From d22358fc3c1011b6b1678c984e577be0471d8754 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Fri, 22 Jan 2021 20:40:02 -0700
Subject: [PATCH] LibertyCell::isBuffer prune level shifters

---
 liberty/Liberty.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/liberty/Liberty.cc b/liberty/Liberty.cc
index 0b3a3d5c..280863f7 100644
--- a/liberty/Liberty.cc
+++ b/liberty/Liberty.cc
@@ -1058,7 +1058,8 @@ LibertyCell::isBuffer() const
   LibertyPort *output;
   bufferPorts(input, output);
   return input && output
-    && hasBufferFunc(input, output);
+    && hasBufferFunc(input, output)
+    && !is_level_shifter_;
 }
 
 bool