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 _ U N S I G N E D _ 16 --
9 -- Copyright (C) 2002 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_Unsigned_16 is
38 type Word is mod 2 ** 32;
39 -- Used to process operands by words
41 type Half is mod 2 ** 16;
43 -- Used to process operands by half words
49 for Uhalf'Alignment use 1;
50 -- Used to process operands when unaligned
52 type WP is access Word;
53 type HP is access Half;
54 type UP is access Uhalf;
56 function W is new Unchecked_Conversion (Address, WP);
57 function H is new Unchecked_Conversion (Address, HP);
58 function U is new Unchecked_Conversion (Address, UP);
60 -----------------------
61 -- Compare_Array_U16 --
62 -----------------------
64 function Compare_Array_U16
65 (Left : System.Address;
66 Right : System.Address;
71 Clen : Natural := Natural'Min (Left_Len, Right_Len);
72 -- Number of elements left to compare
76 -- Pointers to next elements to compare
79 -- Go by words if possible
81 if ((Left or Right) and (4 - 1)) = 0 then
83 and then W (L).all = W (R).all
91 -- Case of going by aligned half words
93 if ((Left or Right) and (2 - 1)) = 0 then
95 if H (L).all /= H (R).all then
96 if H (L).all > H (R).all then
108 -- Case of going by unaligned half words
112 if U (L).H /= U (R).H then
113 if U (L).H > U (R).H then
126 -- Here if common section equal, result decided by lengths
128 if Left_Len = Right_Len then
130 elsif Left_Len > Right_Len then
135 end Compare_Array_U16;
137 end System.Compare_Array_Unsigned_16;