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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . B I G N U M S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2012-2024, 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. --
-- --
------------------------------------------------------------------------------
with System.Generic_Bignums;
with System.Secondary_Stack; use System.Secondary_Stack;
with System.Shared_Bignums; use System.Shared_Bignums;
with System.Storage_Elements; use System.Storage_Elements;
package body System.Bignums is
function Allocate_Bignum (D : Digit_Vector; Neg : Boolean) return Bignum;
-- Allocate Bignum value with the given contents
procedure Free_Bignum (X : in out Bignum) is null;
-- No op when using the secondary stack
function To_Bignum (X : aliased in out Bignum) return Bignum is (X);
---------------------
-- Allocate_Bignum --
---------------------
function Allocate_Bignum (D : Digit_Vector; Neg : Boolean) return Bignum is
Addr : aliased Address;
begin
-- Note: The approach used here is designed to avoid strict aliasing
-- warnings that appeared previously using unchecked conversion.
SS_Allocate (Addr, Storage_Offset (4 + 4 * D'Length));
declare
B : Bignum;
for B'Address use Addr'Address;
pragma Import (Ada, B);
BD : Bignum_Data (D'Length);
for BD'Address use Addr;
pragma Import (Ada, BD);
-- Expose a writable view of discriminant BD.Len so that we can
-- initialize it. We need to use the exact layout of the record
-- to ensure that the Length field has 24 bits as expected.
type Bignum_Data_Header is record
Len : Length;
Neg : Boolean;
end record;
for Bignum_Data_Header use record
Len at 0 range 0 .. 23;
Neg at 3 range 0 .. 7;
end record;
BDH : Bignum_Data_Header;
for BDH'Address use BD'Address;
pragma Import (Ada, BDH);
pragma Assert (BDH.Len'Size = BD.Len'Size);
begin
BDH.Len := D'Length;
BDH.Neg := Neg;
B.D := D;
return B;
end;
end Allocate_Bignum;
package Sec_Stack_Bignums is new System.Generic_Bignums
(Bignum, Allocate_Bignum, Free_Bignum, To_Bignum);
function Big_Add (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Add;
function Big_Sub (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Sub;
function Big_Mul (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Mul;
function Big_Div (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Div;
function Big_Exp (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Exp;
function Big_Mod (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Mod;
function Big_Rem (X, Y : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Rem;
function Big_Neg (X : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Neg;
function Big_Abs (X : Bignum) return Bignum
renames Sec_Stack_Bignums.Big_Abs;
function Big_EQ (X, Y : Bignum) return Boolean
renames Sec_Stack_Bignums.Big_EQ;
function Big_NE (X, Y : Bignum) return Boolean
renames Sec_Stack_Bignums.Big_NE;
function Big_GE (X, Y : Bignum) return Boolean
renames Sec_Stack_Bignums.Big_GE;
function Big_LE (X, Y : Bignum) return Boolean
renames Sec_Stack_Bignums.Big_LE;
function Big_GT (X, Y : Bignum) return Boolean
renames Sec_Stack_Bignums.Big_GT;
function Big_LT (X, Y : Bignum) return Boolean
renames Sec_Stack_Bignums.Big_LT;
function Bignum_In_LLI_Range (X : Bignum) return Boolean
renames Sec_Stack_Bignums.Bignum_In_LLI_Range;
function To_Bignum (X : Long_Long_Integer) return Bignum
renames Sec_Stack_Bignums.To_Bignum;
function From_Bignum (X : Bignum) return Long_Long_Integer
renames Sec_Stack_Bignums.From_Bignum;
end System.Bignums;
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