From: Victor Stinner <victor.stinner@gmail.com>
Date: Mon, 30 Mar 2015 08:22:16 +0000 (+0200)
Subject: Issue #22117: Try to fix rounding in conversion from Python double to _PyTime_t
X-Git-Tag: v3.5.0a4~263^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45cff0c0e6c4a31ed3b5b88ee803320862fbd43a;p=thirdparty%2FPython%2Fcpython.git

Issue #22117: Try to fix rounding in conversion from Python double to _PyTime_t
using the C volatile keyword.
---

diff --git a/Python/pytime.c b/Python/pytime.c
index 98f29acc38bd..5bf8c568e7b6 100644
--- a/Python/pytime.c
+++ b/Python/pytime.c
@@ -207,7 +207,8 @@ int
 _PyTime_FromSecondsObject(_PyTime_t *t, PyObject *obj, _PyTime_round_t round)
 {
     if (PyFloat_Check(obj)) {
-        double d, err;
+        /* volatile avoids unsafe optimization on float enabled by gcc -O3 */
+        volatile double d, err;
 
         /* convert to a number of nanoseconds */
         d = PyFloat_AsDouble(obj);