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1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3084fecd | 3 | -- GNAT RUN-TIME COMPONENTS -- |
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4 | -- -- |
5 | -- S Y S T E M . P A C K _ 4 7 -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
748086b7 | 9 | -- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- |
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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- -- |
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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/>. -- | |
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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. -- |
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29 | -- -- |
30 | ------------------------------------------------------------------------------ | |
31 | ||
32 | with System.Storage_Elements; | |
33 | with System.Unsigned_Types; | |
cecaf88a | 34 | with Ada.Unchecked_Conversion; |
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35 | |
36 | package body System.Pack_47 is | |
37 | ||
38 | subtype Ofs is System.Storage_Elements.Storage_Offset; | |
39 | subtype Uns is System.Unsigned_Types.Unsigned; | |
40 | subtype N07 is System.Unsigned_Types.Unsigned range 0 .. 7; | |
41 | ||
42 | use type System.Storage_Elements.Storage_Offset; | |
43 | use type System.Unsigned_Types.Unsigned; | |
44 | ||
45 | type Cluster is record | |
46 | E0, E1, E2, E3, E4, E5, E6, E7 : Bits_47; | |
47 | end record; | |
48 | ||
49 | for Cluster use record | |
50 | E0 at 0 range 0 * Bits .. 0 * Bits + Bits - 1; | |
51 | E1 at 0 range 1 * Bits .. 1 * Bits + Bits - 1; | |
52 | E2 at 0 range 2 * Bits .. 2 * Bits + Bits - 1; | |
53 | E3 at 0 range 3 * Bits .. 3 * Bits + Bits - 1; | |
54 | E4 at 0 range 4 * Bits .. 4 * Bits + Bits - 1; | |
55 | E5 at 0 range 5 * Bits .. 5 * Bits + Bits - 1; | |
56 | E6 at 0 range 6 * Bits .. 6 * Bits + Bits - 1; | |
57 | E7 at 0 range 7 * Bits .. 7 * Bits + Bits - 1; | |
58 | end record; | |
59 | ||
60 | for Cluster'Size use Bits * 8; | |
61 | ||
62 | for Cluster'Alignment use Integer'Min (Standard'Maximum_Alignment, | |
63 | 1 + | |
64 | 1 * Boolean'Pos (Bits mod 2 = 0) + | |
65 | 2 * Boolean'Pos (Bits mod 4 = 0)); | |
66 | -- Use maximum possible alignment, given the bit field size, since this | |
67 | -- will result in the most efficient code possible for the field. | |
68 | ||
69 | type Cluster_Ref is access Cluster; | |
70 | ||
71 | function To_Ref is new | |
cecaf88a | 72 | Ada.Unchecked_Conversion (System.Address, Cluster_Ref); |
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73 | |
74 | ------------ | |
75 | -- Get_47 -- | |
76 | ------------ | |
77 | ||
78 | function Get_47 (Arr : System.Address; N : Natural) return Bits_47 is | |
79 | C : constant Cluster_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); | |
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80 | begin |
81 | case N07 (Uns (N) mod 8) is | |
82 | when 0 => return C.E0; | |
83 | when 1 => return C.E1; | |
84 | when 2 => return C.E2; | |
85 | when 3 => return C.E3; | |
86 | when 4 => return C.E4; | |
87 | when 5 => return C.E5; | |
88 | when 6 => return C.E6; | |
89 | when 7 => return C.E7; | |
90 | end case; | |
91 | end Get_47; | |
92 | ||
93 | ------------ | |
94 | -- Set_47 -- | |
95 | ------------ | |
96 | ||
97 | procedure Set_47 (Arr : System.Address; N : Natural; E : Bits_47) is | |
98 | C : constant Cluster_Ref := To_Ref (Arr + Bits * Ofs (Uns (N) / 8)); | |
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99 | begin |
100 | case N07 (Uns (N) mod 8) is | |
101 | when 0 => C.E0 := E; | |
102 | when 1 => C.E1 := E; | |
103 | when 2 => C.E2 := E; | |
104 | when 3 => C.E3 := E; | |
105 | when 4 => C.E4 := E; | |
106 | when 5 => C.E5 := E; | |
107 | when 6 => C.E6 := E; | |
108 | when 7 => C.E7 := E; | |
109 | end case; | |
110 | end Set_47; | |
111 | ||
112 | end System.Pack_47; |