1 /*
2  * Copyright (C) 1991-1994,1996-2003,2005,2006,2009
3  *               Free Software Foundation, Inc.
4  *
5  * The GNU C Library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * The GNU C Library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with the GNU C Library; if not, write to the Free
17  * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18  * Boston, MA  02110-1301  USA
19  */
20 
21 #include <sys/time.h>
22 
23 #ifndef timersub
24 # define timersub(a, b, result)                      \
25   do {                                               \
26     (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;    \
27     (result)->tv_usec = (a)->tv_usec - (b)->tv_usec; \
28     if ((result)->tv_usec < 0) {                     \
29       --(result)->tv_sec;                            \
30       (result)->tv_usec += 1000000;                  \
31     }                                                \
32   } while (0)
33 #endif
34