From df65a4ca402cf6ca343be6e1b9da815db7a0a508 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Sun, 14 Jun 2020 18:09:51 -0700
Subject: [PATCH] report -max_cap do not report constant nets

---
 search/CheckCapacitanceLimits.cc | 29 ++++++++++++++++++-----------
 search/CheckFanoutLimits.cc      |  6 +++---
 search/Sta.cc                    |  2 ++
 3 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/search/CheckCapacitanceLimits.cc b/search/CheckCapacitanceLimits.cc
index fe09ff0d..9a3c335f 100644
--- a/search/CheckCapacitanceLimits.cc
+++ b/search/CheckCapacitanceLimits.cc
@@ -25,6 +25,7 @@
 #include "StaState.hh"
 #include "Corner.hh"
 #include "PortDirection.hh"
+#include "Sim.hh"
 
 namespace sta {
 
@@ -244,10 +245,12 @@ CheckCapacitanceLimits::pinCapacitanceLimitViolations(Instance *inst,
 						      PinSeq *violators)
 {
   const Network *network = sta_->network();
+  const Sim *sim = sta_->sim();
   InstancePinIterator *pin_iter = network->pinIterator(inst);
   while (pin_iter->hasNext()) {
     Pin *pin = pin_iter->next();
-    if (network->direction(pin)->isAnyOutput()) {
+    if (network->direction(pin)->isAnyOutput()
+	&& !sim->logicZeroOne(pin)) {
       const Corner *corner1;
       const RiseFall *rf;
       float capacitance, limit, slack;
@@ -287,19 +290,23 @@ CheckCapacitanceLimits::pinMinCapacitanceLimitSlack(Instance *inst,
 						    float &min_slack)
 {
   const Network *network = sta_->network();
+  const Sim *sim = sta_->sim();
   InstancePinIterator *pin_iter = network->pinIterator(inst);
   while (pin_iter->hasNext()) {
     Pin *pin = pin_iter->next();
-    const Corner *corner1;
-    const RiseFall *rf;
-    float capacitance, limit, slack;
-    checkCapacitance(pin, corner, min_max, corner1, rf, capacitance, limit, slack);
-    if (rf
-	&& !fuzzyInf(slack)
-	&& (min_slack_pin == nullptr
-	    || slack < min_slack)) {
-      min_slack_pin = pin;
-      min_slack = slack;
+    if (network->direction(pin)->isAnyOutput()
+	&& !sim->logicZeroOne(pin)) {
+      const Corner *corner1;
+      const RiseFall *rf;
+      float capacitance, limit, slack;
+      checkCapacitance(pin, corner, min_max, corner1, rf, capacitance, limit, slack);
+      if (rf
+	  && !fuzzyInf(slack)
+	  && (min_slack_pin == nullptr
+	      || slack < min_slack)) {
+	min_slack_pin = pin;
+	min_slack = slack;
+      }
     }
   }
   delete pin_iter;
diff --git a/search/CheckFanoutLimits.cc b/search/CheckFanoutLimits.cc
index 96571697..b62e7aa3 100644
--- a/search/CheckFanoutLimits.cc
+++ b/search/CheckFanoutLimits.cc
@@ -220,10 +220,12 @@ CheckFanoutLimits::pinFanoutLimitViolations(Instance *inst,
 					    PinSeq *violators)
 {
   const Network *network = sta_->network();
+  const Sim *sim = sta_->sim();
   InstancePinIterator *pin_iter = network->pinIterator(inst);
   while (pin_iter->hasNext()) {
     Pin *pin = pin_iter->next();
-    if (network->direction(pin)->isAnyOutput()) {
+    if (network->direction(pin)->isAnyOutput()
+	&& !sim->logicZeroOne(pin)) {
       float fanout;
       float limit, slack;
       checkFanout(pin, min_max, fanout, limit, slack );
@@ -264,8 +266,6 @@ CheckFanoutLimits::pinMinFanoutLimitSlack(Instance *inst,
   InstancePinIterator *pin_iter = network->pinIterator(inst);
   while (pin_iter->hasNext()) {
     Pin *pin = pin_iter->next();
-    if (stringEq(network->pathName(pin),"rdrv/Q"))
-      printf("luse\n");
     if (network->direction(pin)->isAnyOutput()
 	&& !sim->logicZeroOne(pin)) {
       float fanout;
diff --git a/search/Sta.cc b/search/Sta.cc
index 44c8f313..984891be 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -4974,6 +4974,8 @@ Sta::checkCapacitanceLimitPreamble()
 {
   if (check_capacitance_limits_ == nullptr)
     makeCheckCapacitanceLimits();
+  // Sim values required to suppress reporting constant nets.
+  ensureLevelized();
 }
 
 Pin *