File : s-fatgen.ads
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-- --
-- GNAT COMPILER COMPONENTS --
-- --
5 -- S Y S T E M . F A T _ G E N --
-- --
-- S p e c --
-- --
-- $Revision: 1.10 $
10 -- --
-- Copyright (C) 1992-2001 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- --
15 -- ware Foundation; either version 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
30 -- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
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35
-- This generic package provides a target independent implementation of the
-- floating-point attributes that denote functions. The implementations here
-- are portable, but very slow. The runtime contains a set of instantiations
-- of this package for all predefined floating-point types, and these should
40 -- be replaced by efficient assembly language code where possible.
generic
type T is digits <>;
45 package System.Fat_Gen is
pragma Pure (Fat_Gen);
subtype UI is Integer;
-- The runtime representation of universal integer for the purposes of
50 -- this package is integer. The expander generates conversions for the
-- actual type used. For functions returning universal integer, there
-- is no problem, since the result always is in range of integer. For
-- input arguments, the expander has to do some special casing to deal
-- with the (very annoying!) cases of out of range values. If we used
55 -- Long_Long_Integer to represent universal, then there would be no
-- problem, but the resulting inefficiency would be annoying.
function Adjacent (X, Towards : T) return T;
60 function Ceiling (X : T) return T;
function Compose (Fraction : T; Exponent : UI) return T;
function Copy_Sign (Value, Sign : T) return T;
65
function Exponent (X : T) return UI;
function Floor (X : T) return T;
70 function Fraction (X : T) return T;
function Leading_Part (X : T; Radix_Digits : UI) return T;
function Machine (X : T) return T;
75
function Model (X : T) return T;
function Pred (X : T) return T;
80 function Remainder (X, Y : T) return T;
function Rounding (X : T) return T;
function Scaling (X : T; Adjustment : UI) return T;
85
function Succ (X : T) return T;
function Truncation (X : T) return T;
90 function Unbiased_Rounding (X : T) return T;
function Valid (X : access T) return Boolean;
-- This function checks if the object of type T referenced by X
-- is valid, and returns True/False accordingly. The parameter is
95 -- passed by reference (access) here, as the object of type T may
-- be an abnormal value that cannot be passed in a floating-point
-- register, and the whole point of 'Valid is to prevent exceptions.
private
100 pragma Inline (Machine);
pragma Inline (Model);
pragma Inline_Always (Valid);
end System.Fat_Gen;