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1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT RUNTIME COMPONENTS -- | |
4 | -- -- | |
5 | -- S Y S T E M . P A C K _ 4 6 -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
cacbc350 RK |
9 | -- Copyright (C) 1992-1999 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, 59 Temple Place - Suite 330, Boston, -- | |
20 | -- MA 02111-1307, 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. -- | |
71ff80dc | 30 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
cacbc350 RK |
31 | -- -- |
32 | ------------------------------------------------------------------------------ | |
33 | ||
34 | with System.Storage_Elements; | |
35 | with System.Unsigned_Types; | |
36 | with Unchecked_Conversion; | |
37 | ||
38 | package body System.Pack_46 is | |
39 | ||
40 | subtype Ofs is System.Storage_Elements.Storage_Offset; | |
41 | subtype Uns is System.Unsigned_Types.Unsigned; | |
42 | subtype N07 is System.Unsigned_Types.Unsigned range 0 .. 7; | |
43 | ||
44 | use type System.Storage_Elements.Storage_Offset; | |
45 | use type System.Unsigned_Types.Unsigned; | |
46 | ||
47 | type Cluster is record | |
48 | E0, E1, E2, E3, E4, E5, E6, E7 : Bits_46; | |
49 | end record; | |
50 | ||
51 | for Cluster use record | |
52 | E0 at 0 range 0 * Bits .. 0 * Bits + Bits - 1; | |
53 | E1 at 0 range 1 * Bits .. 1 * Bits + Bits - 1; | |
54 | E2 at 0 range 2 * Bits .. 2 * Bits + Bits - 1; | |
55 | E3 at 0 range 3 * Bits .. 3 * Bits + Bits - 1; | |
56 | E4 at 0 range 4 * Bits .. 4 * Bits + Bits - 1; | |
57 | E5 at 0 range 5 * Bits .. 5 * Bits + Bits - 1; | |
58 | E6 at 0 range 6 * Bits .. 6 * Bits + Bits - 1; | |
59 | E7 at 0 range 7 * Bits .. 7 * Bits + Bits - 1; | |
60 | end record; | |
61 | ||
62 | for Cluster'Size use Bits * 8; | |
63 | ||
64 | for Cluster'Alignment use Integer'Min (Standard'Maximum_Alignment, | |
65 | 1 + | |
66 | 1 * Boolean'Pos (Bits mod 2 = 0) + | |
67 | 2 * Boolean'Pos (Bits mod 4 = 0)); | |
68 | -- Use maximum possible alignment, given the bit field size, since this | |
69 | -- will result in the most efficient code possible for the field. | |
70 | ||
71 | type Cluster_Ref is access Cluster; | |
72 | ||
73 | function To_Ref is new | |
74 | Unchecked_Conversion (System.Address, Cluster_Ref); | |
75 | ||
76 | -- The following declarations are for the case where the address | |
77 | -- passed to GetU_46 or SetU_46 is not guaranteed to be aligned. | |
78 | -- These routines are used when the packed array is itself a | |
79 | -- component of a packed record, and therefore may not be aligned. | |
80 | ||
81 | type ClusterU is new Cluster; | |
82 | for ClusterU'Alignment use 1; | |
83 | ||
84 | type ClusterU_Ref is access ClusterU; | |
85 | ||
86 | function To_Ref is new | |
87 | Unchecked_Conversion (System.Address, ClusterU_Ref); | |
88 | ||
89 | ------------ | |
90 | -- Get_46 -- | |
91 | ------------ | |
92 | ||
93 | function Get_46 (Arr : System.Address; N : Natural) return Bits_46 is | |
94 | C : constant Cluster_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); | |
95 | ||
96 | begin | |
97 | case N07 (Uns (N) mod 8) is | |
98 | when 0 => return C.E0; | |
99 | when 1 => return C.E1; | |
100 | when 2 => return C.E2; | |
101 | when 3 => return C.E3; | |
102 | when 4 => return C.E4; | |
103 | when 5 => return C.E5; | |
104 | when 6 => return C.E6; | |
105 | when 7 => return C.E7; | |
106 | end case; | |
107 | end Get_46; | |
108 | ||
109 | ------------- | |
110 | -- GetU_46 -- | |
111 | ------------- | |
112 | ||
113 | function GetU_46 (Arr : System.Address; N : Natural) return Bits_46 is | |
114 | C : constant ClusterU_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); | |
115 | ||
116 | begin | |
117 | case N07 (Uns (N) mod 8) is | |
118 | when 0 => return C.E0; | |
119 | when 1 => return C.E1; | |
120 | when 2 => return C.E2; | |
121 | when 3 => return C.E3; | |
122 | when 4 => return C.E4; | |
123 | when 5 => return C.E5; | |
124 | when 6 => return C.E6; | |
125 | when 7 => return C.E7; | |
126 | end case; | |
127 | end GetU_46; | |
128 | ||
129 | ------------ | |
130 | -- Set_46 -- | |
131 | ------------ | |
132 | ||
133 | procedure Set_46 (Arr : System.Address; N : Natural; E : Bits_46) is | |
134 | C : constant Cluster_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); | |
135 | ||
136 | begin | |
137 | case N07 (Uns (N) mod 8) is | |
138 | when 0 => C.E0 := E; | |
139 | when 1 => C.E1 := E; | |
140 | when 2 => C.E2 := E; | |
141 | when 3 => C.E3 := E; | |
142 | when 4 => C.E4 := E; | |
143 | when 5 => C.E5 := E; | |
144 | when 6 => C.E6 := E; | |
145 | when 7 => C.E7 := E; | |
146 | end case; | |
147 | end Set_46; | |
148 | ||
149 | ------------- | |
150 | -- SetU_46 -- | |
151 | ------------- | |
152 | ||
153 | procedure SetU_46 (Arr : System.Address; N : Natural; E : Bits_46) is | |
154 | C : constant ClusterU_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); | |
155 | ||
156 | begin | |
157 | case N07 (Uns (N) mod 8) is | |
158 | when 0 => C.E0 := E; | |
159 | when 1 => C.E1 := E; | |
160 | when 2 => C.E2 := E; | |
161 | when 3 => C.E3 := E; | |
162 | when 4 => C.E4 := E; | |
163 | when 5 => C.E5 := E; | |
164 | when 6 => C.E6 := E; | |
165 | when 7 => C.E7 := E; | |
166 | end case; | |
167 | end SetU_46; | |
168 | ||
169 | end System.Pack_46; |