1 /* This file is part of the Linux Trace Toolkit trace reading library
2 * Copyright (C) 2003-2004 Michel Dagenais
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License Version 2.1 as published by the Free Software Foundation.
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 02111-1307, USA.
23 #include <ltt/compiler.h>
26 typedef struct _LttTime
{
28 unsigned long tv_nsec
;
32 #define NANOSECONDS_PER_SECOND 1000000000
34 /* We give the DIV and MUL constants so we can always multiply, for a
35 * division as well as a multiplication of NANOSECONDS_PER_SECOND */
36 /* 2^30/1.07374182400631629848 = 1000000000.0 */
37 #define DOUBLE_SHIFT_CONST_DIV 1.07374182400631629848
38 #define DOUBLE_SHIFT 30
40 /* 2^30*0.93132257461547851562 = 1000000000.0000000000 */
41 #define DOUBLE_SHIFT_CONST_MUL 0.93132257461547851562
44 /* 1953125 * 2^9 = NANOSECONDS_PER_SECOND */
45 #define LTT_TIME_UINT_SHIFT_CONST 1953125
46 #define LTT_TIME_UINT_SHIFT 9
49 static const LttTime ltt_time_zero
= { 0, 0 };
51 static const LttTime ltt_time_one
= { 0, 1 };
53 static const LttTime ltt_time_infinite
= { G_MAXUINT
, NANOSECONDS_PER_SECOND
};
55 static inline LttTime
ltt_time_sub(LttTime t1
, LttTime t2
)
58 res
.tv_sec
= t1
.tv_sec
- t2
.tv_sec
;
59 res
.tv_nsec
= t1
.tv_nsec
- t2
.tv_nsec
;
60 /* unlikely : given equal chance to be anywhere in t1.tv_nsec, and
61 * higher probability of low value for t2.tv_sec, we will habitually
64 if(unlikely(t1
.tv_nsec
< t2
.tv_nsec
)) {
66 res
.tv_nsec
+= NANOSECONDS_PER_SECOND
;
72 static inline LttTime
ltt_time_add(LttTime t1
, LttTime t2
)
75 res
.tv_nsec
= t1
.tv_nsec
+ t2
.tv_nsec
;
76 res
.tv_sec
= t1
.tv_sec
+ t2
.tv_sec
;
77 /* unlikely : given equal chance to be anywhere in t1.tv_nsec, and
78 * higher probability of low value for t2.tv_sec, we will habitually
81 if(unlikely(res
.tv_nsec
>= NANOSECONDS_PER_SECOND
)) {
83 res
.tv_nsec
-= NANOSECONDS_PER_SECOND
;
88 /* Fastest comparison : t1 > t2 */
89 static inline int ltt_time_compare(LttTime t1
, LttTime t2
)
92 if(likely(t1
.tv_sec
> t2
.tv_sec
)) ret
= 1;
93 else if(unlikely(t1
.tv_sec
< t2
.tv_sec
)) ret
= -1;
94 else if(likely(t1
.tv_nsec
> t2
.tv_nsec
)) ret
= 1;
95 else if(unlikely(t1
.tv_nsec
< t2
.tv_nsec
)) ret
= -1;
100 #define LTT_TIME_MIN(a,b) ((ltt_time_compare((a),(b)) < 0) ? (a) : (b))
101 #define LTT_TIME_MAX(a,b) ((ltt_time_compare((a),(b)) > 0) ? (a) : (b))
103 #define MAX_TV_SEC_TO_DOUBLE 0x7FFFFF
104 static inline double ltt_time_to_double(LttTime t1
)
106 /* We lose precision if tv_sec is > than (2^23)-1
108 * Max values that fits in a double (53 bits precision on normalised
110 * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
112 * So we have 53-30 = 23 bits left for tv_sec.
115 g_assert(t1
.tv_sec
<= MAX_TV_SEC_TO_DOUBLE
);
116 if(t1
.tv_sec
> MAX_TV_SEC_TO_DOUBLE
)
117 g_warning("Precision loss in conversion LttTime to double");
119 return ((double)((guint64
)t1
.tv_sec
<<DOUBLE_SHIFT
)
120 * (double)DOUBLE_SHIFT_CONST_MUL
)
121 + (double)t1
.tv_nsec
;
125 static inline LttTime
ltt_time_from_double(double t1
)
127 /* We lose precision if tv_sec is > than (2^23)-1
129 * Max values that fits in a double (53 bits precision on normalised
131 * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
133 * So we have 53-30 = 23 bits left for tv_sec.
136 g_assert(t1
<= MAX_TV_SEC_TO_DOUBLE
);
137 if(t1
> MAX_TV_SEC_TO_DOUBLE
)
138 g_warning("Conversion from non precise double to LttTime");
141 //res.tv_sec = t1/(double)NANOSECONDS_PER_SECOND;
142 res
.tv_sec
= (guint64
)(t1
* DOUBLE_SHIFT_CONST_DIV
) >> DOUBLE_SHIFT
;
143 res
.tv_nsec
= (t1
- (((guint64
)res
.tv_sec
<<LTT_TIME_UINT_SHIFT
))
144 * LTT_TIME_UINT_SHIFT_CONST
);
148 /* Use ltt_time_to_double and ltt_time_from_double to check for lack
151 static inline LttTime
ltt_time_mul(LttTime t1
, double d
)
155 double time_double
= ltt_time_to_double(t1
);
157 time_double
= time_double
* d
;
159 res
= ltt_time_from_double(time_double
);
164 /* What is that ? (Mathieu) */
171 sec
= t1
.tv_sec
/ (double)d
;
173 res
.tv_nsec
= t1
.tv_nsec
/ (double)d
+ (sec
- res
.tv_sec
) *
174 NANOSECONDS_PER_SECOND
;
175 res
.tv_sec
+= res
.tv_nsec
/ NANOSECONDS_PER_SECOND
;
176 res
.tv_nsec
%= NANOSECONDS_PER_SECOND
;
183 /* Use ltt_time_to_double and ltt_time_from_double to check for lack
186 static inline LttTime
ltt_time_div(LttTime t1
, double d
)
190 double time_double
= ltt_time_to_double(t1
);
192 time_double
= time_double
/ d
;
194 res
= ltt_time_from_double(time_double
);
203 sec
= t1
.tv_sec
/ (double)f
;
205 res
.tv_nsec
= t1
.tv_nsec
/ (double)f
+ (sec
- res
.tv_sec
) *
206 NANOSECONDS_PER_SECOND
;
207 res
.tv_sec
+= res
.tv_nsec
/ NANOSECONDS_PER_SECOND
;
208 res
.tv_nsec
%= NANOSECONDS_PER_SECOND
;
214 static inline guint64
ltt_time_to_uint64(LttTime t1
)
216 return (((guint64
)t1
.tv_sec
*LTT_TIME_UINT_SHIFT_CONST
) << LTT_TIME_UINT_SHIFT
)
217 + (guint64
)t1
.tv_nsec
;
221 #define MAX_TV_SEC_TO_UINT64 0x3FFFFFFFFFFFFFFFULL
223 /* The likely branch is with sec != 0, because most events in a bloc
224 * will be over 1s from the block start. (see tracefile.c)
226 static inline LttTime
ltt_time_from_uint64(guint64 t1
)
228 /* We lose precision if tv_sec is > than (2^62)-1
231 g_assert(t1
<= MAX_TV_SEC_TO_UINT64
);
232 if(t1
> MAX_TV_SEC_TO_UINT64
)
233 g_warning("Conversion from uint64 to non precise LttTime");
236 //if(unlikely(t1 >= NANOSECONDS_PER_SECOND)) {
237 if(likely(t1
>>LTT_TIME_UINT_SHIFT
>= LTT_TIME_UINT_SHIFT_CONST
)) {
238 //res.tv_sec = t1/NANOSECONDS_PER_SECOND;
239 res
.tv_sec
= (t1
>>LTT_TIME_UINT_SHIFT
)
240 /LTT_TIME_UINT_SHIFT_CONST
; // acceleration
241 res
.tv_nsec
= (t1
- res
.tv_sec
*NANOSECONDS_PER_SECOND
);
244 res
.tv_nsec
= (guint32
)t1
;