/* This file is part of the Linux Trace Toolkit trace reading library
* Copyright (C) 2003-2004 Michel Dagenais
+ * 2005 Mathieu Desnoyers
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
#define LTT_TIME_H
#include <glib.h>
-
+#include <ltt/compiler.h>
+#include <math.h>
typedef struct _LttTime {
unsigned long tv_sec;
} LttTime;
-static const unsigned long NANOSECONDS_PER_SECOND = 1000000000;
+#define NANOSECONDS_PER_SECOND 1000000000
+
+/* We give the DIV and MUL constants so we can always multiply, for a
+ * division as well as a multiplication of NANOSECONDS_PER_SECOND */
+/* 2^30/1.07374182400631629848 = 1000000000.0 */
+#define DOUBLE_SHIFT_CONST_DIV 1.07374182400631629848
+#define DOUBLE_SHIFT 30
+
+/* 2^30*0.93132257461547851562 = 1000000000.0000000000 */
+#define DOUBLE_SHIFT_CONST_MUL 0.93132257461547851562
+
+
+/* 1953125 * 2^9 = NANOSECONDS_PER_SECOND */
+#define LTT_TIME_UINT_SHIFT_CONST 1953125
+#define LTT_TIME_UINT_SHIFT 9
+
-static const LttTime ltt_time_zero = { 0, 0};
+static const LttTime ltt_time_zero = { 0, 0 };
-static const LttTime ltt_time_infinite = { G_MAXUINT, G_MAXUINT };
+static const LttTime ltt_time_one = { 0, 1 };
+
+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;
- if(t1.tv_nsec < t2.tv_nsec) {
+ res.tv_nsec = t1.tv_nsec - t2.tv_nsec;
+ /* unlikely : given equal chance to be anywhere in t1.tv_nsec, and
+ * higher probability of low value for t2.tv_sec, we will habitually
+ * not wrap.
+ */
+ if(unlikely(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;
}
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;
- if(res.tv_nsec >= NANOSECONDS_PER_SECOND) {
+ res.tv_sec = t1.tv_sec + t2.tv_sec;
+ /* unlikely : given equal chance to be anywhere in t1.tv_nsec, and
+ * higher probability of low value for t2.tv_sec, we will habitually
+ * not wrap.
+ */
+ if(unlikely(res.tv_nsec >= NANOSECONDS_PER_SECOND)) {
res.tv_sec++;
res.tv_nsec -= NANOSECONDS_PER_SECOND;
}
return res;
}
+/* Fastest comparison : t1 > t2 */
+static inline int ltt_time_compare(LttTime t1, LttTime t2)
+{
+ int ret=0;
+ if(likely(t1.tv_sec > t2.tv_sec)) ret = 1;
+ else if(unlikely(t1.tv_sec < t2.tv_sec)) ret = -1;
+ else if(likely(t1.tv_nsec > t2.tv_nsec)) ret = 1;
+ else if(unlikely(t1.tv_nsec < t2.tv_nsec)) ret = -1;
+
+ return ret;
+}
+
+#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))
-static inline LttTime ltt_time_mul(LttTime t1, float f)
+#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)((guint64)t1.tv_sec<<DOUBLE_SHIFT)
+ * (double)DOUBLE_SHIFT_CONST_MUL)
+ + (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_sec = (guint64)(t1 * DOUBLE_SHIFT_CONST_DIV) >> DOUBLE_SHIFT;
+ res.tv_nsec = (t1 - (((guint64)res.tv_sec<<LTT_TIME_UINT_SHIFT))
+ * LTT_TIME_UINT_SHIFT_CONST);
+ 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;
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;
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)
+static inline guint64 ltt_time_to_uint64(LttTime t1)
{
- 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;
+ return (((guint64)t1.tv_sec*LTT_TIME_UINT_SHIFT_CONST) << LTT_TIME_UINT_SHIFT)
+ + (guint64)t1.tv_nsec;
}
-static inline double ltt_time_to_double(LttTime t1)
-{
- return (double)t1.tv_sec + (double)t1.tv_nsec / NANOSECONDS_PER_SECOND;
-}
-
+#define MAX_TV_SEC_TO_UINT64 0x3FFFFFFFFFFFFFFFULL
-static inline LttTime ltt_time_from_double(double t1)
+/* The likely branch is with sec != 0, because most events in a bloc
+ * will be over 1s from the block start. (see tracefile.c)
+ */
+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 uint64 to non precise LttTime");
+#endif //EXTRA_CHECK
LttTime res;
- res.tv_sec = t1;
- res.tv_nsec = (t1 - res.tv_sec) * NANOSECONDS_PER_SECOND;
+ //if(unlikely(t1 >= NANOSECONDS_PER_SECOND)) {
+ if(likely(t1>>LTT_TIME_UINT_SHIFT >= LTT_TIME_UINT_SHIFT_CONST)) {
+ //res.tv_sec = t1/NANOSECONDS_PER_SECOND;
+ res.tv_sec = (t1>>LTT_TIME_UINT_SHIFT)
+ /LTT_TIME_UINT_SHIFT_CONST; // acceleration
+ res.tv_nsec = (t1 - res.tv_sec*NANOSECONDS_PER_SECOND);
+ } else {
+ res.tv_sec = 0;
+ res.tv_nsec = (guint32)t1;
+ }
return res;
}
projects / lttv.git / blobdiff