From 45cff0c0e6c4a31ed3b5b88ee803320862fbd43a Mon Sep 17 00:00:00 2001
From: Victor Stinner <victor.stinner@gmail.com>
Date: Mon, 30 Mar 2015 10:22:16 +0200
Subject: Issue #22117: Try to fix rounding in conversion from Python double to
 _PyTime_t using the C volatile keyword.

---
 Python/pytime.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Python/pytime.c b/Python/pytime.c
index 98f29ac..5bf8c56 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);
-- 
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