loop.c (strength_reduce): Fix sign of giv lifetime calculation for givs made from biv increments.

	* loop.c (strength_reduce): Fix sign of giv lifetime calculation
	for givs made from biv increments.

From-SVN: r30927

gcc/ChangeLog

+Tue Dec 14 18:13:32 1999  J"orn Rennecke <amylaar@cygnus.co.uk>
+
+	* loop.c (strength_reduce): Fix sign of giv lifetime calculation
+	for givs made from biv increments.
+
 Tue Dec 14 08:11:27 1999  Richard Henderson  <rth@cygnus.com>
 
 	* configure.in (alpha-osf, alpha-linux): Handle ev6[78].

gcc/loop.c

@@ -4480,7 +4480,7 @@ strength_reduce (scan_start, end, loop_top, insn_count,
 		}
     
 	      v->last_use = last_use_insn;
-	      v->lifetime = INSN_LUID (v->insn) - INSN_LUID (last_use_insn);
+	      v->lifetime = INSN_LUID (last_use_insn) - INSN_LUID (v->insn);
 	      /* If the lifetime is zero, it means that this register is really
 		 a dead store.  So mark this as a giv that can be ignored.
 		 This will not prevent the biv from being eliminated.  */