File : s-bitops.ads
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-- --
-- GNU ADA RUNTIME LIBRARY (GNARL) COMPONENTS --
-- --
5 -- S Y S T E M . B I T _ O P S --
-- --
-- S p e c --
-- --
-- $Revision: 1.6 $
10 -- --
-- Copyright (C) 1992-1999, 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- --
15 -- 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 --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
25 -- 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. --
30 -- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
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35
-- Operations on packed bit strings
with System;
40 package System.Bit_Ops is
-- Note: in all the following routines, the System.Address parameters
-- represent the address of the first byte of an array used to represent
-- a packed array (of type System.Unsigned_Types.Packed_Bytes{1,2,4})
45 -- The length in bits is passed as a separate parameter.
procedure Bit_And
(Left : System.Address;
Llen : Natural;
50 Right : Address;
Rlen : Natural;
Result : System.Address);
-- Bitwise "and" of given bit string with result being placed in Result.
-- The or operation is allowed to destroy unused bits in the last byte,
55 -- i.e. to leave them set in an undefined manner. Note that Left, Right
-- and Result always have the same length in bits (Len).
function Bit_Eq
(Left : System.Address;
60 Llen : Natural;
Right : System.Address;
Rlen : Natural)
return Boolean;
-- Left and Right are the addresses of two bit packed arrays with Llen
65 -- and Rlen being the respective length in bits. The routine compares the
-- two bit strings for equality, being careful not to include the unused
-- bits in the final byte. Note that the result is always False if Rlen
-- is not equal to Llen.
70 procedure Bit_Not
(Opnd : System.Address;
Len : Natural;
Result : System.Address);
-- Bitwise "not" of given bit string with result being placed in Result.
75 -- The not operation is allowed to destroy unused bits in the last byte,
-- i.e. to leave them set in an undefined manner. Note that Result and
-- Opnd always have the same length in bits (Len).
procedure Bit_Or
80 (Left : System.Address;
Llen : Natural;
Right : Address;
Rlen : Natural;
Result : System.Address);
85 -- Bitwise "or" of given bit string with result being placed in Result.
-- The or operation is allowed to destroy unused bits in the last byte,
-- i.e. to leave them set in an undefined manner. Note that Left, Right
-- and Result always have the same length in bits (Len).
90 procedure Bit_Xor
(Left : System.Address;
Llen : Natural;
Right : Address;
Rlen : Natural;
95 Result : System.Address);
-- Bitwise "xor" of given bit string with result being placed in Result.
-- The or operation is allowed to destroy unused bits in the last byte,
-- i.e. to leave them set in an undefined manner. Note that Left, Right
-- and Result always have the same length in bits (Len).
100
end System.Bit_Ops;