[PATCH] NTP shift_right cleanup

Create a macro shift_right() that avoids the numerous ugly conditionals in the
NTP code that look like:

        if(a < 0)
                b = -(-a >> shift);
        else
                b = a >> shift;

Replacing it with:

        b = shift_right(a, shift);

This should have zero effect on the logic, however it should probably have
a bit of testing just to be sure.

Also replace open-coded min/max with the macros.

Signed-off-by : John Stultz <johnstul@us.ibm.com>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 19 deletions

diff --git a/kernel/time.c b/kernel/time.c
index a3c2100470e1..245d595a13cb 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -338,30 +338,20 @@ int do_adjtimex(struct timex *txc)
                         if (mtemp >= MINSEC) {
                             ltemp = (time_offset / mtemp) << (SHIFT_USEC -
                                                               SHIFT_UPDATE);
-                            if (ltemp < 0)
-                                time_freq -= -ltemp >> SHIFT_KH;
-                            else
-                                time_freq += ltemp >> SHIFT_KH;
+                            time_freq += shift_right(ltemp, SHIFT_KH);
                         } else /* calibration interval too short (p. 12) */
                                 result = TIME_ERROR;
                     } else {    /* PLL mode */
                         if (mtemp < MAXSEC) {
                             ltemp *= mtemp;
-                            if (ltemp < 0)
-                                time_freq -= -ltemp >> (time_constant +
-                                                        time_constant +
-                                                        SHIFT_KF - SHIFT_USEC);
-                            else
-                                time_freq += ltemp >> (time_constant +
+                            time_freq += shift_right(ltemp,(time_constant +
                                                        time_constant +
-                                                       SHIFT_KF - SHIFT_USEC);
+                                                       SHIFT_KF - SHIFT_USEC));
                         } else /* calibration interval too long (p. 12) */
                                 result = TIME_ERROR;
                     }
-                    if (time_freq > time_tolerance)
-                        time_freq = time_tolerance;
-                    else if (time_freq < -time_tolerance)
-                        time_freq = -time_tolerance;
+                    time_freq = min(time_freq, time_tolerance);
+                    time_freq = max(time_freq, -time_tolerance);
                 } /* STA_PLL || STA_PPSTIME */
             } /* txc->modes & ADJ_OFFSET */
             if (txc->modes & ADJ_TICK) {
@@ -384,10 +374,7 @@ leave:	if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0
         if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
             txc->offset    = save_adjust;
         else {
-            if (time_offset < 0)
-                txc->offset = -(-time_offset >> SHIFT_UPDATE);
-            else
-                txc->offset = time_offset >> SHIFT_UPDATE;
+            txc->offset = shift_right(time_offset, SHIFT_UPDATE);
         }
         txc->freq          = time_freq + pps_freq;
         txc->maxerror      = time_maxerror;