From: Raymond Hettinger <python@rcn.com>
Date: Tue, 9 Feb 2016 04:34:49 +0000 (-0800)
Subject: Issue #26200:  The SETREF macro adds unnecessary work in some cases.
X-Git-Tag: v3.6.0a1~628
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=38418662e0339b6331e0c7e00ea55f41b28bf38d;p=python

Issue #26200:  The SETREF macro adds unnecessary work in some cases.
---

diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 479b0525a6..0b7a88f974 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -1218,6 +1218,7 @@ deque_del_item(dequeobject *deque, Py_ssize_t i)
 static int
 deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v)
 {
+    PyObject *old_value;
     block *b;
     Py_ssize_t n, len=Py_SIZE(deque), halflen=(len+1)>>1, index=i;
 
@@ -1246,7 +1247,9 @@ deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v)
             b = b->leftlink;
     }
     Py_INCREF(v);
-    Py_SETREF(b->data[i], v);
+    old_value = b->data[i];
+    b->data[i] = v;
+    Py_DECREF(old_value);
     return 0;
 }