gcc/testsuite/ada/acats/tests/c3/c35902d.ada

   1 -- C35902D.ADA
   2
   3 --                             Grant of Unlimited Rights
   4 --
   5 --     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,
   6 --     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained
   7 --     unlimited rights in the software and documentation contained herein.
   8 --     Unlimited rights are defined in DFAR 252.227-7013(a)(19).  By making
   9 --     this public release, the Government intends to confer upon all
  10 --     recipients unlimited rights  equal to those held by the Government.
  11 --     These rights include rights to use, duplicate, release or disclose the
  12 --     released technical data and computer software in whole or in part, in
  13 --     any manner and for any purpose whatsoever, and to have or permit others
  14 --     to do so.
  15 --
  16 --                                    DISCLAIMER
  17 --
  18 --     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR
  19 --     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED
  20 --     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
  21 --     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE
  22 --     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
  23 --     PARTICULAR PURPOSE OF SAID MATERIAL.
  24 --*
  25 -- CHECK THAT THE BINARY POINT IN THE MANTISSA OF A FIXED POINT NUMBER
  26 -- CAN LIE OUTSIDE THE MANTISSA (EITHER TO THE LEFT OR TO THE RIGHT).
  27
  28 -- WRG 7/18/86
  29
  30 WITH REPORT; USE REPORT;
  31 WITH SYSTEM; USE SYSTEM;
  32 PROCEDURE C35902D IS
  33
  34 BEGIN
  35
  36      TEST ("C35902D", "CHECK THAT THE BINARY POINT IN THE MANTISSA " &
  37                       "OF A FIXED POINT NUMBER CAN LIE OUTSIDE THE " &
  38                       "MANTISSA (EITHER TO THE LEFT OR TO THE RIGHT)");
  39
  40      COMMENT ("VALUE OF SYSTEM.MAX_MANTISSA IS" &
  41               POSITIVE'IMAGE(MAX_MANTISSA) );
  42
  43   A: DECLARE
  44
  45           RS : CONSTANT := 2.0;
  46
  47           TYPE ONE_TO_THE_RIGHT IS
  48                DELTA RS
  49                RANGE -(2.0 ** (MAX_MANTISSA+1) ) ..
  50                        2.0 ** (MAX_MANTISSA+1);
  51                -- THE BINARY POINT IS ONE PLACE TO THE RIGHT OF THE
  52                -- LARGEST POSSIBLE MANTISSA.
  53
  54           R1, R2 : ONE_TO_THE_RIGHT;
  55
  56      BEGIN
  57
  58           R1 := RS;
  59           FOR I IN POSITIVE RANGE 1 .. MAX_MANTISSA - 1 LOOP
  60                R1 := R1 * IDENT_INT (2);
  61           END LOOP;
  62           R2 := R1 - RS;
  63           R2 := R2 + R1;
  64           -- AT THIS POINT, R2 SHOULD EQUAL ONE_TO_THE_RIGHT'LARGE.
  65           R2 := -R2;
  66           R2 := R2 + (R1 - RS);
  67           FOR I IN POSITIVE RANGE 1 .. MAX_MANTISSA - 1 LOOP
  68                R2 := R2 / IDENT_INT (2);
  69           END LOOP;
  70           IF R2 /= -RS THEN
  71                FAILED ("IDENTITY-PRESERVING OPERATIONS ARE FLAKY - A");
  72           END IF;
  73
  74      EXCEPTION
  75
  76           WHEN OTHERS =>
  77                FAILED ("EXCEPTION RAISED - A");
  78
  79      END A;
  80
  81   B: DECLARE
  82
  83           LS : CONSTANT := 2.0 ** (-(MAX_MANTISSA+1) );
  84
  85           TYPE ONE_TO_THE_LEFT IS
  86                DELTA LS
  87                RANGE -(2.0 ** (-1) ) ..
  88                        2.0 ** (-1);
  89                -- THE BINARY POINT IS ONE PLACE TO THE LEFT OF THE
  90                -- LARGEST POSSIBLE MANTISSA.
  91
  92           L1, L2 : ONE_TO_THE_LEFT;
  93
  94      BEGIN
  95
  96           L1 := LS;
  97           FOR I IN POSITIVE RANGE 1 .. MAX_MANTISSA - 1 LOOP
  98                L1 := L1 * IDENT_INT (2);
  99           END LOOP;
 100           L2 := L1 - LS;
 101           L2 := L2 + L1;
 102           -- AT THIS POINT, L2 SHOULD EQUAL ONE_TO_THE_LEFT'LARGE.
 103           L2 := -L2;
 104           L2 := L2 + (L1 - LS);
 105           FOR I IN POSITIVE RANGE 1 .. MAX_MANTISSA - 1 LOOP
 106                L2 := L2 / IDENT_INT (2);
 107           END LOOP;
 108           IF L2 /= -LS THEN
 109                FAILED ("IDENTITY-PRESERVING OPERATIONS ARE FLAKY - B");
 110           END IF;
 111
 112      EXCEPTION
 113
 114           WHEN OTHERS =>
 115                FAILED ("EXCEPTION RAISED - B");
 116
 117      END B;
 118
 119      RESULT;
 120
 121 END C35902D;