From da2850f93269b8daf0b1c3d6d1303162a98c13f6 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Fri, 27 Feb 2015 12:42:54 -0800 Subject: [PATCH] Since the index is always non-negative, use faster unsigned division and modulo. --- Modules/_collectionsmodule.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index 0df35d959c8..0bc0e98ed88 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -142,7 +142,7 @@ typedef struct { static PyTypeObject deque_type; -/* XXX Todo: +/* XXX Todo: If aligned memory allocations become available, make the deque object 64 byte aligned so that all of the fields can be retrieved or updated in a single cache line. @@ -780,7 +780,9 @@ deque_item(dequeobject *deque, Py_ssize_t i) b = deque->rightblock; } else { i += deque->leftindex; - n = i / BLOCKLEN; + assert(i >= 0); + n = (Py_ssize_t)((unsigned) i / BLOCKLEN); + i = (Py_ssize_t)((unsigned) i % BLOCKLEN); i %= BLOCKLEN; if (index < (Py_SIZE(deque) >> 1)) { b = deque->leftblock; @@ -1848,7 +1850,7 @@ _count_elements(PyObject *self, PyObject *args) (hash = ((PyASCIIObject *) key)->hash) == -1) { hash = PyObject_Hash(key); - if (hash == -1) + if (hash == -1) goto done; }