```------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUNTIME COMPONENTS                          --
--                                                                          --
--                        S Y S T E M . E X P I N T                         --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2003 Free Software Foundation, Inc.          --
--                                                                          --
-- 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,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

package body System.Exp_Int is

-----------------
-- Exp_Integer --
-----------------

--  Note that negative exponents get a constraint error because the
--  subtype of the Right argument (the exponent) is Natural.

function Exp_Integer
(Left  : Integer;
Right : Natural)
return  Integer
is
Result : Integer := 1;
Factor : Integer := 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 base values -1, 0, +1 since
--  the expander does this when the base is a literal, and other cases
--  will be extremely rare.

if Exp /= 0 then
loop
if Exp rem 2 /= 0 then
declare
pragma Unsuppress (All_Checks);
begin
Result := Result * Factor;
end;
end if;

Exp := Exp / 2;
exit when Exp = 0;

declare
pragma Unsuppress (All_Checks);
begin
Factor := Factor * Factor;
end;
end loop;
end if;

return Result;
end Exp_Integer;

end System.Exp_Int;
```