From: Raymond Hettinger <python@rcn.com>
Date: Sat, 28 Feb 2015 15:41:30 +0000 (-0800)
Subject: Convert one more division to unsigned arithmetic to speed-up deque_item().
X-Git-Tag: v3.5.0a2~67^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=63d1ff2a0b5d6d1287472dcc18ed83569f7c1096;p=python

Convert one more division to unsigned arithmetic to speed-up deque_item().
---

diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 8494a47d87..d12f0e8769 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -788,7 +788,9 @@ deque_item(dequeobject *deque, Py_ssize_t i)
             while (n--)
                 b = b->rightlink;
         } else {
-            n = (deque->leftindex + Py_SIZE(deque) - 1) / BLOCKLEN - n;
+            n = (Py_ssize_t)(
+                    ((unsigned)(deque->leftindex + Py_SIZE(deque) - 1))
+                    / BLOCKLEN - n);
             b = deque->rightblock;
             while (n--)
                 b = b->leftlink;