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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . B I T _ O P S --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2009, 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 --
-- <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. --
-- --
------------------------------------------------------------------------------
-- Operations on packed bit strings
pragma Compiler_Unit;
with System;
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})
-- The length in bits is passed as a separate parameter. Note that all
-- addresses must be of byte aligned arrays.
procedure Bit_And
(Left : System.Address;
Llen : Natural;
Right : System.Address;
Rlen : Natural;
Result : System.Address);
-- Bitwise "and" of given bit string with result being placed in Result.
-- The and 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).
function Bit_Eq
(Left : System.Address;
Llen : Natural;
Right : System.Address;
Rlen : Natural) return Boolean;
-- Left and Right are the addresses of two bit packed arrays with Llen
-- 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.
procedure Bit_Not
(Opnd : System.Address;
Len : Natural;
Result : System.Address);
-- Bitwise "not" of given bit string with result being placed in Result.
-- 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
(Left : System.Address;
Llen : Natural;
Right : System.Address;
Rlen : Natural;
Result : System.Address);
-- 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).
procedure Bit_Xor
(Left : System.Address;
Llen : Natural;
Right : System.Address;
Rlen : Natural;
Result : System.Address);
-- Bitwise "xor" of given bit string with result being placed in Result.
-- The xor 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).
end System.Bit_Ops;
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