From: Victor Stinner <vstinner@wyplay.com>
Date: Tue, 13 Mar 2012 18:12:23 +0000 (+0100)
Subject: Issue #14180: Fix an invalid rounding when compiler optimization are enabled
X-Git-Tag: v3.3.0a2~225
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bd273c1ec320e3cfda41e5739180d86e052cbc80;p=thirdparty%2FPython%2Fcpython.git

Issue #14180: Fix an invalid rounding when compiler optimization are enabled

Use volatile keyword to disable localy unsafe float optimizations.
---

diff --git a/Python/pytime.c b/Python/pytime.c
index 75d80e257613..e7dadc7605da 100644
--- a/Python/pytime.c
+++ b/Python/pytime.c
@@ -102,7 +102,9 @@ _PyTime_ObjectToDenominator(PyObject *obj, time_t *sec, long *numerator,
 {
     assert(denominator <= LONG_MAX);
     if (PyFloat_Check(obj)) {
-        double d, intpart, floatpart, err;
+        double d, intpart, err;
+        /* volatile avoids unsafe optimization on float enabled by gcc -O3 */
+        volatile double floatpart;
 
         d = PyFloat_AsDouble(obj);
         floatpart = modf(d, &intpart);