ntpd: fold d_to_tv() into its only caller

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/networking/ntpd.c b/networking/ntpd.c
index ff49550e9..db04eb272 100644
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -551,13 +551,6 @@ gettime1900d(void)
         return G.cur_time;
 }
 
-static void
-d_to_tv(struct timeval *tv, double d)
-{
-        tv->tv_sec = (time_t)d;
-        tv->tv_usec = (d - tv->tv_sec) * 1000000;
-}
-
 static NOINLINE double
 lfp_to_d(l_fixedpt_t lfp)
 {
@@ -1044,8 +1037,17 @@ step_time(double offset)
         time_t tval;
 
         xgettimeofday(&tvc);
+        /* This code adds floating point value on the order of 1.0
+         * to a value of ~4 billion (as of years 203x).
+         * With 52-bit mantissa, "only" 20 bits of offset's precision
+         * are used (0.01 attosecond), the rest is lost.
+         * Some 200 billion years later, when tvc.tv_sec would have
+         * 63 significant bits, the precision loss would be catastrophic,
+         * a more complex code would be needed.
+         */
         dtime = tvc.tv_sec + (1.0e-6 * tvc.tv_usec) + offset;
-        d_to_tv(&tvn, dtime);
+        tvn.tv_sec = (time_t)dtime;
+        tvn.tv_usec = (dtime - tvn.tv_sec) * 1000000;
         xsettimeofday(&tvn);
 
         VERB2 {