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) 1992-2013, 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 Compiler_Unit_Warning;
39
40package System.Unsigned_Types is
41   pragma Pure;
42
43   type Short_Short_Unsigned is mod 2 ** Short_Short_Integer'Size;
44   type Short_Unsigned       is mod 2 ** Short_Integer'Size;
45   type Unsigned             is mod 2 ** Integer'Size;
46   type Long_Unsigned        is mod 2 ** Long_Integer'Size;
47   type Long_Long_Unsigned   is mod 2 ** Long_Long_Integer'Size;
48
49   type Float_Unsigned       is mod 2 ** Float'Size;
50   --  Used in the implementation of Is_Negative intrinsic (see Exp_Intr)
51
52   type Packed_Byte is mod 2 ** 8;
53   for Packed_Byte'Size use 8;
54   --  Component type for Packed_Bytes array
55
56   type Packed_Bytes1 is array (Natural range <>) of Packed_Byte;
57   for Packed_Bytes1'Alignment use 1;
58   for Packed_Bytes1'Component_Size use Packed_Byte'Size;
59   --  This is the type used to implement packed arrays where no alignment
60   --  is required. This includes the cases of 1,2,4 (where we use direct
61   --  masking operations), and all odd component sizes (where the clusters
62   --  are not aligned anyway, see, e.g. System.Pack_07 in file s-pack07
63   --  for details.
64
65   type Packed_Bytes2 is new Packed_Bytes1;
66   for Packed_Bytes2'Alignment use Integer'Min (2, Standard'Maximum_Alignment);
67   --  This is the type used to implement packed arrays where an alignment
68   --  of 2 (is possible) is helpful for maximum efficiency of the get and
69   --  set routines in the corresponding library unit. This is true of all
70   --  component sizes that are even but not divisible by 4 (other than 2 for
71   --  which we use direct masking operations). In such cases, the clusters
72   --  can be assumed to be 2-byte aligned if the array is aligned. See for
73   --  example System.Pack_10 in file s-pack10).
74
75   type Packed_Bytes4 is new Packed_Bytes1;
76   for Packed_Bytes4'Alignment use Integer'Min (4, Standard'Maximum_Alignment);
77   --  This is the type used to implement packed arrays where an alignment
78   --  of 4 (if possible) is helpful for maximum efficiency of the get and
79   --  set routines in the corresponding library unit. This is true of all
80   --  component sizes that are divisible by 4 (other than powers of 2, which
81   --  are either handled by direct masking or not packed at all). In such
82   --  cases the clusters can be assumed to be 4-byte aligned if the array
83   --  is aligned (see System.Pack_12 in file s-pack12 as an example).
84
85   type Bits_1 is mod 2**1;
86   type Bits_2 is mod 2**2;
87   type Bits_4 is mod 2**4;
88   --  Types used for packed array conversions
89
90   subtype Bytes_F is Packed_Bytes4 (1 .. Float'Size / 8);
91   --  Type used in implementation of Is_Negative intrinsic (see Exp_Intr)
92
93   function Shift_Left
94     (Value  : Short_Short_Unsigned;
95      Amount : Natural) return Short_Short_Unsigned;
96
97   function Shift_Right
98     (Value  : Short_Short_Unsigned;
99      Amount : Natural) return Short_Short_Unsigned;
100
101   function Shift_Right_Arithmetic
102     (Value  : Short_Short_Unsigned;
103      Amount : Natural) return Short_Short_Unsigned;
104
105   function Rotate_Left
106     (Value  : Short_Short_Unsigned;
107      Amount : Natural) return Short_Short_Unsigned;
108
109   function Rotate_Right
110     (Value  : Short_Short_Unsigned;
111      Amount : Natural) return Short_Short_Unsigned;
112
113   function Shift_Left
114     (Value  : Short_Unsigned;
115      Amount : Natural) return Short_Unsigned;
116
117   function Shift_Right
118     (Value  : Short_Unsigned;
119      Amount : Natural) return Short_Unsigned;
120
121   function Shift_Right_Arithmetic
122     (Value  : Short_Unsigned;
123      Amount : Natural) return Short_Unsigned;
124
125   function Rotate_Left
126     (Value  : Short_Unsigned;
127      Amount : Natural) return Short_Unsigned;
128
129   function Rotate_Right
130     (Value  : Short_Unsigned;
131      Amount : Natural) return Short_Unsigned;
132
133   function Shift_Left
134     (Value  : Unsigned;
135      Amount : Natural) return Unsigned;
136
137   function Shift_Right
138     (Value  : Unsigned;
139      Amount : Natural) return Unsigned;
140
141   function Shift_Right_Arithmetic
142     (Value  : Unsigned;
143      Amount : Natural) return Unsigned;
144
145   function Rotate_Left
146     (Value  : Unsigned;
147      Amount : Natural) return Unsigned;
148
149   function Rotate_Right
150     (Value  : Unsigned;
151      Amount : Natural) return Unsigned;
152
153   function Shift_Left
154     (Value  : Long_Unsigned;
155      Amount : Natural) return Long_Unsigned;
156
157   function Shift_Right
158     (Value  : Long_Unsigned;
159      Amount : Natural) return Long_Unsigned;
160
161   function Shift_Right_Arithmetic
162     (Value  : Long_Unsigned;
163      Amount : Natural) return Long_Unsigned;
164
165   function Rotate_Left
166     (Value  : Long_Unsigned;
167      Amount : Natural) return Long_Unsigned;
168
169   function Rotate_Right
170     (Value  : Long_Unsigned;
171      Amount : Natural) return Long_Unsigned;
172
173   function Shift_Left
174     (Value  : Long_Long_Unsigned;
175      Amount : Natural) return Long_Long_Unsigned;
176
177   function Shift_Right
178     (Value  : Long_Long_Unsigned;
179      Amount : Natural) return Long_Long_Unsigned;
180
181   function Shift_Right_Arithmetic
182     (Value  : Long_Long_Unsigned;
183      Amount : Natural) return Long_Long_Unsigned;
184
185   function Rotate_Left
186     (Value  : Long_Long_Unsigned;
187      Amount : Natural) return Long_Long_Unsigned;
188
189   function Rotate_Right
190     (Value  : Long_Long_Unsigned;
191      Amount : Natural) return Long_Long_Unsigned;
192
193   pragma Import (Intrinsic, Shift_Left);
194   pragma Import (Intrinsic, Shift_Right);
195   pragma Import (Intrinsic, Shift_Right_Arithmetic);
196   pragma Import (Intrinsic, Rotate_Left);
197   pragma Import (Intrinsic, Rotate_Right);
198
199   --  The following definitions are obsolescent. They were needed by the
200   --  previous version of the compiler and runtime, but are not needed
201   --  by the current version. We retain them to help with bootstrap path
202   --  problems. Also they seem harmless, and if any user programs have
203   --  been (rather improperly) using these types, why discombobulate them?
204
205   subtype Packed_Bytes           is Packed_Bytes4;
206   subtype Packed_Bytes_Unaligned is Packed_Bytes1;
207
208end System.Unsigned_Types;
209