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) 1992-2009, 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 3,  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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package contains definitions of standard unsigned types that
33--  correspond in size to the standard signed types declared in Standard,
34--  and (unlike the types in Interfaces) have corresponding names. It
35--  also contains some related definitions for other specialized types
36--  used by the compiler in connection with packed array types.
37
38pragma Warnings (Off);
39pragma Compiler_Unit;
40pragma Warnings (On);
41
42package System.Unsigned_Types is
43   pragma Pure;
44
45   type Short_Short_Unsigned is mod 2 ** Short_Short_Integer'Size;
46   type Short_Unsigned       is mod 2 ** Short_Integer'Size;
47   type Unsigned             is mod 2 ** Integer'Size;
48   type Long_Unsigned        is mod 2 ** Long_Integer'Size;
49   type Long_Long_Unsigned   is mod 2 ** Long_Long_Integer'Size;
50
51   type Float_Unsigned       is mod 2 ** Float'Size;
52   --  Used in the implementation of Is_Negative intrinsic (see Exp_Intr)
53
54   type Packed_Byte is mod 2 ** 8;
55   for Packed_Byte'Size use 8;
56   --  Component type for Packed_Bytes array
57
58   type Packed_Bytes1 is array (Natural range <>) of Packed_Byte;
59   for Packed_Bytes1'Alignment use 1;
60   for Packed_Bytes1'Component_Size use Packed_Byte'Size;
61   --  This is the type used to implement packed arrays where no alignment
62   --  is required. This includes the cases of 1,2,4 (where we use direct
63   --  masking operations), and all odd component sizes (where the clusters
64   --  are not aligned anyway, see, e.g. System.Pack_07 in file s-pack07
65   --  for details.
66
67   type Packed_Bytes2 is new Packed_Bytes1;
68   for Packed_Bytes2'Alignment use Integer'Min (2, Standard'Maximum_Alignment);
69   --  This is the type used to implement packed arrays where an alignment
70   --  of 2 (is possible) is helpful for maximum efficiency of the get and
71   --  set routines in the corresponding library unit. This is true of all
72   --  component sizes that are even but not divisible by 4 (other than 2 for
73   --  which we use direct masking operations). In such cases, the clusters
74   --  can be assumed to be 2-byte aligned if the array is aligned. See for
75   --  example System.Pack_10 in file s-pack10).
76
77   type Packed_Bytes4 is new Packed_Bytes1;
78   for Packed_Bytes4'Alignment use Integer'Min (4, Standard'Maximum_Alignment);
79   --  This is the type used to implement packed arrays where an alignment
80   --  of 4 (if possible) is helpful for maximum efficiency of the get and
81   --  set routines in the corresponding library unit. This is true of all
82   --  component sizes that are divisible by 4 (other than powers of 2, which
83   --  are either handled by direct masking or not packed at all). In such
84   --  cases the clusters can be assumed to be 4-byte aligned if the array
85   --  is aligned (see System.Pack_12 in file s-pack12 as an example).
86
87   type Bits_1 is mod 2**1;
88   type Bits_2 is mod 2**2;
89   type Bits_4 is mod 2**4;
90   --  Types used for packed array conversions
91
92   subtype Bytes_F is Packed_Bytes4 (1 .. Float'Size / 8);
93   --  Type used in implementation of Is_Negative intrinsic (see Exp_Intr)
94
95   function Shift_Left
96     (Value  : Short_Short_Unsigned;
97      Amount : Natural) return Short_Short_Unsigned;
98
99   function Shift_Right
100     (Value  : Short_Short_Unsigned;
101      Amount : Natural) return Short_Short_Unsigned;
102
103   function Shift_Right_Arithmetic
104     (Value  : Short_Short_Unsigned;
105      Amount : Natural) return Short_Short_Unsigned;
106
107   function Rotate_Left
108     (Value  : Short_Short_Unsigned;
109      Amount : Natural) return Short_Short_Unsigned;
110
111   function Rotate_Right
112     (Value  : Short_Short_Unsigned;
113      Amount : Natural) return Short_Short_Unsigned;
114
115   function Shift_Left
116     (Value  : Short_Unsigned;
117      Amount : Natural) return Short_Unsigned;
118
119   function Shift_Right
120     (Value  : Short_Unsigned;
121      Amount : Natural) return Short_Unsigned;
122
123   function Shift_Right_Arithmetic
124     (Value  : Short_Unsigned;
125      Amount : Natural) return Short_Unsigned;
126
127   function Rotate_Left
128     (Value  : Short_Unsigned;
129      Amount : Natural) return Short_Unsigned;
130
131   function Rotate_Right
132     (Value  : Short_Unsigned;
133      Amount : Natural) return Short_Unsigned;
134
135   function Shift_Left
136     (Value  : Unsigned;
137      Amount : Natural) return Unsigned;
138
139   function Shift_Right
140     (Value  : Unsigned;
141      Amount : Natural) return Unsigned;
142
143   function Shift_Right_Arithmetic
144     (Value  : Unsigned;
145      Amount : Natural) return Unsigned;
146
147   function Rotate_Left
148     (Value  : Unsigned;
149      Amount : Natural) return Unsigned;
150
151   function Rotate_Right
152     (Value  : Unsigned;
153      Amount : Natural) return Unsigned;
154
155   function Shift_Left
156     (Value  : Long_Unsigned;
157      Amount : Natural) return Long_Unsigned;
158
159   function Shift_Right
160     (Value  : Long_Unsigned;
161      Amount : Natural) return Long_Unsigned;
162
163   function Shift_Right_Arithmetic
164     (Value  : Long_Unsigned;
165      Amount : Natural) return Long_Unsigned;
166
167   function Rotate_Left
168     (Value  : Long_Unsigned;
169      Amount : Natural) return Long_Unsigned;
170
171   function Rotate_Right
172     (Value  : Long_Unsigned;
173      Amount : Natural) return Long_Unsigned;
174
175   function Shift_Left
176     (Value  : Long_Long_Unsigned;
177      Amount : Natural) return Long_Long_Unsigned;
178
179   function Shift_Right
180     (Value  : Long_Long_Unsigned;
181      Amount : Natural) return Long_Long_Unsigned;
182
183   function Shift_Right_Arithmetic
184     (Value  : Long_Long_Unsigned;
185      Amount : Natural) return Long_Long_Unsigned;
186
187   function Rotate_Left
188     (Value  : Long_Long_Unsigned;
189      Amount : Natural) return Long_Long_Unsigned;
190
191   function Rotate_Right
192     (Value  : Long_Long_Unsigned;
193      Amount : Natural) return Long_Long_Unsigned;
194
195   pragma Import (Intrinsic, Shift_Left);
196   pragma Import (Intrinsic, Shift_Right);
197   pragma Import (Intrinsic, Shift_Right_Arithmetic);
198   pragma Import (Intrinsic, Rotate_Left);
199   pragma Import (Intrinsic, Rotate_Right);
200
201   --  The following definitions are obsolescent. They were needed by the
202   --  previous version of the compiler and runtime, but are not needed
203   --  by the current version. We retain them to help with bootstrap path
204   --  problems. Also they seem harmless, and if any user programs have
205   --  been (rather improperly) using these types, why discombobulate them?
206
207   subtype Packed_Bytes           is Packed_Bytes4;
208   subtype Packed_Bytes_Unaligned is Packed_Bytes1;
209
210end System.Unsigned_Types;
211