------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME LIBRARY COMPONENTS -- -- -- -- S Y S T E M . C O M P A R E _ A R R A Y _ S I G N E D _ 8 -- -- -- -- B o d y -- -- -- -- Copyright (C) 2002-2009, Free Software Foundation, Inc. -- -- -- -- 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 -- -- . -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with System.Address_Operations; use System.Address_Operations; with Ada.Unchecked_Conversion; package body System.Compare_Array_Signed_8 is type Word is mod 2 ** 32; -- Used to process operands by words type Big_Words is array (Natural) of Word; type Big_Words_Ptr is access Big_Words; for Big_Words_Ptr'Storage_Size use 0; -- Array type used to access by words type Byte is range -128 .. +127; for Byte'Size use 8; -- Used to process operands by bytes type Big_Bytes is array (Natural) of Byte; type Big_Bytes_Ptr is access Big_Bytes; for Big_Bytes_Ptr'Storage_Size use 0; -- Array type used to access by bytes function To_Big_Words is new Ada.Unchecked_Conversion (System.Address, Big_Words_Ptr); function To_Big_Bytes is new Ada.Unchecked_Conversion (System.Address, Big_Bytes_Ptr); ---------------------- -- Compare_Array_S8 -- ---------------------- function Compare_Array_S8 (Left : System.Address; Right : System.Address; Left_Len : Natural; Right_Len : Natural) return Integer is Compare_Len : constant Natural := Natural'Min (Left_Len, Right_Len); begin -- If operands are non-aligned, or length is too short, go by bytes if ModA (OrA (Left, Right), 4) /= 0 or else Compare_Len < 4 then return Compare_Array_S8_Unaligned (Left, Right, Left_Len, Right_Len); end if; -- Here we can go by words declare LeftP : constant Big_Words_Ptr := To_Big_Words (Left); RightP : constant Big_Words_Ptr := To_Big_Words (Right); Words_To_Compare : constant Natural := Compare_Len / 4; Bytes_Compared_As_Words : constant Natural := Words_To_Compare * 4; begin for J in 0 .. Words_To_Compare - 1 loop if LeftP (J) /= RightP (J) then return Compare_Array_S8_Unaligned (AddA (Left, Address (4 * J)), AddA (Right, Address (4 * J)), 4, 4); end if; end loop; return Compare_Array_S8_Unaligned (AddA (Left, Address (Bytes_Compared_As_Words)), AddA (Right, Address (Bytes_Compared_As_Words)), Left_Len - Bytes_Compared_As_Words, Right_Len - Bytes_Compared_As_Words); end; end Compare_Array_S8; -------------------------------- -- Compare_Array_S8_Unaligned -- -------------------------------- function Compare_Array_S8_Unaligned (Left : System.Address; Right : System.Address; Left_Len : Natural; Right_Len : Natural) return Integer is Compare_Len : constant Natural := Natural'Min (Left_Len, Right_Len); LeftP : constant Big_Bytes_Ptr := To_Big_Bytes (Left); RightP : constant Big_Bytes_Ptr := To_Big_Bytes (Right); begin for J in 0 .. Compare_Len - 1 loop if LeftP (J) /= RightP (J) then if LeftP (J) > RightP (J) then return +1; else return -1; end if; end if; end loop; if Left_Len = Right_Len then return 0; elsif Left_Len > Right_Len then return +1; else return -1; end if; end Compare_Array_S8_Unaligned; end System.Compare_Array_Signed_8;