From: Raymond Hettinger <python@rcn.com>
Date: Thu, 5 Sep 2002 14:23:49 +0000 (+0000)
Subject: Micro-optimization for list_contains.  Factored double if test
X-Git-Tag: v2.3c1~4210
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=aae5999b44e54394f91e84b775d29230d3a0a2ef;p=python

Micro-optimization for list_contains.  Factored double if test
out of the loop.
---

diff --git a/Objects/listobject.c b/Objects/listobject.c
index cea8597f23..229d64cfbd 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -320,16 +320,15 @@ list_length(PyListObject *a)
 static int
 list_contains(PyListObject *a, PyObject *el)
 {
-	int i;
+	int i, cmp;
 
-	for (i = 0; i < a->ob_size; ++i) {
-		int cmp = PyObject_RichCompareBool(el, PyList_GET_ITEM(a, i),
+	for (i = 0, cmp = 0 ; cmp == 0 && i < a->ob_size; ++i)
+		cmp = PyObject_RichCompareBool(el, PyList_GET_ITEM(a, i),
 						   Py_EQ);
-		if (cmp > 0)
-			return 1;
-		else if (cmp < 0)
-			return -1;
-	}
+	if (cmp > 0)
+		return 1;
+	if (cmp < 0)
+		return -1;
 	return 0;
 }