From 6c9af4a5fa6fef796f360ec33b6fdfc9a7e10e83 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Sat, 18 Apr 2026 11:39:03 -0700
Subject: [PATCH] LibertyPort::less

Signed-off-by: James Cherry <cherry@parallaxsw.com>
---
 include/sta/TimingArc.hh | 2 +-
 liberty/Liberty.cc       | 3 ++-
 liberty/TimingArc.cc     | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/sta/TimingArc.hh b/include/sta/TimingArc.hh
index 4f9d5445..b2f56230 100644
--- a/include/sta/TimingArc.hh
+++ b/include/sta/TimingArc.hh
@@ -146,7 +146,7 @@ class TimingArcSet
 
 public:
   ~TimingArcSet();
-  std::string to_string();
+  std::string to_string() const;
   LibertyCell *libertyCell() const;
   LibertyPort *from() const { return from_; }
   LibertyPort *to() const { return to_; }
diff --git a/liberty/Liberty.cc b/liberty/Liberty.cc
index 8d7a59e0..97682e1e 100644
--- a/liberty/Liberty.cc
+++ b/liberty/Liberty.cc
@@ -2380,12 +2380,13 @@ LibertyPort::equiv(const LibertyPort *port1,
         && port1->pwr_gnd_type_ == port2->pwr_gnd_type_);
 }
 
+// Note port1 and port2 may be from different cells (timingArcSetLess).
 bool
 LibertyPort::less(const LibertyPort *port1,
                   const LibertyPort *port2)
 {
   if (port1 && port2)
-    return port1->pinIndex() < port2->pinIndex();
+    return port1->name() < port2->name();
   else
     return port1 == nullptr && port2 != nullptr;
 }
diff --git a/liberty/TimingArc.cc b/liberty/TimingArc.cc
index ae99b043..dd1694bd 100644
--- a/liberty/TimingArc.cc
+++ b/liberty/TimingArc.cc
@@ -212,7 +212,7 @@ TimingArcSet::TimingArcSet(const TimingRole *role,
 }
 
 std::string
-TimingArcSet::to_string()
+TimingArcSet::to_string() const
 {
   std::string str = from_->name();
   str += " -> ";