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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . G E N E R I C _ B I G N U M S --
-- --
-- S p e c --
-- --
-- Copyright (C) 2012-2022, 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. --
-- --
------------------------------------------------------------------------------
-- This package provides arbitrary precision signed integer arithmetic
-- and can be used either built into the compiler via System.Bignums or to
-- implement a default version of Ada.Numerics.Big_Numbers.Big_Integers.
with Interfaces;
with System.Shared_Bignums;
generic
type Big_Integer is private;
with function Allocate_Big_Integer
(D : Shared_Bignums.Digit_Vector; Neg : Boolean) return Big_Integer;
-- Allocate Bignum value with the given contents
with procedure Free_Big_Integer (X : in out Big_Integer);
-- Free the memory associated with X
with function To_Bignum
(X : aliased in out Big_Integer) return Shared_Bignums.Bignum;
-- Convert the given Big_Integer to a Bignum
package System.Generic_Bignums is
pragma Preelaborate;
subtype Bignum is Shared_Bignums.Bignum;
-- Note that this package never shares an allocated Big_Integer value, so
-- so for example for X + 0, a copy of X is returned, not X itself.
-- Note: none of the subprograms in this package modify the Bignum_Data
-- records referenced by Bignum arguments of mode IN.
function Big_Add (X, Y : Bignum) return Big_Integer; -- "+"
function Big_Sub (X, Y : Bignum) return Big_Integer; -- "-"
function Big_Mul (X, Y : Bignum) return Big_Integer; -- "*"
function Big_Div (X, Y : Bignum) return Big_Integer; -- "/"
function Big_Exp (X, Y : Bignum) return Big_Integer; -- "**"
function Big_Mod (X, Y : Bignum) return Big_Integer; -- "mod"
function Big_Rem (X, Y : Bignum) return Big_Integer; -- "rem"
function Big_Neg (X : Bignum) return Big_Integer; -- "-"
function Big_Abs (X : Bignum) return Big_Integer; -- "abs"
-- Perform indicated arithmetic operation on bignum values. No exception
-- raised except for Div/Mod/Rem by 0 which raises Constraint_Error with
-- an appropriate message.
function Big_And (X, Y : Bignum) return Big_Integer; -- "and"
function Big_Or (X, Y : Bignum) return Big_Integer; -- "or"
-- Perform indicated bitwise operation on big num values.
-- The negative flags of X and Y are also combined.
function Big_Shift_Left (X : Bignum; Amount : Natural) return Big_Integer;
function Big_Shift_Right (X : Bignum; Amount : Natural) return Big_Integer;
-- Perform indicated bitwise operation on big num values.
-- Constraint_Error is raised if X is negative.
function Big_EQ (X, Y : Bignum) return Boolean; -- "="
function Big_NE (X, Y : Bignum) return Boolean; -- "/="
function Big_GE (X, Y : Bignum) return Boolean; -- ">="
function Big_LE (X, Y : Bignum) return Boolean; -- "<="
function Big_GT (X, Y : Bignum) return Boolean; -- ">"
function Big_LT (X, Y : Bignum) return Boolean; -- "<"
-- Perform indicated comparison on bignums, returning result as Boolean.
-- No exception raised for any input arguments.
function Bignum_In_LLI_Range (X : Bignum) return Boolean;
-- Returns True if the Bignum value is in the range of Long_Long_Integer,
-- so that a call to From_Bignum is guaranteed not to raise an exception.
function To_Bignum (X : Long_Long_Integer) return Big_Integer;
-- Convert Long_Long_Integer to a big integer. No exception can be raised
-- for any input argument.
function To_Bignum (X : Long_Long_Long_Integer) return Big_Integer;
-- Convert Long_Long_Long_Integer to a big integer. No exception can be
-- raised.
function To_Bignum (X : Interfaces.Unsigned_64) return Big_Integer;
-- Convert Unsigned_64 to a big integer. No exception can be raised for any
-- input argument.
function To_Bignum (X : Interfaces.Unsigned_128) return Big_Integer;
-- Convert Unsigned_128 to a big integer. No exception can be raised for
-- any input argument.
function From_Bignum (X : Bignum) return Long_Long_Integer;
-- Convert Bignum to Long_Long_Integer. Constraint_Error raised with
-- appropriate message if value is out of range of Long_Long_Integer.
function To_String
(X : Bignum; Width : Natural := 0; Base : Positive := 10)
return String;
-- Return the image of X, based on the given Width and Base, as defined
-- in the RM for Ada.Text_IO. Base should really be in the range 2 .. 16.
function Is_Zero (X : Bignum) return Boolean;
-- Return True if X = 0
end System.Generic_Bignums;