| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- |
| -- -- |
| -- S Y S T E M . B I T _ O P S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2023, 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 |
| |
| 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; |
