timeval-utils.h: New file.

	include/
	* timeval-utils.h: New file.

	libiberty/
	* timeval-utils.c: New file.
	* Makefile.in (CFILES): Add it.
	(REQUIRED_OFILES): Add timeval-utils.$(objext).
	(INSTALLED_HEADERS): Add timeval-utils.h.
	(timeval-utils.$(objext)): Add rule.

From-SVN: r179319

include/ChangeLog

 2011-09-28  Doug Evans  <dje@google.com>
 
+	* timeval-utils.h: New file.
+
 	* libiberty.h (countargv): Declare.
 
 2011-09-26  Cary Coutant  <ccoutant@google.com>

include/timeval-utils.h

+/* Basic struct timeval utilities.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+This file is part of the libiberty library.
+Libiberty is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+Libiberty is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with libiberty; see the file COPYING.LIB.  If not,
+write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+#ifndef TIMEVAL_UTILS_H
+#define TIMEVAL_UTILS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/* forward decl */
+struct timeval;
+
+extern void timeval_add (struct timeval *result,
+			 const struct timeval *a, const struct timeval *b);
+
+extern void timeval_sub (struct timeval *result,
+			 const struct timeval *a, const struct timeval *b);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* TIMEVAL_UTILS_H */

libiberty/ChangeLog

 2011-09-28  Doug Evans  <dje@google.com>
 
+	* timeval-utils.c: New file.
+	* Makefile.in (CFILES): Add it.
+	(REQUIRED_OFILES): Add timeval-utils.$(objext).
+	(INSTALLED_HEADERS): Add timeval-utils.h.
+	(timeval-utils.$(objext)): Add rule.
+
 	* argv.c (countargv): New function.
 
 2011-09-23  Cary Coutant  <ccoutant@google.com>

libiberty/timeval-utils.c

+/* Basic struct timeval utilities.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+This file is part of the libiberty library.
+Libiberty is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public
+License as published by the Free Software Foundation; either
+version 2 of the License, or (at your option) any later version.
+
+Libiberty is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with libiberty; see the file COPYING.LIB.  If not,
+write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+#include "config.h"
+
+/* On some systems (such as WindISS), you must include <sys/types.h>
+   to get the definition of "time_t" before you include <time.h>.  */
+#include <sys/types.h>
+
+#ifdef TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# if HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  ifdef HAVE_TIME_H
+#   include <time.h>
+#  endif
+# endif
+#endif
+
+#include "timeval-utils.h"
+
+/* 
+
+@deftypefn Extension void timeval_add (struct timeval *@var{a}, @
+  struct timeval *@var{b}, struct timeval *@var{result})
+
+Adds @var{a} to @var{b} and stores the result in @var{result}.
+
+@end deftypefn
+
+*/ 
+
+void
+timeval_add (struct timeval *result,
+	     const struct timeval *a, const struct timeval *b)
+{
+  result->tv_sec = a->tv_sec + b->tv_sec;
+  result->tv_usec = a->tv_usec + b->tv_usec;
+  if (result->tv_usec >= 1000000)
+    {
+      ++result->tv_sec;
+      result->tv_usec -= 1000000;
+    }
+}
+
+/* 
+
+@deftypefn Extension void timeval_sub (struct timeval *@var{a}, @
+  struct timeval *@var{b}, struct timeval *@var{result})
+
+Subtracts @var{b} from @var{a} and stores the result in @var{result}.
+
+@end deftypefn
+
+*/ 
+
+void
+timeval_sub (struct timeval *result,
+	     const struct timeval *a, const struct timeval *b)
+{
+  result->tv_sec = a->tv_sec - b->tv_sec;
+  result->tv_usec = a->tv_usec - b->tv_usec;
+  if (result->tv_usec < 0)
+    {
+      --result->tv_sec;
+      result->tv_usec += 1000000;
+    }
+}