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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . V A L _ R E A L --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2020, 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.Float_Control;
with System.Unsigned_Types; use System.Unsigned_Types;
with System.Val_Util; use System.Val_Util;
with System.Value_R;
package body System.Val_Real is
package Impl is new Value_R (Long_Long_Unsigned, Floating => True);
function Integer_to_Real
(Str : String;
Val : Long_Long_Unsigned;
Base : Unsigned;
Scale : Integer;
Minus : Boolean) return Long_Long_Float;
-- Convert the real value from integer to real representation
---------------------
-- Integer_to_Real --
---------------------
function Integer_to_Real
(Str : String;
Val : Long_Long_Unsigned;
Base : Unsigned;
Scale : Integer;
Minus : Boolean) return Long_Long_Float
is
pragma Unsuppress (Range_Check);
R_Val : Long_Long_Float;
begin
-- We call the floating-point processor reset routine so we can be sure
-- that the processor is properly set for conversions. This is notably
-- needed on Windows, where calls to the operating system randomly reset
-- the processor into 64-bit mode.
System.Float_Control.Reset;
-- Compute the final value
R_Val := Long_Long_Float (Val) * Long_Long_Float (Base) ** Scale;
-- Finally deal with initial minus sign, note that this processing is
-- done even if Uval is zero, so that -0.0 is correctly interpreted.
return (if Minus then -R_Val else R_Val);
exception
when Constraint_Error => Bad_Value (Str);
end Integer_to_Real;
---------------
-- Scan_Real --
---------------
function Scan_Real
(Str : String;
Ptr : not null access Integer;
Max : Integer)
return Long_Long_Float
is
Base : Unsigned;
Scale : Integer;
Extra : Unsigned;
Minus : Boolean;
Val : Long_Long_Unsigned;
begin
Val := Impl.Scan_Raw_Real (Str, Ptr, Max, Base, Scale, Extra, Minus);
return Integer_to_Real (Str, Val, Base, Scale, Minus);
end Scan_Real;
----------------
-- Value_Real --
----------------
function Value_Real (Str : String) return Long_Long_Float is
Base : Unsigned;
Scale : Integer;
Extra : Unsigned;
Minus : Boolean;
Val : Long_Long_Unsigned;
begin
Val := Impl.Value_Raw_Real (Str, Base, Scale, Extra, Minus);
return Integer_to_Real (Str, Val, Base, Scale, Minus);
end Value_Real;
end System.Val_Real;
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