File : g-bytswa.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- G N A T . B Y T E _ S W A P P I N G --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2006-2012, AdaCore --
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 -- --
19 -- --
20 -- --
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 is a general implementation that uses GCC intrinsics to take
33 -- advantage of any machine-specific instructions.
34
35 with Ada.Unchecked_Conversion; use Ada;
36
37 with System.Byte_Swapping; use System.Byte_Swapping;
38
39 package body GNAT.Byte_Swapping is
40
41 --------------
42 -- Swapped2 --
43 --------------
44
45 function Swapped2 (Input : Item) return Item is
46 function As_U16 is new Unchecked_Conversion (Item, U16);
47 function As_Item is new Unchecked_Conversion (U16, Item);
48 pragma Compile_Time_Error (Item'Max_Size_In_Storage_Elements /= 2,
49 "storage size must be 2 bytes");
50 begin
51 return As_Item (Bswap_16 (As_U16 (Input)));
52 end Swapped2;
53
54 --------------
55 -- Swapped4 --
56 --------------
57
58 function Swapped4 (Input : Item) return Item is
59 function As_U32 is new Unchecked_Conversion (Item, U32);
60 function As_Item is new Unchecked_Conversion (U32, Item);
61 pragma Compile_Time_Error (Item'Max_Size_In_Storage_Elements /= 4,
62 "storage size must be 4 bytes");
63 begin
64 return As_Item (Bswap_32 (As_U32 (Input)));
65 end Swapped4;
66
67 --------------
68 -- Swapped8 --
69 --------------
70
71 function Swapped8 (Input : Item) return Item is
72 function As_U64 is new Unchecked_Conversion (Item, U64);
73 function As_Item is new Unchecked_Conversion (U64, Item);
74 pragma Compile_Time_Error (Item'Max_Size_In_Storage_Elements /= 8,
75 "storage size must be 8 bytes");
76 begin
77 return As_Item (Bswap_64 (As_U64 (Input)));
78 end Swapped8;
79
80 -----------
81 -- Swap2 --
82 -----------
83
84 procedure Swap2 (Location : System.Address) is
85 X : U16;
86 for X'Address use Location;
87 begin
88 X := Bswap_16 (X);
89 end Swap2;
90
91 -----------
92 -- Swap4 --
93 -----------
94
95 procedure Swap4 (Location : System.Address) is
96 X : U32;
97 for X'Address use Location;
98 begin
99 X := Bswap_32 (X);
100 end Swap4;
101
102 -----------
103 -- Swap8 --
104 -----------
105
106 procedure Swap8 (Location : System.Address) is
107 X : U64;
108 for X'Address use Location;
109 begin
110 X := Bswap_64 (X);
111 end Swap8;
112
113 end GNAT.Byte_Swapping;