fix compare
[lttv.git] / ltt / branches / poly / ltt / time.h
CommitLineData
9c312311 1/* This file is part of the Linux Trace Toolkit trace reading library
2 * Copyright (C) 2003-2004 Michel Dagenais
1b44b0b5 3 * 2005 Mathieu Desnoyers
9c312311 4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License Version 2.1 as published by the Free Software Foundation.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
18 */
19
308711e5 20#ifndef LTT_TIME_H
21#define LTT_TIME_H
22
a00149f6 23#include <glib.h>
1d1df11d 24#include <ltt/compiler.h>
0a2cbfbe 25#include <math.h>
308711e5 26
27typedef struct _LttTime {
28 unsigned long tv_sec;
29 unsigned long tv_nsec;
30} LttTime;
31
32
0aa6c3a1 33#define NANOSECONDS_PER_SECOND 1000000000
7db8c19d 34
35/* We give the DIV and MUL constants so we can always multiply, for a
36 * division as well as a multiplication of NANOSECONDS_PER_SECOND */
62b45a6e 37/* 2^30/1.07374182400631629848 = 1000000000.0 */
7db8c19d 38#define DOUBLE_SHIFT_CONST_DIV 1.07374182400631629848
62b45a6e 39#define DOUBLE_SHIFT 30
40
7db8c19d 41/* 2^30*0.93132257461547851562 = 1000000000.0000000000 */
42#define DOUBLE_SHIFT_CONST_MUL 0.93132257461547851562
43
44
62b45a6e 45/* 1953125 * 2^9 = NANOSECONDS_PER_SECOND */
46#define LTT_TIME_UINT_SHIFT_CONST 1953125
47#define LTT_TIME_UINT_SHIFT 9
48
308711e5 49
0aa6c3a1 50static const LttTime ltt_time_zero = { 0, 0 };
308711e5 51
18206708 52static const LttTime ltt_time_one = { 0, 1 };
53
0aa6c3a1 54static const LttTime ltt_time_infinite = { G_MAXUINT, NANOSECONDS_PER_SECOND };
308711e5 55
56static inline LttTime ltt_time_sub(LttTime t1, LttTime t2)
57{
58 LttTime res;
59 res.tv_sec = t1.tv_sec - t2.tv_sec;
f3167549 60 res.tv_nsec = t1.tv_nsec - t2.tv_nsec;
1d1df11d 61 /* unlikely : given equal chance to be anywhere in t1.tv_nsec, and
62 * higher probability of low value for t2.tv_sec, we will habitually
63 * not wrap.
64 */
65 if(unlikely(t1.tv_nsec < t2.tv_nsec)) {
308711e5 66 res.tv_sec--;
f3167549 67 res.tv_nsec += NANOSECONDS_PER_SECOND;
308711e5 68 }
69 return res;
70}
71
72
73static inline LttTime ltt_time_add(LttTime t1, LttTime t2)
74{
75 LttTime res;
308711e5 76 res.tv_nsec = t1.tv_nsec + t2.tv_nsec;
f3167549 77 res.tv_sec = t1.tv_sec + t2.tv_sec;
1d1df11d 78 /* unlikely : given equal chance to be anywhere in t1.tv_nsec, and
79 * higher probability of low value for t2.tv_sec, we will habitually
80 * not wrap.
81 */
82 if(unlikely(res.tv_nsec >= NANOSECONDS_PER_SECOND)) {
308711e5 83 res.tv_sec++;
84 res.tv_nsec -= NANOSECONDS_PER_SECOND;
85 }
86 return res;
87}
88
280f9968 89/* Fastest comparison : t1 > t2 */
308711e5 90static inline int ltt_time_compare(LttTime t1, LttTime t2)
91{
280f9968 92 int ret=0;
f0ceeaca 93 //if(likely(t1.tv_sec > t2.tv_sec)) ret = 1;
94 //else if(unlikely(t1.tv_sec < t2.tv_sec)) ret = -1;
95 //else if(likely(t1.tv_nsec > t2.tv_nsec)) ret = 1;
96 //else if(unlikely(t1.tv_nsec < t2.tv_nsec)) ret = -1;
ddf83b7f 97 if(likely((long)t1.tv_sec - (long)t2.tv_sec > 0)) ret = 1;
98 else if(unlikely((long)t1.tv_sec - (long)t2.tv_sec < 0)) ret = -1;
99 else if(likely((long)t1.tv_nsec - (long)t2.tv_nsec > 0)) ret = 1;
100 else if(unlikely((long)t1.tv_nsec - (long)t2.tv_nsec < 0)) ret = -1;
280f9968 101
102 return ret;
308711e5 103}
104
0aa6c3a1 105#define LTT_TIME_MIN(a,b) ((ltt_time_compare((a),(b)) < 0) ? (a) : (b))
106#define LTT_TIME_MAX(a,b) ((ltt_time_compare((a),(b)) > 0) ? (a) : (b))
107
8aee234c 108#define MAX_TV_SEC_TO_DOUBLE 0x7FFFFF
308711e5 109static inline double ltt_time_to_double(LttTime t1)
110{
8aee234c 111 /* We lose precision if tv_sec is > than (2^23)-1
112 *
113 * Max values that fits in a double (53 bits precision on normalised
114 * mantissa):
115 * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
116 *
117 * So we have 53-30 = 23 bits left for tv_sec.
118 * */
c74e0cf9 119#ifdef EXTRA_CHECK
0c5dbe3b 120 g_assert(t1.tv_sec <= MAX_TV_SEC_TO_DOUBLE);
8aee234c 121 if(t1.tv_sec > MAX_TV_SEC_TO_DOUBLE)
122 g_warning("Precision loss in conversion LttTime to double");
c74e0cf9 123#endif //EXTRA_CHECK
21ff84a0 124 return ((double)((guint64)t1.tv_sec<<DOUBLE_SHIFT)
7db8c19d 125 * (double)DOUBLE_SHIFT_CONST_MUL)
21ff84a0 126 + (double)t1.tv_nsec;
308711e5 127}
128
129
130static inline LttTime ltt_time_from_double(double t1)
131{
8aee234c 132 /* We lose precision if tv_sec is > than (2^23)-1
133 *
134 * Max values that fits in a double (53 bits precision on normalised
135 * mantissa):
136 * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
137 *
138 * So we have 53-30 = 23 bits left for tv_sec.
139 * */
c74e0cf9 140#ifdef EXTRA_CHECK
0c5dbe3b 141 g_assert(t1 <= MAX_TV_SEC_TO_DOUBLE);
8aee234c 142 if(t1 > MAX_TV_SEC_TO_DOUBLE)
143 g_warning("Conversion from non precise double to LttTime");
c74e0cf9 144#endif //EXTRA_CHECK
308711e5 145 LttTime res;
0ce58d10 146 //res.tv_sec = t1/(double)NANOSECONDS_PER_SECOND;
7db8c19d 147 res.tv_sec = (guint64)(t1 * DOUBLE_SHIFT_CONST_DIV) >> DOUBLE_SHIFT;
21ff84a0 148 res.tv_nsec = (t1 - (((guint64)res.tv_sec<<LTT_TIME_UINT_SHIFT))
62b45a6e 149 * LTT_TIME_UINT_SHIFT_CONST);
308711e5 150 return res;
151}
152
8d1e6362 153/* Use ltt_time_to_double and ltt_time_from_double to check for lack
154 * of precision.
155 */
156static inline LttTime ltt_time_mul(LttTime t1, double d)
157{
158 LttTime res;
159
160 double time_double = ltt_time_to_double(t1);
161
162 time_double = time_double * d;
163
164 res = ltt_time_from_double(time_double);
165
166 return res;
167
168#if 0
169 /* What is that ? (Mathieu) */
170 if(f == 0.0){
171 res.tv_sec = 0;
172 res.tv_nsec = 0;
173 }else{
174 double d;
175 d = 1.0/f;
176 sec = t1.tv_sec / (double)d;
177 res.tv_sec = sec;
178 res.tv_nsec = t1.tv_nsec / (double)d + (sec - res.tv_sec) *
179 NANOSECONDS_PER_SECOND;
180 res.tv_sec += res.tv_nsec / NANOSECONDS_PER_SECOND;
181 res.tv_nsec %= NANOSECONDS_PER_SECOND;
182 }
183 return res;
184#endif //0
185}
186
187
188/* Use ltt_time_to_double and ltt_time_from_double to check for lack
189 * of precision.
190 */
191static inline LttTime ltt_time_div(LttTime t1, double d)
192{
193 LttTime res;
194
195 double time_double = ltt_time_to_double(t1);
196
197 time_double = time_double / d;
198
199 res = ltt_time_from_double(time_double);
200
201 return res;
202
203
204#if 0
205 double sec;
206 LttTime res;
207
208 sec = t1.tv_sec / (double)f;
209 res.tv_sec = sec;
210 res.tv_nsec = t1.tv_nsec / (double)f + (sec - res.tv_sec) *
211 NANOSECONDS_PER_SECOND;
212 res.tv_sec += res.tv_nsec / NANOSECONDS_PER_SECOND;
213 res.tv_nsec %= NANOSECONDS_PER_SECOND;
214 return res;
215#endif //0
216}
217
62b45a6e 218
90ef7e4a 219static inline guint64 ltt_time_to_uint64(LttTime t1)
220{
709c30b4 221 return (((guint64)t1.tv_sec*LTT_TIME_UINT_SHIFT_CONST) << LTT_TIME_UINT_SHIFT)
62b45a6e 222 + (guint64)t1.tv_nsec;
90ef7e4a 223}
224
225
226#define MAX_TV_SEC_TO_UINT64 0x3FFFFFFFFFFFFFFFULL
62b45a6e 227
228/* The likely branch is with sec != 0, because most events in a bloc
229 * will be over 1s from the block start. (see tracefile.c)
230 */
90ef7e4a 231static inline LttTime ltt_time_from_uint64(guint64 t1)
232{
233 /* We lose precision if tv_sec is > than (2^62)-1
234 * */
c74e0cf9 235#ifdef EXTRA_CHECK
90ef7e4a 236 g_assert(t1 <= MAX_TV_SEC_TO_UINT64);
237 if(t1 > MAX_TV_SEC_TO_UINT64)
49f3c39e 238 g_warning("Conversion from uint64 to non precise LttTime");
c74e0cf9 239#endif //EXTRA_CHECK
90ef7e4a 240 LttTime res;
62b45a6e 241 //if(unlikely(t1 >= NANOSECONDS_PER_SECOND)) {
242 if(likely(t1>>LTT_TIME_UINT_SHIFT >= LTT_TIME_UINT_SHIFT_CONST)) {
243 //res.tv_sec = t1/NANOSECONDS_PER_SECOND;
244 res.tv_sec = (t1>>LTT_TIME_UINT_SHIFT)
245 /LTT_TIME_UINT_SHIFT_CONST; // acceleration
49f3c39e 246 res.tv_nsec = (t1 - res.tv_sec*NANOSECONDS_PER_SECOND);
247 } else {
248 res.tv_sec = 0;
249 res.tv_nsec = (guint32)t1;
250 }
90ef7e4a 251 return res;
252}
8d1e6362 253
308711e5 254#endif // LTT_TIME_H
This page took 0.059474 seconds and 4 git commands to generate.