------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUNTIME COMPONENTS                          --
--                                                                          --
--                        S Y S T E M . X P _ B M L                         --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--                            $Revision: 1.1 $                              --
--                                                                          --
--           Copyright (c) 1992,1993,1994 NYU, All Rights Reserved          --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. --
--                                                                          --
------------------------------------------------------------------------------

function System.Xp_BML
  (Left  : Long_Long_Unsigned;
   Right : Natural)
   return  Long_Long_Unsigned
is
   Result : Long_Long_Unsigned := 1;
   Factor : Long_Long_Unsigned := Left;
   Exp    : Natural := Right;

begin
   --  We use the standard logarithmic approach, Exp gets shifted right
   --  testing successive low order bits and Factor is the value of the
   --  base raised to the next power of 2.

   --  Note: it is not worth special casing the cases of base values -1,0,+1
   --  since the expander does this when the base is a literal, and other
   --  cases will be extremely rare.

   while Exp /= 0 loop
      if Exp rem 2 /= 0 then
         Result := Result * Factor;
      end if;

      Factor := Factor * Factor;
      Exp := Exp / 2;
   end loop;

   return Result;

end System.Xp_BML;
