1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--                  S Y S T E M . B Y T E _ S W A P P I N G                 --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--                     Copyright (C) 2006-2018, 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--  Intrinsic routines for byte swapping. These are used by the expanded code
33--  (supporting alternative byte ordering), and by the GNAT.Byte_Swapping run
34--  time package which provides user level routines for byte swapping.
35
36package System.Byte_Swapping is
37
38   pragma Pure;
39
40   type U16 is mod 2**16;
41   type U32 is mod 2**32;
42   type U64 is mod 2**64;
43
44   function Bswap_16 (X : U16) return U16;
45   pragma Import (Intrinsic, Bswap_16, "__builtin_bswap16");
46
47   function Bswap_32 (X : U32) return U32;
48   pragma Import (Intrinsic, Bswap_32, "__builtin_bswap32");
49
50   function Bswap_64 (X : U64) return U64;
51   pragma Import (Intrinsic, Bswap_64, "__builtin_bswap64");
52
53end System.Byte_Swapping;
54