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Diffstat (limited to 'gcc-4.4.0/gcc/ada/g-bytswa.adb')
| -rw-r--r-- | gcc-4.4.0/gcc/ada/g-bytswa.adb | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/gcc-4.4.0/gcc/ada/g-bytswa.adb b/gcc-4.4.0/gcc/ada/g-bytswa.adb new file mode 100644 index 000000000..36eb12dcf --- /dev/null +++ b/gcc-4.4.0/gcc/ada/g-bytswa.adb @@ -0,0 +1,151 @@ +------------------------------------------------------------------------------ +-- -- +-- 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) 2006-2007, 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 2, 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. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- As a special exception, if other files instantiate generics from this -- +-- unit, or you link this unit with other files to produce an executable, -- +-- this unit does not by itself cause the resulting executable to be -- +-- covered by the GNU General Public License. This exception does not -- +-- however invalidate any other reasons why the executable file might be -- +-- covered by the GNU Public License. -- +-- -- +-- 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; |