accelerate double useage for time

[lttv.git] / ltt / branches / poly / ltt / time.h

diff --git a/ltt/branches/poly/ltt/time.h b/ltt/branches/poly/ltt/time.h
index 61c3e596c3e0bb2ca76707fa12b738be27471ab2..642328e9001d9ac0c5ad08e5a98e4a16748e432d 100644 (file)
--- a/ltt/branches/poly/ltt/time.h
+++ b/ltt/branches/poly/ltt/time.h
@@ -28,24 +28,22 @@ typedef struct _LttTime {
 } LttTime;
 
 
-static const unsigned long NANOSECONDS_PER_SECOND = 1000000000;
+#define NANOSECONDS_PER_SECOND 1000000000
 
-static const LttTime ltt_time_zero = { 0, 0};
+static const LttTime ltt_time_zero = { 0, 0 };
 
 static const LttTime ltt_time_one = { 0, 1 };
 
-static const LttTime ltt_time_infinite = { G_MAXUINT, G_MAXUINT };
+static const LttTime ltt_time_infinite = { G_MAXUINT, NANOSECONDS_PER_SECOND };
 
 static inline LttTime ltt_time_sub(LttTime t1, LttTime t2) 
 {
   LttTime res;
   res.tv_sec  = t1.tv_sec  - t2.tv_sec;
+  res.tv_nsec = t1.tv_nsec - t2.tv_nsec;
   if(t1.tv_nsec < t2.tv_nsec) {
     res.tv_sec--;
-    res.tv_nsec = NANOSECONDS_PER_SECOND + t1.tv_nsec - t2.tv_nsec;
-  }
-  else {
-    res.tv_nsec = t1.tv_nsec - t2.tv_nsec;
+    res.tv_nsec += NANOSECONDS_PER_SECOND;
   }
   return res;
 }
@@ -54,8 +52,8 @@ static inline LttTime ltt_time_sub(LttTime t1, LttTime t2)
 static inline LttTime ltt_time_add(LttTime t1, LttTime t2) 
 {
   LttTime res;
-  res.tv_sec  = t1.tv_sec  + t2.tv_sec;
   res.tv_nsec = t1.tv_nsec + t2.tv_nsec;
+  res.tv_sec = t1.tv_sec + t2.tv_sec;
   if(res.tv_nsec >= NANOSECONDS_PER_SECOND) {
     res.tv_sec++;
     res.tv_nsec -= NANOSECONDS_PER_SECOND;
@@ -64,16 +62,81 @@ static inline LttTime ltt_time_add(LttTime t1, LttTime t2)
 }
 
 
-static inline LttTime ltt_time_mul(LttTime t1, float f)
+static inline int ltt_time_compare(LttTime t1, LttTime t2)
+{
+  if(t1.tv_sec > t2.tv_sec) return 1;
+  if(t1.tv_sec < t2.tv_sec) return -1;
+  if(t1.tv_nsec > t2.tv_nsec) return 1;
+  if(t1.tv_nsec < t2.tv_nsec) return -1;
+  return 0;
+}
+
+#define LTT_TIME_MIN(a,b) ((ltt_time_compare((a),(b)) < 0) ? (a) : (b))
+#define LTT_TIME_MAX(a,b) ((ltt_time_compare((a),(b)) > 0) ? (a) : (b))
+
+#define MAX_TV_SEC_TO_DOUBLE 0x7FFFFF
+static inline double ltt_time_to_double(LttTime t1)
+{
+  /* We lose precision if tv_sec is > than (2^23)-1
+   * 
+   * Max values that fits in a double (53 bits precision on normalised 
+   * mantissa):
+   * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
+   *
+   * So we have 53-30 = 23 bits left for tv_sec.
+   * */
+#ifdef EXTRA_CHECK
+  g_assert(t1.tv_sec <= MAX_TV_SEC_TO_DOUBLE);
+  if(t1.tv_sec > MAX_TV_SEC_TO_DOUBLE)
+    g_warning("Precision loss in conversion LttTime to double");
+#endif //EXTRA_CHECK
+  return ((double)t1.tv_sec * NANOSECONDS_PER_SECOND) + (double)t1.tv_nsec;
+}
+
+
+static inline LttTime ltt_time_from_double(double t1)
 {
+  /* We lose precision if tv_sec is > than (2^23)-1
+   * 
+   * Max values that fits in a double (53 bits precision on normalised 
+   * mantissa):
+   * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
+   *
+   * So we have 53-30 = 23 bits left for tv_sec.
+   * */
+#ifdef EXTRA_CHECK
+  g_assert(t1 <= MAX_TV_SEC_TO_DOUBLE);
+  if(t1 > MAX_TV_SEC_TO_DOUBLE)
+    g_warning("Conversion from non precise double to LttTime");
+#endif //EXTRA_CHECK
   LttTime res;
-  float d;
-  double sec;
+  res.tv_sec = t1/(double)NANOSECONDS_PER_SECOND;
+  res.tv_nsec = (t1 - (res.tv_sec*NANOSECONDS_PER_SECOND));
+  return res;
+}
+
+/* Use ltt_time_to_double and ltt_time_from_double to check for lack
+ * of precision.
+ */
+static inline LttTime ltt_time_mul(LttTime t1, double d)
+{
+  LttTime res;
+
+  double time_double = ltt_time_to_double(t1);
+
+  time_double = time_double * d;
 
+  res = ltt_time_from_double(time_double);
+
+  return res;
+
+#if 0
+  /* What is that ? (Mathieu) */
   if(f == 0.0){
     res.tv_sec = 0;
     res.tv_nsec = 0;
   }else{
+  double d;
     d = 1.0/f;
     sec = t1.tv_sec / (double)d;
     res.tv_sec = sec;
@@ -83,11 +146,27 @@ static inline LttTime ltt_time_mul(LttTime t1, float f)
     res.tv_nsec %= NANOSECONDS_PER_SECOND;
   }
   return res;
+#endif //0
 }
 
 
-static inline LttTime ltt_time_div(LttTime t1, float f)
+/* Use ltt_time_to_double and ltt_time_from_double to check for lack
+ * of precision.
+ */
+static inline LttTime ltt_time_div(LttTime t1, double d)
 {
+  LttTime res;
+
+  double time_double = ltt_time_to_double(t1);
+
+  time_double = time_double / d;
+
+  res = ltt_time_from_double(time_double);
+
+  return res;
+
+
+#if 0
   double sec;
   LttTime res;
 
@@ -98,30 +177,29 @@ static inline LttTime ltt_time_div(LttTime t1, float f)
   res.tv_sec += res.tv_nsec / NANOSECONDS_PER_SECOND;
   res.tv_nsec %= NANOSECONDS_PER_SECOND;
   return res;
+#endif //0
 }
 
-
-static inline int ltt_time_compare(LttTime t1, LttTime t2)
-{
-  if(t1.tv_sec > t2.tv_sec) return 1;
-  if(t1.tv_sec < t2.tv_sec) return -1;
-  if(t1.tv_nsec > t2.tv_nsec) return 1;
-  if(t1.tv_nsec < t2.tv_nsec) return -1;
-  return 0;
-}
-
-
-static inline double ltt_time_to_double(LttTime t1)
+static inline guint64 ltt_time_to_uint64(LttTime t1)
 {
-  return (double)t1.tv_sec + (double)t1.tv_nsec / NANOSECONDS_PER_SECOND;
+  return (guint64)t1.tv_sec*NANOSECONDS_PER_SECOND
+            + (guint64)t1.tv_nsec;
 }
 
 
-static inline LttTime ltt_time_from_double(double t1)
+#define MAX_TV_SEC_TO_UINT64 0x3FFFFFFFFFFFFFFFULL
+static inline LttTime ltt_time_from_uint64(guint64 t1)
 {
+  /* We lose precision if tv_sec is > than (2^62)-1
+   * */
+#ifdef EXTRA_CHECK
+  g_assert(t1 <= MAX_TV_SEC_TO_UINT64);
+  if(t1 > MAX_TV_SEC_TO_UINT64)
+    g_warning("Conversion from non precise uint64 to LttTime");
+#endif //EXTRA_CHECK
   LttTime res;
-  res.tv_sec = t1;
-  res.tv_nsec = (t1 - res.tv_sec) * NANOSECONDS_PER_SECOND;
+  res.tv_sec = t1/NANOSECONDS_PER_SECOND;
+  res.tv_nsec = (t1 - res.tv_sec*NANOSECONDS_PER_SECOND);
   return res;
 }