RTEMS time.h additions

[Eric Norum]

Joel Sherrill (joel@oarcorp.com) asked me to forward this to you.

Attached is a patch to rtems/sys/time.h in newlib.   It just adds some
convenience macros for manipulating timeval structures.  These macros
are now a standard part of FreeBSD so I'd like to have them part of
newlib, too.

-- 
Eric Norum                                 eric@cls.usask.ca
Canadian Light Source                      Phone: (306) 966-6308
University of Saskatchewan                 FAX:   (306) 966-6058
Saskatoon, Canada.
diff -ur /tmp/rttools/newlib-1.8.2/newlib/libc/sys/rtems/sys/time.h newlib-1.8.2/newlib/libc/sys/rtems/sys/time.h
--- /tmp/rttools/newlib-1.8.2/newlib/libc/sys/rtems/sys/time.h	Thu Nov 18 16:34:26 1999
+++ newlib-1.8.2/newlib/libc/sys/rtems/sys/time.h	Sun Apr 23 12:08:59 2000
@@ -65,6 +65,33 @@
   struct timezone *tzp
 );
 
+/* Convenience macros for operations on timevals.
+   NOTE: `timercmp' does not work for >= or <=.  */
+#define	timerisset(tvp)		((tvp)->tv_sec || (tvp)->tv_usec)
+#define	timerclear(tvp)		((tvp)->tv_sec = (tvp)->tv_usec = 0)
+#define	timercmp(a, b, CMP) 						      \
+  (((a)->tv_sec == (b)->tv_sec) ? 					      \
+   ((a)->tv_usec CMP (b)->tv_usec) : 					      \
+   ((a)->tv_sec CMP (b)->tv_sec))
+#define	timeradd(a, b, result)						      \
+  do {									      \
+    (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;					      \
+      }									      \
+  } while (0)
+#define	timersub(a, b, result)						      \
+  do {									      \
+    (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;					      \
+    }									      \
+  } while (0)
 #ifdef __cplusplus
 }
 #endif