| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . F A T _ G E N -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2014, 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 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 |
| -- be replaced by efficient assembly language code where possible. |
| |
| generic |
| type T is digits <>; |
| |
| package System.Fat_Gen is |
| pragma Pure; |
| |
| subtype UI is Integer; |
| -- The runtime representation of universal integer for the purposes of |
| -- 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 |
| -- 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; |
| |
| function Ceiling (X : T) return T; |
| |
| function Compose (Fraction : T; Exponent : UI) return T; |
| |
| function Copy_Sign (Value, Sign : T) return T; |
| |
| function Exponent (X : T) return UI; |
| |
| function Floor (X : T) return T; |
| |
| function Fraction (X : T) return T; |
| |
| function Leading_Part (X : T; Radix_Digits : UI) return T; |
| |
| function Machine (X : T) return T; |
| |
| function Machine_Rounding (X : T) return T; |
| |
| function Model (X : T) return T; |
| |
| function Pred (X : T) return T; |
| |
| function Remainder (X, Y : T) return T; |
| |
| function Rounding (X : T) return T; |
| |
| function Scaling (X : T; Adjustment : UI) return T; |
| |
| function Succ (X : T) return T; |
| |
| function Truncation (X : T) return T; |
| |
| function Unbiased_Rounding (X : T) return T; |
| |
| function Valid (X : not null 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 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. Note that the object of type T must |
| -- have the natural alignment for type T. |
| |
| type S is new String (1 .. T'Size / Character'Size); |
| type P is access all S with Storage_Size => 0; |
| -- Buffer and access types used to initialize temporaries for validity |
| -- checks, if the value to be checked has reverse scalar storage order, or |
| -- is not known to be properly aligned (for example it appears in a packed |
| -- record). In this case, we cannot call Valid since Valid assumes proper |
| -- full alignment. Instead, we copy the value to a temporary location using |
| -- type S (we cannot simply do a copy of a T value, because the value might |
| -- be invalid, in which case it might not be possible to copy it through a |
| -- floating point register). |
| |
| private |
| pragma Inline (Machine); |
| pragma Inline (Model); |
| |
| -- Note: previously the validity checking subprograms (Unaligned_Valid and |
| -- Valid) were also inlined, but this was changed since there were some |
| -- problems with this inlining in optimized mode, and in any case it seems |
| -- better to avoid this inlining (space and robustness considerations). |
| |
| end System.Fat_Gen; |
