gcc/ada/eval_fat.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             E V A L _ F A T                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                            $Revision$
  10 --                                                                          --
  11 --          Copyright (C) 1992-2001 Free Software Foundation, Inc.          --
  12 --                                                                          --
  13 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  14 -- 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- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- 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 --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- GNAT was originally developed  by the GNAT team at  New York University. --
  25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  26 --                                                                          --
  27 ------------------------------------------------------------------------------
  28
  29 --  This package provides for compile-time evaluation of static calls to the
  30 --  floating-point attribute functions. It is the compile-time equivalent of
  31 --  the System.Fat_Gen runtime package. The coding is quite similar, as are
  32 --  the subprogram specs, except that the type is passed as an explicit
  33 --  first parameter (and used via ttypes, to obtain the necessary information
  34 --  about the characteristics of the type for computing the results.
  35
  36 with Types;  use Types;
  37 with Uintp;  use Uintp;
  38 with Urealp; use Urealp;
  39
  40 package Eval_Fat is
  41
  42    subtype UI is Uint;
  43    --  The compile time representation of universal integer
  44
  45    subtype T is Ureal;
  46    --  The compile time representation of floating-point values
  47
  48    subtype R is Entity_Id;
  49    --  The compile time representation of the floating-point root type
  50
  51    type Rounding_Mode is (Floor, Ceiling, Round, Round_Even);
  52    for Rounding_Mode use (0, 1, 2, 3);
  53    --  Used to indicate rounding mode for Machine attribute
  54    --  Note that C code in gigi knows that Round_Even is 3
  55
  56    Rounding_Was_Biased : Boolean;
  57    --  Set if last use of Machine rounded a halfway case away from zero
  58
  59    function Adjacent          (RT : R; X, Towards : T)              return T;
  60
  61    function Ceiling           (RT : R; X : T)                       return T;
  62
  63    function Compose           (RT : R; Fraction : T; Exponent : UI) return T;
  64
  65    function Copy_Sign         (RT : R; Value, Sign : T)             return T;
  66
  67    function Exponent          (RT : R; X : T)                       return UI;
  68
  69    function Floor             (RT : R; X : T)                       return T;
  70
  71    function Fraction          (RT : R; X : T)                       return T;
  72
  73    function Leading_Part      (RT : R; X : T; Radix_Digits : UI)    return T;
  74
  75    function Machine           (RT : R; X : T; Mode : Rounding_Mode) return T;
  76
  77    function Model             (RT : R; X : T)                       return T;
  78
  79    function Pred              (RT : R; X : T)                       return T;
  80
  81    function Remainder         (RT : R; X, Y : T)                    return T;
  82
  83    function Rounding          (RT : R; X : T)                       return T;
  84
  85    function Scaling           (RT : R; X : T; Adjustment : UI)      return T;
  86
  87    function Succ              (RT : R; X : T)                       return T;
  88
  89    function Truncation        (RT : R; X : T)                       return T;
  90
  91    function Unbiased_Rounding (RT : R; X : T)                       return T;
  92
  93 end Eval_Fat;