| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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 _ 1 6 -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2002-2022, 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 -- |
| -- <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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System.Address_Operations; use System.Address_Operations; |
| |
| with Ada.Unchecked_Conversion; |
| |
| package body System.Compare_Array_Signed_16 is |
| |
| type Word is mod 2 ** 32; |
| -- Used to process operands by words |
| |
| type Half is range -(2 ** 15) .. (2 ** 15) - 1; |
| for Half'Size use 16; |
| -- Used to process operands by half words |
| |
| type Uhalf is new Half; |
| for Uhalf'Alignment use 1; |
| -- Used to process operands when unaligned |
| |
| type WP is access Word; |
| type HP is access Half; |
| type UP is access Uhalf; |
| |
| function W is new Ada.Unchecked_Conversion (Address, WP); |
| function H is new Ada.Unchecked_Conversion (Address, HP); |
| function U is new Ada.Unchecked_Conversion (Address, UP); |
| |
| ----------------------- |
| -- Compare_Array_S16 -- |
| ----------------------- |
| |
| function Compare_Array_S16 |
| (Left : System.Address; |
| Right : System.Address; |
| Left_Len : Natural; |
| Right_Len : Natural) return Integer |
| is |
| Clen : Natural := Natural'Min (Left_Len, Right_Len); |
| -- Number of elements left to compare |
| |
| L : Address := Left; |
| R : Address := Right; |
| -- Pointers to next elements to compare |
| |
| begin |
| -- Go by words if possible |
| |
| if ModA (OrA (Left, Right), 4) = 0 then |
| while Clen > 1 |
| and then W (L).all = W (R).all |
| loop |
| Clen := Clen - 2; |
| L := AddA (L, 4); |
| R := AddA (R, 4); |
| end loop; |
| end if; |
| |
| -- Case of going by aligned half words |
| |
| if ModA (OrA (Left, Right), 2) = 0 then |
| while Clen /= 0 loop |
| if H (L).all /= H (R).all then |
| if H (L).all > H (R).all then |
| return +1; |
| else |
| return -1; |
| end if; |
| end if; |
| |
| Clen := Clen - 1; |
| L := AddA (L, 2); |
| R := AddA (R, 2); |
| end loop; |
| |
| -- Case of going by unaligned half words |
| |
| else |
| while Clen /= 0 loop |
| if U (L).all /= U (R).all then |
| if U (L).all > U (R).all then |
| return +1; |
| else |
| return -1; |
| end if; |
| end if; |
| |
| Clen := Clen - 1; |
| L := AddA (L, 2); |
| R := AddA (R, 2); |
| end loop; |
| end if; |
| |
| -- Here if common section equal, result decided by lengths |
| |
| if Left_Len = Right_Len then |
| return 0; |
| elsif Left_Len > Right_Len then |
| return +1; |
| else |
| return -1; |
| end if; |
| end Compare_Array_S16; |
| |
| end System.Compare_Array_Signed_16; |