gcc/ada/s-unstyp.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                          GNAT RUN-TIME COMPONENTS                        --
   4 --                                                                          --
   5 --                S Y S T E M . U N S I G N E D _ T Y P E S                 --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2008, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package contains definitions of standard unsigned types that
  35 --  correspond in size to the standard signed types declared in Standard,
  36 --  and (unlike the types in Interfaces) have corresponding names. It
  37 --  also contains some related definitions for other specialized types
  38 --  used by the compiler in connection with packed array types.
  39
  40 pragma Warnings (Off);
  41 pragma Compiler_Unit;
  42 pragma Warnings (On);
  43
  44 package System.Unsigned_Types is
  45    pragma Pure;
  46
  47    type Short_Short_Unsigned is mod 2 ** Short_Short_Integer'Size;
  48    type Short_Unsigned       is mod 2 ** Short_Integer'Size;
  49    type Unsigned             is mod 2 ** Integer'Size;
  50    type Long_Unsigned        is mod 2 ** Long_Integer'Size;
  51    type Long_Long_Unsigned   is mod 2 ** Long_Long_Integer'Size;
  52
  53    type Float_Unsigned       is mod 2 ** Float'Size;
  54    --  Used in the implementation of Is_Negative intrinsic (see Exp_Intr)
  55
  56    type Packed_Byte is mod 2 ** 8;
  57    for Packed_Byte'Size use 8;
  58    --  Component type for Packed_Bytes array
  59
  60    type Packed_Bytes1 is array (Natural range <>) of Packed_Byte;
  61    for Packed_Bytes1'Alignment use 1;
  62    for Packed_Bytes1'Component_Size use Packed_Byte'Size;
  63    --  This is the type used to implement packed arrays where no alignment
  64    --  is required. This includes the cases of 1,2,4 (where we use direct
  65    --  masking operations), and all odd component sizes (where the clusters
  66    --  are not aligned anyway, see, e.g. System.Pack_07 in file s-pack07
  67    --  for details.
  68
  69    type Packed_Bytes2 is new Packed_Bytes1;
  70    for Packed_Bytes2'Alignment use Integer'Min (2, Standard'Maximum_Alignment);
  71    --  This is the type used to implement packed arrays where an alignment
  72    --  of 2 (is possible) is helpful for maximum efficiency of the get and
  73    --  set routines in the corresponding library unit. This is true of all
  74    --  component sizes that are even but not divisible by 4 (other than 2 for
  75    --  which we use direct masking operations). In such cases, the clusters
  76    --  can be assumed to be 2-byte aligned if the array is aligned. See for
  77    --  example System.Pack_10 in file s-pack10).
  78
  79    type Packed_Bytes4 is new Packed_Bytes1;
  80    for Packed_Bytes4'Alignment use Integer'Min (4, Standard'Maximum_Alignment);
  81    --  This is the type used to implement packed arrays where an alignment
  82    --  of 4 (if possible) is helpful for maximum efficiency of the get and
  83    --  set routines in the corresponding library unit. This is true of all
  84    --  component sizes that are divisible by 4 (other than powers of 2, which
  85    --  are either handled by direct masking or not packed at all). In such
  86    --  cases the clusters can be assumed to be 4-byte aligned if the array
  87    --  is aligned (see System.Pack_12 in file s-pack12 as an example).
  88
  89    type Bits_1 is mod 2**1;
  90    type Bits_2 is mod 2**2;
  91    type Bits_4 is mod 2**4;
  92    --  Types used for packed array conversions
  93
  94    subtype Bytes_F is Packed_Bytes4 (1 .. Float'Size / 8);
  95    --  Type used in implementation of Is_Negative intrinsic (see Exp_Intr)
  96
  97    function Shift_Left
  98      (Value  : Short_Short_Unsigned;
  99       Amount : Natural) return Short_Short_Unsigned;
 100
 101    function Shift_Right
 102      (Value  : Short_Short_Unsigned;
 103       Amount : Natural) return Short_Short_Unsigned;
 104
 105    function Shift_Right_Arithmetic
 106      (Value  : Short_Short_Unsigned;
 107       Amount : Natural) return Short_Short_Unsigned;
 108
 109    function Rotate_Left
 110      (Value  : Short_Short_Unsigned;
 111       Amount : Natural) return Short_Short_Unsigned;
 112
 113    function Rotate_Right
 114      (Value  : Short_Short_Unsigned;
 115       Amount : Natural) return Short_Short_Unsigned;
 116
 117    function Shift_Left
 118      (Value  : Short_Unsigned;
 119       Amount : Natural) return Short_Unsigned;
 120
 121    function Shift_Right
 122      (Value  : Short_Unsigned;
 123       Amount : Natural) return Short_Unsigned;
 124
 125    function Shift_Right_Arithmetic
 126      (Value  : Short_Unsigned;
 127       Amount : Natural) return Short_Unsigned;
 128
 129    function Rotate_Left
 130      (Value  : Short_Unsigned;
 131       Amount : Natural) return Short_Unsigned;
 132
 133    function Rotate_Right
 134      (Value  : Short_Unsigned;
 135       Amount : Natural) return Short_Unsigned;
 136
 137    function Shift_Left
 138      (Value  : Unsigned;
 139       Amount : Natural) return Unsigned;
 140
 141    function Shift_Right
 142      (Value  : Unsigned;
 143       Amount : Natural) return Unsigned;
 144
 145    function Shift_Right_Arithmetic
 146      (Value  : Unsigned;
 147       Amount : Natural) return Unsigned;
 148
 149    function Rotate_Left
 150      (Value  : Unsigned;
 151       Amount : Natural) return Unsigned;
 152
 153    function Rotate_Right
 154      (Value  : Unsigned;
 155       Amount : Natural) return Unsigned;
 156
 157    function Shift_Left
 158      (Value  : Long_Unsigned;
 159       Amount : Natural) return Long_Unsigned;
 160
 161    function Shift_Right
 162      (Value  : Long_Unsigned;
 163       Amount : Natural) return Long_Unsigned;
 164
 165    function Shift_Right_Arithmetic
 166      (Value  : Long_Unsigned;
 167       Amount : Natural) return Long_Unsigned;
 168
 169    function Rotate_Left
 170      (Value  : Long_Unsigned;
 171       Amount : Natural) return Long_Unsigned;
 172
 173    function Rotate_Right
 174      (Value  : Long_Unsigned;
 175       Amount : Natural) return Long_Unsigned;
 176
 177    function Shift_Left
 178      (Value  : Long_Long_Unsigned;
 179       Amount : Natural) return Long_Long_Unsigned;
 180
 181    function Shift_Right
 182      (Value  : Long_Long_Unsigned;
 183       Amount : Natural) return Long_Long_Unsigned;
 184
 185    function Shift_Right_Arithmetic
 186      (Value  : Long_Long_Unsigned;
 187       Amount : Natural) return Long_Long_Unsigned;
 188
 189    function Rotate_Left
 190      (Value  : Long_Long_Unsigned;
 191       Amount : Natural) return Long_Long_Unsigned;
 192
 193    function Rotate_Right
 194      (Value  : Long_Long_Unsigned;
 195       Amount : Natural) return Long_Long_Unsigned;
 196
 197    pragma Import (Intrinsic, Shift_Left);
 198    pragma Import (Intrinsic, Shift_Right);
 199    pragma Import (Intrinsic, Shift_Right_Arithmetic);
 200    pragma Import (Intrinsic, Rotate_Left);
 201    pragma Import (Intrinsic, Rotate_Right);
 202
 203    --  The following definitions are obsolescent. They were needed by the
 204    --  previous version of the compiler and runtime, but are not needed
 205    --  by the current version. We retain them to help with bootstrap path
 206    --  problems. Also they seem harmless, and if any user programs have
 207    --  been (rather improperly) using these types, why discombobulate them?
 208
 209    subtype Packed_Bytes           is Packed_Bytes4;
 210    subtype Packed_Bytes_Unaligned is Packed_Bytes1;
 211
 212 end System.Unsigned_Types;