------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . B I T _ O P S -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2018, 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 -- -- . -- -- -- -- 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_Warning; 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;