Fix cygwin toolchain build failure reported by Geoffrey Noer.

	* unroll.c (loop_iterations): Only call loop_find_equiv_value if we
	have a REG or SUBREG.

From-SVN: r25643

gcc/ChangeLog

+Mon Mar  8 16:04:44 1999  Jim Wilson  <wilson@cygnus.com>
+
+	* unroll.c (loop_iterations): Only call loop_find_equiv_value if we
+	have a REG or SUBREG.
+
 Mon Mar  8 15:27:42 1999  Jeffrey A Law  (law@cygnus.com)
 
 	* flow.c (merge_blocks_nomove): For HAVE_cc0 targets, make sure

gcc/unroll.c

@@ -3830,7 +3830,11 @@ loop_iterations (loop_start, loop_end, loop_info)
 
   if (GET_CODE (increment) != CONST_INT)
     {
-      increment = loop_find_equiv_value (loop_start, increment);
+      /* If we have a REG, check to see if REG holds a constant value.  */
+      /* ??? Other RTL, such as (neg (reg)) is possible here, but it isn't
+	 clear if it is worthwhile to try to handle such RTL.  */
+      if (GET_CODE (increment) == REG || GET_CODE (increment) == SUBREG)
+	increment = loop_find_equiv_value (loop_start, increment);
 
       if (GET_CODE (increment) != CONST_INT)
 	{