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Diffstat (limited to 'gcc-4.3.1/gcc/ada/g-bytswa-x86.adb')
| -rw-r--r-- | gcc-4.3.1/gcc/ada/g-bytswa-x86.adb | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/gcc-4.3.1/gcc/ada/g-bytswa-x86.adb b/gcc-4.3.1/gcc/ada/g-bytswa-x86.adb new file mode 100644 index 000000000..3af951617 --- /dev/null +++ b/gcc-4.3.1/gcc/ada/g-bytswa-x86.adb @@ -0,0 +1,194 @@ +------------------------------------------------------------------------------ +-- -- +-- 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 machine-specific version of this package. +-- It uses instructions available on Intel 486 processors (or later). + +with Interfaces; use Interfaces; +with System.Machine_Code; use System.Machine_Code; +with Ada.Unchecked_Conversion; + +package body GNAT.Byte_Swapping is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + function Swapped32 (Value : Unsigned_32) return Unsigned_32; + pragma Inline_Always (Swapped32); + + -------------- + -- 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 : Unsigned_16 := As_U16 (Input); + + begin + Asm ("xchgb %b0,%h0", + Unsigned_16'Asm_Output ("=q", X), + Unsigned_16'Asm_Input ("0", X)); + return As_Item (X); + 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 : Unsigned_32 := As_U32 (Input); + + begin + Asm ("bswap %0", + Unsigned_32'Asm_Output ("=r", X), + Unsigned_32'Asm_Input ("0", X)); + return As_Item (X); + end Swapped4; + + -------------- + -- Swapped8 -- + -------------- + + function Swapped8 (Input : Item) return Item is + + function As_U64 is new Ada.Unchecked_Conversion + (Source => Item, Target => Unsigned_64); + + X : constant Unsigned_64 := As_U64 (Input); + + type Two_Words is array (0 .. 1) of Unsigned_32; + for Two_Words'Component_Size use Unsigned_32'Size; + + function As_Item is new Ada.Unchecked_Conversion + (Source => Two_Words, Target => Item); + + Result : Two_Words; + + begin + Asm ("xchgl %0,%1", + Outputs => + (Unsigned_32'Asm_Output ("=r", Result (0)), + Unsigned_32'Asm_Output ("=r", Result (1))), + Inputs => + (Unsigned_32'Asm_Input ("0", + Swapped32 (Unsigned_32 (X and 16#0000_0000_FFFF_FFFF#))), + Unsigned_32'Asm_Input ("1", + Swapped32 (Unsigned_32 (Shift_Right (X, 32)))))); + return As_Item (Result); + end Swapped8; + + ----------- + -- Swap2 -- + ----------- + + procedure Swap2 (Location : System.Address) is + + X : Unsigned_16; + for X'Address use Location; + + begin + Asm ("xchgb %b0,%h0", + Unsigned_16'Asm_Output ("=q", X), + Unsigned_16'Asm_Input ("0", X)); + end Swap2; + + ----------- + -- Swap4 -- + ----------- + + procedure Swap4 (Location : System.Address) is + + X : Unsigned_32; + for X'Address use Location; + + begin + Asm ("bswap %0", + Unsigned_32'Asm_Output ("=r", X), + Unsigned_32'Asm_Input ("0", X)); + end Swap4; + + --------------- + -- Swapped32 -- + --------------- + + function Swapped32 (Value : Unsigned_32) return Unsigned_32 is + X : Unsigned_32 := Value; + begin + Asm ("bswap %0", + Unsigned_32'Asm_Output ("=r", X), + Unsigned_32'Asm_Input ("0", X)); + return X; + end Swapped32; + + ----------- + -- Swap8 -- + ----------- + + procedure Swap8 (Location : System.Address) is + + X : Unsigned_64; + for X'Address use Location; + + type Two_Words is array (0 .. 1) of Unsigned_32; + for Two_Words'Component_Size use Unsigned_32'Size; + + Words : Two_Words; + for Words'Address use Location; + + begin + Asm ("xchgl %0,%1", + Outputs => + (Unsigned_32'Asm_Output ("=r", Words (0)), + Unsigned_32'Asm_Output ("=r", Words (1))), + Inputs => + (Unsigned_32'Asm_Input ("0", + Swapped32 (Unsigned_32 (X and 16#0000_0000_FFFF_FFFF#))), + Unsigned_32'Asm_Input ("1", + Swapped32 (Unsigned_32 (Shift_Right (X, 32)))))); + end Swap8; + +end GNAT.Byte_Swapping; |