to_q_set,
 			 // Return values.
@@ -2100,6 +2097,8 @@ LibertyPort::LibertyPort(LibertyCell *cell,
   min_period_exists_(false),
   is_clk_(false),
   is_reg_clk_(false),
+  is_reg_output_(false),
+  is_latch_data_(false),
   is_check_clk_(false),
   is_clk_gate_clk_(false),
   is_clk_gate_enable_(false),
@@ -2547,6 +2546,18 @@ LibertyPort::setIsRegClk(bool is_clk)
   is_reg_clk_ = is_clk;
 }
 
+void
+LibertyPort::setIsRegOutput(bool is_reg_out)
+{
+  is_reg_output_ = is_reg_out;
+}
+
+void
+LibertyPort::setIsLatchData(bool is_latch_data)
+{
+  is_latch_data_ = is_latch_data;
+}
+
 void
 LibertyPort::setIsCheckClk(bool is_clk)
 {

network/Network.cc

@@ -655,7 +655,7 @@ Network::isLatchData(const Pin *pin) const
 {
   LibertyPort *port = libertyPort(pin);
   if (port)
-    return port->libertyCell()->isLatchData(port);
+    return port->isLatchData();
   else
     return false;
 }

sdc/Sdc.cc

@@ -3914,8 +3914,7 @@ Sdc::recordPathDelayInternalFrom(ExceptionPath *exception)
   if (from
       && from->hasPins()) {
     for (const Pin *pin : *from->pins()) {
-      if (!(network_->isRegClkPin(pin)
+      if (!isExceptionStartpoint(pin)) {
-	    || network_->isTopLevelPort(pin))) {
 	path_delay_internal_from_.insert(pin);
         if (exception->breakPath())
           path_delay_internal_from_break_.insert(pin);
@@ -3932,8 +3931,7 @@ Sdc::unrecordPathDelayInternalFrom(ExceptionPath *exception)
       && from->hasPins()
       && !path_delay_internal_from_.empty()) {
     for (const Pin *pin : *from->pins()) {
-      if (!(network_->isRegClkPin(pin)
+      if (!isExceptionStartpoint(pin)
-	    || network_->isTopLevelPort(pin))
 	  && !pathDelayFrom(pin)) {
 	path_delay_internal_from_.erase(pin);
         if (exception->breakPath())
@@ -3943,6 +3941,21 @@ Sdc::unrecordPathDelayInternalFrom(ExceptionPath *exception)
   }
 }
 
+bool
+Sdc::isExceptionStartpoint(const Pin *pin) const
+{
+  Net *net = network_->net(pin);
+  const LibertyPort *port = network_->libertyPort(pin);
+  return ((network_->isTopLevelPort(pin)
+           && network_->direction(pin)->isAnyInput())
+          || (port && port->isRegClk())
+          || (port && port->isLatchData()))
+    // Pins connected to power/ground are invalid.
+    && !(net
+         && (network_->isPower(net)
+             || network_->isGround(net)));
+}
+
 bool
 Sdc::pathDelayFrom(const Pin *pin)
 {
@@ -5304,13 +5317,13 @@ Sdc::filterRegQStates(const Pin *to_pin,
   }
 }
 
-ExceptionStateSet *
+void
 Sdc::exceptionThruStates(const Pin *from_pin,
 			 const Pin *to_pin,
 			 const RiseFall *to_rf,
-			 const MinMax *min_max) const
+			 const MinMax *min_max,
+                         ExceptionStateSet *&states) const
 {
-  ExceptionStateSet *states = nullptr;
   exceptionThruStates(first_thru_pin_exceptions_.findKey(to_pin),
                       to_rf, min_max, states);
   if (!first_thru_edge_exceptions_.empty()) {
@@ -5325,7 +5338,6 @@ Sdc::exceptionThruStates(const Pin *from_pin,
     exceptionThruStates(first_thru_inst_exceptions_.findKey(to_inst),
 			to_rf, min_max, states);
   }
-  return states;
 }
 
 void

sdc/Sdc.tcl

@@ -2355,6 +2355,7 @@ proc set_path_delay { cmd args min_max } {
   set from [parse_from_arg keys arg_error]
   set thrus [parse_thrus_arg args arg_error]
   set to [parse_to_arg keys flags arg_error]
+  check_exception_pins $from $to
   if { $arg_error } {
     delete_from_thrus_to $from $thrus $to
   } else {

search/Search.cc

@@ -980,13 +980,11 @@ Search::visitStartpoints(VertexVisitor *visitor)
     visitor->visit(vertex);
 
   const PinSet &startpoints = sdc_->pathDelayInternalFrom();
-  if (!startpoints.empty()) {
   for (const Pin *pin : startpoints) {
     Vertex *vertex = graph_->pinDrvrVertex(pin);
     visitor->visit(vertex);
   }
 }
-}
 
 void
 Search::visitEndpoints(VertexVisitor *visitor)
@@ -2176,7 +2174,6 @@ PathVisitor::visitFromPath(const Pin *from_pin,
 	  to_tag = search_->thruClkTag(from_path, from_vertex, from_tag, true,
                                        edge, to_rf, arc_delay_min_max_eq,
                                        min_max, path_ap);
-	  if (to_tag)
           to_arrival = from_arrival + arc_delay;
 	}
       }
@@ -2272,11 +2269,10 @@ PathVisitor::visitFromPath(const Pin *from_pin,
   else {
     if (!(sdc_->isPathDelayInternalFromBreak(to_pin)
           || sdc_->isPathDelayInternalToBreak(from_pin))) {
-      arc_delay = search_->deratedDelay(from_vertex, arc, edge, false, path_ap);
-      if (!delayInf(arc_delay)) {
-        to_arrival = from_arrival + arc_delay;
       to_tag = search_->thruTag(from_tag, edge, to_rf, min_max, path_ap);
-      }
+      arc_delay = search_->deratedDelay(from_vertex, arc, edge, false, path_ap);
+      if (!delayInf(arc_delay))
+        to_arrival = from_arrival + arc_delay;
     }
   }
   if (to_tag)
@@ -2643,7 +2639,7 @@ Search::mutateTag(Tag *from_tag,
 
       // Kill path delay tags past the -to pin.
       if ((exception->isPathDelay()
-           && sdc_->isCompleteTo(state, from_pin, from_rf, min_max))
+           && sdc_->isCompleteTo(state, to_pin, to_rf, min_max))
           // Kill loop tags at register clock pins.
           || (exception->isLoop()
               && to_is_reg_clk)) {
@@ -2653,7 +2649,7 @@ Search::mutateTag(Tag *from_tag,
     }
 
     // Get the set of -thru exceptions starting at to_pin/edge.
-    new_states = sdc_->exceptionThruStates(from_pin, to_pin, to_rf, min_max);
+    sdc_->exceptionThruStates(from_pin, to_pin, to_rf, min_max, new_states);
     if (new_states || state_change) {
       // Second pass to apply state changes and add updated existing
       // states to new states.
@@ -2691,7 +2687,7 @@ Search::mutateTag(Tag *from_tag,
   }
   else
     // Get the set of -thru exceptions starting at to_pin/edge.
-    new_states = sdc_->exceptionThruStates(from_pin, to_pin, to_rf, min_max);
+    sdc_->exceptionThruStates(from_pin, to_pin, to_rf, min_max, new_states);
 
   if (new_states)
     return findTag(to_rf, path_ap, to_clk_info, to_is_clk,

search/Sta.cc

@@ -2027,7 +2027,7 @@ Sta::checkExceptionFromPins(ExceptionFrom *from,
     PinSet::ConstIterator pin_iter(from->pins());
     while (pin_iter.hasNext()) {
       const Pin *pin = pin_iter.next();
-      if (exceptionFromInvalid(pin)) {
+      if (!sdc_->isExceptionStartpoint(pin)) {
 	if (line)
 	  report_->fileWarn(1554, file, line, "'%s' is not a valid start point.",
 			    cmd_network_->pathName(pin));
@@ -2039,24 +2039,6 @@ Sta::checkExceptionFromPins(ExceptionFrom *from,
   }
 }
 
-bool
-Sta::exceptionFromInvalid(const Pin *pin) const
-{
-  Net *net = network_->net(pin);
-  // Floating pins are invalid.
-  return (net == nullptr
-	  && !network_->isTopLevelPort(pin))
-    || (net
-	// Pins connected to power/ground are invalid.
-	&& (network_->isPower(net)
-            || network_->isGround(net)))
-    || !((network_->isTopLevelPort(pin)
-	  && network_->direction(pin)->isAnyInput())
-	 || network_->isRegClkPin(pin)
-	 || network_->isLatchData(pin)
-         || network_->direction(pin)->isInternal());
-}
-
 void
 Sta::deleteExceptionFrom(ExceptionFrom *from)
 {