From: Inada Naoki <songofacandy@gmail.com>
Date: Tue, 31 Dec 2019 01:58:37 +0000 (+0900)
Subject: bpo-38588: Optimize list comparison. (GH-17766)
X-Git-Tag: v3.9.0a3~169
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dfef986f12dd92bd6434117bba0db3cbb4e65243;p=thirdparty%2FPython%2Fcpython.git

bpo-38588: Optimize list comparison. (GH-17766)

Mitigate performance regression of the list comparison caused by 2d5bf56.
---

diff --git a/Objects/listobject.c b/Objects/listobject.c
index abe2604573f9..bc8425cae63e 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);