| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNU ADA RUNTIME LIBRARY (GNARL) COMPONENTS -- |
| -- -- |
| -- S Y S T E M . B I T _ O P S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.6 $ |
| -- -- |
| -- 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- -- |
| -- 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 -- |
| -- 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 -- |
| -- 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. -- |
| -- -- |
| -- 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). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- Operations on packed bit strings |
| |
| 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. |
| |
| procedure Bit_And |
| (Left : System.Address; |
| Llen : Natural; |
| 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, |
| -- 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 : 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 : Address; |
| Rlen : Natural; |
| 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). |
| |
| end System.Bit_Ops; |
