gcc/ada/libgnat/s-bignum.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                       S Y S T E M . B I G N U M S                        --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --            Copyright (C) 2012-2020, Free Software Foundation, Inc.       --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This package provides arbitrary precision signed integer arithmetic for
  33 --  use in computing intermediate values in expressions for the case where
  34 --  pragma Overflow_Check (Eliminated) is in effect.
  35
  36 --  Note that we cannot use a straight instantiation of System.Generic_Bignums
  37 --  because the rtsfind mechanism is not ready to handle instantiations.
  38
  39 package System.Bignums is
  40    pragma Preelaborate;
  41
  42    type Bignum is private;
  43
  44    function Big_Add (X, Y : Bignum) return Bignum;  --  "+"
  45    function Big_Sub (X, Y : Bignum) return Bignum;  --  "-"
  46    function Big_Mul (X, Y : Bignum) return Bignum;  --  "*"
  47    function Big_Div (X, Y : Bignum) return Bignum;  --  "/"
  48    function Big_Exp (X, Y : Bignum) return Bignum;  --  "**"
  49    function Big_Mod (X, Y : Bignum) return Bignum;  --  "mod"
  50    function Big_Rem (X, Y : Bignum) return Bignum;  --  "rem"
  51    function Big_Neg (X    : Bignum) return Bignum;  --  "-"
  52    function Big_Abs (X    : Bignum) return Bignum;  --  "abs"
  53    --  Perform indicated arithmetic operation on bignum values. No exception
  54    --  raised except for Div/Mod/Rem by 0 which raises Constraint_Error with
  55    --  an appropriate message.
  56
  57    function Big_EQ  (X, Y : Bignum) return Boolean;  -- "="
  58    function Big_NE  (X, Y : Bignum) return Boolean;  -- "/="
  59    function Big_GE  (X, Y : Bignum) return Boolean;  -- ">="
  60    function Big_LE  (X, Y : Bignum) return Boolean;  -- "<="
  61    function Big_GT  (X, Y : Bignum) return Boolean;  --  ">"
  62    function Big_LT  (X, Y : Bignum) return Boolean;  --  "<"
  63    --  Perform indicated comparison on bignums, returning result as Boolean.
  64    --  No exception raised for any input arguments.
  65
  66    function Bignum_In_LLI_Range (X : Bignum) return Boolean;
  67    --  Returns True if the Bignum value is in the range of Long_Long_Integer,
  68    --  so that a call to From_Bignum is guaranteed not to raise an exception.
  69
  70    function To_Bignum (X : Long_Long_Integer) return Bignum;
  71    --  Convert Long_Long_Integer to Bignum. No exception can be raised for any
  72    --  input argument.
  73
  74    function From_Bignum (X : Bignum) return Long_Long_Integer;
  75    --  Convert Bignum to Long_Long_Integer. Constraint_Error raised with
  76    --  appropriate message if value is out of range of Long_Long_Integer.
  77
  78 private
  79
  80    type Bignum is new System.Address;
  81
  82    pragma Inline (Big_Add);
  83    pragma Inline (Big_Sub);
  84    pragma Inline (Big_Mul);
  85    pragma Inline (Big_Div);
  86    pragma Inline (Big_Exp);
  87    pragma Inline (Big_Mod);
  88    pragma Inline (Big_Rem);
  89    pragma Inline (Big_Neg);
  90    pragma Inline (Big_Abs);
  91    pragma Inline (Big_EQ);
  92    pragma Inline (Big_NE);
  93    pragma Inline (Big_GE);
  94    pragma Inline (Big_LE);
  95    pragma Inline (Big_GT);
  96    pragma Inline (Big_LT);
  97    pragma Inline (Bignum_In_LLI_Range);
  98    pragma Inline (To_Bignum);
  99    pragma Inline (From_Bignum);
 100
 101 end System.Bignums;