[Python-checkins] cpython: New try to fix test_time.test_AsSecondsDouble() on x86 buildbots.

[victor.stinner]

https://hg.python.org/cpython/rev/fa66577f6807
changeset:   97853:fa66577f6807
user:        Victor Stinner <victor.stinner at gmail.com>
date:        Thu Sep 10 13:25:17 2015 +0200
summary:
  New try to fix test_time.test_AsSecondsDouble() on x86 buildbots.

Use volatile keyword in _PyTime_AsSecondsDouble()

files:
  Python/pytime.c |  9 +++++++--
  1 files changed, 7 insertions(+), 2 deletions(-)


diff --git a/Python/pytime.c b/Python/pytime.c
--- a/Python/pytime.c
+++ b/Python/pytime.c
@@ -332,16 +332,21 @@
 double
 _PyTime_AsSecondsDouble(_PyTime_t t)
 {
+    /* volatile avoids optimization changing how numbers are rounded */
+    volatile double d;
+
     if (t % SEC_TO_NS == 0) {
         _PyTime_t secs;
         /* Divide using integers to avoid rounding issues on the integer part.
            1e-9 cannot be stored exactly in IEEE 64-bit. */
         secs = t / SEC_TO_NS;
-        return (double)secs;
+        d = (double)secs;
     }
     else {
-        return (double)t / 1e9;
+        d = (double)t;
+        d /= 1e9;
     }
+    return d;
 }
 
 PyObject *

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