(Fexpt): Use floats for negative exponent.

src/ChangeLog

+2005-08-09  Thien-Thi Nguyen  <ttn@gnu.org>
+
+	* floatfns.c (Fexpt): Use floats for negative exponent.
+
 2005-08-08  Jan Dj,Ad(Brv  <jan.h.d@swipnet.se>
 	* gtkutil.c (xg_modify_menubar_widgets): Remove semicolon that

src/floatfns.c

@@ -461,7 +461,8 @@ DEFUN ("expt", Fexpt, Sexpt, 2, 2, 0,
   CHECK_NUMBER_OR_FLOAT (arg1);
   CHECK_NUMBER_OR_FLOAT (arg2);
   if (INTEGERP (arg1)     /* common lisp spec */
-      && INTEGERP (arg2))   /* don't promote, if both are ints */
+      && INTEGERP (arg2)   /* don't promote, if both are ints, and */
+      && 0 <= XINT (arg2)) /* we are sure the result is not fractional */
     {				/* this can be improved by pre-calculating */
       EMACS_INT acc, x, y;	/* some binary powers of x then accumulating */
       Lisp_Object val;