From f61335a194d8d1e8412699da60ae7e1fc91bdb07 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Wed, 13 Apr 2022 19:35:12 -0700
Subject: [PATCH] Sta::findSlewLimit

Signed-off-by: James Cherry <cherry@parallaxsw.com>
---
 include/sta/Sta.hh        |  2 +-
 search/CheckSlewLimits.cc | 77 ++++++++++++++++++++-------------------
 search/CheckSlewLimits.hh |  2 +-
 search/Sta.cc             |  4 +-
 4 files changed, 43 insertions(+), 42 deletions(-)

diff --git a/include/sta/Sta.hh b/include/sta/Sta.hh
index c28dec8b..08dd5836 100644
--- a/include/sta/Sta.hh
+++ b/include/sta/Sta.hh
@@ -631,7 +631,7 @@ public:
                     Slew &slew,
                     float &slack,
                     float &limit);
-  void findSlewLimit(const Pin *pin,
+  void findSlewLimit(const LibertyPort *port,
                      const Corner *corner,
                      const MinMax *min_max,
                      // Return values.
diff --git a/search/CheckSlewLimits.cc b/search/CheckSlewLimits.cc
index e0b92ea8..abb2d842 100644
--- a/search/CheckSlewLimits.cc
+++ b/search/CheckSlewLimits.cc
@@ -166,24 +166,6 @@ CheckSlewLimits::checkSlews1(Vertex *vertex,
   }
 }
 
-void
-CheckSlewLimits::findLimit(const Pin *pin,
-                           const Corner *corner,
-			   const MinMax *min_max,
-			   // Return values.
-			   float &limit,
-			   bool &exists) const
-{
-  limit = INF;
-  exists = false;
-  for (auto rf : RiseFall::range()) {
-    float limit;
-    bool exists;
-    findLimit(pin, nullptr, corner, rf, min_max, false,
-              limit, exists);
-  }
-}
-
 // Return the tightest limit.
 void
 CheckSlewLimits::findLimit(const Pin *pin,
@@ -196,14 +178,12 @@ CheckSlewLimits::findLimit(const Pin *pin,
 			   float &limit,
 			   bool &exists) const
 {
-  exists = false;
   const Network *network = sta_->network();
   Sdc *sdc = sta_->sdc();
+  LibertyPort *port = network->libertyPort(pin);
+  findLimit(port, corner, min_max,
+            limit, exists);
 
-  // Default to top ("design") limit.
-  Cell *top_cell = network->cell(network->topInstance());
-  sdc->slewLimit(top_cell, min_max,
-		 limit, exists);
   float limit1;
   bool exists1;
   if (check_clks) {
@@ -225,6 +205,7 @@ CheckSlewLimits::findLimit(const Pin *pin,
       }
     }
   }
+
   if (network->isTopLevelPort(pin)) {
     Port *port = network->port(pin);
     sdc->slewLimit(port, min_max, limit1, exists1);
@@ -259,21 +240,41 @@ CheckSlewLimits::findLimit(const Pin *pin,
       }
     }
   }
-  else {
-    LibertyPort *port = network->libertyPort(pin);
-    if (port) {
-      LibertyPort *corner_port = port->cornerPort(corner->libertyIndex(min_max));
-      corner_port->slewLimit(min_max, limit1, exists1);
-      if (!exists1
-	  && corner_port->direction()->isAnyOutput()
-	  && min_max == MinMax::max())
-	corner_port->libertyLibrary()->defaultMaxSlew(limit1, exists1);
-      if (exists1
-	  && (!exists
-	      || min_max->compare(limit, limit1))) {
-	limit = limit1;
-	exists = true;
-      }
+}
+
+void
+CheckSlewLimits::findLimit(const LibertyPort *port,
+                           const Corner *corner,
+			   const MinMax *min_max,
+			   // Return values.
+			   float &limit,
+			   bool &exists) const
+{
+  limit = INF;
+  exists = false;
+
+  const Network *network = sta_->network();
+  Sdc *sdc = sta_->sdc();
+
+  // Default to top ("design") limit.
+  Cell *top_cell = network->cell(network->topInstance());
+  sdc->slewLimit(top_cell, min_max,
+		 limit, exists);
+
+  if (port) {
+    const LibertyPort *corner_port = port->cornerPort(corner->libertyIndex(min_max));
+    float limit1;
+    bool exists1;
+    corner_port->slewLimit(min_max, limit1, exists1);
+    if (!exists1
+        && corner_port->direction()->isAnyOutput()
+        && min_max == MinMax::max())
+      corner_port->libertyLibrary()->defaultMaxSlew(limit1, exists1);
+    if (exists1
+        && (!exists
+            || min_max->compare(limit, limit1))) {
+      limit = limit1;
+      exists = true;
     }
   }
 }
diff --git a/search/CheckSlewLimits.hh b/search/CheckSlewLimits.hh
index 60d0d7da..35926003 100644
--- a/search/CheckSlewLimits.hh
+++ b/search/CheckSlewLimits.hh
@@ -52,7 +52,7 @@ public:
                           bool violators,
                           const Corner *corner,
                           const MinMax *min_max);
-  void findLimit(const Pin *pin,
+  void findLimit(const LibertyPort *port,
                  const Corner *corner,
                  const MinMax *min_max,
                  // Return values.
diff --git a/search/Sta.cc b/search/Sta.cc
index 45e11150..a19ac039 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -5212,7 +5212,7 @@ Sta::maxSlewCheck(// Return values.
 }
 
 void
-Sta::findSlewLimit(const Pin *pin,
+Sta::findSlewLimit(const LibertyPort *port,
                    const Corner *corner,
                    const MinMax *min_max,
                    // Return values.
@@ -5220,7 +5220,7 @@ Sta::findSlewLimit(const Pin *pin,
                    bool &exists)
 {
   checkSlewLimitPreamble();
-  check_slew_limits_->findLimit(pin, corner, min_max,
+  check_slew_limits_->findLimit(port, corner, min_max,
                                 limit, exists);
 }