------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--                      S Y S T E M . M A N T I S S A                       --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--         Copyright (C) 1996-2009 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 3,  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.                                     --
--                                                                          --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception,   --
-- version 3.1, as published by the Free Software Foundation.               --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

package body System.Mantissa is

   --------------------
   -- Mantissa_Value --
   --------------------

   function Mantissa_Value (First, Last : Integer) return Natural is
      Result : Natural := 0;

      Val : Integer := Integer'Max (abs First - 1, abs Last);
      --  Note: First-1 allows for twos complement largest neg number

   begin
      while Val /= 0 loop
         Val := Val / 2;
         Result := Result + 1;
      end loop;

      return Result;
   end Mantissa_Value;

end System.Mantissa;