## Mercurial > hg > CbC > CbC_gcc

### view gcc/ada/libgnat/s-fatgen.ads @ 131:84e7813d76e9

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gcc-8.2

author | mir3636 |
---|---|

date | Thu, 25 Oct 2018 07:37:49 +0900 |

parents | 04ced10e8804 |

children | 1830386684a0 |

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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . F A T _ G E N -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2018, 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;