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cacbc350 RK |
1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3084fecd | 3 | -- GNAT RUN-TIME COMPONENTS -- |
cacbc350 RK |
4 | -- -- |
5 | -- S Y S T E M . P A C K _ 2 4 -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
4b490c1e | 9 | -- Copyright (C) 1992-2020, Free Software Foundation, Inc. -- |
cacbc350 RK |
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- -- | |
748086b7 | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
cacbc350 RK |
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 -- | |
748086b7 JJ |
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/>. -- | |
cacbc350 RK |
26 | -- -- |
27 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
71ff80dc | 28 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
cacbc350 RK |
29 | -- -- |
30 | ------------------------------------------------------------------------------ | |
31 | ||
32 | with System.Storage_Elements; | |
33 | with System.Unsigned_Types; | |
cacbc350 RK |
34 | |
35 | package body System.Pack_24 is | |
36 | ||
7b536495 AC |
37 | subtype Bit_Order is System.Bit_Order; |
38 | Reverse_Bit_Order : constant Bit_Order := | |
39 | Bit_Order'Val (1 - Bit_Order'Pos (System.Default_Bit_Order)); | |
40 | ||
cacbc350 RK |
41 | subtype Ofs is System.Storage_Elements.Storage_Offset; |
42 | subtype Uns is System.Unsigned_Types.Unsigned; | |
43 | subtype N07 is System.Unsigned_Types.Unsigned range 0 .. 7; | |
44 | ||
45 | use type System.Storage_Elements.Storage_Offset; | |
46 | use type System.Unsigned_Types.Unsigned; | |
47 | ||
48 | type Cluster is record | |
49 | E0, E1, E2, E3, E4, E5, E6, E7 : Bits_24; | |
50 | end record; | |
51 | ||
52 | for Cluster use record | |
53 | E0 at 0 range 0 * Bits .. 0 * Bits + Bits - 1; | |
54 | E1 at 0 range 1 * Bits .. 1 * Bits + Bits - 1; | |
55 | E2 at 0 range 2 * Bits .. 2 * Bits + Bits - 1; | |
56 | E3 at 0 range 3 * Bits .. 3 * Bits + Bits - 1; | |
57 | E4 at 0 range 4 * Bits .. 4 * Bits + Bits - 1; | |
58 | E5 at 0 range 5 * Bits .. 5 * Bits + Bits - 1; | |
59 | E6 at 0 range 6 * Bits .. 6 * Bits + Bits - 1; | |
60 | E7 at 0 range 7 * Bits .. 7 * Bits + Bits - 1; | |
61 | end record; | |
62 | ||
63 | for Cluster'Size use Bits * 8; | |
64 | ||
65 | for Cluster'Alignment use Integer'Min (Standard'Maximum_Alignment, | |
66 | 1 + | |
67 | 1 * Boolean'Pos (Bits mod 2 = 0) + | |
68 | 2 * Boolean'Pos (Bits mod 4 = 0)); | |
69 | -- Use maximum possible alignment, given the bit field size, since this | |
70 | -- will result in the most efficient code possible for the field. | |
71 | ||
72 | type Cluster_Ref is access Cluster; | |
73 | ||
7b536495 AC |
74 | type Rev_Cluster is new Cluster |
75 | with Bit_Order => Reverse_Bit_Order, | |
76 | Scalar_Storage_Order => Reverse_Bit_Order; | |
77 | type Rev_Cluster_Ref is access Rev_Cluster; | |
cacbc350 RK |
78 | |
79 | -- The following declarations are for the case where the address | |
80 | -- passed to GetU_24 or SetU_24 is not guaranteed to be aligned. | |
81 | -- These routines are used when the packed array is itself a | |
82 | -- component of a packed record, and therefore may not be aligned. | |
83 | ||
84 | type ClusterU is new Cluster; | |
85 | for ClusterU'Alignment use 1; | |
86 | ||
87 | type ClusterU_Ref is access ClusterU; | |
88 | ||
7b536495 AC |
89 | type Rev_ClusterU is new ClusterU |
90 | with Bit_Order => Reverse_Bit_Order, | |
91 | Scalar_Storage_Order => Reverse_Bit_Order; | |
92 | type Rev_ClusterU_Ref is access Rev_ClusterU; | |
cacbc350 RK |
93 | |
94 | ------------ | |
95 | -- Get_24 -- | |
96 | ------------ | |
97 | ||
7b536495 AC |
98 | function Get_24 |
99 | (Arr : System.Address; | |
100 | N : Natural; | |
101 | Rev_SSO : Boolean) return Bits_24 | |
102 | is | |
103 | A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); | |
104 | C : Cluster_Ref with Address => A'Address, Import; | |
105 | RC : Rev_Cluster_Ref with Address => A'Address, Import; | |
cacbc350 | 106 | begin |
7b536495 AC |
107 | if Rev_SSO then |
108 | case N07 (Uns (N) mod 8) is | |
109 | when 0 => return RC.E0; | |
110 | when 1 => return RC.E1; | |
111 | when 2 => return RC.E2; | |
112 | when 3 => return RC.E3; | |
113 | when 4 => return RC.E4; | |
114 | when 5 => return RC.E5; | |
115 | when 6 => return RC.E6; | |
116 | when 7 => return RC.E7; | |
117 | end case; | |
118 | ||
119 | else | |
120 | case N07 (Uns (N) mod 8) is | |
121 | when 0 => return C.E0; | |
122 | when 1 => return C.E1; | |
123 | when 2 => return C.E2; | |
124 | when 3 => return C.E3; | |
125 | when 4 => return C.E4; | |
126 | when 5 => return C.E5; | |
127 | when 6 => return C.E6; | |
128 | when 7 => return C.E7; | |
129 | end case; | |
130 | end if; | |
cacbc350 RK |
131 | end Get_24; |
132 | ||
133 | ------------- | |
134 | -- GetU_24 -- | |
135 | ------------- | |
136 | ||
7b536495 AC |
137 | function GetU_24 |
138 | (Arr : System.Address; | |
139 | N : Natural; | |
140 | Rev_SSO : Boolean) return Bits_24 | |
141 | is | |
142 | A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); | |
143 | C : ClusterU_Ref with Address => A'Address, Import; | |
144 | RC : Rev_ClusterU_Ref with Address => A'Address, Import; | |
cacbc350 | 145 | begin |
7b536495 AC |
146 | if Rev_SSO then |
147 | case N07 (Uns (N) mod 8) is | |
148 | when 0 => return RC.E0; | |
149 | when 1 => return RC.E1; | |
150 | when 2 => return RC.E2; | |
151 | when 3 => return RC.E3; | |
152 | when 4 => return RC.E4; | |
153 | when 5 => return RC.E5; | |
154 | when 6 => return RC.E6; | |
155 | when 7 => return RC.E7; | |
156 | end case; | |
157 | ||
158 | else | |
159 | case N07 (Uns (N) mod 8) is | |
160 | when 0 => return C.E0; | |
161 | when 1 => return C.E1; | |
162 | when 2 => return C.E2; | |
163 | when 3 => return C.E3; | |
164 | when 4 => return C.E4; | |
165 | when 5 => return C.E5; | |
166 | when 6 => return C.E6; | |
167 | when 7 => return C.E7; | |
168 | end case; | |
169 | end if; | |
cacbc350 RK |
170 | end GetU_24; |
171 | ||
172 | ------------ | |
173 | -- Set_24 -- | |
174 | ------------ | |
175 | ||
7b536495 AC |
176 | procedure Set_24 |
177 | (Arr : System.Address; | |
178 | N : Natural; | |
179 | E : Bits_24; | |
180 | Rev_SSO : Boolean) | |
181 | is | |
182 | A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); | |
183 | C : Cluster_Ref with Address => A'Address, Import; | |
184 | RC : Rev_Cluster_Ref with Address => A'Address, Import; | |
cacbc350 | 185 | begin |
7b536495 AC |
186 | if Rev_SSO then |
187 | case N07 (Uns (N) mod 8) is | |
188 | when 0 => RC.E0 := E; | |
189 | when 1 => RC.E1 := E; | |
190 | when 2 => RC.E2 := E; | |
191 | when 3 => RC.E3 := E; | |
192 | when 4 => RC.E4 := E; | |
193 | when 5 => RC.E5 := E; | |
194 | when 6 => RC.E6 := E; | |
195 | when 7 => RC.E7 := E; | |
196 | end case; | |
197 | else | |
198 | case N07 (Uns (N) mod 8) is | |
199 | when 0 => C.E0 := E; | |
200 | when 1 => C.E1 := E; | |
201 | when 2 => C.E2 := E; | |
202 | when 3 => C.E3 := E; | |
203 | when 4 => C.E4 := E; | |
204 | when 5 => C.E5 := E; | |
205 | when 6 => C.E6 := E; | |
206 | when 7 => C.E7 := E; | |
207 | end case; | |
208 | end if; | |
cacbc350 RK |
209 | end Set_24; |
210 | ||
211 | ------------- | |
212 | -- SetU_24 -- | |
213 | ------------- | |
214 | ||
7b536495 AC |
215 | procedure SetU_24 |
216 | (Arr : System.Address; | |
217 | N : Natural; | |
218 | E : Bits_24; | |
219 | Rev_SSO : Boolean) | |
220 | is | |
221 | A : constant System.Address := Arr + Bits * Ofs (Uns (N) / 8); | |
222 | C : ClusterU_Ref with Address => A'Address, Import; | |
223 | RC : Rev_ClusterU_Ref with Address => A'Address, Import; | |
cacbc350 | 224 | begin |
7b536495 AC |
225 | if Rev_SSO then |
226 | case N07 (Uns (N) mod 8) is | |
227 | when 0 => RC.E0 := E; | |
228 | when 1 => RC.E1 := E; | |
229 | when 2 => RC.E2 := E; | |
230 | when 3 => RC.E3 := E; | |
231 | when 4 => RC.E4 := E; | |
232 | when 5 => RC.E5 := E; | |
233 | when 6 => RC.E6 := E; | |
234 | when 7 => RC.E7 := E; | |
235 | end case; | |
236 | else | |
237 | case N07 (Uns (N) mod 8) is | |
238 | when 0 => C.E0 := E; | |
239 | when 1 => C.E1 := E; | |
240 | when 2 => C.E2 := E; | |
241 | when 3 => C.E3 := E; | |
242 | when 4 => C.E4 := E; | |
243 | when 5 => C.E5 := E; | |
244 | when 6 => C.E6 := E; | |
245 | when 7 => C.E7 := E; | |
246 | end case; | |
247 | end if; | |
cacbc350 RK |
248 | end SetU_24; |
249 | ||
250 | end System.Pack_24; |