From: compudj <compudj@04897980-b3bd-0310-b5e0-8ef037075253>
Date: Sat, 14 Aug 2004 07:47:31 +0000 (+0000)
Subject: time from double optimisation : use double multiplication and integer shift instead... 
X-Git-Tag: v0.12.20~2750
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=0ce58d1076740dda6228e6c0b8629e32b1fdedb0;p=lttv.git

time from double optimisation : use double multiplication and integer shift instead of double division

git-svn-id: http://ltt.polymtl.ca/svn@739 04897980-b3bd-0310-b5e0-8ef037075253
---

diff --git a/ltt/branches/poly/ltt/time.h b/ltt/branches/poly/ltt/time.h
index db85c69c..83c2fb6c 100644
--- a/ltt/branches/poly/ltt/time.h
+++ b/ltt/branches/poly/ltt/time.h
@@ -29,6 +29,7 @@ typedef struct _LttTime {
 
 
 #define NANOSECONDS_PER_SECOND 1000000000
+#define SHIFT_CONST 1.07374182400631629848
 
 static const LttTime ltt_time_zero = { 0, 0 };
 
@@ -110,7 +111,8 @@ static inline LttTime ltt_time_from_double(double t1)
     g_warning("Conversion from non precise double to LttTime");
 #endif //EXTRA_CHECK
   LttTime res;
-  res.tv_sec = t1/(double)NANOSECONDS_PER_SECOND;
+  //res.tv_sec = t1/(double)NANOSECONDS_PER_SECOND;
+  res.tv_sec = (guint64)(t1 * SHIFT_CONST) >> 30;
   res.tv_nsec = (t1 - (res.tv_sec*NANOSECONDS_PER_SECOND));
   return res;
 }