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-- IMPDEFG.A

--

--                             Grant of Unlimited Rights

--

--     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,

--     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained

--     unlimited rights in the software and documentation contained herein.

--     Unlimited rights are defined in DFAR 252.227-7013(a)(19).  By making

--     this public release, the Government intends to confer upon all

--     recipients unlimited rights  equal to those held by the Government.

--     These rights include rights to use, duplicate, release or disclose the

--     released technical data and computer software in whole or in part, in

--     any manner and for any purpose whatsoever, and to have or permit others

--     to do so.

--

--                                    DISCLAIMER

--

--     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR

--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED

--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE

--     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE

--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A

--     PARTICULAR PURPOSE OF SAID MATERIAL.

--*

--

-- DESCRIPTION:

--     This package provides tailorable entities for a particular

--     implementation.  Each entity may be modified to suit the needs

--     of the implementation.  Default values are provided to act as

--     a guide.

--

--     The entities in this package are those which are used exclusively

--     in tests for Annex G (Numerics).

--

-- APPLICABILITY CRITERIA:

--     This package is only required for implementations validating the

--     Numerics Annex.

--

-- CHANGE HISTORY:

--     29 Jan 96   SAIC    Initial version for ACVC 2.1.

--

--!

package ImpDef.Annex_G is

--=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====--

   -- This function must return a "negative zero" value for implementations

   -- for which Float'Signed_Zeros is True.

   function Negative_Zero return Float;

--=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====--

end ImpDef.Annex_G;

     --==================================================================--

package body ImpDef.Annex_G is

--=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====--

   --  This function must return a negative zero value for implementations

   --  for which Float'Signed_Zeros is True.

   --  We generate the smallest normalized negative number, and divide by a

   --  few powers of two to obtain a number whose absolute value equals zero

   --  but whose sign is negative.

   function Negative_Zero return Float is

      negz : float := -1.0 *

         float (float'Machine_Radix)

            ** ( Float'Machine_Emin - Float'Machine_Mantissa);

   begin

      return negz / 8.0;

   end Negative_Zero;

--=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====-=====--

end ImpDef.Annex_G;