From: Robert Bradshaw <robertwb@math.washington.edu>
Date: Fri, 27 Feb 2009 08:15:57 +0000 (-0800)
Subject: Optimize indexing for -1 case.
X-Git-Tag: 0.11.rc~22
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=8145cba6f5fd9b7532dc4788ce17154835f4df9b;p=cython.git

Optimize indexing for -1 case.
---

diff --git a/Cython/Compiler/ExprNodes.py b/Cython/Compiler/ExprNodes.py
index 6d313c68..085decb6 100644
--- a/Cython/Compiler/ExprNodes.py
+++ b/Cython/Compiler/ExprNodes.py
@@ -5412,12 +5412,19 @@ static INLINE PyObject *__Pyx_GetItemInt_Generic(PyObject *o, Py_ssize_t i, int
 """ + ''.join([
 """
 static INLINE PyObject *__Pyx_GetItemInt_%(type)s(PyObject *o, Py_ssize_t i, int is_unsigned) {
-    if (likely(o != Py_None && likely((0 <= i) & (i < Py%(type)s_GET_SIZE(o))))) {
-        PyObject *r = Py%(type)s_GET_ITEM(o, i);
-        Py_INCREF(r);
-        return r;
+    if (likely(o != Py_None)) {
+        if (likely((0 <= i) & (i < Py%(type)s_GET_SIZE(o)))) {
+            PyObject *r = Py%(type)s_GET_ITEM(o, i);
+            Py_INCREF(r);
+            return r;
+        }
+        else if ((i == -1) & likely(Py%(type)s_GET_SIZE(o) > 0)) {
+            PyObject *r = Py%(type)s_GET_ITEM(o, Py%(type)s_GET_SIZE(o) - 1);
+            Py_INCREF(r);
+            return r;
+        }
     }
-    else return __Pyx_GetItemInt_Generic(o, i, is_unsigned);
+    return __Pyx_GetItemInt_Generic(o, i, is_unsigned);
 }
 """ % {'type' : type_name} for type_name in ('List', 'Tuple')
 ]) + """