From dfef986f12dd92bd6434117bba0db3cbb4e65243 Mon Sep 17 00:00:00 2001
From: Inada Naoki <songofacandy@gmail.com>
Date: Tue, 31 Dec 2019 10:58:37 +0900
Subject: [PATCH] bpo-38588: Optimize list comparison. (GH-17766)

Mitigate performance regression of the list comparison caused by 2d5bf56.
---
 Objects/listobject.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Objects/listobject.c b/Objects/listobject.c
index abe2604573f95a..bc8425cae63e12 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2664,6 +2664,9 @@ list_richcompare(PyObject *v, PyObject *w, int op)
     for (i = 0; i < Py_SIZE(vl) && i < Py_SIZE(wl); i++) {
         PyObject *vitem = vl->ob_item[i];
         PyObject *witem = wl->ob_item[i];
+        if (vitem == witem) {
+            continue;
+        }
 
         Py_INCREF(vitem);
         Py_INCREF(witem);