diff --git a/liberty/Liberty.hh b/liberty/Liberty.hh
index d74a5da0..baf2106f 100644
--- a/liberty/Liberty.hh
+++ b/liberty/Liberty.hh
@@ -452,10 +452,6 @@ public:
   OcvDerate *ocvDerate() const;
   OcvDerate *findOcvDerate(const char *derate_name);
 
-  // Next higher/lower drive equivalent cells.
-  LibertyCell *higherDrive() const;
-  LibertyCell *lowerDrive() const;
-
   // Build helpers.
   void makeSequential(int size,
 		      bool is_register,
diff --git a/search/Sta.cc b/search/Sta.cc
index 1c845b64..91ad5a55 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -2918,6 +2918,27 @@ Sta::vertexSlack1(Vertex *vertex,
   return slack;
 }
 
+void
+Sta::vertexSlacks(Vertex *vertex,
+		  Slack (&slacks)[RiseFall::index_count][MinMax::index_count])
+{
+  findRequired(vertex);
+  for(int rf_index : RiseFall::rangeIndex()) {
+    for(MinMax *min_max : MinMax::range()) {
+      slacks[rf_index][min_max->index()] = MinMax::min()->initValue();
+    }
+  }
+  VertexPathIterator path_iter(vertex, this);
+  while (path_iter.hasNext()) {
+    Path *path = path_iter.next();
+    Slack path_slack = path->slack(this);
+    int rf_index = path->rfIndex(this);
+    int mm_index = path->minMax(this)->index();
+    if (path_slack < slacks[rf_index][mm_index])
+      slacks[rf_index][mm_index] = path_slack;
+  }
+}
+
 void
 Sta::findRequired(Vertex *vertex)
 {
diff --git a/search/Sta.hh b/search/Sta.hh
index 75275a5c..7f49a44a 100644
--- a/search/Sta.hh
+++ b/search/Sta.hh
@@ -1010,6 +1010,8 @@ public:
   Slack vertexSlack(Vertex *vertex,
 		    const RiseFall *rf,
 		    const PathAnalysisPt *path_ap);
+  void vertexSlacks(Vertex *vertex,
+		    Slack (&slacks)[RiseFall::index_count][MinMax::index_count]);
   // Slew for one delay calc analysis pt(corner).
   Slew vertexSlew(Vertex *vertex,
 		  const RiseFall *rf,