| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- G N A T . B Y T E _ S W A P P I N G -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2006-2010, AdaCore -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. -- |
| -- -- |
| -- As a special exception under Section 7 of GPL version 3, you are granted -- |
| -- additional permissions described in the GCC Runtime Library Exception, -- |
| -- version 3.1, as published by the Free Software Foundation. -- |
| -- -- |
| -- You should have received a copy of the GNU General Public License and -- |
| -- a copy of the GCC Runtime Library Exception along with this program; -- |
| -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This is a general implementation that does not take advantage of |
| -- any machine-specific instructions. |
| |
| with Interfaces; use Interfaces; |
| with Ada.Unchecked_Conversion; |
| |
| package body GNAT.Byte_Swapping is |
| |
| -------------- |
| -- Swapped2 -- |
| -------------- |
| |
| function Swapped2 (Input : Item) return Item is |
| |
| function As_U16 is new Ada.Unchecked_Conversion |
| (Source => Item, Target => Unsigned_16); |
| |
| function As_Item is new Ada.Unchecked_Conversion |
| (Source => Unsigned_16, Target => Item); |
| |
| X : constant Unsigned_16 := As_U16 (Input); |
| |
| begin |
| return As_Item ((Shift_Left (X, 8) and 16#FF00#) or |
| (Shift_Right (X, 8) and 16#00FF#)); |
| end Swapped2; |
| |
| -------------- |
| -- Swapped4 -- |
| -------------- |
| |
| function Swapped4 (Input : Item) return Item is |
| |
| function As_U32 is new Ada.Unchecked_Conversion |
| (Source => Item, Target => Unsigned_32); |
| |
| function As_Item is new Ada.Unchecked_Conversion |
| (Source => Unsigned_32, Target => Item); |
| |
| X : constant Unsigned_32 := As_U32 (Input); |
| |
| begin |
| return As_Item ((Shift_Right (X, 24) and 16#0000_00FF#) or |
| (Shift_Right (X, 8) and 16#0000_FF00#) or |
| (Shift_Left (X, 8) and 16#00FF_0000#) or |
| (Shift_Left (X, 24) and 16#FF00_0000#)); |
| end Swapped4; |
| |
| -------------- |
| -- Swapped8 -- |
| -------------- |
| |
| function Swapped8 (Input : Item) return Item is |
| |
| function As_U64 is new Ada.Unchecked_Conversion |
| (Source => Item, Target => Unsigned_64); |
| |
| function As_Item is new Ada.Unchecked_Conversion |
| (Source => Unsigned_64, Target => Item); |
| |
| X : constant Unsigned_64 := As_U64 (Input); |
| |
| Low, High : aliased Unsigned_32; |
| |
| begin |
| Low := Unsigned_32 (X and 16#0000_0000_FFFF_FFFF#); |
| Swap4 (Low'Address); |
| High := Unsigned_32 (Shift_Right (X, 32)); |
| Swap4 (High'Address); |
| return As_Item |
| (Shift_Left (Unsigned_64 (Low), 32) or Unsigned_64 (High)); |
| end Swapped8; |
| |
| ----------- |
| -- Swap2 -- |
| ----------- |
| |
| procedure Swap2 (Location : System.Address) is |
| X : Unsigned_16; |
| for X'Address use Location; |
| begin |
| X := (Shift_Left (X, 8) and 16#FF00#) or |
| (Shift_Right (X, 8) and 16#00FF#); |
| end Swap2; |
| |
| ----------- |
| -- Swap4 -- |
| ----------- |
| |
| procedure Swap4 (Location : System.Address) is |
| X : Unsigned_32; |
| for X'Address use Location; |
| begin |
| X := (Shift_Right (X, 24) and 16#0000_00FF#) or |
| (Shift_Right (X, 8) and 16#0000_FF00#) or |
| (Shift_Left (X, 8) and 16#00FF_0000#) or |
| (Shift_Left (X, 24) and 16#FF00_0000#); |
| end Swap4; |
| |
| ----------- |
| -- Swap8 -- |
| ----------- |
| |
| procedure Swap8 (Location : System.Address) is |
| X : Unsigned_64; |
| for X'Address use Location; |
| |
| Low, High : aliased Unsigned_32; |
| |
| begin |
| Low := Unsigned_32 (X and 16#0000_0000_FFFF_FFFF#); |
| Swap4 (Low'Address); |
| High := Unsigned_32 (Shift_Right (X, 32)); |
| Swap4 (High'Address); |
| X := Shift_Left (Unsigned_64 (Low), 32) or Unsigned_64 (High); |
| end Swap8; |
| |
| end GNAT.Byte_Swapping; |
