[Python-checkins] cpython: Convert another post-decrement while-loop to pre-decrement for consistency

[raymond.hettinger]

https://hg.python.org/cpython/rev/f700bc0412bc
changeset:   100061:f700bc0412bc
user:        Raymond Hettinger <python at rcn.com>
date:        Sun Jan 24 12:40:42 2016 -0800
summary:
  Convert another post-decrement while-loop to pre-decrement for consistency
and better generated code (on both GCC and CLang).

files:
  Modules/_collectionsmodule.c |  3 ++-
  1 files changed, 2 insertions(+), 1 deletions(-)


diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -895,7 +895,8 @@
     Py_ssize_t n = Py_SIZE(deque) >> 1;
     PyObject *tmp;
 
-    while (n-- > 0) {
+    n++;
+    while (--n) {
         /* Validate that pointers haven't met in the middle */
         assert(leftblock != rightblock || leftindex < rightindex);
         CHECK_NOT_END(leftblock);

-- 
Repository URL: https://hg.python.org/cpython