From c22eee6b5917568933bbfec2be1069a4340efd84 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Sat, 26 Sep 2015 02:14:50 -0700 Subject: Precomputing the number iterations allows the inner-loop to be vectorizable. --- Modules/_collectionsmodule.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index 2dcdf8b..487c765 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -557,7 +557,7 @@ static void deque_clear(dequeobject *deque); static PyObject * deque_inplace_repeat(dequeobject *deque, Py_ssize_t n) { - Py_ssize_t i, size; + Py_ssize_t i, m, size; PyObject *seq; PyObject *rv; @@ -598,7 +598,11 @@ deque_inplace_repeat(dequeobject *deque, Py_ssize_t n) MARK_END(b->rightlink); deque->rightindex = -1; } - for ( ; i < n-1 && deque->rightindex != BLOCKLEN - 1 ; i++) { + m = n - 1 - i; + if (m > BLOCKLEN - 1 - deque->rightindex) + m = BLOCKLEN - 1 - deque->rightindex; + i += m; + while (m--) { deque->rightindex++; Py_INCREF(item); deque->rightblock->data[deque->rightindex] = item; -- cgit v0.12