fold-const (fold): Also simplify FLOOR_DIV_EXPR to EXACT_DIV_EXPR if...

        * fold-const (fold): Also simplify FLOOR_DIV_EXPR to EXACT_DIV_EXPR
        if the dividend is a multiple of the divisor.

From-SVN: r16181

gcc/ChangeLog

+Sun Oct 26 10:06:11 1997  Toon Moene  <toon@moene.indiv.nluug.nl>
+
+	* fold-const (fold): Also simplify FLOOR_DIV_EXPR to EXACT_DIV_EXPR
+	if the dividend is a multiple of the divisor.
+
 Sun Oct 26 09:21:40 1997  Jeffrey A Law  (law@cygnus.com)
 
 	* toplev.c (flag_rerun_loop_opt): New variable.

gcc/fold-const.c

@@ -4610,11 +4610,10 @@ fold (expr)
       /* If arg0 is a multiple of arg1, then rewrite to the fastest div
 	 operation, EXACT_DIV_EXPR.
 
-	 Note that only CEIL_DIV_EXPR is rewritten now, only because the
-	 others seem to be faster in some cases.  This is probably just
-	 due to more work being done to optimize others in expmed.c than on
-	 EXACT_DIV_EXPR.  */
-      if (code == CEIL_DIV_EXPR
+	 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
+	 At one time others generated faster code, it's not clear if they do
+	 after the last round to changes to the DIV code in expmed.c.  */
+      if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
 	  && multiple_of_p (type, arg0, arg1))
 	return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));