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) 1992-2014, 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   pragma Universal_Aliasing (Packed_Byte);
54   for Packed_Byte'Size use 8;
55   --  Component type for Packed_Bytes1, Packed_Bytes2 and Packed_Byte4 arrays.
56   --  As this type is used by the compiler to implement operations on user
57   --  packed array, it needs to be able to alias any type.
58
59   type Packed_Bytes1 is array (Natural range <>) of aliased Packed_Byte;
60   for Packed_Bytes1'Alignment use 1;
61   for Packed_Bytes1'Component_Size use Packed_Byte'Size;
62   --  This is the type used to implement packed arrays where no alignment
63   --  is required. This includes the cases of 1,2,4 (where we use direct
64   --  masking operations), and all odd component sizes (where the clusters
65   --  are not aligned anyway, see, e.g. System.Pack_07 in file s-pack07
66   --  for details.
67
68   type Packed_Bytes2 is new Packed_Bytes1;
69   for Packed_Bytes2'Alignment use Integer'Min (2, Standard'Maximum_Alignment);
70   --  This is the type used to implement packed arrays where an alignment
71   --  of 2 (is possible) is helpful for maximum efficiency of the get and
72   --  set routines in the corresponding library unit. This is true of all
73   --  component sizes that are even but not divisible by 4 (other than 2 for
74   --  which we use direct masking operations). In such cases, the clusters
75   --  can be assumed to be 2-byte aligned if the array is aligned. See for
76   --  example System.Pack_10 in file s-pack10).
77
78   type Packed_Bytes4 is new Packed_Bytes1;
79   for Packed_Bytes4'Alignment use Integer'Min (4, Standard'Maximum_Alignment);
80   --  This is the type used to implement packed arrays where an alignment
81   --  of 4 (if possible) is helpful for maximum efficiency of the get and
82   --  set routines in the corresponding library unit. This is true of all
83   --  component sizes that are divisible by 4 (other than powers of 2, which
84   --  are either handled by direct masking or not packed at all). In such
85   --  cases the clusters can be assumed to be 4-byte aligned if the array
86   --  is aligned (see System.Pack_12 in file s-pack12 as an example).
87
88   type Bits_1 is mod 2**1;
89   type Bits_2 is mod 2**2;
90   type Bits_4 is mod 2**4;
91   --  Types used for packed array conversions
92
93   subtype Bytes_F is Packed_Bytes4 (1 .. Float'Size / 8);
94   --  Type used in implementation of Is_Negative intrinsic (see Exp_Intr)
95
96   function Shift_Left
97     (Value  : Short_Short_Unsigned;
98      Amount : Natural) return Short_Short_Unsigned;
99
100   function Shift_Right
101     (Value  : Short_Short_Unsigned;
102      Amount : Natural) return Short_Short_Unsigned;
103
104   function Shift_Right_Arithmetic
105     (Value  : Short_Short_Unsigned;
106      Amount : Natural) return Short_Short_Unsigned;
107
108   function Rotate_Left
109     (Value  : Short_Short_Unsigned;
110      Amount : Natural) return Short_Short_Unsigned;
111
112   function Rotate_Right
113     (Value  : Short_Short_Unsigned;
114      Amount : Natural) return Short_Short_Unsigned;
115
116   function Shift_Left
117     (Value  : Short_Unsigned;
118      Amount : Natural) return Short_Unsigned;
119
120   function Shift_Right
121     (Value  : Short_Unsigned;
122      Amount : Natural) return Short_Unsigned;
123
124   function Shift_Right_Arithmetic
125     (Value  : Short_Unsigned;
126      Amount : Natural) return Short_Unsigned;
127
128   function Rotate_Left
129     (Value  : Short_Unsigned;
130      Amount : Natural) return Short_Unsigned;
131
132   function Rotate_Right
133     (Value  : Short_Unsigned;
134      Amount : Natural) return Short_Unsigned;
135
136   function Shift_Left
137     (Value  : Unsigned;
138      Amount : Natural) return Unsigned;
139
140   function Shift_Right
141     (Value  : Unsigned;
142      Amount : Natural) return Unsigned;
143
144   function Shift_Right_Arithmetic
145     (Value  : Unsigned;
146      Amount : Natural) return Unsigned;
147
148   function Rotate_Left
149     (Value  : Unsigned;
150      Amount : Natural) return Unsigned;
151
152   function Rotate_Right
153     (Value  : Unsigned;
154      Amount : Natural) return Unsigned;
155
156   function Shift_Left
157     (Value  : Long_Unsigned;
158      Amount : Natural) return Long_Unsigned;
159
160   function Shift_Right
161     (Value  : Long_Unsigned;
162      Amount : Natural) return Long_Unsigned;
163
164   function Shift_Right_Arithmetic
165     (Value  : Long_Unsigned;
166      Amount : Natural) return Long_Unsigned;
167
168   function Rotate_Left
169     (Value  : Long_Unsigned;
170      Amount : Natural) return Long_Unsigned;
171
172   function Rotate_Right
173     (Value  : Long_Unsigned;
174      Amount : Natural) return Long_Unsigned;
175
176   function Shift_Left
177     (Value  : Long_Long_Unsigned;
178      Amount : Natural) return Long_Long_Unsigned;
179
180   function Shift_Right
181     (Value  : Long_Long_Unsigned;
182      Amount : Natural) return Long_Long_Unsigned;
183
184   function Shift_Right_Arithmetic
185     (Value  : Long_Long_Unsigned;
186      Amount : Natural) return Long_Long_Unsigned;
187
188   function Rotate_Left
189     (Value  : Long_Long_Unsigned;
190      Amount : Natural) return Long_Long_Unsigned;
191
192   function Rotate_Right
193     (Value  : Long_Long_Unsigned;
194      Amount : Natural) return Long_Long_Unsigned;
195
196   pragma Import (Intrinsic, Shift_Left);
197   pragma Import (Intrinsic, Shift_Right);
198   pragma Import (Intrinsic, Shift_Right_Arithmetic);
199   pragma Import (Intrinsic, Rotate_Left);
200   pragma Import (Intrinsic, Rotate_Right);
201
202   --  The following definitions are obsolescent. They were needed by the
203   --  previous version of the compiler and runtime, but are not needed
204   --  by the current version. We retain them to help with bootstrap path
205   --  problems. Also they seem harmless, and if any user programs have
206   --  been using these types, why discombobulate them?
207
208   subtype Packed_Bytes           is Packed_Bytes4;
209   subtype Packed_Bytes_Unaligned is Packed_Bytes1;
210
211end System.Unsigned_Types;
212