1 ------------------------------------------------------------------------------
3 -- GNU ADA RUNTIME LIBRARY COMPONENTS --
5 -- S Y S T E M . C O M P A R E _ A R R A Y _ S I G N E D _ 16 --
9 -- Copyright (C) 2002-2004 Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with Unchecked_Conversion;
36 package body System.Compare_Array_Signed_16 is
38 function "+" (Left, Right : Address) return Address;
39 pragma Import (Intrinsic, "+");
40 -- Provide addition operation on type Address (this may not be directly
41 -- available if type System.Address is non-private and the operations on
42 -- the type are made abstract to hide them from public users of System.
44 type Word is mod 2 ** 32;
45 -- Used to process operands by words
47 type Half is range -(2 ** 15) .. (2 ** 15) - 1;
49 -- Used to process operands by half words
55 for Uhalf'Alignment use 1;
56 -- Used to process operands when unaligned
58 type WP is access Word;
59 type HP is access Half;
60 type UP is access Uhalf;
62 function W is new Unchecked_Conversion (Address, WP);
63 function H is new Unchecked_Conversion (Address, HP);
64 function U is new Unchecked_Conversion (Address, UP);
66 -----------------------
67 -- Compare_Array_S16 --
68 -----------------------
70 function Compare_Array_S16
71 (Left : System.Address;
72 Right : System.Address;
77 Clen : Natural := Natural'Min (Left_Len, Right_Len);
78 -- Number of elements left to compare
82 -- Pointers to next elements to compare
85 -- Go by words if possible
87 if ((Left or Right) and (4 - 1)) = 0 then
89 and then W (L).all = W (R).all
97 -- Case of going by aligned half words
99 if ((Left or Right) and (2 - 1)) = 0 then
101 if H (L).all /= H (R).all then
102 if H (L).all > H (R).all then
114 -- Case of going by unaligned half words
118 if U (L).H /= U (R).H then
119 if U (L).H > U (R).H then
132 -- Here if common section equal, result decided by lengths
134 if Left_Len = Right_Len then
136 elsif Left_Len > Right_Len then
141 end Compare_Array_S16;
143 end System.Compare_Array_Signed_16;