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-- 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 is a general implementation that uses GCC intrinsics to take
33--  advantage of any machine-specific instructions.
34
35with Ada.Unchecked_Conversion; use Ada;
36
37with System.Byte_Swapping; use System.Byte_Swapping;
38
39package 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
113end GNAT.Byte_Swapping;
114